Home

Downloading - All IT eBooks

1. if target null i Sime Seam a Al Check for the ReactiveTarget else component on the object StartCoroutine SphereIndicator hit point 54 3 2 2 CHAPTER 3 Adding enemies and projectiles to the 3D game Notice that you retrieve the object from RaycastHit just like the coordinates were retrieved for the sphere indicators Technically the hit information doesn t return the game object hit it indicates the Transform component hit You can then access gameObject as a property of transform Then you use the method GetComponent on the object to check whether it s a reactive target that is if it has the ReactiveTarget script attached As you saw previ ously that method returns components of a specific type that are attached to the GameObject If no component of that type is attached to the object then Get Component won t return anything You check whether null was returned and run different code in each case If the hit object is a reactive target the code emits a debug message instead of start ing the coroutine for sphere indicators Now let s inform the target object about the hit so that it can react Alert the target that it was hit All that s needed in the code is a one line change as shown in the following listing Listing 3 5 Sending a message to the target object Call a method of the target instead if target null 5 2 of just emitting the debug message target React
2. Building an action RPG by repurposing projects 257 health value if health gt maxHealth health maxHealth else if health lt 0 health 0 Add a line to the end a of this function Messenger Broadcast GameEvent HEALTH_ UPDATED The event is broadcast every time ChangeHealth finishes to tell the rest of the pro gram that the health has changed You want to adjust the health label in response to this event so create a UIController script see the next listing Listing 11 12 The script UlController which handles the interface using UnityEngine using UnityEngine UI using System Collections public class UIController MonoBehaviour Reference Ul object in scene SerializeField private Text healthLabel a SerializeField private InventoryPopup popup void Awake Messenger AddListener GameEvent HEALTH UPDATED OnHealthUpdated void OnDestroy Messenger RemoveListener GameEvent HEALTH UPDATED OnHealthUpdated Call function manually void Start at startup OnHealthUpdated a popup gameObject SetActive false eee a Initialize pop up to be hidden void Update if Input GetKeyDown KeyCode M p bool isShowing popup gameObject activeSelf Toggle pop up popup gameObject SetActive isShowing with M key popup Refresh Event listener calls function A to update health label private void OnHealthUpdated string message Health Manage
3. CHAPTER 10 Playing audio sound effects and music public bool soundMute o get return AudioListener pause Add a similar property to mute set AudioListener pause value public void Startup NetworkService service Debug Log Audio manager starting Aa Italicized code was already in script shown here for reference _network service soundVolume 1f D Initialize the value 0 to I range is full volume status ManagerStatus Started ange is full volume Properties for soundVolume and soundMute were added to AudioManager For both properties the get and set functions were implemented using global values on Audio Listener The AudioListener class can modulate the volume of all sounds received by all AudioListener instances Setting AudioManager s soundVolume property has the same effect as setting the volume on AudioListener The advantage here is encapsula tion everything having to do with audio is being handled in a single manager without code outside the manager needing to know the details of the implementation With those methods added to AudioManager you can now write a script for the pop up Create a script called SettingsPopup and add the contents of the following listing Listing 10 5 SettingsPopup script with controls for adjusting the volume using UnityEngine using System Collections public class SettingsPopup MonoBehaviour This button will toggle the mute f Audi
4. Listing 11 31 Broadcasting Game Complete from MissionManager public void GoToNext else Debug Log Last level Messenger Broadcast GameEvent GAME COMPLETE Respond to that message in UIController as shown in the following listing Listing 11 32 Adding an event listener to UlController Messenger AddListener GameEvent GAME COMPLETE OnGameComplete 274 CHAPTER 11 Putting the parts together into a complete game Messenger RemoveListener GameEvent GAME COMPLETE OnGameComplete private void OnGameComplete levelEnding gameObject SetActive true levelEnding text You Finished the Game Try completing the level to watch what happens move the player to the level objective to complete the level as before You ll first see the Level Complete message but after a couple of seconds it ll change to a message about completing the game ADDING MORE LEVELS At this point you can add an arbitrary number of additional levels and Mission Manager will watch for the last level The final thing you ll do in this chapter is add a few more levels to the project in order to demonstrate the game progressing through multiple levels Duplicate the Levell scene file twice Unity should automatically increment the numbers to Level2 and Level3 and add the new levels to Build Settings so that they can be loaded during gameplay Modify each scene so that you can tell the difference between levels fee
5. Undo Cmd Z W Edit Mode end sections Figure C 6 In the Mesh menu use Extrude Individual to pull out extra sections Switch to Face Selection mode use the button indicated in figure C 4 and select both small ends of the plank Now click on the Mesh menu at the bottom of the view port and select Extrude Individual see figure C 6 As you move the mouse you ll see additional sections added to the ends of the plank move them out slightly and then left click to confirm This additional section is only the width of the bench legs giving you a little additional geometry to work with DEFINITION Extrude is when you push out new geometry with a cross section in the shape of the selected faces The two different extrude commands define what to do when multiple elements are selected Extrude Individual treats each element as a separate piece to extrude whereas Extrude Region treats the entire selection as a single piece Now look at the bottom of the plank and select the two thin faces on each end Use the Extrude Individual command again to pull down legs for the bench refer to fig ure C 7 The shape is complete But before you export the model over to Unity you want to take care of texturing the model Select thin faces underneath and Extrude them down to make legs Figure C 7 Select the thin faces underneath the bench and pull down legs 312 C 2 APPENDIX C Modeling a bench in Blender Texture mapping the model 3D
6. a aE er amp a Ai CNS QI F Ta GQ ASS Ned AH ew VA SA Q gt ea EA Ls m EE MANNING Covers Unity 5 Unity in Action www allitebooks com www allitebooks com Unity in Action Multiplatform Game Development in C JOSEPH HOCKING MANNING SHELTER ISLAND www allitebooks com For online information and ordering of this and other Manning books please visit www manning com The publisher offers discounts on this book when ordered in quantity For more information please contact Special Sales Department Manning Publications Co 20 Baldwin Road PO Box 761 Shelter Island NY 11964 Email orders manning com 2015 by Manning Publications Co All rights reserved No part of this publication may be reproduced stored in a retrieval system or transmitted in any form or by means electronic mechanical photocopying or otherwise without prior written permission of the publisher Many of the designations used by manufacturers and sellers to distinguish their products are claimed as trademarks Where those designations appear in the book and Manning Publications was aware of a trademark claim the designations have been printed in initial caps or all caps Recognizing the importance of preserving what has been written it is Manning s policy to have the books we publish printed on acid free paper and we exert our best efforts to that end Recognizing a
7. v changed status ManagerStatus Initializing aie TE E ET E eee daa Instead of custom XML container r Seeii ee ee a parse into Dictionary Dictionary lt string object gt dict dict Json Deserialize data as Dictionary lt string object gt Dictionary lt string object gt clouds Dictionary lt string object gt dict clouds cloudValue long clouds all 100f The syntax has changed Debug Log Value cloudValue but this code is still doing the same things Messenger Broadcast GameEvent WEATHER UPDATED status ManagerStatus Started As you can see the code for working with JSON looks similar to the code for XML The only real difference is that this JSON parser works with a standard Dictionary instead of a custom document container like XML did There s a command to deserialize and that may be an unfamiliar word DEFINITION Deserialize means pretty much the same thing as parse This is the reverse of serialize which means to encode a batch of data into a form that can be transferred and stored such as a JSON string Aside from the different syntax all the steps are exactly the same Extract the value from the data chunk for some reason the value is called a11 this time but that s just a quirk of the API and do some simple math to convert the value to a 0 1 float With that done it s time to apply the value to the visible scene Affecting the scene based on Weather Data
8. Listing 11 23 Broadcast Level Failed from PlayerManager public void Startup NetworkService service Debug Log Player manager starting _network service Call the update method instead of setting variables directly UpdateData 50 100 ar g y status ManagerStatus Started public void UpdateData int health int maxHealth this health health this maxHealth maxHealth public void ChangeHealth int value health value if health gt maxHealth health maxHealth else if health lt 0 health 0 if health 0 Messenger Broadcast GameEvent LEVEL FAILED Messenger Broadcast GameEvent HEALTH_ UPDATED public void Respawn UpdateData 50 100 ae Reset the player to the initial state Add a small method to MissionManager for restarting the level see the next listing Listing 11 24 MissionManager which can restart the current level public void RestartCurrent string name Level curLevel Debug Log Loading name Application LoadLevel name 11 3 11 3 1 Handling the player s progression through the game 269 With that in place add another event listener to UIController shown in the following listing Listing 11 25 Responding to Level Failed in UlController Messenger AddListener GameEvent LEVEL FAILED OnLevelFailed Messenger RemoveListener GameEvent LEVEL FAILED OnLevelFailed private void
9. ManagerStatus Initializing Instead of Started make the status Initializing public void OnXMLDataLoaded string data Debug Log data A Callback method once the data is loaded status ManagerStatus Started Three primary changes are made to the code in this manager starting a coroutine to download data from the internet setting a different startup status and defining a call back method to receive the response 9 2 2 Downloading weather data from an internet service 207 Starting the coroutine is simple Most of the complexity behind coroutines was already handled in NetworkService so calling StartCoroutine is all you need to do here Then you set a different startup status because the manager isn t actually fin ished initializing it needs to receive data from the internet before startup is complete WARNING Always start networking methods using StartCoroutine don t just call the function normally This can be easy to forget because creating WWW objects outside of a coroutine doesn t generate any sort of compiler error When you call the StartCoroutine method you need to invoke the method That is actually type the parentheses and don t just provide the name of the func tion In this case the coroutine method needs a callback function as its one parame ter so let s define that function We ll use OnXMLDataLoaded for the callback notice that this method has a string parameter
10. Note the lt gt syntax used with the Action keyword the type written in the angle brackets declares the parameters required to fit this Action In other words the func tion this Action points to must take parameters matching the declared type In this case the parameter is a single string so the callback method must have a signature like this MethodName string value The concept of a callback may make more sense after you ve seen it in action which you will in listing 9 6 this initial explanation is so that you ll recognize what s going on when you see that additional code The rest of listing 9 5 is pretty straightforward IsResponseValid checks for errors in the HTTP response There are two kinds of errors the request could ve failed due to a bad internet connection or the data returned could be malformed in some way A const value is declared with the URL to make the request to Incidentally you can change this URL to get weather for different locations MAKING USE OF THE NETWORKING CODE That wraps up the code in NetworkService Now let s use NetworkService in WeatherManager the next listing shows the additions to that script Listing 9 6 Adjusting WeatherManager to use NetworkService public void Startup NetworkService service Debug Log Weather manager starting Start loading data network service A from the internet StartCoroutine _network GetWeatherXML OnXMLDataLoaded status
11. The script in the listing defines a constant for a couple of event messages the messages are more organized this way and you don t have to remember and type the message string all over the place 6 4 2 Updating the game by responding to events 137 Now the event messenger system is ready to use so let s start using it First we ll communicate from the scene to the HUD and then we ll go in the other direction Broadcasting and listening for events from the scene Up to now the score display has displayed a timer as a test of the text display function ality But we want to display a count of enemies hit so let s modify the code in UIController First delete the entire Update method because that was the test code When an enemy dies it will emit an event so the following listing makes UIController listen for that event Listing 6 8 Adding event listeners to UlController private int score Declare which void Awake method responds to Messenger AddListener GameEvent ENEMY HIT OnEnemyHit event ENEMY _HIT void OnDestroy Messenger RemoveListener GameEvent ENEMY HIT OnEnemyHit T When an object is destroyed use void Start the cleanup listener to avoid errors Score 07 scorelabel text score Tostring AL Initialize the score to 0 settingsPopup Close private void OnEnemyHit score 1 pS th scoreLabel text score ToString nerement tne scare in respon
12. int count Managers Inventory GetItemCount item ae Texture2D image Resources Load lt Texture2D gt Icons item GUI Box new Rect posxX posY width height new GUIContent count image osX width buffer a a Shift sideways each time through the loop This listing displays the collected items in a horizontal row see figure 8 9 along with displaying the number collected As mentioned in chapter 3 every MonoBehaviour automatically responds to an OnGUI method That function runs every frame right after the 3D scene is rendered Inside OnGUI first define a bunch of values for positioning UI ele ments These values are incremented when we loop through all the items in Figure 8 9 Ul display of the inventory order to position UI elements in a row The specific UI element drawn is GUI Box those are noninteractive displays that show text and images inside boxes The method Resources Load is used to load assets from the Resources folder This method is a handy way to load assets by name notice that the name of the item is passed as a parameter We have to specify a type to load otherwise the return value for that method is a generic object The UI shows us what items have been collected Now we can actually use the items Equipping a key to use on locked doors Let s go over a couple of examples of using inventory items so that you can extrapo late out to any type of item you
13. int lastReady numReady numReady 0 foreach IGameManager manager in _startSequence if manager status ManagerStatus Started numReady if numReady gt lastReady Debug Log Progress numReady numModules yield return null Debug Log All managers started up As you have in previous chapters create the Game Managers object in the scene and then attach both Managers and AudioManager to the empty object Playing the game will show the managers startup messages in the console but the audio manager doesn t do anything yet Volume control Ul With the bare bones AudioManager set up it s time to give it volume control function ality These volume control methods will then be used by UI displays in order to mute the sound effects or adjust the volume You ll use the new UI tools that were the focus of chapter 6 Specifically you re going to create a pop up window with a button and a slider to control volume settings Property with getter and setter for volume Image Audio control interface 233 Button with pop up sprite T Slider Figure 10 4 Ul display for mute and volume control see figure 10 4 PI list the steps involved without going into detail if you need a refresher refer back to chapter 6 oO OO N O ow W N FEF e e BP BP PRPP y Oo 7 FB WH BR O 18 Import popup png as a sprite set Texture Type to Sprite In Sprite Editor set
14. let s delete everything we don t need for this chapter First disconnect the camera from the player in the Hierarchy list drag the camera object off the player object Now delete the player object if you hadn t disconnected the camera first then that would be deleted too but what you want is to delete only the player capsule and leave the camera Alternatively if you already deleted the camera by accident create a new camera object by selecting GameObject gt Camera Delete all the scripts as well which involves removing the script component from the camera as well as deleting the files in the Project view leaving only the walls floor and lights Adjusting the camera view for third person Before we can write code to make the player move around we need to put a character in the scene and set up the camera to look at that character We ll import a faceless humanoid model to use as the player character and then place the camera above at an angle to look down at the player obliquely Figure 7 3 compares what the scene looks like in first person view with what the scene will look like in third person view shown with a few large blocks that we ll add in this chapter We prepared the scene already so now let s put a character model into the scene Importing a character to look at The scratch folder for this chapter s download includes both the model and the tex ture as you ll recall from chapter 4 FBX is the model and
15. null _firstRevealed card else _secondRevealed card StartCoroutine CheckMatch The only changed line in this function calls the coroutine when both cards are revealed private IEnumerator CheckMatch if _firstRevealed id _secondRevealed id SCOre Debug Logirecores Score LS Increment the score if the l i revealed cards have matching IDs else yield return new WaitForSeconds 5 _firstRevealed Unreveal secondRevealed Unreveal ae Unreveal the cards if p they do not match _firstRevealed null ae a ee a AL Clear out the variables whether or not a match was made First add a _score value to track then launch a coroutine to CheckMatch when a second card is revealed In that coroutine there are two code paths depending on whether the cards match If they do match the coroutine doesn t pause the yield command gets skipped over But if the cards don t match the coroutine pauses for half a second before calling Unreveal on both cards hiding them again Finally whether or not a match was made the variables for storing cards are both nulled out paving the way for revealing more cards When you play the game mismatched cards will display briefly before hiding again There are debug messages when you score matches but we want the score dis played as a label on the screen Text display for the score Displaying information to the player is half of
16. s add a second UI control for the music volume start by adjusting SettingsPopup according to the next listing Listing 10 12 Music volume controls in SettingsPopup public void OnMusicToggle Managers Audio musicMute Managers Audio musicMute Repeat the mute Managers Audio PlaySound sound control only use musicMute instead public void OnMusicValue float volume Managers Audio musicVolume volume ES Repeat the volume control only use musicVolume instead There s not a lot to explain about this code it s mostly repeating the sound volume controls Obviously the AudioManager properties used have changed from sound Mute soundVolume to musicMute musicVolume In the editor create a button and slider just as you did before Here are those steps again Change the pop up s height to 225 to fit more controls Create a UI button Parent the button to the pop up Position the button at 0 60 Expand the button s hierarchy in order to select its text label Change the text to Toggle Music Create a slider from the same UI menu on O AA OO N F Parent the slider to the pop up and position at 0 85 Link up these UI controls to the code in SettingsPopup Find the OnClick OnValueChanged panel in the UI element s settings click the button to add an entry drag the pop up object to the object slot and select the function from the menu The functions you need to pick are OnMusicToggle and
17. s only one way to build up your fin ishing ability and that s to complete lots of projects That seems like a catch 22 to gain the ability to complete projects you first need to complete a lot of projects but the key point to recognize is that small projects are way easier to complete than large projects Thus the path forward is to first build a lot of small projects because those are easy to complete and work up to larger projects Many new game developers make the mistake of tackling a project that s too large They make this mistake for two main reasons they want to copy their favorite big game and everyone under estimates how much work it takes to make a game The project seemingly starts off fine but quickly gets bogged down in too many challenges and eventually the developer gets dejected and quits Instead someone new to game development should start small Start with proj ects so small that they almost seem trivial the projects in this book are the sort of small almost to the point of trivial projects that you should start with If you ve done all the projects in this book then you ve already gotten a lot of these starter projects out of the way Try something bigger for your next project but be wary of making too big a jump You ll build up your skills and confidence so you can get a little more ambitious each time You ll hear this same advice almost any time you ask how to start developing games For exa
18. see figure C 9 This tells Blender to separate the bottom of the bench for purposes of texture mapping Do the same thing for the sides of the bench but don t separate the sides entirely Instead only seam edges running up the legs of the bench this way the sides will remain connected to the bench while spreading out like wings Once all the seams are marked run the Texture Unwrap command First select the entire mesh don t forget the side of the object facing away Next choose Mesh gt UV Unwrap gt Unwrap to create the texture coordinates But you can t see the texture coor dinates in this view Blender defaults to a 3D view of the scene To see the texture coor dinates you must switch from 3D View to UV Editor using the Viewports menu located on the far left of the toolbar not the word View but the little icon see figure C 10 Now you can see the texture coordinates You can see the polygons of the bench laid out flat separated and unfolded according to the seams you marked To paint a text ure you have to see these UV coordinates in your image editing program Referring 314 APPENDIX C Modeling a bench in Blender Export UV Layout menu 2 Python Console File Browser i Info User Preferences Outliner an Properties Logic Editor Node Editor mA Texture coordinates Text Editor aera a e B PESE ASN displayed as points ei Video Sequence Editor i of the flattened out a He bench NLA Editor
19. 121 Immediate mode GUI or advanced 2D interface 121 Planning the layout 122 Importing Ul images 122 6 2 Setting up the GUI display 123 Creating a canvas for the interface 123 Buttons images and text labels 124 Controlling the position of UI elements 127 6 3 Programming interactivity in the UI 128 Programming an invisible UlController 129 Creating a pop up window 131 Setting values using sliders and input fields 133 6 4 Updating the game by responding to events 135 Integrating an event system 136 Broadcasting and listening for events from the scene 137 Broadcasting and listening for events from the HUD 138 6 5 Summary 139 Creating a third person 3D game player movement and animation 140 7 1 Adjusting the camera view for third person 142 Importing a character to look at 142 Adding shadows to the scene 144 Orbiting the camera around the player character 145 T2 Programming camera relative movement controls 148 Rotating the character to face movement direction 149 Moving forward in that direction 151 7 3 Implementing the jump action 152 Applying vertical speed and acceleration 153 Modifying the ground detection to handle edges and slopes 154 7 4 Setting up animations on the player character 158 Defining animation clips in the imported model 160 Creating the animator controller for these animations 162 Writing code that operates the animator 165 7 5 Summary 166 CONTENTS xl Adding interactive devices and it
20. Figure 8 5 illustrates the setup I m describing _ PlayerManager Managers e static Player j IGameManager e static Inventory j i InventoryMan r e List lt IGameManager gt entorylVianage Figure 8 5 Diagram of the various modules and how they re related IGameManager 180 8 3 2 CHAPTER 8 Adding interactive devices and items within the game Incidentally whereas all of the code architecture I ve been talking about consists of invisible modules that exist in the background Unity still requires scripts to be linked to objects in the scene in order to run that code As we ve done with the scene specific controllers in previous projects we re going to create an empty GameObject to link these data managers to Programming the game managers All right so that explained all the concepts behind what we ll do it s time to write the code To start with create a new script called IGameManager see the next listing Listing 8 9 Base interface that the data managers will implement public interface IGameManager ManagerStatus status get AL This is an enum we need to define void Startup Hmm there s barely any code in this file Note that it doesn t even inherit from MonoBehaviour an interface doesn t do anything on its own and exists only to impose structure on other classes This interface declares one property a variable that has a getter function and one method both need to be
21. MonoBehaviour Aa Correct the name after pasting scripts public float deceleration 20 0f public float targetBuffer 175E private float _curSpeed Of private Vectors tCargetros Vector one void Update Vector3 movement Vector3 zero Sai Set target position l Ss when mouse clicks if Input GetMouseButton 0 Ray ray Camera main ScreenPointToRay Input mousePosition T RaycastHit mouseHit if Physics Raycast ray out mouseHit Raycast at the Set target to E _targetPos mouseHit point mouse position position hit _curSpeed moveSpeed Move if target osition is set if _targetPos Vector3 one M P Vector3 adjustedPos new Vector3 _targetPos x transform position y _targetPos 2 Quaternion targetRot Quaternion LookRotation adjustedPos transform position transform rotation Quaternion Slerp transform rotation targetRot rotSpeed Time deltaTime DY Rotate toward the target movement _curSpeed Vector3 forward amp movement transform TransformDirection movement Decelerate to 0 when close to target Building an action RPG by repurposing projects 253 if Vector3 Distance targetPos transform position lt targetBuffer _curSpeed deceleration Time deltaTime if _curSpeed lt 0 _targetPos Vectors one Everything stays the ay same from here down _animator SetFloat Speed movement sqrMagnitude Almost everything at th
22. The Ul object displays Text text typed here j Character Import a TrueType font to Font use that font set it here Font Style Font Size Line Spacing Eoo These buttons adjust Ma the horizontal and Nines vertical alignment a of the text Vertical Overflow Best Fit LJ Figure 6 7 Settings Color E 7 for a UI text object view to assign images to the objects Assign the enemy sprite to the image object and the gear sprite to the button object click Set Native Size after assigning sprites to properly size the image object That took care of the appearance of both the enemy image and the gear button As for the text object there are a bunch of settings in the Inspector First type a single number in the large Text box this text will be overwritten later but it s useful because it looks like a score display within the editor The text is small so increase the Font Size to 24 and make the style Bold You also want to set this label to left horizontal alignment see figure 6 7 and middle vertical alignment For now the remaining set tings can be left at their default values NOTE Besides the Text box and alignment the most common property to adjust is the font You can import a TrueType font into Unity and then put that font in the Inspector Now that sprites have been assigned to the UI images and the score text is set up you can hit Play to see the HUD on top of the 3D game As shown in figure 6 8 the canvas The Canvas
23. The status property was defined so that the status could be read from anywhere the getter is public but only set within this script the setter is private The method in the interface is Startup so both managers define that function In both manag ers initialization completes right away InventoryManager doesn t do anything yet 182 CHAPTER 8 Adding interactive devices and items within the game whereas PlayerManager sets a couple of values so the status is set to Started But data modules may have long running tasks as part of their initialization such as load ing saved data in which case Startup will launch those tasks and set the manager s status to Initializing Change status to Started after those tasks complete Great we re finally ready to tie everything together with a main manager of man agers Create one more script and call it Managers see the following listing Listing 8 13 The Manager of Managers using UnityEngine using System Collections using System Collections Generic Ensure that the various a managers exist ReguireComponent typeof PlayerManager RequireComponent typeof InventoryManager Static properties that public class Managers MonoBehaviour other code uses to public static PlayerManager Player get private set a access managers public static InventoryManager Inventory get private set private List lt IGameManager gt startSequence aa The list of m
24. Two dimensions are just those X and Y axes that s what your teacher was talking about in math class Setting everything up for 2D graphics We re going to create the classic game of Memory For those unfamiliar with this game a series of cards will be dealt out facedown Every card will have a matching card located somewhere else but the player can t tell what the various cards are The player can turn over two cards at a time attempting to find matching cards if the two cards chosen aren t a match they ll flip back and then the player can guess again Figure 5 1 shows a mockup of the game we re going to build compare this to the roadmap diagram from chapter 2 E Score 1 a Score the number Reset button click of matches made this to start over Cards initially facedown show image when clicked Figure 5 1 Mockup of what the Memory game will look like 5 1 1 Setting everything up for 2D graphics 97 Note that the mockup this time depicts exactly what the player will see whereas the mockup for a 3D scene depicted the space around the player and then where the cam era went for the player to see through Now that you know what we ll be building it s time to get to work Preparing the project The first step is to gather up and display graphics for our game In much the same way as building the 3D demo previously you want to start the new game by putting
25. Y width height text label The core of the code in this listing is the OnGUI method Much like Start and Update every MonoBehaviour automatically responds to OnGUI That function runs every frame after the 3D scene is rendered providing a place to put GUI drawing commands This code draws a button note that the command for a button is exe cuted every frame that is in immediate mode style The button command is used in a conditional that responds when the button is clicked Because the immediate mode GUI makes it easy to get a few buttons onscreen with a minimum of effort we ll use it for examples in future chapters especially chapter 8 But making default buttons is about the only thing easy to create with that system so the latest versions of Unity now have a new interface system based on 2D graphics laid out in the editor It takes a bit more effort to set up but you ll probably 122 6 1 2 6 1 3 CHAPTER 6 Putting a 2D GUI in a 3D game P Settings button 2 d Open pop up window Score display na with both an image and text Q Name nn Close button a Al Speed Close the pop up Pop up window window in the center of the screen Input controls Open with the Text input for name gear button slider for speed Figure 6 2 Planned GUI want to use the newer interface system in finished games because it produces more polished resu
26. a the start of the existing function void Update CharacterController has an ee isGrounded property to check if if _charController isGrounded a the controller is on the ground if Input GetButtonDown Jump a _vertSpeed jumpSpeed React to the Jump else button while on _vertSpeed minFall If not on the ground then the ground apply gravity until terminal else a velocity is reached _vertSpeed gravity 5 Time deltaTime if _vertSpeed lt terminalVelocity _vertSpeed terminalVelocity movement y vertSpeed The end of listing 7 3 so S that you can see where movement Time deltaTime this new code goes _charController Move movement As usual we start by adding a few new variables to the top of the script for various movement values and initialize the values correctly Then we skip down to just after the big if statement for horizontal movement where we ll add another big if state ment for vertical movement Specifically the code will check if the character is on the ground because the vertical speed will be adjusted differently depending on whether the character is on the ground CharacterController includes isGrounded for check ing whether the character is on the ground this value is true if the bottom of the character controller collided with anything in the last frame If the character is on the ground then the vertical speed value the private vari able _vertSpeed sh
27. but games usually have all the frames of animation laid out on a single image called a sprite sheet Sprite sheets can be generated automatically by Unity or they can be created using a tool like Texture Packer See appendix B When importing a sprite sheet set Sprite Mode to Multiple in the Sprite settings Multiple frames are laid out in a grid in one image saseg A iai Tae cu in the import Texture Type Sprite Mode Multiple settings Packing Tag Pixels To Units A sprite sheet image can be imported into Unity The sprite sheet will still appear in the Project view as a single asset but if you click the arrow on the asset it Il expand out and show all the individual sprites Instead of dragging sprites into the scene one at a time you can select a bunch to drag in together The 0 for X and Y position are straightforward this sprite will fill the entire screen so you want it at the center but that 5 for Z position might seem odd For 2D graphics shouldn t only X and Y matter Well X and Y are the only coordinates that matter for 100 CHAPTER 5 Building a Memory game using Unity s new 2D functionality Stacked sprites seen in 2D t _ 3D Perspective view Orthographic view Sprites Z axis Figure 5 4 How sprites stack along the Z axis positioning the object on the 2D screen Z coordinates still matter for stacking objects on top of each other though Lower Z values are
28. in the Default row to change the quality setting Select from the menu that appears Beautiful Grid of quality settings in the Inspector Customizing the icon and name of the application are important for giving it a fin ished appearance Another useful way of customizing the behavior of built applica tions is with platform dependent code Platform dependent compilation By default all the code you write will run the same way on all platforms But Unity provides a number of compiler directives known as platform defines that cause differ ent code to run on different platforms You ll find the full list of platform defines on this page of the manual http docs unity3d com Manual PlatformDependent Compilation html As that page indicates there are directives for every platform that Unity supports allowing you to run separate code on every platform Usually the majority of your code doesn t have to be inside platform directives but occasionally small bits of the code need to run differently on different platforms Some code assemblies only exist on one platform for example chapter 11 mentioned that filesystem access isn t avail able on the web player so you need to have platform compiler directives around those commands The following listing shows how to write such code Listing 12 1 PlatformTest script showing how to write platform dependent code using UnityEngine using System Collections public class
29. is the topic of the final section of this chapter Updating the game by responding to events Up to now the HUD and main game have been ignoring each other but they ought to be communicating back and forth That could be accomplished via script references as we ve done for other sorts of interobject communication but that approach would have major downsides In particular doing so would tightly couple the scene and the HUD you want to keep them fairly independent from each other so that you can freely edit the game without worrying that you ve broken the HUD 136 6 4 1 CHAPTER 6 Putting a 2D GUI in a 3D game Messenger is a central module that routes messages between broadcasters and listeners Other objects can tell the Objects can register to Messenger to broadcast specific listen for specific events assigning a function events Messenger will route the as the callback message to everything listening Messenger for that event ListenObject gt e Add listener j BroadcastObj e Awake e Broadcast message lt e Update e OnEventReceived lt Figure 6 17 Diagram of the broadcast event system we ll implement To alert the UI of actions in the scene we re going to make use of a broadcast messen ger system Figure 6 17 illustrates how this event messaging system works scripts can register to listen for an event other code can broadcast an event and listeners will be alerted about broadcast message
30. literally the totality of what the term means don t confuse yourself by think ing that any of the various uses of textures are part of how the term is defined No matter how the image is being used it s still referred to as a texture NOTE The word texture is routinely used as both a verb and a noun In addi tion to the noun definition the word describes the action of using 2D images in 3D graphics Textures have a number of uses in 3D graphics but the most straightforward use is to be displayed on the surface of 3D models Later in the chapter we ll discuss how this works for more complex models but for our whiteboxed level the 2D images will act as wallpaper covering the walls see figure 4 4 Before texturing After applying textures only shading from lights 1 floor texture 1 on all walls Figure 4 4 Comparing the level before and after textures 76 4 3 1 CHAPTER 4 Developing graphics for your game As you can see from the comparison in figure 4 4 textures turn what was an obviously unreal digital construct into a brick wall Other uses for textures include masks to cut out shapes and normal maps to make surfaces bumpy later you may want to look up more information about textures in resources mentioned in appendix D Choosing a file format A variety of file formats is available for saving 2D images so which should you use Unity supports the use of many different file formats so you could choose any of t
31. only context involves images downloaded from the internet The key is to provide a callback function in ImagesManager that first saves the image and then calls the callback from WebLoadingBillboard This is tricky to do as opposed to the current code that uses the callback from WebLoadingBillboard because the code doesn t know ahead of time what the callback from WebLoading Billboard will be Put another way there s no way to write a method in Images Manager that calls a specific method in WebLoadingBillboard because the code doesn t know what that specific method will be The way around this conundrum is to use lambda functions DEFINITION A lambda function also called an anonymous function is a function that doesn t have a name Such functions are usually created on the fly inside other functions Lambda functions are a tricky code feature supported in a number of programming languages including C By using a lambda function for the callback in Images Manager the code can create the callback function on the fly using the method passed in from WebLoadingBillboard Thus you don t need to know the method to call ahead of time because this lambda function doesn t exist ahead of time The follow ing listing shows how to do this voodoo in ImagesManager Posting data to a web server 217 Listing 9 16 Lambda function for callback in ImagesManager using System public void GetWebImage Action lt Texture2D gt callbac
32. s DopeSheet X Graph Editor Timeline 3D View ye Figure C 10 Switch from 3D View to UV Editor where the texture coordinates are displayed again to figure C 10 under the UVs menu choose Export UV Layout save the image as bench png this name will also be used later when importing into Unity Open this image in your image editor and paint colors for the various parts of your texture Painting different colors for different UVs will put different colors on those faces For example figure C 11 shows darker blue where the bottom of the bench was unfolded on the top of the UV layout and red was painted on the sides of the bench Now the image can be brought back into Blender to texture the model select Image gt Open Image UV Editor after choosing Open in the Image menu Exported UV layout Texture image painted rn Figure C 11 Paint colors over the exported UVs and then bring the texture into Blender Texture mapping the model 315 3 Presto I Return to Object mode and delete the light and the camera Hit X to delete port Shading a 2 Then switch Viewport Solid Shading to Texture Wireframe Bounding Box eed BiN Goba 5 Figure C 12 Delete the default light and view the texture on the model At this point you can return to the 3D view using the same menu you used to switch to UV Editor You still can t see the texture on the model but that only requires a cou ple more
33. so you don t have to worry about handling it yourself There s one more rotation setting for MouseLook that needs code horizontal and vertical rotation at the same time 38 CHAPTER 2 Building a demo that puts you in 3D space 2 4 3 Horizontal and vertical rotation at the same time This last chunk of code won t use Rotate either for the same reason the vertical rotation angle is clamped between limits after being incremented That means the horizontal rotation needs to be calculated directly now Remember Rotate was automating the process of incrementing the rotation angle see the next listing Listing 2 6 Horizontal and vertical MouseLook delta is the amount to a change the rotation by _rotationxX Input GetAxis Mouse Y sensitivityVert _rotationxX Mathf Clamp _rotationX minimumVert maximumVert D Increment the rotation angle Float delta Input GetAxis Mouse X sensitivityHor by delta float rotationY transform localEulerAngles y delta transform localEulerAngles new Vector3 _ rotationxX rotationY 0 The first couple of lines dealing with _rotationX are exactly the same as in the last section Just remember that rotating around the object s X axis is vertical rotation Because horizontal rotation is no longer being handled using the Rotate method that s what the delta and rotationy lines are doing Deltais a common mathematical term for the amount of change so our ca
34. this book after learning how to program Don t worry about the exact programming language C is used throughout this book but skills from other languages will transfer quite well Although the first half of the book will take its time introducing new concepts and will carefully and deliber ately step you through developing your first game in Unity the remaining chapters will move a lot faster in order to take readers through projects in multiple game XX ABOUT THIS BOOK XXi genres The book will end with a chapter describing deployment to various platforms like the web and mobile but the main thrust of the book won t make any reference to the ultimate deployment target because Unity is wonderfully platform agnostic As for other aspects of game development extensive coverage of art disciplines would water down how much the book can cover and would be largely about software external to Unity for example the animation software used Discussion of art tasks will be limited to aspects specific to Unity or that all game developers should know Note though that there is an appendix about modeling custom objects Roadmap Chapter introduces you to Unity the cross platform game development environ ment You ll learn about the fundamental component system underlying everything in Unity as well as how to write and execute basic scripts Chapter 2 progresses to writing a demo of movement in 3D covering topics like mouse and keyboa
35. together the minimum set of graphics for the game to operate and after that s in place you can start programming the functionality That means we ll need to create everything depicted in figure 5 1 card backs for hidden cards a series of card fronts for when they turn over a score display in one corner and a reset button in the opposite corner We also need a background for the screen so all together our art requirements sum up to figure 5 2 Card back Background table top Card front 4 different symbols Reset button Figure 5 2 Art assets required for the Memory game TIP As always a finished version of the project including all necessary art assets can be downloaded from www manning com hocking this book s web site You can copy the images from there to use in your own project Gather together the needed images and then create a new project in Unity In the New Project window that comes up you ll notice a couple of buttons at the bottom shown in figure 5 3 that let you switch between 2D and 3D mode In previous chap ters we ve worked with 3D graphics and because that s the default value we haven t 2D setting M o 3D 2D of the window Asset narkanes Figure 5 3 Create new projects in either 2D or 3D mode with these buttons 98 CHAPTER 5 Building a Memory game using Unity s new 2D functionality been concerned with this setting In this chapter though you ll want to switch to 2D mode when cre
36. which in this case will be the player You ll do this in 34 CHAPTER 2 Building a demo that puts you in 3D space several steps progressively adding new movement abilities to the character First the player will only rotate side to side and then the player will only rotate up and down Eventually the player will be able to look around in all directions rotating horizon tally and vertically at the same time a behavior referred to as mouse look Given that there will be three different types of rotation behavior horizontal ver tical and both you ll start by writing the framework for supporting all three Create a new C script name it MouseLook and write in the code from the next listing Listing 2 2 MouseLook framework with enum for the Rotation setting using UnityEngine using System Collections Define an enum data public class MouseLook MonoBehaviour a structure 7 associate public enum RotationAxes pames With setungs MouseXAndy 0O MouseX 1 MouseY 2 Declare a public es variable to set in public RotationAxes axes RotationAxes MouseXAndY Unity s editor void Update if axes RotationAxes MouseX horizontal rotation here else if axes RotationAxes MouseY vertical rotation here Put code here for horizontal rotation only l Put code here for vertical rotation only else both horizontal and vertical rotation here Put code here for both horizontal and v
37. 1 Creating an outdoor scene 197 4 Download and display an image from the internet 5 Post data to your own server in this case a log of what the weather was The actual game that you ll use for this chapter s project matters little Everything in this chapter will add new scripts to an existing project and won t modify any of the existing code For the sample code I used the movement demo from chapter 2 mostly so that we can see the sky in first person view when it gets modified The proj ect for this chapter isn t directly tied into the gameplay but obviously for most games you create you would want the networking tied to the gameplay for example spawn ing enemies based on responses from the server On to the first step Creating an outdoor scene Because we re going to be downloading weather data we ll first set up an outdoor area where the weather will be visible The trickiest part of that will be the sky but first let s take a moment to apply outdoors looking textures on the level geometry Just as in chapter 4 I obtained a couple images from www cgtextures com to apply to the walls and floor of the level Remember to change the size of the downloaded images to a power of 2 such as 256x256 Then import the images into the Unity proj ect create materials and assign the images to the materials that is drag an image into the texture slot of the material Drag the materials onto the walls or floor in the scene a
38. 2D image editors 2D images are crucial to all games be they displayed directly for 2D games or as tex tures on the surface of 3D models Several 2D graphics tools come up often in game development as you ll see in this section Photoshop Photoshop is easily the most widely used 2D image application there is The tools in Photoshop can be used for touching up existing images applying image filters or even painting pictures from scratch Photoshop supports dozens of different file for mats including all image formats used in Unity www photoshop com GIMP An acronym standing for GNU Image Manipulation Program this is the best known open source 2D graphics application GIMP trails Photoshop in both features and usability but it s still a useful image editor and you can t beat the price www gimp org TexturePacker Whereas the previously mentioned tools are all used beyond just the field of game development TexturePacker is only useful for game development But it s very good at the task it was designed for assembling sprite sheets to use in 2D games If you re developing a 2D game then you probably want to try out TexturePacker www codeandweb com texturepacker Audio software A dizzying array of audio production tools are available including both sound editors that work with raw waveforms and sequencers that compose music using a B 4 1 B 4 2 Audio software 307 sequence of notes To give a taste o
39. 60 This value tells Unity which sounds are most important when layering multiple sounds somewhat counterintuitively lower values are higher priority When too many sounds are playing simultaneously the audio system will start discarding sounds by making music higher priority than sound effects you ensure the music will keep playing when too many sound effects trigger at the same time STEP 3 WRITE CODE TO PLAY THE AUDIO CLIPS IN AUDIOMANAGER The Music audio source has been set up so add the code shown in the next listing to AudioManager Listing 10 9 Playing music in AudioManager SerializeField private AudioSource musiclSource Load main music from Resources Background music 239 SerializeField private string introBGMusic SerializeField private string levelBGMusic AURIS ATU SIC NAMES M ENESE Sings public void PlayIntroMusic PlayMusic Resources Load Music introBGMusic as AudioClip Load intro public void PlayLevelMusic music from PlayMusic Resources Load Music levelBGMusic as AudioClip Resources private void PlayMusic AudioClip clip musiclSource clip clip AL Play music by setting musiclSource Play PUEIGS QUECHEE public void StopMusic musiclSource Stop As usual the new serialized variables will be visible in the Inspector when you select the object Game Managers Drag Music 1 into the audio source slot Then type in the names of the music files
40. Building collectible items that players store in their inventory Using code to manage game state such as inventory data Equipping and using inventory items Implementing functional items is the next topic we re going to focus on Previous chapters covered a number of different elements of a complete game movement enemies the user interface and so forth But our projects have lacked anything to interact with other than enemies nor have they had much in the way of game state In this chapter you ll learn how to create functional devices like doors We ll also discuss collecting items which involves both interacting with objects in the level and tracking game state Games often have to track state like the player s current 167 168 8 1 8 1 1 CHAPTER 8 Adding interactive devices and items within the game stats progress through objectives and so on The player s inventory is an example of this sort of state so you ll build a code architecture that can keep track of items col lected by the player By the end of this chapter you ll have built a dynamic space that really feels like a game We ll start by exploring devices such as doors that are operated with keypresses from the player After that you ll write code to detect when the player collides with objects in the level enabling interactions like pushing objects around or collecting inventory items Then you ll set up a robust MVC Model View Controller style c
41. Click the arrow to expand an asset and see its contents player body pelvis body idle jump run walk playerAvatar The imported model contains the various animation clips Figure 7 17 Expanded model asset in Project view 164 CHAPTER 7 Creating a third person 3D game player movement and animation Auto Live Link idle gt run Uncheck this value for 1 AnimatorTransitionBase i most transitions so Transitions painan that the animation can be interrupted eel ens idle gt run Has Exit Time Change this setting if Click a transition to select it and see its settings Y Settings e e aie CH the transition itself can Transition Duratior 0 04347826 also be interrupted Transition Offset 00 Interruption Source Curemsae K Ordered Interruptic M Gg 41002 00 fiers These arrows control noted goon eee hoi how long the transition in vu Suwa N P IUU ihat aba Pa ia ti L takes hold Alt to navigate this graph Graphics Models player controller Define conditions for Conditions s transitioning between Speed z Greater__ animation states when o the parameters change Figure 7 18 Transition settings in the Inspector WARNING While working in the Animator view you may see an error about AnimationStateMachine TransitionEditionContext BuildNames Simply restart Unity this seems to be a harmless bug The transitions rely on a set of controlling values so let
42. Debug Log Inventory manager starting status ManagerStatus Started A For long running tasks use status Initializing instead Listing 8 12 PlayerManager using UnityEngine using System Collections using System Collections Generic public class PlayerManager MonoBehaviour IGameManager a public ManagerStatus status get private set Inherit a class and public int health get private set implement an interface public int maxHealth get private set public void Startiup Debug Log Player manager starting health 50 maxHealth 100 These values could be initialized with saved data status ManagerStatus Started public void ChangeHealth int value health value if health gt maxHealth AO Other scripts can t set health directly but can call this function health maxHealth else if health lt 0 health 0 Debug Log Health health maxHealth For now InventoryManager is a shell that will be filled in later whereas Player Manager has all the functionality needed for this project These managers both inherit from the class MonoBehaviour and implement the interface IGameManager That means the managers both gain all the functionality of MonoBehaviour while also need ing to implement the structure imposed by IGameManager The structure in IGame Manager was one property and one method so the managers define those two things
43. File gt New Project and then name your new project in the win dow that pops up After creating the new project immediately save the current empty default scene because the project doesn t have any Scene file initially The scene starts out empty and the first objects to create are the most obvious ones The scenery floor outer walls inner walls Select the GameObject menu at the top of the screen and then hover over 3D Object to see that drop down menu Select Cube to create a new cube object in the scene Lights Both directional and l point lights are in this scene Camera view The camera object is located right on top of the player these X angled white lines indicate the camera s field of view Player This is a basic capsule object Figure 2 5 Scene in the Editor with floor walls lights a camera and the player www allitebooks com 26 CHAPTER 2 Building a demo that puts you in 3D space Inspector w Floor Static v Tag Untagged Layer Default 2 Position and scale the YA Transform mE e Position xo Y 0 5 ZO cube in order to create Pe Be a CL C a floor for the room Or Scale X50 Yl 250 rather cube since it Yo Cube Mesh Filter g won t look like a cube anymore after being irate d l stretched out with Material o s Center differing scale values _ e on different axes Size C a Meanwhile the position ieee aa is lowered very slightly Re
44. HelloWorld cs 8 42 error CS51525 Unexpected symbol expecting Script containing i lt Description the error Location within that script of the crror line character 20 CHAPTER 1 Getting to know Unity 1 4 Summary In this chapter you ve learned that Unity is a multiplatform development tool Unity s visual editor has several sections that work in concert Scripts are attached to objects as components Code is written inside scripts using MonoDevelop Building a demo that puts you in 3D space This chapter covers Understanding 3D coordinate space Putting a player in a scene Writing a script that moves objects Implementing FPS controls Chapter 1 concluded with the tra ditional Hello World introduc tion to a new programming tool now it s time to dive into a nontriv ial Unity project a project with interactivity and graphics You ll put some objects into a scene and write code to enable a player to walk around that scene Basically it Il be Doom without the monsters Figure 2 1 Screenshot of the 3D demo basically something like what figure 2 1 Doom without the monsters 21 22 2 1 2 1 5 CHAPTER 2 Building a demo that puts you in 3D space depicts The visual editor in Unity enables new users to start assembling a 3D proto type right away without needing to write a lot of boilerplate code first for things like initializing a 3D view or establi
45. SPEED CHANGED OnSpeedChanged void OnDestroy 6 5 Summary 139 Messenger lt float gt RemoveListener GameEvent SPEED CHANGED OnSpeedChanged private void OnSpeedChanged float value speed baseSpeed value Finally broadcast the speed values from SettingsPopup in response to the slider as shown in the following listing Listing 6 12 Broadcast message from SettingsPopup public void OnSpeedValue float speed Messenger lt float gt Broadcast GameEvent SPEED CHANGED speed es Send slider value as lt float gt event Now the enemy and player have their speed changed when you adjust the slider Hit Play and try it out Exercise Changing the speed of spawned enemies Currently the speed value is only updated for enemies already in the scene and not for newly spawned enemies new enemies aren t created at the correct speed setting l II leave it as an exercise for you to figure out how to set the speed on spawned ene mies Here s a hint add a SPEED CHANGED listener to SceneController because that script is where enemies are spawned from You now know how to build a graphical interface using the new UI tools offered by Unity This knowledge will come in handy in all future projects even as we explore dif ferent game genres Summary In this chapter you ve learned that Unity has both an immediate mode GUI system as well as a newer system based on 2D sprites Using 2D
46. TGA is the texture Import the FBX file into the project either drag the file into the Project view or right click in the Project view and select Import New Asset Then look in the Inspector to adjust import settings for the model Later in the chapter you ll adjust imported animations Adjusting the camera view for third person 143 First person demo Third person demo Figure 7 3 Side by side comparison of first person and third person views but for now you need to make only a couple of adjustments in the Model tab First change the Scale Factor value to 10 to partially counteract the File Scale value of 01 so that the model will be the correct size A bit farther down you ll find the Normals option see figure 7 4 This setting con trols how lighting and shading appear on the model using a 3D math concept known as well normals DEFINITION Normals are direction vectors sticking out of polygons that tell the computer which direction the polygon is facing This facing direction is used for lighting calculations The default setting for Normals is Import which will use the normals defined in the imported mesh geometry But this particular model doesn t have correctly defined normals and will react in odd ways to lights Instead change the setting to Calculate so that Unity will calculate a vector for the facing direction of every polygon Once you ve adjusted these two settings click the Apply button in the Inspector Next
47. The File Create method will create a binary file call File CreateText if you want a text file WARNING When constructing file paths the path separator is different on different computer platforms C has Path DirectorySeparatorChar to account for this Open the Startup scene to find Game Managers Add the DataManager script compo nent to the Game Managers object and then add the new manager to the Managers script listing 11 29 Listing 11 29 Adding DataManager to Managers cs RequireComponent typeof DataManager public static DataManager Data get private set void Awake DontDestroyOnLoad gameObject Data GetComponent lt DataManager gt Player GetComponent lt PlayerManager gt Inventory GetComponent lt InventoryManager gt Mission GetComponent lt MissionManager gt _startSequence new List lt IGameManager gt _StartSequence Add Player Managers start in this order _startSequence Add Inventory _startSequence Add Mission _startSequence Add Data StartCoroutine StartupManagers WARNING Because DataManager uses other managers in order to update them you should make sure that the other managers appear earlier in the startup sequence Finally add buttons to use functions in DataManager figure 11 9 shows the but tons Create two buttons parented to the Figure 11 9 Save and Load buttons on the HUD Canvas not in the Inventory pop up
48. Unity Not only is the manual useful for looking up information but the list of topics is useful by itself for giving users a full idea of what Unity is capable of http docs unity3d com Documentation Manual index html SCRIPT REFERENCE Unity programmers end up reading this resource more than any other at least I do The user manual covers the capabilities of the engine and use of the editor but the script reference is a thorough reference to Unity s entire API application programming interface Every Unity command is listed here http docs unity3d com Documentation ScriptReference index html UNITY3D STUDENT This site provides a large library of tutorials covering an array of topics Most impor tantly the tutorials are all videos This may be good or bad depending on your per spective if you are someone who likes to watch video tutorials then this is a good site to check out www unity3dstudent com LEARN UNITY3D Part of the same family of websites as Unity 3D Student the Learn Unity 3D site is similar in purpose but provides slightly different information in a very different 316 D 2 Code libraries 317 format more of a news site with articles of interest to learners It s another good site to browse through for tutorials http learnunity3d com GAME DEVELOPMENT AT STACKEXCHANGE This is another great information site with a different format from the previous ones listed Rather than a series of self
49. a message to all the targets This loop happens inside the OnTriggerEnter and OnTriggerExit methods These functions are called once when another object first enters and exits the trigger as opposed to being called over and over while the object is inside the trigger volume Notice that the messages being sent are different than before now we need to define the functions Activate and Deactivate on the door Add the code in the next listing to the door script Listing 8 7 Adding activate and deactivate functions to the DoorOpenDevice script public void Activate if open con Vector3 pos transform position dPos ne iit il ae if it transform position pos y Open _open true Similarly only close the door public void Deactivate S if it isn t already closed if _open Vector3 pos transform position dPos transform position pos _open false The new Activate and Deactivate methods are much the same code as the Operate method from earlier except now there are separate functions to open and close the door instead of only one function that handles both cases With all the needed code in place you can now use the trigger volume to open and close the door Put the DeviceTrigger script on the trigger volume and then link the door to the targets property of that script in the Inspector first set the size of the array and then drag objects from the Hierarchy view over to slot
50. according to the A Quaternion rotation Quaternion Euler 0 _roty 0 camera s rotation transform position Gargec position rotation offset transform LookAt target T No matter where the camera is relative to the target always face the target As you re reading through the listing note the serialized variable for target The code needs to know what object to orbit the camera around so this variable is serial ized in order to appear within Unity s editor and have the player character linked to it The next couple of variables are rotation values that are used in the same way as in the camera control code from chapter 2 And there s an offset value declared _offset is set within Start to store the position difference between the camera and target This way the relative position of the camera can be maintained while the script runs In other words the camera will stay at the initial distance from the character regardless of which way it rotates The remainder of the code is inside the Late Update function Adjusting the camera view for third person 147 TIP LateUpdate is another method provided by MonoBehaviour and it s very similar to Update it s a method run every frame The difference as the name implies is that LateUpdate is called on all objects after Update has run on all objects This way we can ensure that the camera updates after the target has moved First the code incre
51. an art asset that s imported by Unity I use Blender in appendix C when explaining how to model download it from www blender org but that s just because Blender is open source and thus available to all readers 72 4 2 4 2 1 CHAPTER 4 Developing graphics for your game NOTE The project download for this chapter includes a folder named scratch Although that folder is in the same place as the Unity project it s not part of the Unity project that s where I put extra external files As you work through the project for this chapter you ll see examples of most of these types of art assets animations are a bit too complex for now and will be addressed later in the book You re going to build a scene that uses 2D images 3D models mate rials and a particle system In some cases you ll bring in already existing art assets and learn how to import them into Unity but at other times especially with the particle system you ll create the art asset from scratch within Unity This chapter only scratches the surface of game art creation Because this book focuses on how to do programming in Unity extensive coverage of art disciplines would reduce how much the book could cover Creating game art is a giant topic in and of itself easily able to fill several books In most cases a game programmer would need to partner with a game artist who specializes in that discipline That said it s extremely useful for game programmers to
52. and drop ping them on other objects will feel routine A lot of different linkages in Unity are created by dragging things on top of each other not just attaching scripts to objects When a script is linked to an object you ll see something like figure 1 16 with the script showing up as a compo nent in the Inspector Now the script will execute when you play the scene although nothing is going to happen Script yet because you haven t written any code Let s do that next Open the script in MonoDevelop to get back to listing 1 1 The classic place to start when learning a new program Inspector ming environment is having it print the text Hello World so add this line inside the Start method as shown in the following listing Click and drag the script from the Project view up to the Hierarchy view and release on the GameObject Inspector M Game0bject Tag untagged Layer Defaut xo iyo xo yo sd E G ke HelloWorld Add Component Y G M Hello World Script Figure 1 16 Linked script being displayed in the Getting up and running with Unity programming 19 Listing 1 2 Adding a console message void Start Debug Log Hello World Add the logging command here What the Debug Log command does is print a message to the Console view in Unity Meanwhile that line goes in the Start method because as was explained earlier that method i
53. and the exact controls mapped to those names Both the left right arrow keys and the letters A D are mapped to Horizontal whereas both the up down arrow keys and the letters W S are mapped to Vertical Note that the movement values are applied to the X and Z coordinates As you probably noticed while experimenting with the Translate method the X coordi nate moves from side to side and the Z coordinate moves forward and backward Put in this new movement code and you should be able to move around by press ing either the arrow keys or WASD letter keys the standard in most FPS games The movement script is nearly complete but we have a few more adjustments to go over 2 5 2 Setting a rate of movement independent of the computer s speed It s not obvious right now because you ve only been running the code on one com puter yours but if you ran it on different machines it d run at different speeds That s because some computers can process code and graphics faster than others Right now the player would move at different speeds on different computers because the movement code is tied to the computer s speed That is referred to as frame rate dependent because the movement code is dependent on the frame rate of the game For example imagine you run this demo on two different computers one that gets 30 fps frames per second and one that gets 60 fps That means Update would be called twice as often on the second computer and t
54. at the same time 38 2 5 Keyboard input component first person controls 40 Responding to key presses 40 Setting a rate of movement independent of the computer s speed 41 Moving the CharacterController for collision detection 42 Adjusting components for walking instead of flying 43 2 6 Summary 45 Adding enemies and projectiles to the 3D game 46 3 1 Shooting via raycasts 47 What ts raycasting 47 Using the command ScreenPointToRay for shooting 48 Adding visual indicators for aiming and hits 50 3 2 Scripting reactive targets 53 Determining what was hit 53 Alert the target that it was hit 54 3 3 Basic wandering AI 55 Diagramming how basic AI works 56 Seeing obstacles with a raycast 56 Tracking the character s state 58 3 4 Spawning enemy prefabs 60 What is a prefab 60 Creating the enemy prefab 60 Instantiating from an invisible SceneController 61 3 5 Shooting via instantiating objects 63 Creating the projectile prefab 64 Shooting the projectile and colliding with a target 65 Damaging the player 67 3 6 Summary 68 www allitebooks com CONTENTS 1x Developing graphics for your game 69 4 1 Understanding art assets 69 4 2 Building basic 3D scenery whiteboxing 72 Whiteboxing explained 72 Drawing a floor plan for the level 73 Laying out primitives according to the plan 74 4 3 Texture the scene with 2D images 75 Choosing a file format 76 Importing an image file 77 Applying the im
55. bottom right of the screen 11 3 2 Handling the player s progression through the game 273 Call them set the attached text objects Save Game and Load Game set Anchor to bot tom right and position them at 100 65 and 100 30 These buttons will link to functions in UIController so write those methods as shown in the following listing Listing 11 30 Save and Load methods in UlController public void SaveGame Managers Data SaveGameState public void LoadGame Managers Data LoadGameState Link these functions to OnClick listeners in the buttons add a listing in the OnClick setting drag in the UIController object and select functions from the menu Now play the game pick up a few items use a health pack to increase your health and then save the game Restart the game and check your inventory to verify that it s empty Hit Load you now have the health and items you had when you saved the game Beating the game by completing three levels As implied by our saving of the player s progress this game can have multiple levels not just the one level you ve been testing To properly handle multiple levels the game must detect not only the completion of a single level but also the completion of the entire game First add yet another GameEvent public const string GAME COMPLETE GAME COMPLETE Now modify MissionManager to broadcast that message after the last level see the next listing
56. built this image will appear as the application s icon Quality settings The built application is also affected by project settings located under the Edit menu In particular the visual quality of the final app can be tuned here Go to Project Settings in the Edit menu and then choose Quality from the drop down menu Quality settings appear in the Inspector and the most important settings are the grid of check marks at the top The different platforms that Unity can target are listed as icons across the top and the possible quality settings are listed along the side The boxes are checked for quality settings available for that platform and the check box is highlighted green for the setting being used Most of the time these settings default to Fastest which is the lowest quality but you can change to Fantastic quality if things look bad if you click the down arrow underneath a platform s column a pop up menu will appear 12 1 3 Start by building for the desktop Windows Mac and Linux 281 It seems a bit redundant that this Ul has both check boxes and the Default menu but there you have it Different platforms often have different graphical capabilities so Unity allows you to set different quality levels for different build targets Such as highest quality on desktop and lower quality on mobile i QualitySettings g The green highlights indicate the current quality setting for each platform Click the down arrow
57. chapter you ll build a 2D interface display for a 3D game So far we ve focused on the virtual scene itself while building a first person demo But every game needs abstract interaction and information displays in addition to the virtual scene the gameplay takes place in This is true for all games whether 2D or 3D first person shooter or puzzle game These abstract interaction displays are referred to as the UI or more specifically the GUI GUI refers to the visual part of the interface such as text and buttons see figure 6 1 Technically the UI includes nongraphical controls such as the key board or gamepad but people tend to be referring to the graphical parts when they say user interface 119 120 CHAPTER 6 Putting a 2D GUI in a 3D game Settings button Part of the HUD displayed over the game view Pop up window displayed over the game view A wall within the scene This is the main game view Figure 6 1 The GUI a heads up display or HUD you ll create for a game Although any software requires some sort of UI in order for the user of that software to control it games often use their GUI in a slightly different way from other software In a website for example the GUI basically zs the website in terms of visual represen tation In a game though text and buttons are often an additional overlay on top of the game view a kind of display called a HUD DEFINITION A heads up display HUD superim
58. character controller which is the height without the rounded ends and then add the rounded ends Divide this value in half because the ray was cast from the middle of the char acter that is already halfway down to get the distance to the bottom of the character But we really want to check a little beyond the bottom of the char acter to account for tiny inaccuracies in the raycasting so divide by 1 9 instead of 2 to get a distance that s slightly too far Having done this raycasting use hitGround instead of isGrounded in the if statement for vertical movement Most of the vertical movement code will remain the same but add code to handle when the character controller collides with the ground even though the player isn t over the ground that is when the player walks off the edge of the platform There s a new isGrounded conditional added but note that it s nested inside the hitGround conditional so that isGrounded is only checked when hitGround doesn t detect the ground The collision data includes a normal property again a normal vector says which way something is facing that tells us the direction to move away from the point of col lision But one tricky thing is that we want the nudge away from the contact point to be handled differently depending on which direction the player is already moving when the previous horizontal movement is toward the platform we want to replace that movement so that the character won t keep mo
59. contained tutorials StackExchange presents a mostly text QA that encourages searching StackExchange has sections about a huge array of topics this is the area of the site focused on game development For what it s worth I look for Unity information here almost as often as I use the script reference http gamedev stackexchange com MAYA LT GUIDE As described earlier in appendix B external art applications are a crucial part of creat ing visually stunning games Many resources are available that teach about Maya 3ds Max Blender or any of the other 3D art applications out there Appendix C offers a tutorial about Blender Meanwhile here s one online guide about using Maya LT which is a less expensive and game development oriented version of Maya http steamcommunity com sharedfiles filedetails id 242847724 Code libraries Although the previously listed resources provide tutorials and or learning informa tion about Unity the sites in this section provide code that can be used in your proj ects Libraries and plug ins are another kind of resource that can be useful for new developers both for using directly but also for learning from by reading their code UNIFY COMMUNITY WIKI This wiki is a central database of code contributions from many developers and the scripts hosted here cover a wide range of functionality Throughout this book I some times directed you to specific scripts hosted here the event system a
60. coroutines overview 203 204 HTTP requests 204 205 overview 201 203 206 207 parsing JSON 209 210 parsing XML 207 209 NetworkService 248 normals 143 324 0 OBJ format 75 83 OGG format 223 OnClick event 130 OnControllerColliderHit call back function 158 OnGUI method 52 121 188 OnMouseDown method 254 orthographic defined 101 outdoor scenes changing based on data 210 212 generating sky visuals using skybox 197 198 setting up atmosphere con trolled by code 198 200 P parent defined 27 parsing data defined 207 JSON 209 210 XML 207 209 particle systems attaching effects to 3D objects 90 default effect 87 88 defined 71 fire texture 88 90 overview 86 87 Path DirectorySeparatorChar 272 PCM Pulse Code Modulation 226 persistent data 135 Photoshop 306 PICT format 76 pixel perfect 102 platforms 281 282 PlayerPrefs 135 players damaging 67 68 disallowing physics rotation on 38 progress beating game by complet ing levels 273 275 saving and loading 269 273 PNG format 76 point lights 28 point and click controls movement code 251 253 operating devices using mouse 253 255 INDEX overview 250 255 top down view of scene 251 POST method 196 postbuild scripts 279 posting data overview 217 218 sending post requests 218 220 server side code in PHP 220 PowerVR 290 prefabs projectile 64 65 spawning enemies instantiation from invisible SceneController 61 62 overview 60 61 pressure plate 1
61. dPos private bool _open ao A Boolean to keep track of the TE TE TE open state of the door if _open Vector3 pos transform position dPos AL Open or close the door transform position pos depending on the open state else Vector3 pos transform position dPos transform position pos _open open The first variable defines the offset that s applied when the door opens The door will move this amount when it opens and then it will subtract this amount when it closes The second variable is a private Boolean for tracking whether the door is open or closed In the Operate method the object s transform is set to a new position add ing or subtracting the offset depending on whether the door is already open then _open is toggled on or off As with other serialized variables dPos appears in the Inspector But this is a Vector3 value so instead of one input box there are three all under the one variable name Type in the relative position of the door when it opens I decided to have the door slide down to open so the offset was 0 2 9 0 because the door object has a height of 3 mov ing down 2 9 leaves just a tiny sliver of the door sticking up out of the floor 170 CHAPTER 8 Adding interactive devices and items within the game NOTE The transform is applied instantly but you may prefer seeing the movement when the door opens As mentioned back in chapter 3 you can use tweens to make obje
62. directly if you want some simple modifications could be part of the postbuild script Building for mobile apps 1OS and Android 287 Regardless open the Xcode project the built folder has many files but double click the xcodeproj file it has an icon of a blueprint Xcode will open with this project loaded Unity already took care of most of the needed settings in the project but you do need to adjust the provisioning profiles being used iOS provisioning profiles Of all the aspects of iOS development provisioning profiles change the most frequently and are the most unusual In short these are files used for identification and autho rization Apple tightly controls what apps can run on what devices apps submitted to Apple for approval use special provisioning profiles that allow them to work through the App Store whereas apps in development use provisioning profiles that are specific to registered devices You ll need to add both your iPhone s UDID an ID specific to your device and the app s ID the Bundle Identifier in Unity to a control panel at iOS Dev Center Apple s website for iOS developers For a complete explanation of this process visit https developer apple com devcenter ios index action Hi Joseph Hocking My Profile Sign out Click here to add devices IOS Developer Program al app IDs and generate Certificates Identifiers amp Profiles provisioning profiles Apple Developer Forums Wher
63. drag that script onto the pop up object Listing 6 4 SettingsPopup script for the pop up object using UnityEngine using System Collections public class SettingsPopup MonoBehaviour Turn the object on to public void Open _ open the window gameObject SetActive true a ea Dd Deactivate this object Dee ee oer a to close the window gameObject SetActive false 6 3 3 Programming interactivity in the UI 133 Next open UIController cs to make a few adjustments as shown in the following listing Listing 6 5 Adjusting UlController to handle the pop up SerializeField private SettingsPopup settingsPopup void Start settingsPop p Close DS Close the pop up when the game starts public void OnOpenSettings settingsPopup Open et ae Replace the debug text with the pop up s method This code adds a slot for the pop up object so drag the pop up to UIController Now the pop up will be closed initially when you play the game and it ll open when you click the settings button At the moment there s no way to close it again so add a close button to the pop up The steps are pretty much the same as for the button created earlier choose GameObject gt UI gt Button position the new button in the top right corner of the pop up drag the close sprite to this UI element s Source Image property and then click Set Native Size to correctly resize the image Unlike with the
64. elaborate code architecture though is to keep all the data in separate flexible modules a useful pattern once the game gets more complex For example now we can write UI displays and the separate parts of the code will be much easier to handle Inventory Ul for using and equipping items The collection of items in your inventory can be used in multiple ways within the game but all of those uses first rely on some sort of inventory UI so that players can see their collected items Then once the inventory is being shown to the player you can program interactivity into the UI by enabling players to click on their items Again we ll program a couple of specific examples equipping a key and consuming health packs and then you should be able to adapt this code to work with other types of items NOTE As mentioned in chapter 6 Unity has both an older immediate mode GUI and a newer sprite based UI system We ll use the immediate mode GUI in this chapter because that system is faster to implement and requires less setup less setup is great for practice exercises The sprite based UI system is more polished though and for an actual game you d want a more polished interface Displaying inventory items in the UI To show the items in a UI display we first need to add a couple more methods to InventoryManager Right now the item list is private and only accessible within the manager in order to display the list though that information must
65. ends this primitive shape will rep resent the player Position this object at 1 1 on the Y axis half the height of the object plus a bit to avoid overlapping the floor You can move the object on X and Z wher ever you like as long as it s inside the room and not touching any walls Name the object Player In the Inspector you ll notice that this object has a capsule collider assigned to it That s a logical default choice for a capsule object just like cube objects had a box col lider by default But this particular object will be the player and thus needs a slightly different sort of component than most objects Remove the capsule collider by click ing the gear icon toward the top right of that component shown in figure 2 10 that will display a menu that includes the option Remove Component The collider is a green mesh surrounding the object so you ll see the green mesh disappear after deleting the capsule collider Instead of a capsule collider we re going to assign a character controller to this object At the bottom of the Inspector there s a button labeled Add Component click that button to open a menu of components that you can add In the Physics section of dae eE S ee T E Vv Capsule Mesh Filter na Mesh o v b M Capsule Collider o Is Trigger Click this icon to access Material o a menu with the Center Remove Component option x i Z Radius Height Z Direction Y Lo M Mesh Renderer Figure 2 10 Re
66. establish a value for how far away to operate devices from Then in the Update function look for keyboard input since the Jump key is already being used by the RelativeMovement script this time we ll respond to Fire3 which is defined in the project s input settings as the left Command key Now we get to the crucial new method OverlapSphere This method returns an array of all objects that are within a given distance of a given position By passing in the position of the player and the radius variable this detects all objects near the player What you actually do with this list can vary for example perhaps you just set off a bomb and want to apply an explosive force but in this situation we want to attempt to call Operate on all nearby objects That method is called via SendMessage instead of the typical dot notation an approach you also saw with UI buttons in previous chapters As was the case there the 8 1 3 Creating doors and other devices 171 reason to use SendMessage is because we don t know the exact type of the target object and that command works on all GameObjects But this time we re going to pass the option DontRequireReceiver to the method This is because most of the objects returned by OverlapSphere won t have an Operate method normally Send Message prints an error message if nothing in the object received the message but in this case the error messages would be distracting because we alread
67. filled with our tabletop sprite As you saw getting to this point wasn t completely obvious again that s because Unity was a 3D game engine that recently had 2D graphics grafted in But the tabletop is completely bare so our next step is to put a card on the table Building a card object and making it react to clicks Now that the images are all imported and ready to use let s build the card objects that form the core of this game In Memory all the cards are initially face down and they re only face up temporarily when you choose a pair of cards to turn over To implement this functionality we re going to create objects that consist of multiple sprites stacked on top of one another Then we ll write code that makes the cards reveal themselves when clicked with the mouse Building the object out of sprites Drag one of the card images into the scene Use one of the card fronts because you ll add a card back on top to hide the image Technically the position right now doesn t matter but eventually it will matter so you may as well position the card at 3 1 0 Now drag the card_back sprite into the scene Make this new sprite a child of the previous card sprite remember in the Hierarchy drag the child object onto the parent object and then set its position to 0 0 1 Keep in mind that this position is relative to the parent so this means Put it at the same X Y but move it closer on Z TIP Instead of the Move Rota
68. folders for Scripts and Textures and then move assets into the appropriate folders Sim ply drag files to their new folder WARNING Unity has several keywords that it responds to in folder names with special ways of handling the contents of these special folders Those key words are Resources Plugins Editor and Gizmos Later in the book we ll go over what some of these special folders do but for now avoid naming any folders with those words Now the images are imported into Unity as textures ready to use But how do we apply the textures to objects in the scene Applying the image Technically textures aren t applied to geometry directly Instead textures can be part of materials and materials are applied to geometry As explained in the intro a mate rial is a set of information defining the properties of a surface that information can include a texture to display on that surface This indirection is significant because the same texture can be used with multiple materials That said typically each texture Texture the scene with 2D images 79 Assets Textures Round0067 Texture2D Figure 4 7 One way to apply textures is by dragging them from Project onto Scene objects goes with a different material so for convenience Unity allows you to drop a texture onto an object and then it creates a new material automatically If you drag a texture from Project view onto an object in the scene Unity will create a new ma
69. for the Anchor setting this controls how letters expand out as they re typed so change this if needed By default the text appears blurry but that s easily fixed by adjusting the settings shown in figure 5 10 If we imported a new TrueType font into the project we could use that instead but for our purposes the default font is fine Oddly enough a bit of size adjustment is needed to make the default text sharp and clear First set the TextMesh component s Font Size setting to a very large value I used 80 Now scale the object down to be very small like 1 1 1 Increasing Font Size added a lot of pixels to the text displayed and scaling the object compressed those pixels into a smaller space YA Transform Gy Set the object s Position x 4 75__ y 3 6s___ z 10 scale very small Rotation xo lvo ko gt Scale X 0 1 Y 0 1 Z 0 1 v L M Mesh Renderer ga Cast Shadows fon Receive Shadows wM Materials Use Light Probes M Reflection Probes end robes Anchor Override i Offset Z Character Size i Line Spacing Set the font Other settings gt Anchor size very large mentioned Alignment Text Anchor and Font Tab Size Font Size Font Style Rich Text gt Font a Arial o Color A Figure 5 10 Inspector settings for a text object to make the text sharp and clear 114 5 5 CHAPTER 5 Building a Memory game using Unity s new 2D functionality Manipulating this text object requires just
70. for your game is certainly one way to market it But there are lots of low cost or even free ways to get the word out about your game Specifics tend to change over time but overall strategies mentioned in that video include tweeting about your game or posting on social media in general not just Twitter and creating a trailer video to share on YouTube with reviewers bloggers and so on Be persistent and get creative Now go and create some great games Unity is an excellent tool for doing just that and you ve learned how to use it Good luck on your journey A 1 appendix A Scene navigation and keyboard shortcuts Operating Unity is done through mouse and keyboard but it isn t obvious to a new comer how the mouse and keyboard are used in Unity In particular the most basic sort of mouse and keyboard input is navigating around the scene and looking around the 3D objects Unity also has a number of keyboard commands for com monly used operations Pll explain the input controls here but there are also a couple of web pages you could refer to these are the relevant pages in Unity s online manual http docs unity3d com Documentation Manual SceneViewNavigation html http docs unity3d com Documentation Manual UnityHotkeys html Scene navigation using the mouse Scene navigation is primarily done with three main navigation maneuvers Move Orbit and Zoom The three different movements involve clicking and dragging while
71. gt _startSequence Add Weather Downloading weather data from an internet service 203 StartCoroutine StartupManagers Instantiate NetworkService private IEnumerator StartupManagers ah to inject in all managers NetworkService network new NetworkService foreach IGameManager manager in _startSequence Ber ee ae ie eee a Pass the network service to managers during startup yield return null int numModules Stlarceequence Count int numReady 0 while numReady lt numModules int lastReady numReady numReady 0 foreach IGameManager manager in _startSequence if manager status ManagerStatus Started numReady if numReady gt lastReady Debug Log Progress numReady numModules yield return null Debug Log All managers started up And that s everything needed codewise for the Managers code architecture As you have in previous chapters create the game managers object in the scene and then attach both Managers and WeatherManager to the empty object Even though the manager isn t doing anything yet you can see startup messages in the console when it s set up correctly Whew there were quite a few boilerplate things to get out of the way Now we can get on with writing the networking code 9 2 1 Requesting WWW data using coroutines NetworkService is currently an empty script so you can write code in it to make HTT
72. has a stored image GetWebImage will send back the stored image rather than downloading the image anew NOTE Currently the downloaded image is never being stored which means _webImage will always be empty Code that specifies what to do when _webImage is not empty is already in place so you ll adjust the code to store that image in the following sections This adjustment is in a separate section because it involves some tricky code wizardry Of course just like all manager modules ImagesManager needs to be added to Manag ers the following listing details the additions to Managers cs Listing 9 14 Adding the new manager to Managers cs RequireComponent typeof ImagesManager public static ImagesManager Images get private set void Awake Weather GetComponent lt WeatherManager gt Images GetComponent lt ImagesManager gt _startSequence new List lt IGameManagers gt _startSequence Add Weather _startSequence Add Images StartCoroutine StartupManagers j Unlike how we set up WeatherManager GetWebImage in ImagesManager isn t called automatically on startup Instead the code waits until invoked that ll happen in the next section Displaying images on the billboard The ImagesManager you just wrote doesn t do anything until it s called upon so now we ll create a billboard object that will call methods in ImagesManager First create a Adding a networked billboard 215 Bi
73. have public meth ods for accessing the data Add two methods shown in the following listing to InventoryManager Inventory UI for using and equipping items 187 Listing 8 17 Adding data access methods to InventoryManager public List lt string gt GetItemList List lt string gt list new List lt string gt items Keys return list a Returns a List of all the Dictionary keys public int GetItemCount string name if _items ContainsKey name return _items name return 0 aoe Returns how many of that item are in inventory The GetItemList method returns a list of items in the inventory You might be thinking Wait a minute didn t we just spend lots of effort to convert the inventory away from a List The difference now is that each type of item will only appear once in the list If the inventory contains two health packs for example the name health will still only appear once in the list That s because the List was created from the keys in the Dictionary not from every individual item The Get ItemCount method returns a count of how many of a given item are in the inventory For example call GetItemCount health to ask How many health packs are in the inventory This way the UI can display a number of each item along with displaying each item With these methods added to InventoryManager we can create the UI display Let s display all the items in a horizontal row across the t
74. holding down some combination of Alt or Option on the Mac and Control The exact controls vary for one two and three button mice table A 1 lists all the controls Table A 1 Scene navigation controls for various kinds of mice e Three button mouse Two button mouse One button mouse Move Middle button click drag Alt Command left click drag Alt Command click drag Orbit Hold Alt left click drag Alt left click drag Alt click drag Zoom Hold Alt right click drag Alt right click drag Alt Ctrl click drag 302 A 2 Commonly used keyboard shortcuts 303 NOTE Although Unity can be used with one or two button mice I highly rec ommend getting a three button mouse and yes a three button mouse works fine on Mac OSX Besides the navigation maneuvers done using the mouse there are also some view controls based on the keyboard If you hold down the right button on the mouse the WASD keys on the keyboard can be used to walk around in the manner common to most first person games Hold Shift during any other control to move faster But most important if you press F while an object is selected the view will pan and zoom to focus on that object If you get lost while navigating your scene a common escape hatch is to select an object listed in the Hierarchy and then press F Commonly used keyboard shortcuts Unity has a number of keyboard commands to quickly access important functions The most important keyboard shortc
75. implementing shooting Another approach involves instantiating prefabs so let s take that approach to making the enemies shoot back The goal of this section is to see figure 3 9 when playing Figure 3 9 Enemy shooting a fireball at the player 64 3 5 1 CHAPTER 3 Adding enemies and projectiles to the 3D game Creating the projectile prefab Whereas the shooting before didn t involve any actual projectile in the scene this time shooting will involve a projectile in the scene Shooting with raycasting was basi cally instantaneous registering a hit the moment the mouse was clicked but this time enemies are going to emit fireballs that fly through the air Admittedly they ll be mov ing pretty fast but it won t be instantaneous giving the player a chance to dodge out of the way Instead of using raycasting to detect hits we ll use collision detection the same collision system that keeps the moving player from passing through walls The code will spawn fireballs in the same way that enemies spawn by instantiating a prefab As explained in the previous section the first step when creating a prefab is to create an object in the scene that will become the prefab so let s create a fireball To start choose GameObject gt 3D Object gt Sphere Rename the new object Fireball Now create a new script also called Fireball and attach that script to this object Even tually we ll write code in this script bu
76. import the TGA file into the project and then assign this image as the texture in a material Select the player material in the Materials folder Drag the texture image onto the empty texture slot in the Inspector Once the texture is applied you won t see a dramatic change in the model s color this texture image is mostly white but there are shadows painted into the texture that ll improve the look of the model Set the Scale Factor to partially counteract File Scale This determines how big the model is in Unity compared to how big it was in the 3D art tool Select how to handle Normals Figure 7 4 Import settings for the on the model character model 144 7 1 2 CHAPTER 7 Creating a third person 3D game player movement and animation With the texture applied drag the player model from the Project view up into the scene Position the character at 0 1 1 0 so that it ll be in the center of the room and raised up to stand on the floor Great we have a third person character in the scene NOTE The imported character has his arms stuck straight out to the sides rather than the more natural arms down pose That s because animations haven t been applied yet that arms out position is referred to as the T pose and the standard is for animated characters to default to a T pose before they re animated Adding shadows to the scene Before we move on I want to explain a bit about the shadow being cast by the charac
77. in its scene graph Thus even if you removed all references to the GameObject in your code there would still be this scene graph reference preventing the object from being destroyed automatically Because of this Unity provided the method Destroy to tell the game engine Remove this object from the scene graph As part of that behind the scenes functionality Unity also overloaded the operator to return true when checking for null Technically that object still exists in memory but it may as well not exist any more so Unity has it appearing to be null You could confirm this by calling Get InstanceID on the destroyed object Note though that the developers of Unity are considering changing this behavior to more standard memory management If they do then the spawning code will need to change as well probably by swapping the _enemy null check with a new param eter like _enemy isDestroyed Refer to their blog Facebook page https www facebook com unity3d posts 101522 710985917 73 If most of this discussion was Greek to you then don t worry about it this was a tangential technical discussion for people interested in these obscure details Shooting via instantiating objects All right let s add another bit of functionality to the enemies Much as we did with the player first we made them move now let s make them shoot As I mentioned back when introducing raycasting that was just one of the approaches to
78. in the scene 7 if _enemy null Only spawn a new _enemy Instantiate enemyPrefab as GameObject eae if there _enemy transform position new Vector3 0 1 0 A The method that copies isnt already one float angle Random Range 0 360 the prefab object in the scene _enemy transform Rotate 0 angle 0 Attach this script to the controller object and in the Inspector you ll see a variable slot for the enemy prefab This works similarly to public variables but there s an impor tant difference see the following warning WARNING I recommend private variables with SerializeField to reference objects in Unity s editor because you want to expose that variable in the 62 CHAPTER 3 Adding enemies and projectiles to the 3D game Inspector but don t want the value to be changed by other scripts As explained in chapter 2 public variables show up in the Inspector by default in other words they re serialized by Unity so most tutorials and sample code you ll see use public variables for all serialized values But these variables can also be modified by other scripts these are public variables after all in many cases you don t want the value to be modified in code but only set in the Inspector Drag up the prefab asset from Project to the empty variable slot when the mouse gets near you should see the slot highlight to indicate that the object can be linked there see figure 3 8 Once the enemy prefab
79. into memory before it s needed and consuming too much memory when loaded Optimizing when music loads is done using the Resources Load command intro duced in chapter 8 As you learned this command allows you to load assets by name though that s certainly one handy feature that s not the only reason to load assets from the Resources folder Another key consideration is delaying loading normally Unity loads all assets in a scene as soon as the scene loads but assets from Resources aren t loaded until the code manually fetches them In this case we want to lazy load the audio clips for music Otherwise the music could consume a lot of memory while it isn t even being used DEFINITION Lazy loading is when a file isn t loaded ahead of time but rather is delayed until it s needed Typically data responds faster for example the sound plays immediately if it s loaded in advance of use but lazy loading can save a lot of memory when responsiveness doesn t matter as much The second memory consideration is dealt with by streaming music off the disc As explained in section 10 1 2 streaming the audio saves the computer from ever need ing to have the entire file loaded at once The style of loading was a setting in the Inspector of the imported audio clip Ultimately there are several steps to go through for playing background music including steps to cover these memory optimizations Playing music loops The process of playi
80. is linked to the SceneController script play the scene in order to see the code in action Inspector M Controller OStatic v Tag Untagged Layer Default YA Transform w Position xo YO zo Rotation xo yo zo scale X11 21 Y M Scene Controller Script w Script SceneController A Enemy Prefab None Game Object lt Add Camnanan An enemy will appear in the middle of the room just like before but now if you shoot the enemy it will be replaced by a new enemy Much better than just one enemy that s gone forever Drag the prefab from Project view to a slot in the Inspector TIP This approach of dragging objects onto the Inspector s variable slots is a handy technique that comes up in a lot of different scripts Here we linked a pre fab to the script but you can also link to objects in the scene or even specific components because the code needs to call public methods in that specific component In future chapters we ll use this technique again Figure 3 8 Drag the enemy prefab from Project up to the Enemy Prefab slot in the Inspector The core of this script is the Instantiate method so take note of that line When we instantiate the prefab that creates a copy in the scene By default Instantiate returns the new object as a generic Object type but Object is pretty useless directly and we need to handle it as a GameObject In C use the as keyword for typec
81. like this if you click a different tab the view is replaced by the new 1 2 2 How to use Unity 11 Options for aspects of the scene to display e g toggle button to show lighting Play Toolbar A ER Rect Scale Rotate Translate ina Navigate Light scene ee Mesh object Figure 1 10 Editor screenshot cropped to show Toolbar Scene and Game active tab When the game is running what you see in this view is the game It isn t necessary to manually switch tabs every time you run the game because the view auto matically switches to Game when the game starts TIP While the game is running you can switch back to the Scene view allow ing you to inspect objects in the running scene This capability is hugely use ful for seeing what s going on while the game is running and is a helpful debugging tool that isn t available in most game engines Speaking of running the game that s as simple as hitting the Play button just above the Scene view That whole top section of the interface is referred to as the Toolbar and Play is located right in the middle Figure 1 10 breaks apart the full editor interface to show only the Toolbar at the top as well as the Scene Game tabs right underneath At the left side of the Toolbar are buttons for scene navigation and transforming objects how to look around the scene and how to move objects I suggest you spend some time practicing looking around the scene and moving objec
82. listing Listing 10 8 Adding sound effects to SettingsPopup SerializeField private AudioClip sound e i t lot t f nspector siot to reference public void OnSoundToggle the sound clip Managers Audio soundMute Managers Audio soundMute Managers Audio PlaySound sound bS Play the sound effect when the button is pressed Drag the UI sound effect onto the variable slot I used the 2D sound thump When you press the UI button that sound effect plays at the same time well when the sound isn t muted of course Even though the UI doesn t have any audio source itself AudioManager has an audio source that plays the sound effect Great we ve set up all our sound effects Now let s turn our attention to music Background music You re going to add some background music to the game and you ll do that by add ing music to AudioManager As explained in the chapter introduction music clips aren t fundamentally different from sound effects The way digital audio functions 10 4 1 Background music 237 through waveforms is the same and the commands for playing the audio are largely the same The main difference is the length of the audio but that difference cascades out into a number of consequences For starters music tracks tend to consume a large amount of memory on the com puter and that memory consumption must be optimized You must watch out for two areas of memory issues having the music loaded
83. m Figure 4 8 Select a ae Metallic oo Lisi to see it in the caddie TA pector then drag Normal Map textures to the material l le Heinht Man properties 80 4 4 4 4 1 CHAPTER 4 Developing graphics for your game then change the Tiling number in the Inspector with separate X and Y values for til ing in each direction Make sure you re setting the tiling of the main map and not the secondary map this material supports a secondary texture map for advanced effects The default tiling is 1 that s no tiling with the image being stretched over the entire surface change the number to something like 8 and see what happens in the scene Change the numbers in both materials to tiling that looks good Great now the scene has textures applied to the floor and walls You can also apply textures to the sky of the scene let s look at that process Generating sky visuals using texture images The brick and stone textures gave a much more natural look to the walls and floor Yet the sky is currently blank and unnatural we also want a realistic look for the sky The most common approach to this task is a special kind of texturing using pictures of the sky What is a skybox By default the camera s background color is dark blue Ordinarily that color fills in any empty area of the view for example above the walls of this scene but it s possi ble to render pictures of the sky as background This is where the concept o
84. method appears in both sections of the list in the latter case it will only receive a single value typed in ahead of time The settings controls are now working but there s one more script we need to address the fact that the pop up is currently always covering up the screen A simple fix is to make the pop up only open when you hit the M key Create a new script called UICon troller link that script to the Controller object in the scene and write the code shown in the next listing Listing 10 6 UlController that toggles the settings pop up using UnityEngine using System Collections bli 1 ULControll MonoBehavi Pe renees popup public e aeg ontro LE onore aviour WA object in scene SerializeField private SettingsPopup popup void Start Initializes pop up hidden popup gameObject SetActive false Pa void Update Toggles pop up with M key if Input GetKeyDown KeyCode M a bool isShowing popup gameObject activeSelf popup gameObject SetActive isShowing if isShowing Cursor lockState CursorLockMode Locked Cursor visible false wise Also toggles cursor Cursor lockState CursorLockMode None along with pop up Cursor visible true To wire up this object reference drag the settings pop up to the slot on this script Play now and try changing the slider remember to activate the UI by hitting M while shooting around to hear the sound effects you ll hear the sound effects change v
85. mode gle object in detail you must switch to Edit mode figure C 3 Object Mode H Object Mode shows the menu you use Edit appears in this menu only when The editing mode menu an object is selected and Blender starts out with the Figure C 3 Menu for switching from Object to Edit mode object selected Similarly when you first switch to Edit mode Blender is set to Vertex Selection mode but there are buttons refer to figure C 4 that let you switch between Vertex Edge and Face Selec tion modes The various selection modes allow you to select different mesh elements 310 APPENDIX C Modeling a bench in Blender Transform tool Selection mode Toggle select back translate rotate scale vertex edge or face of object too dit Mode Figure C 4 Controls along the bottom of the viewport DEFINITION Mesh elements are the vertices edges and faces that comprise the geometry of the mesh in other words the individual corner points the lines connecting the points and the shapes filled in between connected lines Fundamental mouse and keyboard shortcuts in Blender Also depicted in figure C 4 are the various transform tools As in Unity the transforms are Translate Rotate and Scale The first button toggles the Transform Gizmo the arrows in the scene on and off recommend leaving that gizmo on because otherwise you can only access the transform tools via keyboard shortcuts The keyboard short cuts in Bl
86. models can have 2D images referred to as textures displayed on their surface How exactly the 2D images relate to the 3D surface is straightforward for a large flat surface like a wall simply stretch the image across the flat surface But what about an oddly shaped surface like the sides of the bench This is where it becomes important to understand the concept of texture coordinates Texture coordinates define how parts of the texture relate to parts of the mesh These coordinates assign mesh elements to areas of the texture Think about it like wrapping paper see figure C 8 the 3D model is the box being wrapped the texture is the wrapping paper and the texture coordinates represent where on the wrapping paper each side of the box will go The texture coordinates define points and shapes on the 2D image those shapes correlate to polygons on the mesh and that part of the image appears on that part of the mesh TIP Another name for texture coordinates is UV coordinates This name comes from the fact that texture coordinates are defined using the letters U and V like coordinates on the 3D model are defined using X Y and Z The technical term for correlating part of one thing to part of another is mapping hence the term texture mapping for the process of creating texture coordinates Com ing from the wrapping paper analogy another name for the process is unwrapping And then there are terms created by mashing up the other terminology l
87. multiplayer online 195 mobile deployment Android build tools 288 289 developing plug ins Android plug ins 294 298 iOS plug ins 291 294 overview 290 291 example games built for 8 iOS build tools 286 288 overview 285 286 texture compression 289 290 MOD format 224 Model View Controller See MVC modeling in Blender building mesh geometry 309 311 texture mapping model 312 MonoBehaviour class 27 147 185 254 MonoDevelop 16 17 304 mouse operating devices using 253 255 scene navigation using 302 303 mouse picking 48 MouseLook script component horizontal and vertical rota tion together 38 40 horizontal rotation 35 overview 33 35 vertical rotation 35 37 323 movement local vs global coordinate space 32 33 overview 30 32 MP3 format 223 music controlling volume separately 240 242 fading between songs 242 overview 236 237 playing music loops 237 240 MVC Model View Controller 168 navigation mouse 302 303 Near clipping plane 251 network connected games billboard caching downloaded images 216 217 displaying images 214 216 loading images from internet 212 214 general discussion 195 197 outdoor scene generating sky visuals using skybox 197 198 setting up atmosphere con trolled by code 198 200 posting data to web server overview 217 218 sending post requests 218 220 server side code in PHP 220 weather data service callbacks 205 206 cascading coroutine methods 205 changing scene based on data 210 212
88. name if items ContainsKey name aa n F Check for existing entries t 1 A A before entering new data else _items name 1 DisplayItems 186 8 4 8 4 1 CHAPTER 8 Adding interactive devices and items within the game Overall this code looks the same as before but a few tricky differences exist If you aren t already familiar with Dictionary data structures note that it was declared with two types Whereas List was declared with only one type the type of values that ll be listed a Dictionary declares both the type of keys that is what the identifiers will be and the type of values A bit more logic exists in the AddItem method Whereas before every item was appended to the List now we need to check if the Dictionary already contains that item that s what the ContainsKey method is for If it s a new entry then we ll start the count at 1 but if the entry already exists then increment the stored value Play with the new code and you ll see the inventory messages have an aggregated o PEI health 2 ore 2 key 1 count of each item refer to figure 8 7 Enos Dania Erna ia Whew finally collected items are man Figure 8 7 Console message with multiples of the same item aggregated aged in the player s inventory This proba bly seems like a lot of code to handle a relatively simple problem and if this were the entire purpose then yeah it was over engineered The point of this
89. noticeable pause while the image downloads from the internet But when you then walk over to the second billboard the image will appear immediately because it has already been downloaded This is an important optimization for downloading images there s a reason web browsers cache images by default There s one more major networking task remain ing to go over sending data back to the server 9 4 Posting data to a web server We ve gone over multiple examples of downloading data but we still need to see an example of sending data This last section does require you to have a server to send requests to so this section is optional But it s easy to download open source software to set up a server to test on 218 9 4 1 CHAPTER 9 Connecting your game to the internet Trigger volume Box with a semitransparent material Figure 9 7 The checkpoint object that triggers data sending I recommend XAMPP for a test server Go to www apachefriends org to download XAMPP Once that s installed and the server is running you can access XAMPP s htdocs folder with the address http localhost just like you would a server on the internet Once you have XAMPP up and running create a folder called ch9 in htdocs that s where you ll put the server side script Whether you use XAMPP or your own existing web server the actual task will be to post weather data to the server when the player reaches a checkpoint in the scene This checkpoi
90. objects allowing you to use the higher i This mesh darkens from shadows projected onto it quality lightmaps for other objects in the scene Similarly though you almost Figure 7 6 The Cast Shadows and Receive always want the main character to cast Shadows settings in the Inspector shadows sometimes you don t want the character to receive shadows all mesh objects have settings to cast and receive shad ows see figure 7 6 DEFINITION Culling is a general term for removing unwanted things The word comes up a lot in computer graphics in many different contexts but in this case culling mask is the set of objects you want to remove from shadow casting All right now you understand the basics of how to apply shadows to your scenes Lighting and shading a level can be a big topic unto itself books about level editing will often spend multiple chapters on lightmapping but here we restrict ourselves to turning on real time shadows on one light And with that let s turn our attention to the camera Orbiting the camera around the player character In the first person demo the camera was linked to the player object in Hierarchy view so that they d rotate together In third person movement though the player charac ter will be facing different directions independently of the camera Therefore you don t want to drag the camera onto the player character in the Hierarchy view this time Instead the camera s code will move
91. of script that s most commonly encountered with JavaScript running in a browser the code is executed within the Unity game engine versus compiled code that runs as its own executable But don t get confused because many people define the word differently for example scripts often refer to short self contained utility programs Scripts in Unity are more akin to individual OOP classes and scripts attached to objects in the scene are the object instances As you ve probably surmised from this description in Unity scripts are components not all scripts mind you only scripts that inherit from MonoBehaviour the base class for script components MonoBehaviour defines the invisible groundwork for how com ponents attach to game objects and as shown in listing 1 1 inheriting from it pro vides a couple of automatically run methods that you can override Those methods include Start which is called once when the object becomes active which is gener ally as soon as the level with that object has loaded and Update which is called every frame Thus your code is run when you put it inside these predefined methods DEFINITION A frame is a single cycle of the looping game code Nearly all video games not just in Unity but video games in general are built around a core game loop where the code executes in a cycle while the game is run ning Each cycle includes drawing the screen hence the name frame just like the seri
92. of a website but through clever use of enumerators Unity makes coroutines behave simi larly to asynchronous functions The secret sauce in coroutines is the yield keyword that keyword causes the coroutine to temporarily pause handing back the program flow and picking up again from that point in the next frame In this way coroutines seemingly run in the background of a program through a repeated cycle of running partway and then returning to the rest of the program As the name implies StartCoroutine sets a coroutine in motion Once a corou tine is started it keeps running until the function is finished it just pauses along the way Note the subtle but significant point that the method passed to Start Corout ine 52 CHAPTER 3 Adding enemies and projectiles to the 3D game has a set of parentheses following the name this syntax means you re calling that func tion as opposed to passing its name The called function runs until it hits a yield com mand at which point the function pauses SphereIndicator creates a sphere at a specific point pauses for the yield state ment and then destroys the sphere after the coroutine resumes The length of the pause is controlled by the value returned at yield A few different types of return val ues work in coroutines but the most straightforward is to return a specific length of time to wait Returning WaitForSeconds 1 causes the coroutine to pause for one sec ond Create a sphere pa
93. poses Bake Into Pose loop match oO Based Upon at Star Body Orientation KX offset Root Transform Position Y Select how each component of Bake Into Pose _ loop march the root will be transformed Based Upon rotation vertical position ba as horizontal position Root Transform Position XZ Bake Into Pose m loop match oO Based Upon Center of Mass f Figure 7 14 Information about the selected animation clip DEFINITION Loop refers to a recording that plays over and over repeatedly A looping animation clip is one that plays again from the start as soon as play back reaches the end The idle animation loops so select both Loop Time and Loop Pose Incidentally the green indicator dot tells you when the pose at the beginning of the clip matches the pose at the end for correct looping this indicator turns yellow when the poses are somewhat off and it turns red when the start and end poses are completely different Below the Loop settings are a series of settings related to the root transform The word root means the same thing for skeletal animation as it does for a hierarchy con nected within Unity the root object is the base object that everything else is con nected to Thus the animation root can be thought of as the base of the character and everything else moves relative to that base There are a few different settings here for setting up that base and you may want to experiment here when working with your
94. public const string MANAGERS PROGRESS MANAGERS PROGRESS Now it s time to start adjusting Managers including broadcasting these new events Controlling mission flow and multiple levels Currently the project has only one scene and the Game Managers object is in that scene The problem with that is that every scene will have its own set of game manag ers whereas you actually want a single set of game managers shared by all scenes To do that you ll create a separate Startup scene that initializes the managers and then shares that object with the other scenes of the game We re also going to need a new manager to handle progress through the game Create a new script called MissionManager as shown in the next listing Listing 11 16 MissionManager using UnityEngine using System Collections using System Collections Generic public class MissionManager MonoBehaviour IGameManager public ManagerStatus status get private set public int curLevel get private set public int maxLevel get private set private NetworkService network public void Startup NetworkService service Debug Log Mission manager starting _network service curLevel 0 maxLevel 1 status ManagerStatus Started Send arguments along with public void GoToNext JS WWW using WWWForm if curLevel lt maxLevel curLevel string name Level curLevel Debug Log Loading name Check if las
95. s create those parameters In the top left of figure 7 16 is a tab called Parameters click that to see a panel with a button for adding parameters Add a float called Speed and a Boolean called Jump ing Those values will be adjusted by our code and they ll trigger transitions between animation states Click on the transition lines to see their settings in the Inspector see figure 7 18 Here s where we ll adjust how the animation states change when the parameters change For example click on the Idle to Run transition to adjust the conditions of that transition Under Conditions choose Speed Greater and 0 1 Turn off Has Exit Time that would force playing the animation all the way through as opposed to cut ting short immediately when the transition happens Then click the arrow next to the Settings label in order to see that entire menu other transitions should be able to interrupt this one so change the Interruption Source menu from None to Current State Repeat this for all the transitions in table 7 1 Table 7 1 Conditions for all transitions in this animation controller Transition Condition Interruption Idle to Run Speed greater than 1 Current State Run to Idle Speed less than 1 None 1 4 3 Setting up animations on the player character 165 Table 7 1 Conditions for all transitions in this animation controller continued Transition Condition Interruption Idle to Jump Jumping is true None Run to J
96. screen so dividing those values in half gives you the center of the screen Although screen coordinates are 2D with only hor izontal and vertical components and no depth a Vector3 was created because Screen PointToRay requires that data type presumably because calculating the ray involves arithmetic on 3D vectors ScreenPointToRay was called with this set of coordinates resulting in a Ray object code object that is not a game object the two can be confusing sometimes 50 3 1 3 CHAPTER 3 Adding enemies and projectiles to the 3D game The ray is then passed to the Raycast method but it s not the only object passed in There s also a RaycastHit data structure RaycastHit is a bundle of information about the intersection of the ray including where the intersection happened and what object was intersected The C syntax out ensures that the data structure manip ulated within the command is the same object that exists outside the command as opposed to the objects being separate copies in the different function scopes Finally the code calls the Physics Raycast method This method checks for intersections with the given ray fills in data about the intersection and returns true if the ray hit anything Because a Boolean value is returned this method can be put ina conditional check just as you used Input GetMouseButtonDown earlier For now the code emits a console message to indicate when an intersection occurred
97. section but before that let s get code in place that will retrieve the image The code architecture for downloading an image looks Figure 9 5 Image of Moraine Lake in Banff National much the same as the architecture Park Canada Adding a networked billboard 213 for downloading data A new manager module called ImagesManager will be in charge of downloaded images to be displayed Once again the details of connecting to the internet and sending HTTP requests will be handled in NetworkService and ImagesManager will call upon NetworkService to download images for it The first addition to code is in NetworkService The following listing adds image downloading to that script Listing 9 12 Downloading an image in NetworkService private const string webImage http upload wikimedia org wikipedia commons c c5 AL Put this const up near the ith the other URLs Moraine lake _17092005 jpg top with the other URLs public IEnumerator DownloadImage Action lt Texture2D gt callback aa WWW www new WWW webImage yield return www This callback takes a callback www texture Texture2D instead of a string The code that downloads an image looks almost identical to the code for download ing data The primary difference is the type of callback method note that the callback takes a Texture2D this time instead of a string That s because you re sending back the relevant response you downloaded a string of data be
98. set up the inventory code structure Managing inventory data and game state Now that we ve programmed the features of collecting items we need background data managers similar to web coding patterns for the game s inventory The code we ll write will be similar to the MVC architectures behind many web applications Their advantage is in decoupling data storage from the objects that are displayed on screen allowing for easier experimentation and iterative development Even when the data and or displays are complex changes in one part of the application don t affect other parts of the application That said such structures vary a lot between different games Not every game has the same data management needs so it wouldn t make sense for Unity to enforce a rule that Every game must use such and such design pattern It would ve been coun terproductive to introduce those sorts of concepts too soon because people would be misled into thinking they need that before they can make any game For example a roleplaying game will have very high data management needs so you probably want to implement something like an MVC architecture A puzzle game though has little data to manage so building a complex decoupled structure of data managers would be overkill Instead the game state can be tracked in the scene specific controller objects indeed that s how we handled game state in previous chapters In this project we need to mana
99. sprites for a GUI requires that the scene have a canvas object Ulelements can be anchored to relative positions on the adjustable canvas Set the Active property to turn UI elements on and off A decoupled messaging system is a great way to broadcast events between the interface and the scene Creating a third person 3D game player movement and animation This chapter covers Adding real time shadows to the scene Making the camera orbit around its target Changing rotation smoothly using the Lerp algorithm Handling ground detection for jumping ledges and slopes Applying and controlling animation for a lifelike character In this chapter you ll create another 3D game but this time you ll be working in a new game genre If you think back to chapter 2 you built a movement demo for a first person game Now you re going to write another movement demo but this time itll involve third person movement The most important difference is the placement of the camera relative to the player a player sees through their charac ter s eyes in first person view and the camera is placed outside the character in third person view This view is probably familiar to you from adventure games like 140 141 3 Turn on shadows for this scene We can see the player now so shadows are important I Set up the walls floor and lights in the room Simply import this from previous projects p 2 Import the character
100. take a lot of time Build an app for the current platform LS gt Switch Platform Player Settings K Build Build And Run Figure 12 1 The Build Settings window WARNING When in a big project switching platforms often takes quite a bit of time to complete make sure you re ready to wait This is because Unity recompresses all assets such as textures in an optimal way for each platform Also across the bottom of this window are the Player Settings and Build buttons Click Player Settings to view settings for the app in the Inspector such as the name and icon for the app Clicking Build launches the build process TIP Build And Run does the same thing as Build plus it automatically runs the built application I usually want to do that part manually so I rarely use Build And Run When you click Build the first thing that comes up is a file selector so that you can tell Unity where to generate the app package Once you select a file location the build process starts Unity creates an executable app package for the currently active plat form let s go over the build process for the most popular platforms desktop web and mobile Start by building for the desktop Windows Mac and Linux The simplest place to start when first learning to build Unity games is by deploying to desktop computers Windows PC Mac OS X or Linux Because Unity runs on desk top computers that means you ll build an app for the co
101. that it doesn t interfere with the inventory pop up 11 4 Summary 275 You now know how to create a full game with multiple levels The obvious next task is the final chapter getting your game into the hands of players Summary In this chapter you ve learned that Unity makes it easy to repurpose assets and code from a project in a different game genre Another great use for raycasting is to determine where in the scene the player is clicking Unity has simple methods for both loading levels and persisting certain objects between levels You progress through levels in response to various events within the game You can use the I O methods that come with C to store data at Application persistentDataPath Deploying your game to players devices This chapter covers Building an application package for various platforms Assigning build settings such as the app icon or name m Interacting with the web page for web games Developing plug ins for apps on mobile platforms Throughout the book you ve learned how to program various games within Unity but the crucial last step has been missing deploying those games to players Until a game is playable outside the Unity editor it s of little interest to anyone other than the developer Unity shines at this last step with the ability to build applications for a huge variety of gaming platforms This final chapter will go over how to build g
102. that your projects won t always end with just blank boxes sliding around All of the visual content in a game is made up of what are called art assets But what exactly does that mean Understanding art assets An art asset is an individual unit of visual information usually a file used by the game It s an overarching umbrella term for all visual content image files are art 69 70 CHAPTER 4 Developing graphics for your game assets 3D models are art assets and so on Indeed the term art asset is simply a specific case of an asset which you ve learned is any file used by the game such as a script hence the main Assets folder in Unity Table 4 1 lists and describes the five main kinds of art assets used in building a game Table 4 1 Types of art assets Type of art asset Definition of this type 2D image Flat pictures To make a real world analogy 2D images are like paintings and photographs 3D model 3D virtual objects almost a synonym for mesh objects To make a real world analogy 3D models are like sculptures Material A packet of information that defines the surface properties of any object that the material is attached to These surface properties can include color shini ness and even subtle roughness Animation A packet of information that defines movement of the associated object These are detailed movement sequences created ahead of time aS opposed to code that calculates positions on the fl
103. the image used as a the application s icon Company Name by dragging an image Product Name from the Project view Names for the development Default Icon company and the application itself These names 1 appear in the menu of the game and E Cate 2 are used to keep files organized behind the scenes You can even provide a new image for the J mouse cursor Cursor Hotspot X oo Y o s g Settings continue l below look in Unity s manual for explanations Settings for PC Mac amp Linux Standalone Figure 12 2 Player settings displayed in the Inspector 12 1 2 Adjusting Player Settings setting the game s name and icon Go back to the Build Settings window but this time click Player Settings instead of Build A huge list of settings will appear in the Inspector see figure 12 2 these set tings control a number of aspects of the built application Because of the large number of settings you ll probably want to look them up in Unity s manual the relevant doc page is http docs unity3d com Manual class PlayerSettings html The first three settings at the top are easiest to understand Company Name Prod uct Name and Default Icon Type in values for the first two Company Name is the name for your development studio and Product Name is the name of this specific game Then drag an image from the Project view import an image into the project if needed to set that image as the icon when the app is
104. the man agers have started up and won t proceed until they all have Once all the managers are started the startup function finally alerts us to this fact before finally completing TIP The managers we wrote earlier have such simple initialization that there s no waiting but in general this coroutine based startup sequence can elegantly handle long running asynchronous startup tasks like loading saved data Now all of the code structure has been written Go back to Unity and create a new empty GameObject as usual with these sorts of empty code objects position it at 0 0 0 and give the object a descriptive name like Game Managers Attach the script compo nents Managers PlayerManager and InventoryManager to this new object 184 8 3 3 CHAPTER 8 Adding interactive devices and items within the game When you play the game now there should be no visible change in the scene but in the console you should see a series of messages logging the progress of the startup sequence Assuming the managers are starting up correctly it s time to start program ming the inventory manager Storing inventory in a collection object List vs Dictionary The actual list of items collected could also be stored as a List object The next listing adds a List of items to InventoryManager Listing 8 14 Adding items to InventoryManager private List lt string gt _ items public void Startup Debug Log Inventory manager starting _it
105. the reason for a UI in a game the other half is receiving input from the player UI buttons are discussed in the next section DEFINITION U7 stand for user interface Another closely related term is GUI graphical user interface which refers to the visual part of the interface such as text and buttons and which is what a lot of people mean when they say UI Making and scoring matches 113 Unity has multiple ways to create text displays One way is to create a 3D text object in the scene This is a special mesh component so first create an empty object to attach this component to From the GameObject menu choose Create Empty Then click the Add Component button and choose Mesh gt Text Mesh NOTE That name 3D text might sound incompatible with a 2D game but don t forget that this is technically a 3D scene that looks flat because it s being seen through an orthographic camera That means we can put 3D objects into the 2D game if we want they re just displayed in a flat perspective Position this object at 4 75 3 65 10 that s 475 pixels to the left and 365 pixels up putting it in the top left corner and nearer to the camera so that it ll appear on top of other game objects In the Inspector look for the Font setting toward the bottom click the little circle button to bring up a file selector and then pick the Arial font that s available Enter Score as the Text setting Correct positioning also requires Upper Left
106. the start it had a lot of promise as a game develop ment tool but it didn t come into its own until several versions later In particular plat forms like 10S and Android collectively referred to as mobile didn t emerge until later and those platforms factor heavily into Unity s growing prominence Initially I viewed Unity as a curiosity an interesting development tool to keep an eye on but not actually use During this time I was programming games for both desktop computers and websites and doing projects for a range of clients I was using tools like Blitz3D and Flash which were great to program in but were limiting in a lot of ways As those tools started to show their age I kept looking for better ways to develop games I started experimenting with Unity around version 3 and then completely switched to it when Synapse Games the company I work for now started developing mobile games At first I worked for Synapse on web games but we eventually moved over to mobile games And then we came full circle because Unity enabled us to deploy to the web in addition to mobile all from one codebase I ve always seen sharing knowledge as important and I ve taught game develop ment for the last several years In large part I do this because of the example set for me by the many mentors and teachers I ve had Incidentally you may even have heard of one of my teachers because he was such an inspiring person Randy Pausch deliv
107. these options boils down to whether or not the file supports anima tion Because Collada and FBX are the only two options that include animation data those are the two options to choose Whenever it s available not all 3D tools have it as an export option FBX export tends to work best but if you re using a tool without FBX export then Collada works well too In our case Blender supports FBX export so we ll use that file format Note that the bottom of table 4 3 lists several 3D art applications Unity allows you to directly drop those application s files into your project which seems handy at first but that functionality has several caveats For starters Unity doesn t load those appli cation files directly instead it exports the model behind the scenes and loads that exported file Because the model is being exported to FBX or Collada anyway it s pref erable to do that step explicitly Furthermore this export requires that you have the relevant application installed This requirement is a big hassle if you plan to share files among multiple computers for example a team of developers working together I don t recommend using Blender or Maya or whatever files directly in Unity Exporting and importing the model All right it s time to export the model from Blender and then import it into Unity First open the bench in Blender and then choose File gt Export gt FBX Once the file is saved import it into Unity the s
108. to content in video games audio is crucial too Most games play background music and have sound effects Accordingly Unity has audio functionality so that you can put sound effects and music into your games Unity can import and play a variety of audio file for mats adjust the volume of sounds and even handle sounds playing from a specific position within the scene This chapter starts with sound effects rather than music Sound effects are short clips that play along with actions in the game such as a gunshot that plays when 222 10 1 10 1 1 Importing sound effects 223 the player fires whereas the sound clips for music are longer often running into minutes and playback isn t directly tied to events in the game Ultimately both boil down to the same kind of audio files and playback code but the simple fact that the sound files for music are usually much larger than the short clips used for sound effects indeed files for music are often the largest files in the game merits covering them in a separate section The complete roadmap for this chapter will be to take a game without sound and do the following Import audio files for sound effects Play sound effects for the enemy and for shooting Program an audio manager to control volume Optimize the loading of music ao A W N P Control music volume separately from sound effects including cross fading tracks NOTE This chapter is largely independent of the pro
109. to need it as a 0 1 float in order to adjust the scene later Converting that is a simple bit of math added to the code Finally after extracting out the cloudiness value from the full data broadcast a message that the weather data has been updated Currently nothing is listening for that message but the broadcaster doesn t need to know anything about listeners indeed that s the entire point of a decoupled messenger system Later we ll add a listener to the scene Great we ve written code to parse XML data But before we move on to applying this value to the visible scene I want to go over another option for data transfer Parsing JSON Before continuing to the next step in the project let s explore an alternative format for transferring data XML is one common format for data transferred over the inter net but another common format is called JSON DEFINITION JSON stands for JavaScript Object Notation Similar in purpose to XML JSON was designed to be a lightweight alternative Although the syntax for JSON was originally derived from JavaScript the format is not language specific and is readily used with a variety of programming languages Unlike XML Mono doesn t come with a parser for this format There are a number of good JSON parsers available that you could download such as MiniJSON https gist github com darktable 1411710 Create a script called MiniJSON and paste in that code Now you can use this library to
110. understand how Unity works with art assets and possibly even create their own rough stand ins to be replaced later com monly known as programmer art NOTE Nothing in this chapter directly requires projects from the previous chapters But you ll want to have movement scripts like the ones from chapter 2 so that you can walk around the scene you ll build if necessary you can grab the player object and scripts from the project download Similarly this chapter ends with moving objects that are similar to the ones created in previ ous chapters Building basic 3D scenery whiteboxing The first content creation topic we ll go over is whiteboxing This process is usually the first step in building a level on the computer following designing the level on paper As the name implies you block out the walls of the scene with blank geometry that is white boxes Looking at the list of different art assets this blank scenery is the most basic sort of 3D model and it provides a base on which to display 2D images If you think back to the primitive scene you created in chapter 2 that was basically whiteboxing you just hadn t learned the term yet Some of this section will be a rehash of work done in the beginning of chapter 2 but we ll cover the process a lot faster this time as well as discuss more new terminology NOTE Another term that is frequently used is grayboxing It means the same thing I tend to use whiteboxing because that was th
111. values are read only for transforms This is a common mistake that can trip you up Euler angles vs quaternion You re probably wondering why the property is called localEulerAngles and not localRotation First you need to know about a concept called quaternions Quaternions are a different mathematical construct for representing rotations They re distinct from Euler angles which is the name for the X Y Zaxes approach we ve been taking Remember the whole discussion of pitch yaw and roll Well that method of representing rotations is Euler angles Quaternions are different It s hard to explain what quaternions are because they re an obscure aspect of higher math involving movement through four dimensions If you want a detailed explanation try reading the document found here www fliocode com documents matrfaq html Q4 7 It s a bit easier to explain why quaternions are used to represent rotations interpo lating between rotation values that is going through a bunch of in between values to gradually change from one value to another looks smoother and more natural when using quaternions To return to the initial question it s because localRotation is a quaternion not Euler angles Unity also provides the Euler angles property to make manipulating rotations easier to understand the Euler angles property is converted to and from quaternion values automatically Unity handles the harder math for you behind the scenes
112. want The first example involves equipping a key required to open the door Inventory UI for using and equipping items 189 At the moment the DeviceTrigger script doesn t pay attention to your items because that script was written before the inventory code The next listing shows how to adjust that script Listing 8 19 Requiring a key in DeviceTrigger public bool requireKey void OnTriggerEnter Collider other if requireKey amp amp Managers Inventory equippedItem key return As you can see all that s needed is a new public variable in the script and a condition that looks for an equipped key The requireKey Boolean appears as a check box in the Inspector so that you can require a key from some triggers but not others The condition at the beginning of OnTriggerEnter checks for an equipped key in InventoryManager that requires that you add the code from the next listing to InventoryManager Listing 8 20 Equipping code for InventoryManager public string equippedItem get private set public bool EquipItem string name if _items ContainsKey name amp amp equippedItem name a Check that inventory equippeditem name has the item and it Debug Log Equipped name isn t already equipped returni true egquippeditem null Debug Log Unequipped return false At the top add the equippedItem property that gets checked by other code Then add the public method EquipIt
113. when you play the game will be top down At the moment though the movement controls still use the keyboard so let s write a script for point and click movement WRITING THE MOVEMENT CODE The general idea for this code illustrated in figure 11 3 will be to automatically move the player toward its target position This position is set by clicking in the scene In this way the code that moves the player isn t directly reacting to the mouse but the player s movement is being controlled indirectly by clicking NOTE This movement algorithm is useful for AI characters as well Rather than using mouse clicks the target position could be on a path that the char acter follows 252 CHAPTER 11 Putting the parts together into a complete game Every frame the following sequence of steps is run 1 Check for mouse 2 Always rotate to face 3 Move forward which clicks set target position the target position will be toward the target Figure 11 3 Diagram of how point and click controls work To implement this create a new script called PointClickMovement and replace the RelativeMovement component on the player Start coding PointClickMovement by pasting in the entirety of RelativeMovement because you still want most of that script for handling falling and animations Then adjust the code according to the next listing Listing 11 6 New movement code in PointClickMovement script public class PointClickMovement
114. which fits the Action lt string gt declaration from NetworkService The callback function doesn t do a lot right now the debug line simply prints the received data to the console to verify that the data was received correctly Then the last line of the function changes the startup status of the manager to say that it s completely started up Hit Play to run the code Assuming you have a solid internet connection you should see a bunch of data appear in the console This data is simply a long string but the string is formatted in a specific way that we can make use of Parsing XML Data that exists as a long string usually has individual bits of information embedded within the string You extract those bits of information by parsing the string DEFINITION Parsing means analyzing a chunk of data and dividing it up into separate pieces of information In order to parse the string it needs to be formatted in a way that allows you or rather the parser code to identify separate pieces There are a couple of standard formats commonly used to transfer data over the internet the most common standard format is XML DEFINITION XML stands for Extensible Markup Language It s a set of rules for encoding documents in a structured way similar to HTML web pages Fortunately Unity or rather Mono the code framework built into Unity provides functionality for parsing XML The weather data we requested is formatted in XML so we re going to a
115. window Switch the platform to Web Player and then click the 12 2 3 Building for the web 283 Build button A file selector will come up type in the name WebTest for this applica tion and change to a safe location if necessary that is a location not within the Unity project The build process will now create two files the actual Unity game will have the extension unity3d and there will be a bare bones web page for playing that game Open this web page and the game should be embedded in the middle of the other wise blank page There s nothing particularly special about this page it s just an example to test your game with It s possible to customize the code on that page or even provide your own web page with the Unity code copied over One of the most important custom izations to make is enabling communication between Unity and the browser so let s go over that next Communicating with JavaScript in the browser A Unity web game can communicate with the browser or rather with JavaScript run ning in the browser and these messages can go in both directions from Unity to the browser and from the browser to Unity Sending messages to the browser is straightfor ward Unity has a couple of special commands that directly run code in the browser For messages from the browser the methodology is slightly more involved Java Script in the browser identifies an object by name and then Unity passes the message to the name
116. 0 sliced images 131 sliders 133 135 sound effects importing files 225 226 looping sound 228 229 overview 2260 228 supported formats 223 225 triggering from code 229 230 soundMute property 234 soundVolume property 234 SphereCast method 57 spot lights 28 Sprite Packer 100 SpriteRenderer component 105 sprites animation using 99 atlases 100 defined 96 overview 98 100 spritesheets 100 SSAO screen space ambient occlusion 4 StackExchange 317 Start method 15 18 StartCoroutine method 207 state machines 58 structure game completing levels 265 267 controlling mission flow and levels 262 265 losing levels 268 269 overview 261 262 SVN Subversion 7 305 SyntaxTree 304 T T pose 144 Target Platform menu 279 targets alerting target to being hit 54 55 determining hits 53 54 terminology 4 TestFlight 288 texture coordinates 85 312 TexturePacker 306 textures applying 78 80 325 compression for mobile deployment 289 290 defined 75 file formats 76 77 importing files 77 78 mapping model for 312 overview 75 76 TGA format 76 The Golf Club 8 third person view adding shadows 144 145 camera adjustments 142 camera relative movement controls changing character position 151 152 overview 148 149 rotating character relative to camera 149 151 character animation controller for 162 165 defining clips for 160 162 overview 165 skeletal animation 158 160 importing character 142 144 jumping action applying ve
117. 20 Listing 9 20 Server script written in PHP that receives our data lt php Extract post data into variables Smessage POST message a Scloudiness POSTI cloud value Stimestamp POST timestamp Scombined message cloudiness S cloudiness time Stimestamp n Sfilename data txt file put _contents S filename combined FILE APPEND oaeo N echo Logged Define the filename to write to gt 9 5 Summary 221 Note that this script writes received data into data txt so you also need to put a text file with that name on the server Once api php is in place you ll see weather logs appear in data txt when triggering checkpoints in the game Great Summary In this chapter you ve learned that Skybox is designed for sky visuals that render behind everything else Unity provides WWW to download data Common data formats like XML and JSON can be parsed easily Materials can display images downloaded from the internet WWW can also post data to a web server Playing audio sound effects and music This chapter covers Importing and playing audio clips for various sound effects Using 2D sounds for the UI and 3D sounds in the scene Modulating the volume of all sounds when they play Playing background music while the game is going on Fading in and out between different background tunes Although graphics get most of the attention when it comes
118. 51 152 overview 148 149 rotating character relative to camera 149 151 Near Far clipping planes 251 object placement 27 29 orbiting around character 145 148 switching to 2D mode 101 102 for third person view 142 canvas adding objects to 124 127 creating 123 124 positioning elements 127 128 characters animating controller for 162 165 defining clips for 160 162 overview 165 skeletal animation 158 160 camera relative movement controls changing position 151 152 rotating relative to camera 149 151 importing model 142 144 orbiting camera around 145 148 children defined 27 Clamp method 37 clips animation 160 162 Collada format 83 collections 184 186 collision detection 42 43 color changing monitor example 171 172 compiler directives 281 compression 76 audio files 224 mobile deployment 289 290 platform changes and 278 console errors in 19 example games built for 8 9 Console tab 13 14 ContainsKey method 186 controllers 162 165 coordinates left handed vs right handed 24 coroutines 50 cascading methods 205 overview 203 204 cross platform support 5 culling defined 145 D Dead Trigger 8 delta 38 deltaTime property 42 57 dependency injection 179 deployment desktop adjusting Player settings 280 281 building application 279 platform dependent compilation 281 282 mobile Android build tools 288 289 Android plug ins 294 298 iOS build tools 286 288 iOS plug ins 291 294 overview 285 286 texture compres
119. 7 Tracking current weather sending post requests 218 Server side code in PHP 220 9 5 Summary 221 Xii CONTENTS Playing audio sound effects and music 222 10 1 Importing sound effects 223 Supported file formats 223 Importing audio files 225 10 2 Playing sound effects 226 Explaining what s involved audio clip vs source vs listener 226 Assigning a looping sound 228 Triggering sound effects from code 229 10 3 Audio control interface 230 Setting up the central AudioManager 230 Volume control UI 232 Playing UI sounds 236 10 4 Background music 236 Playing music loops 237 Controlling music volume separately 240 Fading between songs 242 10 5 Summary 245 Putting the parts together into a complete game 246 11 1 Building an action RPG by repurposing projects 247 Assembling assets and code from multiple projects 248 Programming point and click controls movement and devices 250 Replacing the old GUI with a new interface 255 11 2 Developing the overarching game structure 261 Controlling mission flow and multiple levels 262 Completing a level by reaching the exit 265 Losing the level when caught by enemies 268 11 3 Handling the player s progression through the game 269 Saving and loading the player s progress 269 Beating the game by completing three levels 273 11 4 Summary 275 Deploying your game to players devices 276 12 1 Start by building for the desktop Windows Mac and Linux 278 Bu
120. 74 176 prime 31 318 Pro Tools 307 ProBuilder 318 programmer art 72 progress beating game by completing levels 273 275 saving and loading 269 273 Project tab 13 14 projects planning 22 23 Prototype 318 provisioning profiles 287 PSD format 76 Pulse Code Modulation See PCM Q QuadsBox 74 Quality settings 280 quaternions 37 RakNet networking library 212 Range method 107 Raycast method 50 raycasts seeing objects with 56 58 shooting with overview 47 48 ScreenPointToRay method 48 50 visual indicators for aiming 50 53 rays 47 reactive targets alerting target to being hit 54 55 determining hits 53 54 real time shadow 144 remote procedure calls See RPCs rendering defined 52 RequireComponent method 44 151 resources FMOD Studio 318 FPS Control 318 Google Play Games 318 iIween 317 Learn Unity3D 316 317 Maya LT guide 317 prime 31 318 ProBuilder 318 Prototype 318 script reference 316 StackExchange 317 Unify community wiki 317 Unity manual 316 Unity patterns 317 Unity3D Student 316 Resources folder 187 Resources Load command 237 239 retained mode vs immediate mode 121 122 right handed coordinates 24 Rotate method 31 32 rotation horizontal 35 38 40 vertical 35 40 RPCs remote procedure calls 212 RPG example adding GUI 255 261 assembling assets from multi ple projects 248 250 overarching game structure completing levels 265 267 controlling mission flow and levels 262 265 l
121. Also as mentioned in chapter 7 there are settings for removing the shadows cast from this object whether or not to use the shadows is a judgment call but for small pickup items like this I prefer to turn them off Now that the object in the scene is ready create a new script to attach to that object Call the script CollectibleItem see the following listing Listing 8 8 Script that makes an item delete itself on contact with the player using UnityEngine using System Collections public class CollectibleItem MonoBehaviour SerializeField private string itemName ES Type the name of this item in the Inspector void OnTriggerEnter Collider other P Debug Log Item collected itemName Destroy this gameObject This script is extremely short and simple Give the item a name value so that there can be different items in the scene OnTriggerEnter destroys itself There s also a debug message being printed to the console eventually it will be replaced with useful code WARNING Be sure to call Destroy on this gameObject and not this Don t get confused between the two this only refers to this script compo nent whereas this gameObject refers to the object the script is attached to Back in Unity the variable you added to the code should become visible in the Inspec tor Type in a name to identify this item I went with energy for my first item Then duplicate the item a few times and change the
122. Audio manager starting network service i Any long running a startup tasks go here Initialize music sources here listing 10 10 status ManagerStatus Started Sas ee AL Set status to Initializing if there are long running startup tasks This initial code looks just like managers from previous chapters this is the minimum amount that IGameManager requires that the class implements The Managers script can now be adjusted with the new manager see the next listing Listing 10 3 Managers script adjusted with AudioManager using UnityEngine using System Collections using System Collections Generic RequireComponent typeof AudioManager public class Managers MonoBehaviour public static AudioManager Audio get private set private List lt IGameManager gt startSequence 232 10 3 2 CHAPTER 10 Playing audio sound effects and music void Awake Audio GetComponent lt AudioManager gt ES Only list AudioManager in this project instead of _startSequence new List lt IGameManager gt PlayerManager and so on _startSequence Add Audio StartCoroutine StartupManagers private IEnumerator StartupManagers NetworkService network new NetworkService foreach IGameManager manager in _startSequence manager Startup network yield return null int numModules Startcsequence Count int numReady 0 while numReady lt numModules
123. Clips panel shown in figure 7 13 this lists all the defined animation clips which initially are one imported clip You ll notice and buttons at the bottom of the list you use these buttons to add and remove clips on the list Ultimately we need four clips for this character so add and remove clips as neces sary while you work When you select a clip information about that clip shown in figure 7 14 will appear in the area below the list The top of this information area shows the name of this clip and you can type in a new name Name our first clip idle Define Start and End frames for this animation clip this allows you to slice a chunk out of the longer imported animation For the idle animation enter Start 3 and End 141 Next up are the Loop settings a Clips Start End buttons to add Animation clips listed _____ if MONE CAPS Lean MISL by name along with the start and end frames o Figure 7 13 The Clips list in Animation settings Setting up animations on the player character 161 The name of the o m Turn on looping playback animation clip including an option to blend type a new one here together the start and end poses Length 5 750 00 Start 3 This color indicates when the start Set Start and End iaap tine and end poses match for looping frames for this clip tee Pine Use Green is very matched Cycle Offset Yellow is similar poses aaa eee Red is completely different
124. D model is the puppet the animator is the puppeteer who makes the puppet move and the animation is a recording of the pup pet s movements The movements defined this way are created ahead of time and are usually small scale movements that don t change the overall positioning of the object This is in contrast to the sort of large scale movements that were done in code in pre vious chapters The final kind of art asset from table 4 1 is a particle system see the following def inition DEFINITION A particle system is an orderly mechanism for creating and control ling large numbers of moving objects These moving objects are usually small hence the name particle but they don t have to be Particle systems are useful for creating visual effects such as fire smoke or spraying water The particles that is the individual objects under the control of a particle sys tem can be any mesh object that you choose but for most effects the particles will be a square displaying a picture a flame spark or a smoke puff for example Much of the work of creating game art is done in external software not within Unity itself Materials and particle systems are created within Unity but the other art assets are created using external software Refer to appendix B to learn more about external tools a variety of art applications are used for creating 3D models and anima tion Three dimensional models created in an external tool are then saved as
125. D modelis almost a synonym for mesh object the 3D model is the static shape defined by vertices and polygons that is mesh geometry For a humanoid character this mesh geometry is shaped into a head arms legs and so forth see figure 7 2 Figure 7 2 Wireframe view of the model we ll use in this chapter 142 7 1 7 1 1 CHAPTER 7 Creating a third person 3D game player movement and animation As usual we ll focus on the last step in the roadmap programming objects in the scene Here s a recap of our plan of action Import a character model into the scene Implement camera controls to look at the character Write a script that enables the player to run around on the ground Add the ability to jump to the movement script ao A W N P Play animations on the model based on its movements Copy the project from chapter 2 to modify it or create a new Unity project be sure it s set to 3D not the 2D project from chapter 5 and copy over the scene file from chapter 2 s project either way also grab the scratch folder from this chapter s down load to get the character model we ll use NOTE We re going to build this chapter s project in the walled area from chapter 2 We ll keep the walls and lights but replace the player and all scripts If you need them download the sample files from that chapter Assuming you re starting with the completed project from chapter 2 the movement demo not later projects
126. ED OnHealthUpdated Messenger RemoveListener GameEvent LEVEL COMPLETE OnLevelComplete void Start OnHealthUpdated levelEnding gameObject SetActive false popup gameObject SetActive false private void OnLevelComplete StartCoroutine CompleteLevel private IEnumerator CompleteLevel levelEnding gameObject SetActive true levelEnding text Level Complete yield return new WaitForSeconds 2 AL Show message for two seconds Managers Mission GoToNext and then go to next level Developing the overarching game structure 267 Healthy 50 100 T 4 AS The objective object The code triggers when the player touches this Save Game Load Game Figure 11 8 Objective object that the player touches to complete the level You ll notice that this listing has a reference to a text label Open the Levell scene to edit it and create a new UI text object This label will be a level completion message that appears in the middle of the screen Set this text to Width 240 Height 60 Center for both Align and Vertical align and Font Size 22 Type Level Complete in the text area and then link this text object to the levelEnding reference of UIController Finally we ll create an object that the player touches to complete the level figure 11 8 shows what the objective looks like This will be similar to collectible items it needs a material and a script and you l
127. I ll cover things at a high level but you should look for up to date documentation online Also plug ins for both platforms are put in the same place within Unity Create a folder in the Project view called Plugins much as with folders like Editor Unity han dles the Plugins folder in a special way In this case Unity looks for plug in files within the Plugins folder Then inside Plugins create two folders for Android and iOS Unity copies the contents of those folders when doing a build IOS PLUG INS The plug in is really just some native code that gets called by Unity First create a script in Unity to handle the native code call this script TestPlugin see the next listing Listing 12 4 TestPlugin script that calls iOS native code from Unity using UnityEngine using System using System Collections using System Runtime InteropServices public class TestPlugin MonoBehaviour ject is cr in thi private static TestPlugin instance Object s created in this static function so you don t have to create it in the editor public static void Initialize if instance null Debug Log TestPlugin instance was found Already initialized return Debug Log TestPlugin instance not found Initializing GameObject owner new GameObject TestPlugin instance _instance owner AddComponent lt TestPlugins gt DontDestroyOnLoad _ instance Tag that identifies section of code ae ta
128. Knuth also known as Fisher Yates shuffle algorithm a simple yet effective way of shuffling the elements of an array This algorithm loops through the array and swaps every element of the array with a randomly chosen other array position You can click on all the cards to reveal them but the game of Memory is supposed to proceed in pairs a bit more code is needed Making and scoring matches The last step in making a fully functional Memory game is checking for matches Although we now have a grid of cards that are revealed when clicked the various cards don t affect each other in any way In the game of Memory every time a pair of cards is revealed we should check to see if the revealed cards match This abstract logic checking for matches and responding appropriately requires that cards notify SceneController when they ve been clicked That requires the additions to SceneController cs shown in the next listing Listing 5 8 SceneController which must keep track of revealed cards private MemoryCard firstRevealed private MemoryCard _secondRevealed Getter function that returns public bool canReveal false if there s already a get return _secondRevealed null second card revealed public void CardRevealed MemoryCard card initially empty The CardRevealed method will be filled in momentarily we needed the empty scaf folding for now to refer to in MemoryCard cs without any compiler errors Note that th
129. Load Type menu Similarly turn on Load In Background so that the game won t pause or slow down while music is loading Even after you adjust all the import settings the asset Segcs fresieee Pras files must be moved to the correct location in order to Go e load correctly Remember that the Resources Load command requires that the assets be in the Resources folder Create a new folder called Resources create a folder within that called Music and drag the audio files pos aop into the Music folder see figure 10 5 Figure 10 5 Music audio That took care of step number 1 clips placed inside the Resources folder STEP 2 SET UP AN AUDIOSOURCE FOR AUDIOMANAGER TO USE Step 2 is to create a new AudioSource for music playback Create another empty GameObject name this object Music 1 instead of just Music because we ll add Music 2 later in the chapter and parent it to the Audio object Add an AudioSource component to Music 1 and then adjust the settings in the com ponent Deselect Play On Awake but turn on the Loop option this time whereas sound effects usually only play once music plays over and over in a loop Leave the Spatial Blend setting at 2D because music doesn t have any specific position in the scene You may want to reduce the Priority value too For sound effects this value didn t matter so we left the value at the default 128 But for music you probably want to lower this value so I set the music source to
130. OnLevelFailed StartCoroutine FailLevel private IEnumerator FailLevel Reuse the same tart label levelEnding gameObject SetActive true but s t a different message levelEnding text Level Failed A yield return new WaitForSeconds 2 Restart the current level M P1 SR anager Py LAYON ask eae ae after a 2 second pause Managers Mission RestartCurrent Play the game and let the enemy shoot you several times the level failure message will appear Great job the player can now complete and fail levels Building off that the game must keep track of the player s progress Handling the player s progression through the game Right now the individual level operates independently without any relation to the overall game You ll add two things that will make progress through the game feel more complete saving the player s progress and detecting when the game not just the level is complete Saving and loading the player s progress Saving and loading the game is an important part of most games Unity and Mono provide I O functionality that you can use for this purpose Before you can start using that though you must add UpdateData for both MissionManager and Inventory Manager That method will work just as it does in PlayerManager and will enable code outside the manager to update data within the manager Listing 11 26 and listing 11 27 show the changed managers Listing 11 26 UpdateData me
131. OnMusicValue from the Dynamic Float section of the menu Now run this code and you ll see that the controls affect sound effects and music separately This is getting pretty sophisticated but there s one more bit of polish remaining cross fade between music tracks Fading between songs As a final bit of polish lets make AudioManager fade in and out between different background tunes Currently the switch between different music tracks is pretty jar ring with the sound suddenly cutting off and changing to the new track We can smooth out that transition by having the volume of the previous track quickly dwindle Background music 243 away while the volume quickly rises from 0 on the new track This is a simple but clever bit of code that combines both the volume control methods you just saw along with a coroutine to change the volume incrementally over time Listing 10 13 adds a lot of bits to AudioManager but most revolve around a simple concept now that we ll have two separate audio sources play separate music tracks on separate audio sources and incrementally increase the volume of one source while simultaneously decreasing the volume of the other as usual italicized code was already in the script and is shown here for reference Listing 10 13 Cross fade between music in AudioManager SerializeField private AudioSource music2Source AL Second AudioSource keep the first too private AudioSource _activeMusic a
132. P requests The primary class you need to know about is WWW Unity provides the WWW class to communicate with the internet Instantiating a WWW object using a URL will send a request to that URL Coroutines can work with the Www class to wait for the request to complete Corou tines were first introduced back in chapter 3 where we used them to pause some code for a set period of time Recall the explanation given there coroutines are special functions that seemingly run in the background of a program in a repeated cycle of running partway and then returning to the rest of the program When used along with 204 CHAPTER 9 Connecting your game to the internet the StartCoroutine method the yield keyword causes the coroutine to temporar ily pause handing back the program flow and picking up again from that point next frame In chapter 3 the coroutines yielded at WaitForSeconds an object that caused the function to pause for a specific number of seconds Yielding a coroutine with WWW will pause the function until that network request completes The program flow here is similar to making asynchronous Ajax calls in a web application first you send a request then you continue with the rest of the program and after some time you receive a response THAT WAS THE THEORY NOW LET S WRITE THE CODE All right let s implement this stuff in our code First open the NetworkService script and replace the default template with the contents of the fol
133. Planes ai Camera settings to p half the screen height E i adjust for 2D graphics 102 5 2 5 2 1 CHAPTER 5 Building a Memory game using Unity s new 2D functionality DEFINITION Pixel perfect means one pixel on the screen corresponds to one pixel in the image otherwise the video card will make the images subtly blurry while scaling up to fit the screen For example let s say you want a pixel perfect 1024x768 screen That means the cam era height should be 384 pixels Divide that by 100 because of the pixels to units scale and you get 3 84 for the camera size Again that math is SCREEN_SIZE 2 100f f as in float rather than an int value Given that the background image is 1024x768 select the asset to check its dimensions then clearly this value of 3 84 is what we want for our camera The two remaining adjustments to make in the Inspector are the camera s back ground color and Z position As mentioned previously for sprites higher Z positions are further away into the scene Thus the camera should have a pretty low Z position set the position of the camera to 0 0 100 The camera s background color should probably be black the default color is blue and that ll look odd displayed along the sides if the screen is wider than the background image which is likely Click the color swatch next to Background and set the color picker to black Now save the scene as Scene and hit Play you ll see the Game view
134. PlatformTest MonoBehaviour This section only runs De ical a within the editor if UNITY EDITOR GUI Label new Rect 10 10 200 20 Running in Editor 282 Only in desktop stand alone applications 12 2 12 2 1 12 2 2 CHAPTER 12 Deploying your game to players devices elif UNI TY STANDALONE GUI Label new Rect 10 10 200 20 Running on Desktop else GUI Label new Rect 10 10 200 20 Running on other platform endif Create a script called PlatformTest and write the code from this listing in it Attach that script to an object in the scene any object will do for testing and a small mes sage will appear in the top left of the screen When you play the game within Unity s editor the message will say Running in the Editor but if you build the game and run the built application the message will say Running on Desktop Different code is being run in each case For this test we used the platform define that treats all desktop platforms as one but as indicated on that doc page separate platform defines are available for Win dows Mac and Linux In fact there are platform defines for all the platforms sup ported by Unity so that you can run different code on each Let s move on to the next important platform the web Building for the web Although desktop platforms are the most basic targets to build for another important platform for Unity games is deployment t
135. Regardless of exactly how the data is formatted once the cloudiness value is extracted from the response data we can use that value in the SetOvercast method of WeatherController Whether XML or JSON the data string ultimately gets parsed into Downloading weather data from an internet service 211 a series of words and numbers The SetOvercast method takes a number as a parameter In section 9 1 2 we used a number incremented every frame but we could just as easily use the number returned by the weather API The next listing shows the full WeatherController script again after modifications Listing 9 11 WeatherController that reacts to downloaded weather data using UnityEngine using System Collections public class WeatherController MonoBehaviour SerializeField private Material sky SerializeField private Light sun private float fullintensity Add Remove event listeners void Awake ae Messenger AddListener GameEvent WEATHER UPDATED OnWeatherUpdated void OnDestroy Messenger RemoveListener GameEvent WEATHER UPDATED OnWeatherUpdated void Start f llIntensity san intensity Use the cloudiness value private void OnWeatherUpdated S from WeatherManager SetOvercast Managers Weather cloudValue private void SetOvercast float value sky SetFloat Blend value Ssun intensity fullintensity _fullintensity value Notice that the changes aren t only a
136. Shooter _fireball transftorm position The Instantiate transform TransformPoint Vector3 forward 1 5f method here is _fireball transform rotation transform rotation just like it was in SceneController Place the fireball in front of the enemy and point else if hit distance lt obstacleRange h f in the same direction float angle Random Range 110 110 transform Rotate 0 angle 0 You ll notice that all the annotations in this listing refer to similar or the same bits in previous scripts Previous code listings already showed everything needed for emitting fireballs now we re mashing together and remixing bits of code to fit in the new con text Just like in SceneController you need to add two GameObject fields toward the top of the script a serialized variable for linking the prefab to and a private variable for keeping track of the instance copied by the code After doing a raycast the code checks for the PlayerCharacter on the object hit this works just like when the shoot ing code checked for ReactiveTarget on the object hit The code that instantiates a fireball when there isn t already one in the scene works like the code that instantiates an enemy The positioning and rotation are different though this time you place the instance just in front of the enemy and point it in the same direction Once all the new code is in place a new Fireball Prefab slot will appear when you view the com
137. This console message displays the 3D coordinates of the point where the ray hit the XYZ values we discussed in chapter 2 But it can be hard to visualize where exactly the ray hit similarly it can be hard to tell where the center of the screen is that is where the ray shoots through Let s add visual indicators to address both problems Adding visual indicators for aiming and hits Our next step is to add two kinds of visual indicators an aiming spot on the center of the screen and a mark in the scene where the ray hit For a first person shooter the latter is usually bullet holes but for now you re going to put a blank sphere on the spot and use a coroutine to remove the sphere after one second Figure 3 3 shows what you ll see DEFINITION Coroutines are a Unity specific way of handling tasks that execute incrementally over time as opposed to how most functions make the pro gram wait until they finish First let s add indicators to mark where the ray hits Listing 3 2 shows the script after making this addition Run around the scene shooting it s pretty fun seeing the sphere indicators Sphere indicates where the wall was hit Target point in the center of the screen Figure 3 3 Shooting repeatedly after adding visual indicators for aiming and hits Shooting via raycasts 51 Listing 3 2 RayShooter script with sphere indicators added using UnityEngine using System Collections public class RayShoot
138. ToHit Pi J else StartCoroutine SphereIndicator hit point Now the shooting code calls a method of the target so let s write that target method In the ReactiveTarget script write in the code from the next listing The target object will fall over and disappear when you shoot it refer to figure 3 4 Listing 3 6 ReactiveTarget script that dies when hit using UnityEngine using System Collections public class ReactiveTarget MonoBehaviour public void ReactToHit StartCoroutine Die ag eee the private IEnumerator Die Cn ee ee ee Oj mA Topple the enemy wait 1 5 seconds then destroy the enemy yield return new WaitForSeconds 1 5f Destroy this gameObject l Object can destroy itself ae J y just like a separate object 3 3 Basic wandering AI 55 Figure 3 4 The target object falling over when hit Most of this code should already be familiar to you from previous scripts so we ll only go over it briefly First you define the method ReactToHit because that s the method name called in the shooting script This method starts a coroutine that s similar to the sphere indicator code from earlier the main difference is that it operates on the object of this script rather than creating a separate object Expressions like this gameObject refer to the GameObject that this script is attached to and the this keyword is optional so code could refer to gameObject witho
139. Unity so great 5 advantages over other similarly cutting edge game development tools an extremely productive visual workflow and a high degree of cross platform support The visual workflow is a fairly unique design different from most other game development environments Whereas other game development tools are often a com plicated mishmash of disparate parts that must be wrangled or perhaps a program ming library that requires you to set up your own integrated development environment IDE build chain and whatnot the development workflow in Unity is anchored by a sophisticated visual editor The editor is used to lay out the scenes in your game and to tie together art assets and code into interactive objects The beauty of this editor is that it enables professional quality games to be built quickly and effi ciently giving developers tools to be incredibly productive while still using an exten sive list of the latest technologies in video gaming NOTE Most other game development tools that have a central visual editor are also saddled with limited and inflexible scripting support but Unity doesn t suffer from that disadvantage Although everything created for Unity ultimately goes through the visual editor this core interface involves a lot of linking projects to custom code that runs in Unity s game engine That s not unlike linking in classes in the project settings for an IDE like Visual Studio or Eclipse Experienced programme
140. Use a humanoid model this time because in a third person view the player can see the character 4 Position the camera for this demo The camera should be outside the character looking down at it 5 Write movement scripts for the camera and player First write code to orbit the camera around the character then write code to move the character around including jumping Figure 7 1 Roadmap for the third person movement demo the long lived Legend of Zelda series or the more recent Uncharted series of games refer ahead to figure 7 3 if you want to see a comparison of first person and third per son views The project in this chapter is one of the more visually exciting prototypes we ll build in this book Figure 7 1 shows how the scene will be constructed Compare this with the diagram figure 2 2 of the first person scene we created in chapter 2 You can see that the room construction is the same and the use of scripts is much the same But the look of the player as well as the placement of the camera are differ ent in each case Again what defines this as a third person view is that the camera is outside the player s character and looking inward at that character We ll use a model that looks like a humanoid character rather than a primitive capsule because now players can actually see themselves Recall that two of the types of art assets discussed in chapter 4 were 3D models and animations The term 3
141. Y know a fair amount about Unity by now You know how to program the player s controls how to create enemies that wander around and how to add interactive devices to the game You even know how to build a game using both 2D and 3D graphics That s almost everything you need to know in order to develop a complete game but not quite You still need to learn about a few final tasks like putting audio in the game and you need to understand how to put together all the disparate pieces we ve been working with This is the home stretch with just four chapters left Connecting your game to the internet This chapter covers Generating visuals for the sky using a skybox Downloading data using www objects in coroutines Parsing common data formats like XML and JSON Displaying images downloaded from the internet Sending data to a web server In this chapter you ll learn how to send and receive data over a network The proj ects built in previous chapters represented a variety of game genres but all have been isolated to the player s machine As you know connecting to the internet and exchanging data is increasingly important for games in all genres Many games exist almost entirely over the internet with constant connection to a community of other players games of this sort are referred to as MMOs massively multiplayer online and are most widely known through MMORPGs MMO role playing games Even when a game d
142. a 12 pixel border on all sides remember to apply changes Create a canvas in the scene GameObject gt UI gt Canvas Turn on the Pixel Perfect setting for the canvas Optional Name the object HUD Canvas and switch to 2D view mode Create an image connected to that canvas GameObject gt UI gt Image Name the new object Settings Popup Assign the popup sprite to the image s Source Image Set Image Type to Sliced and turn on Fill Center Position the pop up image at 0 0 to center it Scale the pop up to 250 width and 150 height Create a button GameObject gt UI gt Button Parent the button to the pop up that is drag it in the Hierarchy Position the button at 0 40 Expand the button s hierarchy in order to select its text label Change the text to say Toggle Sound Create a slider GameObject gt UI gt Slider Parent the slider to the pop up and position at 0 15 Those were all the steps to create the settings pop up Now that the pop up has been created let s write code that it ll work with This will involve both a script on the pop up object itself as well as volume control functionality that the pop up script calls First adjust the code in AudioManager according to the next listing Listing 10 4 Volume control added to AudioManager public float soundVolume get return AudioListener volume Implement the getter setter set AudioListener volume value using AudioListener 234
143. a few adjustments in the scoring code see the next listing Listing 5 12 Displaying the score on a text object SerializeField private TextMesh scoreLabel private IEnumerator CheckMatch if _firstRevealed id _secondRevealed id The text displayed is _score a property to set scorehabel text Score score a on text objects As you can see text is a property of the object that you can set to a new string Drag the text in the scene to the variable you just added to SceneController and then hit Play Now you should see the score displayed while you play the game and make matches Huzzah the game works Restart button At this point the Memory game is fully functional You can play the game and all the essential features are in place But this playable core is still lacking the overarching functionality that players expect or need in a finished game For example right now you can play the game only once you need to quit and restart in order to play again Let s add a control to the screen so that players can start the game over without having to quit This functionality breaks down into two tasks create a UI button and reset the game when that button is clicked Figure 5 11 shows what the game will look like with the restart button Neither task is specific to 2D games by the way all games need UI buttons and all games need the ability to reset We ll go over both topics to round out this chapter Scor
144. a specialized role within game development Unity has a sophisticated system for managing animations on models a system called Mecanim The special name Mecanim identifies the newer more advanced animation system that was recently added to Unity as a replacement for the older animation sys tem The older system is still around identified as legacy animation But the legacy animation system may be phased out in a future version of Unity at which point Mecanim will be the animation system Although we don t work with any animations in this chapter we ll play animations on a character model in chapter 7 Creating effects using particle systems Besides 2D images and 3D models the remaining type of visual content that game artists create are particle systems The definition in this chapter s introduction expla ined that particle systems are orderly mechanisms for creating and controlling large 4 6 1 Creating effects using particle systems numbers of moving objects Particle systems are useful for creating visual effects such as fire smoke or spraying water For example the fire effect in figure 4 18 was created using a particle system Whereas most other art assets are created in exter nal tools and imported into the project particle sys tems are created within Unity itself Unity provides some flexible and powerful tools for creating particle effects NOTE Much like the situation with the Mecanim animation system the
145. a vector later with the movement values calculated because the vertical and horizontal movement values will be calculated in different steps and yet they all need to be part of the same vector 150 CHAPTER 7 Creating a third person 3D game player movement and animation Next we check the input controls just as we have in previous scripts Here s where X and Z values are set in the movement vector for horizontal movement around the scene Remember that Input GetAxis returns 0 if no button is pressed and it var ies between 1 and 1 when those keys are being pressed putting that value in the movement vector sets the movement to the positive or negative direction of that axis the X axis is left right and the Z axis is forward backward The next several lines are where the movement vector is adjusted to be camera rel ative Specifically TransformDirection is used to transform from Local to Global coordinates This is the same thing we did with TransformDirection in chapter 2 except this time we re transforming from the target s coordinate system instead of from the player s coordinate system Meanwhile the code just before and after the TransformDirection line is aligning the coordinate system for our needs first store the target s rotation to restore later and then adjust the rotation so that it s only around the Y axis and not all three axes Finally perform the transformation and restore the target s rotation Al
146. ab object to spawn in the scene so let s write code to cre ate instances of the prefab 3 4 3 Instantiating from an invisible SceneController Although the prefab itself doesn t exist in the scene there has to be some object in the scene for the enemy spawning code to attach to What we ll do is create an empty game object we can attach the script to that but the object won t be visible in the scene TIP The use of empty GameObjects for attaching script components is a com mon pattern in Unity development This trick is used for abstract tasks that don t apply to any specific object in the scene Unity scripts are intended to be attached to visible objects but not every task makes sense that way Choose GameObject gt Create Empty rename the new object to Controller and then set its position to 0 0 0 technically the position doesn t matter because the object isn t visible but putting it at the origin will make life simpler if you ever parent any thing to it Create a script called SceneController as shown in the following listing Listing 3 10 SceneController that spawns the enemy prefab using UnityEngine using System Collections e r Ta Serialized variable for linking to the public class SceneController MonoBehaviour S 8 Rom l l l prefab object SerializeField private GameObject enemyPrefab private GameObject _enemy A private variable to keep track of void Update the enemy instance
147. ady to stretch yourself by tackling some other game genres At this point the rhythms of working within Unity should feel familiar create a script with such and such function drag this object to that slot in the Inspector and so forth You re not tripping over details of the interface so much anymore which means the remaining chapters don t need to rehash the basics Let s run through a succession of additional projects that will progressively teach you more and more about developing games in Unity Building a Memory game using Unity s new 2D functionality This chapter covers Displaying 2D graphics in Unity Making objects clickable Loading new images programmatically Maintaining and displaying state using Ul text Loading levels and restarting the game Up to now we ve been working with 3D graphics But you can also work with 2D graphics in Unity so in this chapter you ll build a 2D game to learn about that We re going to develop the classic children s game Memory we ll display a grid of card backs reveal the card front when it s clicked and score matches These mechanics cover the basics you need to know in order to develop 2D games in Unity Although Unity originated as a tool for 3D games it s used often for 2D games as well Recent versions of Unity starting with version 4 3 released near the end of 2013 have added the ability to display 2D graphics but even before then 2D games were already being developed
148. age 78 4 4 Generating sky visuals using texture images 80 What is a skybox 80 Creating a new skybox material S amp 1 4 5 Working with custom 3D models 83 Which file format to choose 53 Exporting and importing the model 84 4 6 Creating effects using particle systems 86 Adjusting parameters on the default effect 87 Applying a new texture for fire 88 Attaching particle effects to 3D objects 90 4 7 Summary 91 PART 2 GETTING COMFORTABLE ccccccccccccccccccccccccccees JI Building a Memory game using Unity s new 2D functionality 95 5 1 Setting everything up for 2D graphics 96 Preparing the project 97 Displaying 2D images aka sprites 98 Switching the camera to 2D mode 101 5 2 Building a card object and making it react to clicks 102 Building the object out of sprites 102 Mouse input code 103 Revealing the card on click 104 5 3 Displaying the various card images 104 Loading images programmatically 104 Setting the image from an invisible SceneController 105 Instantiating a grid of cards 107 Shuffling the cards 109 5 4 Making and scoring matches 110 Storing and comparing revealed cards 111 Hiding mismatched cards 111 Text display for the score 112 www allitebooks com CONTENTS 5 5 Restart button 114 Programming a UIButton component using SendMessage 115 Calling LoadLevel from SceneController 117 5 6 Summary 118 Putting a 2D GUI ina 3D game 119 6 1 Before you start writing code
149. ake me in and help guide me toward becoming a good performer When you stand on a stage he pronounced you make a promise And that promise is I will not waste your time What I love most about Unity in Action is the action part Joe Hocking wastes none of your time and gets you coding fast and not just nonsense code but interesting code that you can understand and build from because he knows you don t just want to read his book and you don t just want to program his examples you want to be coding your own game And with his guidance you ll be able to do that sooner than you might expect Fol low Joe s steps but when you feel ready don t be shy about diverging from his path and breaking out on your own Skip around to what interests you most try experi ments be bold and brave You can always return to the text if you get too lost XV Xvi FOREWORD But let s not dally in this foreword the entire future of game development is impatiently waiting for you to begin Mark this day on your calendar for today is the day that everything changed It will be forever remembered as the day you started making games JESSE SCHELL CEO OF SCHELL GAMES AUTHOR OF THE ART OF GAME DESIGN preface I ve been programming games for quite some time but only started using Unity rela tively recently Unity didn t exist when I first started developing games the first version was released in 2005 Right from
150. ame sort of code to have the player activate the device We ll implement a couple of examples in this chapter and then you should be able to adapt this same code to work with all sorts of other devices Doors that open and close on a keypress The first kind of device we ll program is a door that opens and closes and we re going to start with operating the door by pressing a key There are lots of different kinds of devices you could have in a game and lots of different ways of operating those devices We re eventually going to look at a couple of variations but doors are the most com mon interactive devices found in games and using items with a keypress is the most straightforward approach to start with The scene has a few spots where a gap exists between walls so place a new object that blocks the gap I created a new cube object and then set its transform to Position 2 5 1 5 17 and Scale 5 3 5 creating the door shown in figure 8 1 Creating doors and other devices 169 Figure 8 1 Door object fit into a gap in the wall Create a C script call it DoorOpenDevice and put that script on the door object This code shown in the next listing will cause the object to operate as a door Listing 8 1 Script that opens and closes the door on command using UnityEngine using System Collections The position to offset to public class DoorOpenDevice MonoBehaviour WA when the door opens SerializeField private Vector3
151. ame way that you import images Drag the FBX file from the computer into Unity s Project view or right click in Project and choose Import New Asset The 3D model will be copied into the Unity project and show up ready to be put in the scene NOTE The sample download includes the blend file so that you can practice exporting the FBX file from Blender even if you don t end up modeling any thing yourself you may need to convert downloaded models into a format Unity accepts If you want to skip all steps involving Blender use the provided FBX file There are a few default settings used to import the model that you want to change immediately First Unity defaults imported models to a very small scale refer to fig ure 4 15 which shows what you see in the Inspector when you select the model change the Scale Factor to 100 to partially counteract the 01 File Scale You may also want to click the Generate Colliders check box but that s optional without a collider you can walk through the bench Then switch to the Animation tab in the import set tings and deselect Import Animation you didn t animate this model Working with custom 3D models 85 Inspector J bench Import Settings lt lt Inspector J bench Import Settings Open Turn off Default size is too small so set scale to 100 e e a e animation ani c Mesh Compression of ImportAnimation O because ptional Generate Read Write Enabl
152. ames for these various platforms When I speak of building for a platform I m referring to generating an applica tion package that will run on that platform On every platform Windows iOS and so on the exact form of a built application differs but once the executable has 276 277 been generated that app package can be played without Unity and can be distributed to players A single Unity project can be deployed to any platform without needing to be redone for each This build once deploy anywhere capability applies to the vast majority of the features in your games but not to everything I would estimate that 95 of the code written in Unity for example almost everything we ve done so far in this book is platform agnostic and will work just as well across all platforms But there are a few specific tasks that differ for different platforms so we ll go over those platform specific areas of development In total the basic free version of Unity is capable of building apps for the following platforms Windows PC Mac OSX Linux Web both the web player and WebGL m iOS Android Blackberry 10 In addition through specially licensed modules Unity can build apps for the follow ing XBox 360 XBox One PlayStation 3 PlayStation 4 PS Vita Wii U Windows Phone 8 Whew that full list is really long Frankly that s almost comically long way more than the supported platforms o
153. an AudioSource component to the player object not the camera object You don t have to link in a specific audio clip because the audio clips will be defined in code You can turn off Play On Awake because sounds from this source will be trig gered in code Also adjust Spatial Blend to 3D because this sound is located in the scene Now make the additions shown in the next listing to RayShooter the script that handles shooting Listing 10 1 Sound effects added in the RayShooter script SerializeField private AudioSource soundSource SerializeField private AudioClip hitWallSound References the two sound SerializeField private AudioClip hitEnemySound files you want to play 230 10 3 10 3 1 CHAPTER 10 Playing audio sound effects and music If target is not null the i a ie aoiay J a player has hit an enemy so target ReactToHit soundSource PlayOneShot hitEnemySound else StartCoroutine SphereIndicator hit point soundSource PlayOneShot hitWallSound GS call PlayOneShot to play the Hit An Enemy sound or pS call PlayOneShot to play the Hit A Wall sound if the player missed The new code includes several new serialized variables at the top of the script Drag the player object the object with an AudioSource component to the soundSource slot in the Inspector Then drag the audio clips to play onto the sound slots swish is for hitting the wall and ding is for hitt
154. anag ers and then injecting the NetworkService object into the various managers when they re initialized In this way not only will WeatherManager have a reference to the NetworkService but so will any other managers you create later To start bringing over the Managers code architecture from chapter 8 first copy over ManagerStatus and IGameManager remember that IGameManager is the inter face that all managers must implement whereas ManagerStatus is an enum that IGameManager uses You ll need to modify IGameManager slightly to accommodate the new NetworkService class so create a new script called NetworkService leave it empty for now you ll fill it in later and then adjust IGameManager as shown in listing 9 2 I Manager gets asked for data WeatherManager 2 Manager tells Service to make request NetworkService e GetData e HT TPRequest 3 Service sends HTTP response back to Manager e OnResponse IGameManager Figure 9 3 Diagram showing how the networking code will be structured 202 CHAPTER 9 Connecting your game to the internet Listing 9 2 Adjusting GameManager to include NetworkService public interface IGameManager ManagerStatus status get The Startup function now takes one a parameter the injected object void Startup NetworkService service Next let s create WeatherManager to implement this slightly adjusted interface Cre ate a new C script see the foll
155. anagers from individual levels of the game In Project view duplicate the scene file Edit gt Duplicate and then rename the two files appropriately one Startup and the other Levell Open Levell and delete the Game Managers object it ll be provided by Startup Open Startup and delete everything other than Game Managers Controller HUD Canvas and EventSystem Remove the script components on Controller and delete the UI objects health label and InventoryPopup parented to the Canvas The UI is currently empty so create a new slider see figure 11 7 and then turn off its Interactable setting The Controller object also has no script components any more so create a new StartupController script and attach that to the Controller object see the following listing Listing 11 18 The new StartupController script using UnityEngine using UnityEngine UI using System Collections public class StartupController MonoBehaviour SerializeField private Slider progressBar void Awake Messenger lt int int gt AddListener StartupEvent MANAGERS PROGRESS OnManagersProgress 11 2 2 Developing the overarching game structure 265 Messenger AddListener StartupEvent MANAGERS STARTED OnManagersStarted void OnDestroy Messenger lt int int gt RemoveListener StartupEvent MANAGERS PROGRESS OnManagersProgress Messenger RemoveListener StartupEvent MANAGERS STARTED OnManagersStarted private void O
156. anagers to loop void Awake through during startup sequence Player GetComponent lt PlayerManager gt Inventory GetComponent lt InventoryManager gt _startSequence new List lt IGameManagers gt _startSequence Add Player _startSequence Add Inventory Launch the startup a sequence asynchronously StartCoroutine StartupManagers private IEnumerator StartupManagers foreach IGameManager manager in startSequence manager Startup yield return null int numModules startsSequence Count int numReady 0 Keep looping until all i managers are started while numReady lt numModules int lastReady numReady numReady 0 foreach IGameManager manager in _startSequence if manager status ManagerStatus Started numReady if numReady gt lastReady Debug Log Progress numReady numModules Managing inventory data and game state 183 yield return null A Pause for one frame before checking again Debug Log All managers started up The most important parts of this pattern are the static properties at the very top Those enable other scripts to use syntax like Managers Player or Managers Inven tory to access the various modules Those properties are initially empty but they re filled immediately when the code runs in the Awake method TIP Just like Start and Update Awake is another method automati cally provide
157. another function If you re unfamiliar with the concept of delegates realize that they enable you to pass around functions just as you do numbers and strings Without delegates you can t pass around functions to call later you can only directly call the function then With delegates you can tell code about other methods to call later This is useful for many purposes especially for implementing callback functions I Manager tells Service WeatherManager to make request NetworkService do this by starting e GetData coroutine gt HTTPRequest 2 In Service one StartCoroutine 7 CallAPI method calls another e OnResponse lt e CallAPI a SOO yield WWW 3 Coroutine pauses ie oe ae at yield statement 4 Service sends HTTP callback inthe second method response back to Manager Figure 9 4 Diagram showing how the network coroutine works 206 CHAPTER 9 Connecting your game to the internet DEFINITION A callback is a function used to communicate back to the calling object Object A could tell Object B about one of the methods in A B could later call A s method to communicate back to A For example in this case the callback is used to communicate the response data back after waiting for the HTTP request to complete In CallAPI the code first makes an HTTP request then yields until that request completes and finally uses callback to send back the response
158. anything about Unity that s okay I m going to start by explaining what Unity is including fundamentals of how to program games in it Then we ll walk through a tutorial about developing a simple game in Unity This first project will teach you a num ber of specific game development techniques as well as give you a good overview of how the process works Onward to chapter 1 Getting to know Unity This chapter covers What makes Unity a great choice Operating the Unity editor Programming in Unity Comparing C and JavaScript If you re anything like me you ve had developing a video game on your mind for a long time But it s a big jump from simply playing games to actually making them Numerous game development tools have appeared over the years and we re going to discuss one of the most recent and most powerful of these tools Unity is a professional quality game engine used to create video games targeting a variety of platforms Not only is it a professional development tool used daily by thousands of seasoned game developers it s also one of the most accessible modern tools for novice game developers Until recently a newcomer to game development espe cially 3D games would face lots of imposing barriers right from the start but Unity makes it easy to start learning these skills Because you re reading this book chances are you re curious about computer technology and you ve either developed ga
159. arkup Langauge See XML ExternalCall method 284 ExternalEval method 284 extrude commands 311 F 321 G facing objects 170 171 Fade Duration setting 129 Far clipping plane 251 FBX format 83 142 159 field of vision 250 FingerGestures 285 finite state machines See FSM first person shooter See FPS floor plans 73 74 FMOD library 245 FMOD Studio 318 FPS first person shooter 22 120 FPS Control 318 frame rate dependent 41 frames 15 freezeRotation property 38 FSM finite state machines 58 Game view 10 11 GameObject class 27 GET method 196 GetAxis method 40 GetComponent method 43 54 GetInstanceID method 63 GetMouseButtonDown method 49 GetTouch method 285 GIF format 76 GIMP 306 Git 7 305 global vs local coordinate space 32 33 Gone Home 8 Google Play Games 318 graphical user interface See GUI graphics 3D models file formats 83 84 importing and exporting 84 86 overview 83 3D scenery floorplans 73 74 laying out primitives 74 75 whiteboxing 72 73 art assets 69 72 particle systems attaching effects to 3D objects 90 default effect 87 88 fire texture 88 90 overview 86 87 sky visuals 80 83 textures applying 78 80 file formats 76 77 importing files 77 78 overview 75 76 grayboxing 72 ground detection 154 158 GUI graphical user interface 112 120 Guns of Icarus Online 7 H heads up display See HUD health player 190 191 Hello World example 17 Hierar
160. asic AI we just need to track whether or not the character is alive The next listing adds a Boolean value alive toward the top of the script and the code needs occasional conditional checks of that value With those checks in place the movement code only runs while the enemy is alive Listing 3 8 WanderingAl script with alive state added private bool alive AL Boolean value to track void Start whether the enemy is alive alive true ae Initialize that value Basic wandering AI 59 void Update if alive transform Translate 0 0 speed Time deltaTime p3 Only move if the character is alive public void SetAlive bool alive See Public method allowing outside code to affect the alive state The ReactiveTarget script can now tell the WanderingAI script when the enemy is or isn t alive see the following listing Listing 3 9 ReactiveTarget tells WanderingAl when it dies public void ReactToHit WanderingAI behavior GetComponent lt WanderingAI gt if behavi l 11 o i a EN E N bg Check if this character has a WanderingAl script it might not StartCoroutine Die Al code structure The Al code in this chapter is contained within a single class so that learning and under standing it is straightforward This code structure is perfectly fine for simple Al needs so don t be afraid that you ve done something wrong and that a more
161. ast modification when compared to other projects Ultimately we ll pull together assets from several chapters so techni cally it s not that different than if we started with one of those projects and pulled in assets from chapter 8 248 CHAPTER 11 Putting the parts together into a complete game Here s a recap of what s in the project from chapter 8 A character with an animation controller already set up A third person camera that follows the character around A level with floors walls and ramps Lights and shadows all placed Operable devices including a color changing monitor Collectible inventory items Back end managers code framework This hefty list of features covers quite a bit of the action in the RPG demo already but there s a bit more that we ll either need to modify or add 11 1 1 Assembling assets and code from multiple projects All right the first modifications will be to update the managers framework and to bring in computer controlled enemies For the former task recall that updates to the frame work were made in chapter 9 which means those updates aren t in the project from chapter 8 For the latter task recall that you programmed an enemy in chapter 3 UPDATING THE MANAGERS FRAMEWORK Updating the managers is a fairly simple task so let s get that out of the way first The IGameManager interface was modified in chapter 9 see the next listing Listing 11 1 Adjusted IGa
162. asting to convert from one type of code object into another type written with the syntax original object as new type The instantiated object is stored in _enemy a private variable of type GameObject and again keep straight the distinction between a prefab and an instance of the pre fab enemyPrefab stores the prefab whereas enemy stores the instance The if state ment that checks the stored object ensures that Instantiate is called only when _enemy is empty or null in coder speak The variable starts out empty so the instan tiating code runs once right from the beginning of the session The object returned by Instantiate is then stored in enemy so that the instantiating code won t run again Because the enemy destroys itself when shot that empties the _enemy variable and causes Instantiate to be run again In this way there s always an enemy in the scene 3 5 Shooting via instantiating objects 63 Destroying GameObjects and memory management Its somewhat unexpected that existing references become null when an object destroys itself In a memory managed programming language like C normally you aren t able to directly destroy objects you can only dereference them so that they can be destroyed automatically This is still true within Unity but the way GameObjects are handled behind the scenes makes it look like they were destroyed directly To display objects in the scene Unity has to have a reference to all objects
163. at s found by going to SampleScenes Scenes in the file browser at the bottom of the editor You should be looking at a screen similar to figure 1 9 The interface in Unity is split up into different sections the Scene tab the Game tab the Toolbar the Hierarchy tab the Inspector the Project tab and the Console tab Each section has a different purpose but all are crucial for the game building lifecycle You can browse through all the files in the Project tab You can place objects in the 3D scene being viewed using the Scene tab The Toolbar has controls for working with the scene You can drag and drop object relationships in the Hierarchy tab The Inspector lists information about selected objects including linked code You can test playing in Game view while watching error output in the Console tab 10 1 2 1 CHAPTER 1 Getting to know Unity Scene and Game are The whole top area is the Toolbar The inspector fills the right side tabs for viewing the To the left are buttons for looking This displays information about 3D scene and playing around and moving objects and in the currently selected object the game respectively the middle is the Play button a list of components mostly a gt aan Hierarchy shows a text list of all objects in the scene nested according to how they re linked together Drag objects in the hierarchy to link them A Project and Console are tabs for viewin
164. at for a bit you can move on to adding keyboard input Listing 2 8 Spin code from the first listing with a couple of minor changes using UnityEngine using System Collections Not required but you probably public class FPSInput MonoBehaviour a want to increase the speed public float speed 6 0f void Update transform Translate 0 speed 0 bS Changing Rotate to Translate Responding to key presses The code for moving according to key presses shown in the following listing is simi lar to the code for rotating according to the mouse The GetAxis method is used here as well and in a very similar way The following listing demonstrates how to use that command Keyboard input component first person controls 41 Listing 2 9 Positional movement responding to key presses void Update float deltaX Input GetAxis Horizontal speed ae Horizontal and Vertical float deltaZ Input GetAxis Vertical speed are indirect names for transform Translate deltax 0 deltaZ keyboard mappings As before the GetAxis values are multiplied by speed in order to determine the amount of movement Whereas before the requested axis was always Mouse some thing now we pass in either Horizontal or Vertical These names are abstractions for input settings in Unity if you look in the Edit menu under Project Settings and then look under Input you ll find a list of abstract input names
165. ata and what the native code uses TIP This sample only communicates in one direction from Unity to the plug in But the native code could also communicate to Unity by using the UnitySendMessage method You can send a message to a named object in the scene during initialization the plug in created TestPlugin_ instance to send messages to With the native code in place you can build the iOS app and test it on a device Very cool That s how to make an iOS plug in so let s look at Android too ANDROID PLUG INS To create an Android plug in the Unity side of things is almost exactly the same We don t need to change MobileTestObject at all Make the additions shown in the follow ing listing in TestPlugin Listing 12 8 Modifying TestPlugin to use the Android plug in region 10S DllImport __Internal private static extern float TestNumber Dilimport Internal private static extera tring T estStrang string test endregion iOS if UNITY ANDROID private static Exception pluginError private static AndroidJavaClass pluginClass private static AndroidJavaClass GetPluginClass AndroidjNI functionality if _pluginClass null amp amp pluginError null provided by Unity AndroidJNI AttachCurrentThread Building for mobile apps iOS and Android 295 try 4 _pluginClass new AndroiddJavaClass com companyname testplugin TestPlugin n catch Exception e _pluginError e Name of th
166. ate the rotation angle in various ways aside from only incrementing it The rotation value is multiplied by Input GetAxis just like in the code for horizontal rotation except now we ask for Mouse Y because that s the vertical axis of the mouse The rotation angle is manipulated further on the very next line We use Mathf Clamp to keep the rotation angle between minimum and maximum limits Script component for looking around MouseLook 37 Those limits are public variables declared earlier in the code and they ensure that the view can only tilt 45 degrees up or down The Clamp method isn t specific to rota tion but is generally useful for keeping a number variable between limits Just to see what happens try commenting out the Clamp line now the tilt doesn t stop at upper and lower limits allowing you to even rotate completely upside down Clearly viewing the world upside down is undesirable hence the limits Because the angles property of transform is a Vector3 we need to create a new Vector3 with the rotation angle passed in to the constructor The Rotate method was automating this process for us incrementing the rotation angle and then creating a new vector DEFINITION A vector is multiple numbers stored together as a unit For exam ple a Vector3 is 3 numbers labeled x y z WARNING The reason why we need to create a new Vector3 instead of chang ing values in the existing vector in the transform is because those
167. ating a new project 2D Editor mode and 2D Scene view The 2D 3D setting for new projects adjusts two 2D view toggle button different settings within Unity s editor both of which you can adjust manually later if you wish Those two settings are the 2D Editor mode and the 2D Scene view The 2D Scene view controls how the scene is displayed within Unity toggle the 2D button along the top of the Scene view 2D Scene view toggle You set 2D Editor mode by opening the Edit menu and selecting Editor from the Project Settings drop down menu Within those settings you ll see the Default Behavior Mode setting with selections for either 3D or 2D W INSPECTOF MEE i Editor Settings Unity Remote Device Version Control Mode WWW Security Emulation Host URL http weew mydomain ce Asset Serialization Mode 2D 3D Behavior Mode menu Default Behavior Mode Mode Fy Sprite Packer Mode Default Behavior Mode setting within Edit gt Project Settings gt Editor Setting the editor to 2D mode causes imported images to be set to Sprite as you saw in chapter 4 normally images import as textures 2D Editor mode also causes new scenes to lack the default 3D lighting setup this lighting doesn t harm 2D scenes but it s unnecessary If you ever need to remove it manually delete the directional light that comes with new scenes and turn off the skybox in the lighting window click the tiny circle icon for a file picker and c
168. ator StartupManagers if numReady gt lastReady Debug Log Progress numReady numModules Messenger lt int int gt Broadcast StartupEvent MANAGERS PROGRESS numReady numModules Startup event broadcast with yield return null data related to the event Startup event broadcast 5 a Beet without A Debug Log A managers started up parameters Messenger Broadcast StartupEvent MANAGERS STARTED 264 CHAPTER 11 Putting the parts together into a complete game Remaining objects Game Managers Controller HUD Canvas EventSystem The non interactive slider Figure 11 7 The Startup scene with everything unnecessary removed Most of this code should already be familiar to you adding MissionManager is just like adding other managers but there are two new parts One is the event that sends two integer values you saw both generic valueless events and messages with a single number before but you can send an arbitrary number of values with the same syntax The other new bit of code is the DontDestroyOnLoad method It s a method pro vided by Unity for persisting an object between scenes Normally all objects in a scene are purged when a new scene loads but by using DontDestroyOnLoad on an object you ensure that that object will still be there in the new scene SEPARATE SCENES FOR STARTUP AND LEVEL Because the Game Managers object will persist in all scenes you must separate the m
169. axis picture the sides and hypotenuse of a right triangle But there s one tricky aspect to the movement vector here and it has to do with local versus global as we discussed earlier for rotations We ll create the vector with a value to move say to the left That s the player s left though which may be a com pletely different direction from the world s left That is we re talking about left in local space not global space We need to pass a movement vector defined in global space to the Move method so we re going to need to convert the local space vector into global space Doing that conversion is extremely complex math but fortunately for us Unity takes care of that math for us and we simply need to call the method TransformDirection in order to well transform the direction DEFINITION Transform used as a verb means to convert from one coordinate space to another refer back to section 2 3 3 if you don t remember what a coordinate space is Don t get confused with the other definitions of trans form including both the Transform component and the action of moving the object around the scene It s sort of an overloaded term because all these meanings refer to the same underlying concept Test playing the movement code now If you haven t done so already set the Mouse Look component to both horizontal and vertical rotation You can look around the scene fully and fly around the scene using keyboard control
170. billboard will look like after you play the game AssetBundles How to download other kinds of assets Downloading an image is fairly straightforward using the Www object but what about other kinds of assets like mesh objects and prefabs WWW has properties for text and images but other assets are a bit more complicated 216 9 3 3 CHAPTER 9 Connecting your game to the internet continued Unity can download any kind of asset through a mechanism called AssetBundles Long story short you first package up some assets into a bundle and then Unity can extract the assets after downloading the bundle The details of both creating and downloading AssetBundles are beyond the scope of this book if you want to learn more start by reading this section of Unity s manual http docs unity3d com Manual AssetBundlesIntro html Great the downloaded image is displayed on the billboard But this code could be optimized further to work with multiple billboards Let s tackle that optimization in the next section Caching the downloaded image for reuse As noted in section 9 3 1 ImagesManager doesn t yet store the downloaded image That means the image will be downloaded over and over for multiple billboards This is inefficient because it ll be the same image each time To address this we re going to adjust ImagesManager to cache images that have been downloaded DEFINITION Cache means to keep stored locally The most common but not
171. bjects and lights in a room set the scene The player in a first person scene is essentially a camera Movement code applies small transforms repeatedly in every frame FPS controls consist of mouse rotation and keyboard movement www allitebooks com Adding enemies and projectiles to the 3D game This chapter covers Taking aim and firing both for the player and for enemies Detecting and responding to hits Making enemies that wander around Spawning new objects in the scene The movement demo from the previous chapter was pretty cool but still not really a game Let s turn that movement demo into a first person shooter If you think about what else we need now it boils down to the ability to shoot and things to shoot at First we re going to write scripts that enable the player to shoot objects in the scene Then we re going to build enemies to populate the scene including code to both wander around aimlessly and react to being hit Finally we re going to enable the enemies to fight back emitting fireballs at the player None of the scripts from chapter 2 need to change instead we ll add scripts to the project scripts that handle the additional features I ve chosen a first person shooter for this project for a couple of reasons One is simply that FPS games are popular people like shooting games so let s make a 46 3 1 3 1 1 Shooting via raycasts 47 shooting game A subtler reason has to do
172. blic Color haghlightColor Color cyan public void OnMouseOver SpriteRenderer sprite GetComponent lt SpriteRenderer gt if sprite null sprite color highlightColor AL Tint the button when the mouse hovers over it public void OnMouseExit SpriteRenderer sprite GetComponent lt SpriteRenderer gt if sprite null sprite color Color white The button s size pops a a bit when it s clicked public void OnMouseDown transform localScale new Vector3 1 1f 1 1f 1 1f public void OnMouseUp tCranstorm LocalScale Vectors one if targetObject null targetObject SendMessage targetMessage baw Senda message to the target object when the button is clicked 116 CHAPTER 5 Building a Memory game using Unity s new 2D functionality The majority of this code happens inside a series of OnMouseSomething functions like Start and Update these are a series of functions automatically available to all script components in Unity MouseDown was mentioned back in section 5 2 2 but all these functions respond to mouse interactions if the object has a collider MouseOver and MouseExit are a pair of events used for hovering the mouse cursor over an object MouseOver is the moment when the mouse cursor first moves over an object and MouseExit is the moment when the mouse cursor moves away Similarly MouseDown and MouseUp are a pair of events for clicking t
173. boxBlended and then double click the shader to open the script Copy the code from that wiki page and paste it into the shader script The top line says Shader Skybox Blended which tells Unity to add the new shader into the shader list under the Skybox category the same category as the regular skybox NOTE We re not going to go over all the details of the shader program right now Shader programming is a pretty advanced computer graphics topic and thus outside the scope of this book You may want to look that up after you ve finished this book if so start here http docs unity3d com Manual Shaders Overview html Now you can set your material to the Skybox Blended shader There are 12 texture slots in two sets of six images Assign TropicalSunnyDay images to the first six textures just as before for the remaining textures use the DarkStormy set of skybox images Creating an outdoor scene 199 This new shader also added a Blend slider near the top of the settings The Blend value controls how much of each set of skybox images you want to display when you adjust the slider from one side to the other the skybox transitions from sunny to overcast You can test by adjusting the slider and playing the game but manually adjusting the sky isn t terribly helpful while the game is running so let s write some code to transition the sky Create an empty object in the scene and name it Controller Create a new script and name it WeatherCon
174. cading coroutine methods 205 changing scene based on data 210 212 coroutines overview 203 204 HTTP requests 204 205 overview 201 203 206 207 parsing JSON 209 210 parsing XML 207 209 web deployment communicating with Java Script in browser 283 285 saving game data 270 test web page for 282 283 Unity Player vs HTML5 WebGL 282 web services 201 WebGL 282 whiteboxing 72 73 World Space 124 WWW class 203 215 X XAMPP 218 Xcode 286 305 XM format 224 XML Extensible Markup Langauge 207 209 Y yield keyword 55 Z z fighting 251 GAME PROGRAMMING Unity IN Action Joseph Hocking T his book helps readers build successful games with the Unity game development platform You will use the powerful C language Unity s intuitive workflow tools and a state of the art rendering engine to build and deploy mobile desktop and console games Unity s single code base approach minimizes inefficient switching among development tools and concentrates your attention on making great interac tive experiences Unity in Action teaches you how to write and deploy games You ll master the Unity toolset from the ground up add ing the skills you need to go from application coder to game developer Each sample project illuminates specific Unity features and game development strategies As you read and practice youll build up a well rounded skill set for creating graphically driven 2D and 3D game applications W
175. casionally games do it the other way most third person games make their controls camera relative When the player presses the left button the character moves to the left of the screen not the character s left Over time and through experiments with trying out different control schemes game designers have figured out that players find the controls more intuitive and easier to understand when left means left side of the screen which not coincidentally is also the player s left Programming camera relative movement controls 149 Implementing camera relative controls involves two primary steps first rotate the player character to face the direction of the controls and then move the character forward Let s write the code for these two steps next 7 2 1 Rotating the character to face movement direction First we ll write code to make the character face in the direction of the arrow keys Create a C script called RelativeMovement see listing 7 2 Drag that script onto the player character and then link the camera to the target property of the script com ponent just like you d linked the character to the target of the camera script Now the character will face different directions when you press the controls facing direc tions relative to the camera or stand still when you re not pressing any arrow keys that is when rotating using the mouse Listing 7 2 Rotating the character relative to the camera using Un
176. cause we haven t written a Restart method in SceneController so let s add that next Calling LoadLevel from SceneController The SendMessage from the button attempts to call Restart in the Scene Controller so let s add that see the next listing Listing 5 14 SceneController code that reloads the level public void Restart Application LoadLevel Scene ae The scene asset is loaded with this command You can see the one thing Restart does is call Application LoadLevel That command loads a saved scene asset that is the file created when you click Save Scene in Unity Pass the method the name of the scene you want to load in my case the scene was saved with the name Scene but if you used a different name pass that to the method instead Hit Play to see what happens Reveal a few cards and make a few matches if you then click the Reset button the game starts over with all cards hidden and a score of 0 Great just what we wanted As the name LoadLevel implies this method can load different levels But what exactly happens when a level loads and why does this reset the game What happens is that everything from the current level all objects in the scene and thus all scripts attached to those objects is flushed from memory and then everything from the new scene is loaded Because the new scene in this case is the saved asset of the current scene everything is flushed from memory and then re
177. ceive Shadows Materials to compensate for the ml height we set the Y scale to I and the object is positioned around Sea its center Base RGB Tiling Default Diffuse Shader Diffuse Edit I At the top you can type in a name for the object For example call the floor object Floor The remaining components filling the view come with a new Cube object but don t need to be adjusted right now These components include a Mesh Filter to define the geometry of the object a Mesh Renderer to define the material on the object and a Box Collider so that the object can be collided with during movement Add Component hee Figure 2 6 Inspector view for the floor later we ll use other shapes like Sphere and Capsule Adjust the position and scale of this object as well as its name in order to make the floor figure 2 6 shows what val ues the floor should be set to in the Inspector it s only a cube initially before you stretch it out NOTE The numbers for position can be any units you want as long as you re consistent throughout the scene The most common choice for units is meters and that s what I generally choose but I also use feet sometimes and I ve even seen other people decide that the numbers are inches Repeat the same steps in order to create outer walls for the room You can create new cubes each time or you can copy and paste existing objects using the
178. ch in Blender Besides custom made models created by Figure 4 14 The bench model in Blender yourself or an artist you re working with many 3D models are available for download from game art websites One great resource for 3D models is Unity s Asset Store here https www assetstore unity3d com Which file format to choose Now that you ve made the model in Blender you need to export the asset out from that software Just as with 2D images a number of different file formats are available for you to use when exporting out the 3D model and these file types have various pros and cons Table 4 3 lists the 3D file formats that Unity supports Table 4 3 3D Model file formats supported by Unity File type Pros and cons FBX Mesh and Animation recommended option when available Collada DAE Mesh and Animation another good option when FBX isn t available OBJ Mesh only this is a text format so sometimes useful for streaming over the internet 30S Mesh only a pretty old and primitive model format DXF Mesh only a pretty old and primitive model format Maya Works via FBX requires this application to be installed 84 4 5 2 CHAPTER 4 Developing graphics for your game Table 4 3 3D Model file formats supported by Unity continued File type Pros and cons 3ds Max Works via FBX requires this application to be installed Blender Works via FBX requires this application to be installed Choosing between
179. chy tab 12 13 322 horizontal rotation 35 38 40 HTML5 Hypertext Markup Language 5 282 HTTP requests 196 204 205 HUD heads up display adding objects to canvas 124 127 creating canvas 123 124 event system for HUD events 138 139 overview 136 137 scene events 137 138 immediate mode vs retained mode 121 122 importing images 122 123 interactivity creating pop up window 131 133 setting values using sliders and input fields 133 135 UIController 129 130 overview 119 121 planning layout 122 positioning UI elements 127 128 humanoid characters 141 Hypertext Markup Language 5 See HIML5 IDE integrated development environment 5 IGameManager interface 179 201 248 ignoreListenerPause property 241 ignoreListenerVolume property 241 images caching downloaded 216 217 displaying 214 216 editing tools 306 loading from internet 212 214 immediate mode vs retained mode 121 122 Initialize function 292 input fields 133 135 instances 60 instantiation defined 60 shooting with instantiating objects creating projectile prefabs 64 65 INDEX damaging player 67 68 overview 63 68 shooting projectiles 65 67 integrated development envi ronment See IDE interactivity bumping into objects collecting scattered items 176 178 overview 172 173 physics enabled obstacles 173 174 pressure plate 174 176 color changing monitor example 171 172 creating pop up window 131 133 doors facing before opening 170 171 opening a
180. cking for collisions on the bottom of the character isn t a great way of determining if the character is on the ground Instead let s use raycasting to detect the ground In chapter 3 the AI used raycasting to detect obstacles in front of it let s use the same approach to detect surfaces below the character Cast a ray straight down from the player s position If it registers a hit just below the character s feet that means the player is standing on the ground This does introduce a new situation to handle when the raycast doesn t detect ground below the character but the character controller is colliding with the ground As in figure 7 9 the capsule still collides with the platform while the character is walk ing off the edge Figure 7 10 adds raycasting to the diagram in order to show what will but the collision capsule around the character is still touching the platform edge The code must handle this situation Raycasting straight down from the middle correctly detects that the character isn t standing on the ground Figure 7 10 Diagram of raycasting downward while stepping off a ledge 156 CHAPTER 7 Creating a third person 3D game player movement and animation happen now the ray doesn t hit the platform but the capsule does touch the edge The code needs to handle this special situation In this case the code should make the character slide off the ledge The character will still fall because
181. closer to the camera so sprites with lower Z values are displayed on top of other sprites refer to figure 5 4 Accordingly the background sprite should have the highest Z value We ll set our background to a positive Z position and then give everything else a 0 or negative Z position Other sprites will be positioned with values up to two decimal places because of the Pixels To Units setting mentioned earlier A ratio of 100 1 means that 100 pixels in the image are l unit in Unity put another way l pixel is 01 units But before we put any more sprites into the scene let s set up the camera for this game Creating atlases using Sprite Packer As mentioned in the sidebar Animated Sprites you can have multiple sprites laid out ina single image The image is usually called a sprite sheet when multiple frames of a single 2D animation are combined into one but the more general term for multiple images combined into one is an atlas Sprite sheets are useful in order to keep frames of animation together but sprite atlases are also often used for still images That s because atlases can optimize the performance of sprites in two ways 1 by reducing the amount of wasted space in images by packing them tightly and 2 by reducing the draw calls of the video card every new image that s loaded causes a bit more work for the video card Sprite atlases can be created using external tools switch to Multiple in the Sprite settings and
182. cluding SDKs for Apple platforms Although you d still be doing the vast major ity of the work within Unity you need to use Xcode to deploy a game to 10S That work often involves debugging or profiling your app using the tools in Xcode https developer apple com xcode Android SDK Similar to how you need to install Xcode in order to deploy to iOS you need to down load the Android SDK in order to deploy to Android Unlike when building an 10S game you don t need to fire up any development tools outside of Unity you simply have to set preferences in Unity that point to the Android SDK http developer android com sdk index html SVN Git or Mercurial Any decent sized software development project will involve a lot of complex revisions to code files so programmers have developed a class of software called VCS version control system to handle this problem Three of the most popular systems are Sub version also known as SVN Git and Mercurial if you don t already use a VCS I highly recommend starting to use one Unity fills the project folder with temp files and workspace settings but the only two folders that need to be in version control are Assets make sure your version control is picking up the meta files generated by Unity and Project Settings http subversion apache org http git scm com http mercurial selenic com wiki Mercurial 3D art applications Although Unity is perfectly capable of handl
183. comparison In a component system objects exist on a flat hierarchy and different objects have different collections of components rather than an inheritance structure where dif ferent objects are on completely different branches of the tree This arrangement facilitates rapid prototyping because you can quickly mix and match different compo nents rather than having to refactor the inheritance chain when the objects change Although you could write code to implement a custom component system if one didn t exist Unity already has a robust component system and this system is even inte grated seamlessly with the visual editor Rather than only being able to manipulate components in code you can attach and detach components within the visual editor Meanwhile you aren t limited to only building objects through composition you still have the option of using inheritance in your code including all the best practice design patterns that have emerged based on inheritance Downsides to be aware of Unity has many advantages that make it a great choice for developing games and I highly recommend it but I d be remiss if I didn t mention its weaknesses In particu lar the combination of the visual editor and sophisticated coding though very effec tive with Unity s component system is unusual and can create difficulties In complex scenes you can lose track of which objects in the scene have specific components attached Unity does provi
184. complex code structure is an absolute requirement For more complex Al needs such as a game with a wide variety of highly intelligent characters a more robust code structure can help facilitate developing the Al As alluded to in chapter 1 s example for composition versus inheritance sometimes you ll want to split chunks of the Al into separate scripts Doing so will enable you to mix and match components generating unique behavior for each character Think about the similarities and differences between your characters and those differences will guide you as you design your code architecture For example if your game has some enemies that move by charging headlong at the player and some that slink around in the shadows you may want to make Locomotion a separate component Then you can create scripts for both LocomotionCharge and LocomotionSlink and use different Locomotion components on different enemies The exact Al code structure you want depends on the design of your specific game there s no one right way to do it Unity makes it easy to design flexible code archi tectures like this 60 3 4 3 4 1 3 4 2 CHAPTER 3 Adding enemies and projectiles to the 3D game Spawning enemy prefabs At the moment there s just one enemy in the scene and when it dies the scene is empty Let s make the game spawn enemies so that whenever the enemy dies a new one appears This is easily done in Unity using a concept called pr
185. contact normal moveSpeed else movement _contact normal moveSpeed movement y _vertSpeed movement Time deltaTime Store the collision data _charController Move movement in the callback when a collision is detected void OnControllerColliderHit ControllerColliderHit hit a Contacte fic Implementing the jump action 157 This listing contains much of the same code as the previous listing the new code is interspersed throughout the existing movement script and this listing needed the exist ing code for context The first line adds a new variable to the top of the RelativeMove ment script This variable is used to store data about collisions between functions The next several lines do raycasting This code also goes below horizontal move ment but before the if statement for vertical movement The actual Physics Raycast call should be familiar from previous chapters but the specific parame ters are different this time Although the position to cast a ray from is the same the character s position the direction will be down this time instead of forward Then we check how far away the raycast was when it hit something if the distance of the hit is at the distance of the character s feet then the character is standing on the ground so set hitGround to true WARNING It s a little nonobvious how the check distance is calculated so let s go over that in detail First take the height of the
186. ct making that object invisible If we now drag card_back in the scene to this script s variable in the Inspector when you play the game the card back disappears when you click the card Hiding the card back will reveal the card front we ve accomplished yet another important task for the Memory game But this is still only one card so now let s create a bunch of cards Displaying the various card images We ve programmed a card object that initially shows the card back but reveals itself when clicked That was a single card but the game needs a whole grid of cards with different images on most cards We ll implement the grid of cards using a couple con cepts seen in previous chapters along with some new concepts you haven t seen before Chapter 3 included both the notions of 1 using an invisible SceneController component and 2 instantiating clones of an object This time the SceneController will apply different images to different cards Loading images programmatically There are four card images in the game we re creating All eight cards on the table two for each symbol will be created by cloning the same original so initially all cards 5 3 2 Displaying the various card images 105 will have the same symbol We ll have to change the image on the card in the script loading different images programmatically To examine how images can be assigned programmatically let s write some simple test code that will be rep
187. ction 42 43 overview 40 responding to key presses 40 41 setting rate of movement 41 42 keyboard shortcuts 303 310 Knuth algorithm 110 L lambda functions 216 latency 212 LateUpdate method 147 lazy loading 237 Learn Unity3D site 316 317 left handed coordinates 24 Lerp 150 levels completing 265 267 designing 73 losing 268 269 libraries FMOD Studio 318 FPS Control 318 Google Play Games 318 iIween 317 prime 31 318 ProBuilder 318 Prototype 318 Unify community wiki 317 Unity patterns 317 lighting 27 29 200 lightmapping 144 145 200 List objects 184 186 Load method 187 local vs global coordinate space 32 33 looping audio playing music 237 240 sounds 228 229 lossy compression 76 managers inventory data 178 184 massively multiplayer online See MMOs materials 64 71 Maya 83 305 317 Mecanim system 86 87 159 memory game card objects buidling from sprites 102 103 instantiating grid of cards 107 109 loading images programmatically 104 105 responding to clicks 103 104 revealing card 104 INDEX setting image from SceneController 105 107 shuffling cards 109 110 overview 96 97 planning project 97 98 restart button 114 118 scoring comparing revealed cards 111 displaying score text 112 114 hiding mismatched cards 111 112 overview 110 111 sprites 98 100 switching camera to 2D mode 101 102 Mercurial 7 305 mesh objects 10 70 310 MMORPGs MMO role playing games 195 MMOs massively
188. cts move smoothly over time The word tween means different things in different contexts but in game programming it refers to code commands that cause objects to move around appendix D mentions iTween one good tweening system for Unity Now other code needs to call Operate to make the door open and close the single function call handles both cases We don t yet have that other script on the player writing that is the next step 8 1 2 Checking distance and facing before opening the door Create a new script and name it DeviceOperator The following listing implements a control key that operates nearby devices Listing 8 2 Device control key for the player using UnityEngine using System Collections How far away from the public class DeviceOperator MonoBehaviour aA player to activate devices public float radius 1 5f Respond to the input button void Update _ 4efined in Unity s input settings if Input GetButtonDown Fire3 Collider hitColliders Physics OverlapSphere transform position radius o foreach Collider hitCollider in hitColliders OverlapSphere hitCollider SendMessage Operate returns a list of SendMessageOptions DontRequireReceiver nearby objects T SendMessage tries to call the named function regardless of the target s type The majority of the script in this listing should look familiar but a crucial new method is at the center of this code First
189. cus on programming To start go to the website www unity3d com to download the software This book uses Unity 5 0 which is the latest version as of this writing The URL is a leftover from Unity s original focus on 3D games support for 3D games remains strong but Unity works great for 2D games as well Meanwhile although advanced features are avail able in paid versions the base version is completely free Everything in this book works in the free version and doesn t require Unity Pro the differences between those versions are in advanced features that are beyond the scope of this book and com mercial licensing terms Why is Unity so great Let s take a closer look at that description from the beginning of the chapter Unity is a professional quality game engine used to create video games targeting a variety of platforms That is a fairly straightforward answer to the straightforward question What is Unity However what exactly does that answer mean and why is Unity so great Unity s strengths and advantages A game engine provides a plethora of features that are useful across many different games so a game implemented using that engine gets all those features while adding custom art assets and gameplay code specific to that game Unity has physics simula tion normal maps screen space ambient occlusion SSAO dynamic shadows and the list goes on Many game engines boast such features but Unity has two main Why is
190. d by MonoBehaviour It s similar to Start running once when the code first starts running But in Unity s code execution sequence Awake is even sooner than Start allowing for initialization tasks that absolutely must run before any other code modules The Awake method also lists the startup sequence and then launches the coroutine to start all the managers Specifically the function creates a List object and then uses List Add to add the managers DEFINITION List is a collection data structure provided by C List objects are similar to arrays they re declared with a specific type and store a series of entries in sequence But a List can change size after being created whereas arrays are created at a Static size that can t change later WARNING The collection data structures are contained in a new namespace that you must include in the script notice the additional using statement at the top of the script Don t forget this detail in your scripts Because all the managers implement IGameManager this code can list them all as that type and can call the Startup method defined in each The startup sequence is run as a coroutine so that it will run asynchronously with other parts of the game proceed ing too for example a progress bar animated on a startup screen The startup function first loops through the entire list of managers and calls Startup on each one Then it enters a loop that keeps checking whether
191. d change the Wrap Mode setting shown in fig ure 4 13 from Repeat to Clamp don t forget to click Apply when you re done Ordi narily textures can be tiled repeatedly over a surface for this to appear seamless opposite edges of the image bleed together But this blending of edges can create faint lines in the sky where images meet so the Clamp setting similar to the Clamp function in chapter 2 will limit the boundaries of the texture and get rid of this blending Now you can drag these images to the texture slots of the skybox material The names of the images correspond to the texture slot to assign them to such as left or front Once all six textures are linked up you can use this new material as the skybox for the scene Open the lighting window again and set this new material to the Skybox slot either drag the material to that slot or click the tiny circle icon to bring up a file picker TIP By default Unity will display the skybox or at least its main color in the editor s Scene view You may find this color distracting while editing objects so you can toggle the skybox on or off Across the top of the Scene view s pane are buttons that control what s visible look for the Effects button to tog gle the skybox on or off Faint lines Inspector may be EZS TropicalSunnyDayBack2048 Import Settings visible at So Change the edges of Texture Type the Wrap Mode Alpha from Grayscale the s
192. d object in the scene Thus you must have an object in the scene that will receive communications from the browser To demonstrate these tasks create a new script in Unity called WebTestObject Also create an empty object in the active scene called Listener the object in the scene must have that exact name because that s the name used in the code Attach the new script to that object and then write in the code from the next listing Listing 12 2 WebTestObject script for testing communication with the browser using UnityEngine using System Collections public class WebTestObject MonoBehaviour private string message Initial value for void Start af the message _message No message yet ia updacet 1 On mouse click call ee es Pa function in browser if Input GetMouseButtonDown 0 Application ExternalCall ShowAlert Hello out there Display message void OnGUI a in top left of screen GUI Label new Rect 10 10 200 20 _message 284 Button that calls the JavaScript function CHAPTER 12 Deploying your game to players devices public void RespondToBrowser string message _message message ae Function for the browser to call Now build for web again to update the game with this new code Unity s web build is ready now but the web page also needs to be adjusted You need to add a couple of functions to the JavaScript on the page as well as add a button to th
193. dd code to WeatherManager to parse the response and extract the cloudiness Put the URL into a web browser in order to see the code there s a lot there but we re only interested in the node that contains something like lt clouds value 40 name scattered clouds gt In addition to adding code to parse XML we re going to make use of the same messenger system we did in chapter 6 That s because once the weather data is 208 Convert the value toa 0 I float CHAPTER 9 Connecting your game to the internet downloaded and parsed we still need to inform the scene about that Create a script called Messenger and paste in the code from this page on the Unify wiki http wiki unity3d com index php CSharpMessenger_Extended Then you need to create a script called GameEvent see the next listing As explained in chapter 6 this messenger system is great for providing a decoupled way of communicating events to the rest of the program Listing 9 7 GameEvent code public static class GameEvent public const string WEATHER UPDATED WEATHER UPDATED Once the messenger system is in place adjust WeatherManager as shown in the follow ing listing Listing 9 8 Parsing XML in WeatherManager Be sure to add needed Ee tng Sy Rees ea using statements using System Xml public float cloudValue get private set AO Cloudiness is modified internally public void OnXMLDataLoaded string data but read only elsewhere XmlDocum
194. dditions several bits of test code got removed Specifically we removed the local cloudiness value that was incremented every frame we don t need that anymore because we ll use the value from WeatherManager A listener gets added and removed in Awake OnDestroy these are MonoBehaviour s functions called when the object awakes or is removed This listener is part of the broadcast messaging system and it calls OnWeatherUpdated when that message is received OnWeatherUpdated retrieves the cloudiness value from WeatherManager and calls SetOvercast using that value In this way the appear ance of the scene is controlled by downloaded weather data Run the scene now and you ll see the sky update according to the cloudiness in the weather data You may see it take time to request the weather in a real game you d probably want to hide the scene behind a loading screen until the sky updates 212 9 3 9 3 1 CHAPTER 9 Connecting your game to the internet Game networking beyond HTTP HTTP requests are robust and reliable but the latency between making a request and receiving a response can be a little slow for many games HTTP requests are therefore a good way of doing relatively slow paced messages to a server Such aS moves in a turn based game or submission of high scores for any game but something like a multiplayer FPS would need a different approach to networking These different approaches involve various communicat
195. de and value m in the main area Figure 3 10 Setting the color of a material Shooting via instantiating objects 65 Now you can turn the fireball object into a prefab by dragging the object down from Hierarchy into Project just as you did with the enemy prefab Great we have a new prefab to use as a projectile Next up is writing code to shoot using that projectile 3 5 2 Shooting the projectile and colliding with a target Let s make some adjustments to the enemy in order to emit fireballs Because code to recognize the player will require a new script just like Reactive Target was required by the code to recognize the target first create a new script and name that script Player Character Attach this script to the player object in the scene Now open up WanderingAI and add to the code from the following listing Listing 3 11 WanderingAl additions for emitting fireballs SerializeField private GameObject fireballPrefab Add these two fields before private GameObject fireball any methods just like in SceneController The same null if Physics SphereCast ray 0 75f out hit A GameObject hitObject hit transform gameObject i GameObject oe te eae l a M The player is logic as if hitObject GetComponent lt PlayerCharacter gt g pN l detected in the same SceneController if _fireball null wa h l l l y as the target fireball Instantiate fireballPrefab as GameObject g a 7 ae object in Ray
196. de in RayShooter cs using UnityEngine EventSystems Italicized code was already in void Update A script shown for reference if Input GetMouseButtonDown 0 amp amp EventSystem current IsPointerOoverGameObject Vector3 point new Vector3 camera pixelWidth 2 camera pixelHeight 2 0 SN Check that GUI isn t being used Now you can play the game and click the button although it doesn t do anything yet You can watch the tinting of the button change as you mouse over it and click This mouseover and click behavior is a default tint that can be changed for each button but the default looks fine for now You could speed up the default fading behavior Programming interactivity in the UI 129 Fade Duration is a setting in the button component so try decreasing that to 01 to see how the button changes TIP Sometimes the default interaction controls of the UI also interfere with the game Remember the EventSystem object that was created automatically along with the canvas That object controls the UI interaction controls and by default it uses the arrow keys to interact with the GUI You may need to turn off the arrow keys in EventSystem in the settings for EventSystem dese lect the check box Send Navigation Event But nothing else happens when you click the button because you haven t yet linked it up to any code Let s take care of that next 6 3 1 Programming an invisible UlController In general UI i
197. de search functionality for finding attached scripts but that search could be more robust sometimes you still encounter situations where you need 1 1 3 Why is Unity so great 7 to manually inspect everything in the scene in order to find script linkages This doesn t happen often but when it does happen it can be tedious Another disadvantage that can be surprising and frustrating for experienced pro grammers is that Unity doesn t support linking in external code libraries The many libraries available must be manually copied into every project where they ll be used as opposed to referencing one central shared location The lack of a central location for libraries can make it awkward to share functionality between multiple projects This disadvantage can be worked around through clever use of version control systems but Unity doesn t support this functionality out of the box NOTE Difficulty working with version control systems such as Subversion Git and Mercurial used to be a significant weakness but more recent ver sions of Unity work just fine You may find out of date resources telling you that Unity doesn t work with version control but newer resources will describe meta files the mechanism Unity introduced for working with version control systems and which folders in the project do or don t need to be put in the repository To start out with read this page in the documentation http docs unity3d com Manual Externa
198. ding both the material and a light For the material you want to reference the blended skybox material we just created but what s with the light That s so that the scene will also darken when transitioning from sunny to overcast as the Blend value increases we ll turn down the light The directional light in the scene acts as the main light and provides illumina tion everywhere drag that light into the Inspector 200 CHAPTER 9 Connecting your game to the internet NOTE The advanced lighting system called Enlighten in Unity takes the skybox into account in order to achieve realistic results However this light ing approach won t work right with a changing skybox so you may want to turn it off In the Lighting window you can turn off Continuous Baking this term was defined in chapter 7 at the bottom now it will only update when you click the button Set the Blend of the skybox to the middle for an average look and then click Build at the bottom of the Lighting window to bake light maps a folder called Scene is added to your project don t touch that folder When the script starts it initializes the intensity of the light The script will store the starting value and consider that to be full intensity This full intensity will be used later in the script when dimming the light Then the code increments a value every frame and uses that value to adjust the sky Specifically it calls SetOvercast every frame and t
199. discuss other pieces of soft ware but those are treated as optional extras and not core to what you re learning WARNING Unity projects remember which version of Unity they were created in and will issue a warning if you attempt to open them in a different version If you see that warning while opening this book s sample downloads click Continue and ignore it The code listings sprinkled throughout the book generally show what to add or change in existing code files unless it s the first appearance of a given code file don t replace the entire file with subsequent listings Although you can download complete working sample projects to refer to you ll learn best by typing out the code listings and only looking at the working samples for reference Those downloads are available from the publisher s website at www manning com UnityinAction Author Online The purchase of Unity in Action includes free access to a private web forum run by Manning Publications where you can make comments about the book ask technical questions and receive help from the author and from other users To access the forum and subscribe to it point your web browser to www manning com Unityin Action This page provides information on how to get on the forum once you are reg istered what kind of help is available and the rules of conduct on the forum Manning s commitment to our readers is to provide a venue where a meaningful dialogue between individua
200. displayed HUD overlays the main in the editor game scene when playing Figure 6 8 The GUI as seen in the editor left and when playing the game right 6 2 3 Setting up the GUI display 127 displayed in Unity s editor shows the bounds of the screen and UI elements are drawn onto the screen in those positions Great you made a HUD with 2D images displayed over the 3D game One more complex visual setting remains positioning UI elements relative to the canvas Controlling the position of UI elements o Anchor point icon All UI objects have an anchor displayed in the editor as a target X see figure 6 9 An anchor is a flexible way of positioning objects on the UI The Image object DEFINITION The anchor of an object is the point where an object attaches to the canvas or screen It determines what that object s Figure 6 9 The anchor point of an position is measured relative to image object Positions are values like 50 pixels on the X axis But that leaves the question 50 pix els from what This is where anchors come in The purpose of an anchor is that while the object stays in place relative to the anchor point the anchor moves around rela tive to the canvas The anchor is defined as something like center of the screen and then the anchor will stay centered while the screen changes size Similarly setting the anchor to the right side of the screen will keep the object rooted to the right side even
201. don t click the card in the scene because the card back is on top and yov ll select that part instead and then click the Add Component button in the Inspector Select Physics 2D not Physics because that system is for 3D physics and this is a 2D game and then choose a box collider Besides a collider the card needs a script in order to be reactive to the player click ing on it so let s write some code Create a new script called MemoryCard cs and attach this script to the root card object again not the card back The following list ing shows the code that makes the card emit debug messages when clicked Listing 5 1 Emitting debug messages when clicked using UnityEngine using System Collections This function is called a when the object is clicked public class MemoryCard MonoBehaviour public void OnMouseDown Debug Log testing 1 2 3 a 2 ae Just emit a test message to the console for now TIP If you re not in this habit yet organizing your assets into separate folders is probably a good idea create folders for scripts and drag files within the Project view Just be careful to avoid the special folder names Unity responds to Resources Plugins Editor and Gizmos Later in the book we ll go over what some of these special folders do but for now avoid naming any folders with those words Nice we can click on the card now Just like Update OnMouseDown is another function provided by MonoBe
202. dsBox because all the whitebox geometry will be replaced by new art later anyway The first object will be the floor of the scene in Name of the object the Inspector rename the object and lower it to re 5 Y in order to account for the height of the m OStatic box itself figure 4 2 depicts this Then stretch Tag Untagged Layer Defaut YA Transform D a postion xo vos zo potation x0 0210 Scale x 60 YT Position of the floor mon base object remember position the root lowered slightly to Scale cii object at 0 0 0 and then drag objects onto it in account for thickness on X and Z the object along the X and Z axes Repeat these steps to create the walls of the scene You probably want to clean up the Hier archy view by making walls as children of a com few simple lights around the scene so that you positioned and scaled for the floor can see it referring back to chapter 2 create lights by selecting them in the Light submenu of the GameObject menu The level should look something like figure 4 3 once you re done with whiteboxing Set up your player object or camera to move around create the player with a char acter controller and movement scripts refer to chapter 2 if you need a full explana tion Now you can walk around the primitive scene in order to experience your work The Player object A room blocked out with interior walls A light there are several throughout the lev
203. e 2 ot g g gimi c Figure 5 11 Complete Memory game screen including the Start button 5 5 1 Restart button 115 Programming a UlButton component using SendMessage First place the button sprite in the scene drag it up from the Project view Give it a position like 4 5 3 25 10 that will place the button in the top right corner that s 450 pixels to the right and 325 pixels up and move it nearer to the camera so that it ll appear on top of other game objects Because we want to be able to click on this object give it a collider just as with the card object select Add Component gt Physics 2D gt Box Collider NOTE As alluded to in the previous section Unity provides multiple ways to create UI displays including an advanced UI system introduced in the most recent versions of Unity For now we ll build the single button out of standard display objects The next chapter will teach you about the advanced UI func tionality the UI for both 2D and 3D games is ideally built with that system Now create a new script called UIButton cs and assign that script shown in the follow ing listing to the button object Listing 5 13 Code to make a generic and reusable UI button using UnityEngine using System Collections Reference a target object public class UIButton MonoBehaviour sf to intorn about clicks SerializeField private GameObject targetObject SerializeField private string targetMessage pu
204. e game and watch the console while you move the slider or press Enter after typing input Saving settings between plays using PlayerPrefs A few different methods are available for saving persistent data in Unity and one of the simplest is called PlayerPrefs Unity provides an abstracted way that is you don t worry about the details to save small amounts of information that works on all plat forms with their differing filesystems PlayerPrefs aren t too useful for large amounts of data in chapter 11 we ll use other methods to save the game s progress but they re perfect for saving settings PlayerPrefs provide simple commands to get and set named values it works a lot like a hash table or dictionary For example you can save the speed setting by adding the line PlayerPrefs SetFloat speed speed inside the OnSpeedValue meth od of the SettingsPopup script That method will save the float in a value called speed Similarly you ll want to initialize the slider to the saved value Add the following code to SettingsPopup using UnityEngine UI SerializeField private Slider speedSlider void Stare 4 speedSlider value PlayerPrefs GetFloat Speed 1 Note that the get command has both the value to get as well as a default value in case speed wasn t previously saved Although the controls generate debug output they still don t actually affect the game Making the HUD affect the game and vice versa
205. e that moves the character around Programming camera relative movement controls Now that the character model is imported into Unity and we ve written code to con trol the camera view it s time to program controls for moving around the scene Let s program camera relative controls that ll move the character in various directions when arrow keys are pressed as well as rotate the character to face those different directions What does camera relative mean The whole notion of camera relative is a bit nonobvious but very crucial to under stand This is similar to the local versus global distinction mentioned in previous chap ters left points in different directions when you mean left of the local object or left of the entire world In a similar way when you move the character to the left do you mean toward the character s left or the left side of the screen The camera in a first person game is placed inside the character and moves with it SO no distinction exists between the character s left and the camera s left A third person view places the camera outside the character though and thus the camera s left may be pointed in a different direction from the character s left For example they re literally opposite directions if the camera is looking at the front of the character Thus we have to decide what we want to have happen in our specific game and controls setup Although oc
206. e HTML Add the JavaScript code and the HTML tag in the following listing the JavaScript functions go at the end of the lt script gt tag and the HTML button goes at the end of the page s lt body gt Listing 12 3 JavaScript and HTML that enable browser Unity communication function ShowAlert arg ae Display an alert box alert arg SendMessage calls a PERSEA TAN function SendToUnity af function within Unity u getUnity SendMessage Listener RespondToBrowser Hello from the browser gt lt script gt lt input type button value Send to Unity onclick SendToUnity gt C lt body gt lt html gt Open the web page to test this code out To test communication from Unity to the browser the WebTestObject script in Unity will call a function in the browser when you click within Unity try clicking a few times and you ll see an alert box appear in the browser The Application ExternalCall method will run the named JavaScript function Unity also has Application ExternalEval for sending messages to the browser in that case arbitrary snippets of JavaScript are run in the browser rather than calling a defined function Most of the time it s better to call functions to keep JavaScript and Unity compartmentalized but sometimes it s useful to run arbitrary snippets such as this code to reload the page Application ExternalEval location reload JavaScript in the w
207. e Keep track of which private AudioSource inactiveMusic x source Is active vs inactive public float crossFadeRate 1 5f private bool _crossFading ae A toggle to avoid bugs while public float musicVolume Acro SSTG IE Happening set _musicVolume value if musiclSource null amp amp crossFading wusiclSource volume m sicVolums music2Source volume musicVolume DJ Adjust the volume on both music sources public bool musicMute set if musiclSource null musiclSource mute value music2Source mute value public void Startup NetworkService service Debug Log Audio manager starting _network service musiclSource ignoreListenerVolume true music2Source ignoreListenerVolume true musiclSource ignoreListenerPause true music2Source ignoreListenerPause true 244 CHAPTER 10 Playing audio sound effects and music soundVolume 1f musicVolume 1f _activeMusic musiclSource a Initial i _inactiveMusic music2Source nitiatize one as tne active AudioSource status ManagerStatus Started private void PlayMusic AudioClip clip Galia aoroutine when if _crossFading return Eo changing music StartCoroutine CrossFadeMusic claip private IEnumerator CrossFadeMusic AudioClip clip _CrossFading true _inactiveM sic clip clip _inactiveMusic volume 0 _inactiveMusic Play Float scaledRate crossFadeRate _
208. e are actually two waveforms in the file one Should stereo sounds be T inspector I yy yas converted to mono ding Import Settings Ready the sound by loading ria Open it ahead of time and or NF Force To Mono LJ i Data format to store the _ E T E ore a possibly compressed audio Preload Audio Data 8 in Choose PCM or Vorbis A slider for Quality will appear if you choose Vorbis format Default D a oO Load Type Decompress On Load r a X Compression Format PCM Sample Rate Setting Preserve Sample Rate Figure 10 1 Import settings for audio files di Load all at once or stream this audio 226 10 2 10 2 1 CHAPTER 10 Playing audio sound effects and music each for the left and right ears speakers To save on file size you might want to halve the audio information so that the same waveform is sent to both speakers rather than separate waves sent to the left and right speakers Next are check boxes for Load In Background and Preload Audio Data The pre load setting relates to balancing playback performance and memory usage preload ing audio will consume memory while the sound waits to be used but will avoid having to wait to load Loading audio in the background of the program will allow the pro gram to keep running while the audio is loading this is generally a good idea for long music clips so that the program won t freeze But this means the audio won t start play in
209. e beginning of the Update method was gutted because that code was handling keyboard movement Notice that this new code has two main if statements one that runs when the mouse clicks and one that runs when a target is set When the mouse clicks set the target according to where the mouse clicked Here s yet another great use for raycasting to determine which point in the scene is under the mouse cursor The target position is set to where the mouse hits As for the second conditional first rotate to face the target Quaternion Slerp rotates smoothly to face the target rather than immediately snapping to that rotation Then transform the forward direction from the player s local coordinates to global coordinates in order to move forward Finally check the distance between the player and the target if the player has almost reached the target decrement the movement speed and eventually end movement by removing the target position Exercise Turn off jump control Currently this script still has the jump control from RelativeMovement The player still jumps when the spacebar is pressed but there shouldn t be a jump button with point and click movement Here s a hint adjust the code inside the if hitGround conditional branch This takes care of moving the player using mouse controls Play the game to test it out Next let s make devices operate when clicked on OPERATING DEVICES USING THE MOUSE In chapter 8 and he
210. e class we programmed change this name return pluginClass as needed private static AndroidJavaObject _unityActivity private static AndroidJavaObject GetUnityActivity if wnityActivity mull AndroidJavaClass unityPlayer new a AndroidJavaClass com unity3d player UnityPlayer unityActivity Unity creates an unityPlayer GetStatic lt AndroidJavaObject gt currentActivity activity for the Android app return unityActivity endif public static float TestNumber float val Of if Application platform RuntimePlatform IPhonePlayer val _TestNumber if UNITY ANDROID if Application isEditor amp amp _pluginError null val GetPluginClass CallStatic lt int gt getNumber Nandit bs Call to functions return val in plugin jar public static string TestString string test string val if Application platform RuntimePlatform IPhonePlayer Val Tesesering test if UNITY ANDROID if Application isEditor amp amp pluginError null val GetPluginClass CallStatic lt string gt getString test endif return val You ll notice most of the additions happen inside UNITY_ANDROID platform defines as explained earlier in the chapter these compiler directives cause code to apply only to certain platforms and are omitted on other platforms Whereas the iOS code wasn t doing anything that would break on other platforms it won t do anythi
211. e developed by The Fullbright Company MOBILE IOS ANDROID Unity can also deploy games to mobile platforms like iOS iPhones and iPads and Android phones and tablets Here are a few examples of mobile games in different genres Dead Trigger figure 1 4 a first person shooter developed by Madfinger Games Bad Piggies figure 1 5 a physics puzzle game developed by Rovio Tyrant Unleashed figure 1 6 a collectible card game developed by Synapse Games CONSOLE PLAYSTATION XBOX WII Unity can even deploy to game consoles although the developer must obtain licensing from Sony Microsoft or Nin tendo Because of this requirement and Unity s easy cross platform deployment console games are often available on desktop computers as well Here are a couple examples of console games in different genres Assault Android Cactus figure 1 7 an arcade shooter developed by Witch Beam The Golf Club figure 1 8 a sports simulation developed by HB Studios As you can see from these examples Unity s strengths definitely can translate into commercial quality games But even with Unity s significant advantages over other game development tools newcomers may have a misunderstand ing about the involvement of program ming in the development process Unity Figure 1 3 Gone Home Figure 1 4 Dead Trigger Figure 1 6 Tyrant Unleashed 1 2 How to use Unity 9 is often portrayed as simp
212. e directly for them to install through iTunes but it s more convenient to use TestFlight https developer apple com testflight to han dle distributing and installing ad hoc builds SETTING UP ANDROID BUILD TOOLS 8 0 0 Unity Preferences Unlike iOS apps Unity can generate the External Tools ternal Scr r APK Android Application Package Tapae directly This requires pointing Unity to Image application Caors Revision Control Diff Merge Apple File Merge the Android SDK which includes the nec YS Android SDK Location Browse essary compiler Download the Android GI Cache 7 SDK from the Android website then Cache Server choose this file location in Unity s prefer Click this menu in the External Tools ences see figure 12 5 You can download section of Unity s preferences the SDK nee http developer android Figure 12 5 Unity preference setting to point com sdk index html to Android SDK 12 3 2 Building for mobile apps iOS and Android 289 After setting the Android SDK in Unity s preferences you need to specify the Bun dle Identifier just as you did for iOS You ll find Bundle Identifier in Player Settings set it to com companyname productname as explained in section 12 3 1 Then click Build to start the process As with all builds it ll first ask where to save the file Then it ll create an APK file in that location Now that you have the app package you mus
213. e frameworks are available to streamline the use of touch input For example use FingerGestures http fingergestures fatalfrog com 286 12 3 1 CHAPTER 12 Deploying your game to players devices All right with those caveats out of the way I ll explain the overall build process for both iOS and Android Keep in mind that these platforms occasionally change the details of the build process Setting up the build tools Mobile devices are all separate from the computer you re developing on and that sep arateness makes the process of building and deploying to devices slightly more com plex You ll need to set up a variety of specialized tools before you can click Build SETTING UP IOS BUILD TOOLS Ata high level the process of deploying a Unity game on iOS requires first building an Xcode project from Unity and then building the Xcode project into an IPA iOS App Package using Xcode Unity can t build the final IPA directly because all iOS apps have to go through Apple s build tools That means you need to install Xcode Apple s programming IDE including the 10S SDK WARNING That means you have to be working on a Mac Xcode only runs on OS X Developing a game within Unity can be done on either Windows or Mac but building the iOS app must be done on a Mac Get Xcode from Apple s website in the developer section https developer apple com xcode downloads NOTE You need membership in the Apple Develope
214. e manipulated in code and anne that s precisely what this script does As it did with CharacterController and custom scripts in previous chapters the GetComponent method returns other components on the same object so we use it to reference the SpriteRenderer object The sprite property of SpriteRenderer can be set to any sprite asset so this code sets that property to the Sprite variable declared at the top which we filled with a sprite asset in the editor Well that wasn t too hard But it s only a single image we have four different images to use so now delete the new code from listing 5 3 it was only a quick demon stration of how the technique works to prepare for the next section Setting the image from an invisible SceneController Recall in chapter 3 how we created an invisible object in the scene to control spawn ing objects We re going to take that approach here as well using an invisible object to 106 CHAPTER 5 Building a Memory game using Unity s new 2D functionality control more abstract features that aren t tied to any specific object in the scene First create an empty GameObject remember select menu GameObject gt Create Empty Then create a new script SceneController cs in the Project view and drag this script asset onto the controller GameObject Before writing code in the new script first add the contents of the next listing to the MemoryCard script instead of what you saw in listing 5 3 L
215. e same two steps 1 Import images if needed set them to Sprite 2 Drag the sprites into the scene To accomplish these steps first drag the images into Project view to import them and then in the Inspector change their Texture Type setting to Sprite 2D And UI 6 2 6 2 1 Setting up the GUI display 123 O T LJ close enemy gear popup This image will be This image will be This image will be This image will be a the close button the score display in the settings button in scaled background on the pop up the top left corner the top right corner of the pop up Figure 6 3 Images that are needed for this chapter s project WARNING The Texture Type setting defaults to Texture in 3D projects and to Sprite in 2D projects If you want sprites in a 3D project you need to adjust this setting manually Get all the needed images from the sample download see figure 6 3 and then import the images into your project Make sure all the imported assets are set to Sprite you ll probably need to adjust Texture Type in the settings displayed after importing These sprites comprise the buttons score display and pop up that you ll create Now that the images are imported let s put these graphics onto the screen Setting up the GUI display The art assets are the same kind of 2D sprites we used in chapter 5 but the use of those assets in the scene is a bit different Unity provides special tools to make the images a HUD that s d
216. e term I first learned but others use grayboxing and that term is just as accepted The actual color used varies anyway similar to how blueprints aren t necessarily blue Whiteboxing explained Blocking out the scene with blank geometry serves a couple of purposes First this process enables you to quickly build a sketch that will be progressively refined over time This activity is closely associated with level design and or level designers 4 2 2 Building basic 3D scenery whiteboxing 73 DEFINITION Level design is the discipline of planning and creating scenes in the game or levels A level designer is a practitioner of level design As game development teams have grown in size and team members have become more specialized a common level building workflow is for the level designer to create a first version of the level through whiteboxing This rough level is then handed over to the art team for visual polish But even on a tiny team where the same person is both designing levels and creating art for the game this workflow of first doing whiteboxing and then polishing the visuals generally works best you have to start somewhere after all and whiteboxing gives a clear foundation on which to build up the visuals A second purpose served by whiteboxing is that the level reaches a playable state very quickly It may not be finished indeed a level right after whiteboxing is far from finished but this rough version is functio
217. e to manage provisioning profiles in iOS Dev Center Developer Support Center Select your app in the project list on the left side of Xcode Several tabs relevant to the selected project will appear go to Build Settings and scroll down to Code Signing to set the provisioning profiles see figure 12 3 Also make sure Scheme Destination at Select your Scheme Destination may need to be set app here to iOS Device instead of the simulator E Unity iPhone P j E unity ehane im Device Ueery iPhene Ready Teday an 11 33 AM Set provisioning aoe By unyon fil h a E unipy hone General Capabilities Inte Build Settings Bid Fhovet pro l es ere Basic Aliy Combined Levels Oj Cede Signing e aa You probably want Debug OS Developer the Debug identity Any ii feet Ok Crevelcguer D5 Disrribatien oes 99 aes anne ey set to iOS Developer Sede Santen MeNi Paes Fos and the Release identity H f ing Mogi e e e e Provesigning Profile ct set to iOS Distribution Figure 12 3 Provisioning profile settings in Xcode 288 CHAPTER 12 Deploying your game to players devices paces Secon Click Distribute after Ei Ie selecting the archive Look in the PE Selec thet method of disribatior Archives tab of the Organizer vadar Distribute window Subenit to the IOS App Store Sign package and adhe application to the H05 App nee Menu wizard will C tave for Enterp
218. e void OnLogged string response Debug Log response 220 9 4 2 Write the file r CHAPTER 9 Connecting your game to the internet Finally make use of that code by adding a checkpoint script to the trigger volume in the scene Create a script called Checkpoint Irigger put that script on the trigger vol ume and enter the contents of the next listing Listing 9 19 CheckpointTrigger script for the trigger volume using UnityEngine using System Collections public class CheckpointTrigger MonoBehaviour eee eile ane Track if the checkpoint has a already been triggered private bool triggered void OnTriggerEnter Collider other if triggered return ae Call to send data Managers Weather Logweather identifier triggered true An Identifier slot will appear in the Inspector name it something like checkpointl Run the code and data will be sent when you enter the checkpoint The response will indicate an error though because there s no script on the server to receive the request That s the last step in this section Server side code in PHP The server needs to have a script to receive data sent from the game Coding server scripts is beyond the scope of this book so we won t go into detail here We ll just whip up a PHP script because that s the easiest approach Create a text file in htdocs or wherever your web server is located and name the file api php see listing 9
219. eb page can also send a message to Unity click the button on the web page and you ll see the changed message displayed in Unity The button s HTML tag links to a JavaScript function and that function calls SendMessage on the Unity instance This method calls a named function on a named object within Unity the first parameter is the name of the object the second parameter is the name of the method and the third parameter is a string to pass in while calling the method List ing 12 3 calls RespondToBrowser from the WebTestObject script 12 3 Building for mobile apps iOS and Android 285 NOTE WebGL builds can also communicate with JavaScript in the web page and the code to do so is almost exactly the same Indeed it 7s exactly the same for communicating from Unity to the page As for the other direction from the page to Unity the SendMessage method has the same parameters but no longer requires the u getUnity prefix That wraps up browser communication for web builds there s one more platform or rather set of platforms to discuss building apps for mobile apps Building for mobile apps iOS and Android Mobile apps are another important build target for Unity My gut impression totally not scientific is that mobile games are the largest number of commercial games cre ated using Unity DEFINITION Mobile refers to handheld computing devices that people carry around The designation started with smartphones but now i
220. ec tion for the three axes and this coordinate system moves around with the object This is referred to as local coordinates The overall 3D scene also has its own origin point and its own direction for the three axes and this coordinate system never moves This is referred to as global coordinates Thus when you specify local or global for the Rotate method you re telling it whose X Y and Z axes to rotate around see fig ure 2 14 If you re new to 3D graphics this is somewhat of a mind bending concept The dif ferent axes are depicted in figure 2 14 notice how left to the plane is a different direction than left to the world but the easiest way to understand local and global is through an example First select the player object and then tilt it a bit something like 30 for X rota tion This will throw off the local coordinates so that local and global rotations will look different Now try running the Spin script both with and without Space World added to the parameters if it s too hard for you to visualize what s happening try removing the spin component from the player object and instead spin a tilted cube placed in front of the player You ll see the object rotating around different axes when you set the command to local or global coordinates Script component for looking around MouseLook Now you ll make rotation respond to input from the mouse that is rotation of the object this script is attached to
221. ect for all other grid slots Because the origi nal card already exists in the scene if you copied the card at every iteration of the loop you d end up with one too many cards in the scene The cards are then posi tioned by offsetting them according to the number of iterations through the loop TIP Just as when moving 3D objects 2D objects can be moved by manipulat ing transform position to different points on the screen and this position could be incremented repeatedly in Update But as you saw when moving the first person player collision detection isn t applied when adjusting transform position directly To move 2D objects with collision detection you ll probably want to adjust rigidbody2D velocity after assigning Physics2D components Run the code now and a grid of eight cards will be created as depicted in figure 5 9 The last step in preparing the grid of cards is to organize them into pairs instead of them being random Displaying the various card images 109 Cig E oj o o 5 3 4 Shuffling the cards Instead of making every card random we ll define an array of all the card IDs num bers 0 through 3 twice for a pair of each card and then shuffle that array We ll then use this array of card IDs when setting cards rather than making each one random Figure 5 9 The grid of eight cards that are revealed when you click on them The following listing shows the code Listing 5 7 Placing cards from a shuff
222. ect is par ented to the player object remember when we did that in the Hierarchy view so even though it rotates vertically independently from the player the camera rotates horizontally along with the player Polishing the finished script Use the RequireComponent method to ensure that other components needed by the script are also attached Sometimes other components are optional that is code that says If this other component is also attached then but sometimes you want to make the other components mandatory Add the method to the top of the script in order to enforce that dependency and give the required component as a parameter Similarly if you add the method AddComponentMenu to the top of your scripts that script will be added to the component menu in Unity s editor Tell the command the name of the menu item you want to add and then the script can be selected when you click Add Component at the bottom of the Inspector Handy A script with both methods added to the top would look something like this using UnityEngine using System Collections RequireComponent typeof CharacterController AddComponentMenu Control Script FPS Input public class FPSInput MonoBehaviour Listing 2 13 shows the full finished script Along with the small adjustments to how components are set up on the player the player can walk around the room Even with 2 6 Summary 45 the gravity variable being appli
223. ects are all imported and ready to use Playing sound effects Now that you have some sound files added to the project you naturally want to play the sounds The code for triggering sound effects isn t terribly hard to understand but the audio system in Unity does have a number of different parts that must work in concert Explaining what s involved audio clip vs source vs listener Although you might expect that playing a sound is simply a matter of telling Unity which clip to play it turns out that you must define three different parts in order to play sounds in Unity AudioClip AudioSource and AudioListener The reason for breaking apart the sound system into multiple components has to do with Unity s sup port for 3D sounds the different components tell Unity positional information that it uses for manipulating 3D sounds Playing sound effects 227 2D vs 3D sound Sounds in games can be either 2D or 3D 2D sounds are what you re already familiar with standard audio that plays normally The moniker 2D sound mostly means not 3D sound 3D sounds are specific to 3D simulations and may not already be familiar to you these are sounds that have a specific location within the simulation Their volume and pitch are influenced by the movement of the listener For example a sound effect triggered in the distance will sound very faint Unity supports both kinds of audio and you decide if an audio source should pla
224. ed the bench a collider or you is static can walk through the bench Figure 4 15 Adjust import settings for the 3D model That takes care of the imported mesh Now for the texture when Unity imported the FBX file it also created a material for the bench This material defaults to blank just like any new material so assign the bench texture the image in figure 4 16 in the same way that you assigned bricks to the walls earlier drag the texture image into Proj ect to import it into Unity and then drag the imported texture onto the texture slot of the bench material The image looks somewhat odd with different parts of the image appearing on different parts of the bench the model s texture coordinates were edited to define this mapping of image to mesh DEFINITION Texture coordinates are an extra set of values for each vertex that assigns polygons to areas of the texture image Think about it like wrapping paper the 3D model is the box being wrapped the texture is the wrapping paper and the texture coordinates represent where on the wrapping paper each side of the box will go NOTE Even if you don t want to model the bench you may want to read the detailed explanation of texture coordinates in appendix C The concept of tex ture coordinates as well as other related terms like UVs and mapping can be useful to know when programming games New materials are often too shiny so you may want to reduce the Smoothness
225. ed Pi movement along an axis movement Time deltaTime local to global NG movement transform TransformDirection movement coordinates _charController Move movement R3 Tell the CharacterController to move by that vector 2 5 4 Keyboard input component first person controls 43 This code excerpt introduces several new concepts The first concept to point out is the variable for referencing the CharacterController This variable simply creates a local reference to the object code object that is not to be confused with scene objects multiple scripts can have references to this one CharacterController instance That variable starts out empty so before you can use the reference you need to assign an object to it for it to refer to This is where Get Component comes into play that method returns other components attached to the same GameObject Rather than pass a parameter inside the parentheses you use the C syntax of defining the type inside angle brackets lt gt Once you have a reference to the CharacterController you can call Move on the controller Pass in a vector to that method similar to how the mouse rotation code used a vector for rotation values Also similar to how rotation values were limited use Vector3 ClampMagnitude to limit the vector s magnitude to the movement speed the clamp is used because otherwise diagonal movement would have a greater magni tude than movement directly along an
226. ed you can still use this script for flying movement by setting Gravity to 0 in the Inspector Listing 2 13 The finished FPSInput script using UnityEngine using System Collections RequireComponent typeof CharacterController AddComponentMenu Control Script FPS Input public class FPSInput MonoBehaviour public float speed 6 0f public float gravity 9 8f private CharacterController _charController void Start _CharControll r GetComponent lt CharacterController gt void Update float deltaX Input GetAxis Horizontal speed float deltaZ Input GetAxis Vertical speed Vector3 movement new Vector3 deltax 0 deltaZ movement Vector3 ClampMagnitude movement speed movement y gravity movement Time deltaTime movement transform TransformDirection movement _charController Move movement Congratulations on building this 3D project We covered a lot of ground in this chap ter and now you re well versed in how to code movement in Unity As exciting as this first demo is it s still a long way from being a complete game After all the project plan described this as a basic FPS scene and what s a shooter if you can t shoot So give yourself a well deserved pat on the back for this chapter s project and then get ready for the next step Summary In this chapter you learned that 3D coordinate space is defined by X Y and Z axes O
227. eed Time deltaTime g 8 p This function is called when another object na collides with this trigger void OnTriggerEnter Collider other PlayerCharacter player other GetComponent lt PlayerCharacter gt 1 if player null Debug Log Player hit Check if the other object is a PlayerCharacter Destroy this gameObject The crucial new bit to this code is the OnTriggerEnter method That method is called automatically when the object has a collision such as colliding with the walls or with the player At the moment this code won t work entirely if you run it the fireball will fly forward thanks to the Translate line but the trigger won t run queuing up a new fireball by destroying the current one There need to be a couple of other adjustments made to components on the fireball object The first change is making the collider a trigger To adjust that click the Is Trigger check box in the Sphere Collider component 3 5 3 Shooting via instantiating objects 67 TIP A Collider component set as a trigger will still react to touching overlap ping other objects but it will no longer stop other objects from physically passing through The fireball also needs a Rigidbody a component used by the physics system in Unity By giving the fireball a Rigidbody component you ensure that the physics system is able to register collision triggers for that object In the Inspector click Add Compo nent a
228. efabs What is a prefab Prefabs are a flexible approach to visually defining interactive objects In a nutshell a prefab is a fully fleshed out game object with components already attached and set up that doesn t exist in any specific scene but rather exists as an asset that can be cop ied into any scene This copying can be done manually to ensure that the enemy object or other prefab is the same in every scene More important though prefabs can also be spawned from code you can place copies of the object into the scene using commands in scripts and not only by doing it manually in the visual editor DEFINITON An asset is any file that shows up in the Project view these could be 2D images 3D models code files scenes and so on I mentioned the term asset briefly in chapter 1 but I didn t emphasize it until now The term for one of these copies of a prefab is an instance analogous to how the word instance refers to a specific code object created from a class Try to keep the terminol ogy straight prefab refers to the game object existing outside of any scene whereas instance refers to a copy of the object that s placed in a scene DEFINITION Also analogous to object oriented terminology instantiate is the action of creating an instance Creating the enemy prefab To create a prefab first create an object in the scene that will become the prefab Because our enemy object will become a prefab we ve already done thi
229. el Figure 4 3 Whitebox level of the floor plan in figure 4 1 4 3 Texture the scene with 2D images 75 and test it out And that s how you do whiteboxing Pretty simple but all you have right now is blank geometry so let s dress up the geometry with pictures on the walls Exporting whitebox geometry to external art tools Much of the work when adding visual polish to the level is done in external 3D art applications like Blender Because of this you may want to have the whitebox geometry in your art tool to refer to By default there s no export option for primitives laid out within Unity But third party scripts are available that add this functionality to the editor Most such scripts allow you to select the geometry in the scene and then hit an Export button chapter 1 mentioned that scripts can customize the editor These custom scripts usually export geometry as an OBJ file OBJ is one of several file types discussed later in this chapter On the Unity3D website click the search button and type obj exporter Or you can go here for one example http wiki unity3d com index php title ObjExporter Texture the scene with 2D images The level at this point is a rough sketch It s playable but clearly a lot more work needs to be done on the visual appearance of the scene The next step in improving the look of the level is applying textures DEFINITION A fexture is a 2D image being used to enhance 3D graphics That s
230. em to allow other code to change which item is equipped That method equips an item if it isn t already equipped or unequips if that item is already equipped Finally in order for the player to equip an item add that functionality to the UI The following listing will add a row of buttons for that purpose Listing 8 21 Equip functionality added to BasicUl foreach string item in itemList ae Italicized code was already in the script shown here for reference 190 8 4 3 CHAPTER 8 Adding interactive devices and items within the game int count Managers Inventory GetItemCount item GUI Box new Rect posxX posY width height item n 4 count posX width buffer Display the currently string equipped Managers Inventory equippeditem ea equipped tem if equipped null B posxX Screen width width buffer Texture2D image Resources Load Icons equipped as Texture2D GUI Box new Rect posxX posY width height new GUIContent Equipped image posx 10 posY height buffer Loop through all items a ah to make buttons foreach string item in itemList if GUI Button new Rect posxX posY width height Equip item Managers Inventory EquipItem item ne Run the contained code if the button is clicked posxX width buffer GUI Box is used again to display the equipped item But that element is noninterac tive so the row of Equip bu
231. em code frameworks CHAPTER 6 Putting a 2D GUI in a 3D game Drag the side of the Scene view to change the size of the screen The Canvas scales with it and the images stay positioned at their anchors in the corners Figure 6 11 Anchors stay in place while the screen changes corners while the canvas changes size As figure 6 11 shows these UI elements are now rooted in place while the screen moves TIP Anchor points can adjust scale as well as position We re not going to explore that functionality in this chapter but each corner of the image can be rooted to a different corner of the screen In figure 6 11 the images didn t change size but we could adjust the anchors so that when the screen changes size the image stretches with it All of the visual setup is done so it s time to program interactivity Programming interactivity in the UI Before you can interact with the UI you need to have a mouse cursor If you recall this game adjusted Cursor settings in the Start method of the RayShooter code Those settings lock and hide the mouse cursor a behavior that works for the controls in an FPS game but that interferes with using the UI Remove those lines from Ray Shooter cs so that you can click on the HUD As long as you have RayShooter cs open you could also make sure not to shoot while interacting with the GUI The following listing shows the code for that Listing 6 2 Adding a GUI check to the co
232. ems new List lt string gt ine Initialize the empty item list status ManagerStatus Started private void DisplayItems string itemDisplay Items foreach string item in items itemDisplay item AL Print console message of the current inventory Debug Log itemDisplay public void AddItem string name _ items Add name AL Other scripts can t manipulate the item list directly but can call this DisplayItems Two key additions were made to InventoryManager One we added a List object to store items in Two we added a public method AddItem that other code can call This function adds the item to the list and then prints the list to the console Now let s make a slight adjustment in the CollectibleItem script to call the new AddItem method see the following list Listing 8 15 Using the new InventoryManager in Collectibleltem void OnTriggerEnter Collider other Managers Inventory AddItem name Destroy this gameObject Managing inventory data and game state 185 Now when you run around collecting o Items energy health ore health energy ore key items you should see your inventory grow Unity Engine Debug LonOhiect ing in the console messages This is pretty Figure 8 6 Console message with multiples of cool but it does expose one limitation of Pe amie em Eee nen wee List data structures as you collect multi ples of the same type of item such a
233. ems within the game 167 8 1 Creating doors and other devices 168 Doors that open and close on a keypress 168 Checking distance and facing before opening the door 170 Operating a color changing monitor 171 8 2 Interacting with objects by bumping into them 172 Colliding with physics enabled obstacles 173 Triggering the door with a pressure plate 174 Collecting items scattered around the level 176 8 3 Managing inventory data and game state 178 Setting up player and inventory managers 178 Programming the game managers 180 Storing inventory in a collection object List vs Dictionary 184 8 4 Inventory UI for using and equipping items 186 Displaying inventory items in the UI 186 Equipping a key to use on locked doors 188 Restoring the player s health by consuming health packs 190 8 5 Summary 191 PARTS STRONG FINISH iscswocdesiesdostevicsiosdoscastessessanas L93 Connecting your game to the internet 195 9 1 Creating an outdoor scene 197 Generating sky visuals using a skybox 197 Setting up an atmosphere that s controlled by code 198 9 2 Downloading weather data from an internet service 201 Requesting WWW data using coroutines 203 Parsing XML 207 Parsing JSON 209 Affecting the scene based on Weather Data 210 9 3 Adding a networked billboard 212 Loading images from the internet 212 Displaying images on the billboard 214 Caching the downloaded image for reuse 216 9 4 Posting data to a web server 21
234. en have 9 somewhere in the name such as 9 slice 9 patch scale 9 to indicate the 9 sections of the image After you switch to a sliced image Unity may display an error in the component set tings complaining that the image doesn t have a border That s because the popup sprite doesn t have the nine sections defined yet To set that up first select the popup sprite in the Project view In the Inspector you should see a Sprite Editor button see figure 6 14 click that button and the Sprite Editor window will appear Cison M poreenor m to open a window and popup Import Settings os e oy g Seen edit the sprite s borders Texture Type Lipnie PD ares Wa f Sprite Mode Lung LE packing Tag Type in LR BT Left Right CUO pen Bottom Top numbers to adjust the green border slices For the pop up sprite set all borders to 12 pixels Generate Mip Mapi GA Click the Sprite Editor button Figure 6 14 Sprite Editor button in the Inspector and a pop up window 132 CHAPTER 6 Putting a 2D GUI in a 3D game In the Sprite Editor you can see green lines that indicate how the image will be sliced Initially the image won t have any border that is all of the Border settings are 0 Increase the border width of all four sides which will result in the border shown in fig ure 6 14 Because all four sides Left Right Bottom and Top have the border set to 12 pixels wide the border lines will overla
235. ender are often unexpected as is the mouse functionality For example though the use of the middle mouse to manipulate the camera makes intuitive sense selecting elements in the scene is done with the right mouse button in most applications the left mouse button selects things Even weirder a box selec tion is done by pressing B and then left clicking and dragging You add to the selection as opposed to replace the selection by holding Shift while clicking on elements and you clear the selection by pressing A These are the basic controls for using Blender so now we ll see some functions for editing the model To start with scale the cube into a long thin plank Select every vertex of the model be sure to also select vertices on the side of the object facing away and then switch to the Scale tool Click drag the blue arrow for the Z axis to scale down vertically and then click drag the green arrow for Y to scale out sideways see figure C 5 Long thin plank that will be top of bench Blue arrow of the Transform Gizmo 1 Cube FigureC 5 Meshscaled Edit Mode es ace into a long thin plank Building the mesh geometry 311 Delete Add Duplicate Select the thin polygons on either end of the bench then choose Extrude Region Extrude Individual i ale i in the Mesh menu UV Unwrap Snap Mirror Only move the mouse Tenim out slightly in order Undo History Alt Cmd Z to extrude small Redo Shift Cmd Z
236. ent doc new XmlDocument doc LoadxXml data e pS Parse XML into a XmlNode root doc DocumentElement searchable structure XmlNode node root SelectSingleNode clouds B i g AL Pull out a single string value node Attributes value Value cloudValue Convert ToInt32 value 100f node from the data Debug Log Value cloudValue Messenger Broadcast GameEvent WEATHER UPDATED 7 DS Broadcast message to status ManagerStatus Started inform the other Scripts You can see that the most important changes were made inside OnXMLDataLoaded Previously this method simply logged the data to the console to verify that data was coming through correctly This listing adds a lot of code to parse the XML First create a new empty XML document this is an empty container that you can fill with a parsed XML structure The next line parses the data string into a structure contained by the XML document Then we start at the root of the XML tree so that everything can search up the tree in subsequent code At this point you can search for nodes within the XML structure in order to pull out individual bits of information In this case lt clouds gt is the only node we re 9 2 3 Downloading weather data from an internet service 209 interested in First find that node in the XML document and then extract the value attribute from that node This data defines the cloud value as a 0 100 integer but we re going
237. er MonoBehaviour private Camera _camera void Start 4 _camera GetComponent lt Camera gt void Update if Input GetMouseButtonDown 0 Vector3 point new Vector3 _camera pixelWidth 2 _camera pixelHeight 2 0 Ray ray _camera ScreenPointToRay point R CH1 Hit e a Launch a coroutine if Physics Raycast ray out hit J in response to a hit StartCoroutine SphereIndicator hit point Coroutines use This function is mostly the same a raycasting code from listing 3 1 S lEnumerator functions private IEnumerator SphereIndicator Vector3 pos GameObject sphere GameObject CreatePrimitive PrimitiveType Sphere sphere transform position pos yield return new WaitForSeconds 1 ae The yield keyword tells Destroy lephetel coroutines where to pause A Remove this GameObject and clear its memory The new method is SphereIndicator plus a one line modification in the existing Update method This method creates a sphere at a point in the scene and then removes that sphere a second later Calling SphereIndicator from the raycasting code ensures that there will be visual indicators showing exactly where the ray hit This function is defined with IEnumerator and that type is tied in with the concept of coroutines Technically coroutines aren t asynchronous asynchronous operations don t stop the rest of the code from running think of downloading an image in the script
238. er that you can move tabs around in Unity and dock them wherever you like in order to organize the interface I like to dock the Anima tor right next to the Scene and Game windows Initially there are only two default nodes for Entry and Any State You re not going to use the Any State node Instead you ll drag in animation clips to create new nodes In the Project view click the arrow on the side of the model asset to expand that asset and see what it contains Among the contents of this asset are the animation clips you defined see figure 7 17 so drag those clips into the Animator view Don t bother with the walking animation that could be useful for other projects and drag in idle run and jump Right click on the Idle node and select Set As Layer Default State That node will turn orange while the other nodes stay gray the default animation state is where the network of nodes starts before the game has made any changes You ll need to link the nodes together with lines indicating transitions between animation states right click on a node and select Make Transition in order to start dragging out an arrow that you can click on another node to connect Connect nodes in the pattern shown in figure 7 16 be sure to make transitions in both directions for most nodes but not from jump to run These transition lines determine how the animation states connect to each other and control the changes from one state to another during the game
239. ere is a read only getter again this time used to determine whether another card can be revealed the player can only reveal another card when there aren t already two cards revealed We also need to modify MemoryCard cs to call the currently empty method in order to inform SceneController when a card is clicked Modify the code in Memory Card cs according to the following listing Making and scoring matches 111 Listing 5 9 MemoryCard cs modifications for revealing cards H ublic void OnMouseDown Notify the T l Check the controller s if cardBack activeSelf amp amp controller canReveal tne l A canReveal property to when this cardBack SetActive false make sure only two cards card is controller CardRevealed this are revealed at a time revealed public void Unreveal ne A public method so that SceneController cardBack SetActive true can hide the card again by turning card_back back on If you were to put a debug statement inside CardRevealed in order to test the com munication between objects you d see the test message appear whenever you click a card Let s first handle one revealed card 5 4 1 Storing and comparing revealed cards The card object was passed into CardRevealed so let s start keeping track of the revealed cards Write the code from the following listing Listing 5 10 Keeping track of revealed cards in SceneController public void CardRevealed MemoryCard ca
240. ered the Last Lecture shortly before he passed away in 2008 I ve taught classes at several schools and I ve always wanted to write a book about game development XVii xviii PREFACE In many ways what I ve written here is the book I wish had existed back when I was first learning Unity Among Unity s many virtues is the availability of a huge treasure trove of learning resources but those resources tend to take the form of unfocused fragments like the script reference or isolated tutorials and require a great deal of digging to find what you need Ideally I d have a book that wrapped up everything I needed to know in one place and presented it in a clear and logically constructed manner so now I m writing such a book for you I m targeting people who already know how to program but who are newcomers to Unity and possibly new to game development in general The choice of projects reflects my experience of gaining skills and confidence by doing a variety of freelance projects in rapid succession In learning to develop games using Unity you re setting out on an exciting adven ture For me learning how to develop games meant putting up with a lot of hassles You on the other hand have the advantage of a single coherent resource to learn from this book acknowledgments I would like to thank Manning Publications for giving me the opportunity to write this book The editors I worked with including Robin de Jongh a
241. erspersed throughout the existing movement script Pick out the _animator lines in order to find additions to make in your code The script needs a reference to the Animator component and then the code sets values either floats or Booleans on the animator The only somewhat nonobvious bit of code is the condition _contact null before setting the Jumping Boolean That condition prevents the animator from playing the jump animation right from the start Even though the character is technically falling for a split second there won t be any collision data until the character touches the ground for the first time And there you have it Now we have a nice third person movement demo with camera relative controls and character animation playing Summary In this chapter you ve learned that Third person view means the camera moves around the character instead of inside the character Simulated shadows like real time shadows and lightmaps improve the graphics Controls can be relative to the camera instead of relative to the character You can improve on Unity s ground detection by casting a ray downward Sophisticated animation set up with Unity s animator controller results in lifelike characters Adding interactive devices and items within the game This chapter covers Programming doors that the player can open triggered with a keypress or collision Enabling physics simulations that scatter a stack of boxes
242. ertical rotation Notice that an enum is used to choose horizontal or vertical rotation for the Mouse Look script Defining an enum data structure allows you to set values by name rather than typing in numbers and trying to remember what each number means is 0 hori zontal rotation Is it 1 If you then declare a public variable typed to that enum that will display in the Inspector as a drop down menu see figure 2 15 which is useful for selecting settings Remove the Spin component the same way you removed the capsule collider ear lier and attach this new script to the player object instead Use the Axes menu to switch between code branches while working through the code With the horizontal vertical rotation setting in place you can fill in code for each branch of the conditional Y G M Mouse Look Script x Script MouseLook Figure 2 15 The Inspector displays public Axes enum variables as a drop down menu Script component for looking around MouseLook 35 2 4 1 Horizontal rotation that tracks mouse movement The first and simplest branch is horizontal rotation Start by writing the same rotation command you used in listing 2 1 to make the object spin Don t forget to declare a public variable for the rotation speed declare the new variable after axes but before Update and call the variable sensitivityHor because speed is too generic a name once you have multiple rotations involved Increase the value of the var
243. es MouseX transform Rotate 0 Input GetAxis Mouse X sensitivityHor 0 Clamp the vertical angle between else if axes RotationAxes MouseyY minimum and _Y tationxX Tnpult GetAxis Mose Y S nsictivityVert maximum limits _rotationxX Mathf Clamp _ rotationX minimumVert maximumVert ne float rotationY transform localEulerAngles y Keep the same transform localEulerAngles new Vector3 _rotationxX rotationY 0 T Y angle i e no horizontal Create a new vector from rotation the stored rotation values Set the Axes menu of the MouseLook component to vertical rotation and play the new script Now the view won t rotate sideways but it ll tilt up and down when you move the mouse up and down The tilt stops at upper and lower limits There are several new concepts in this code that need to be explained First off we re not using Rotate this time so we need a variable called _rotationxX here because vertical rotation goes around the X axis in which to store the rotation angle The Rotate method increments the current rotation whereas this code sets the rotation angle directly In other words it s the difference between saying add 5 to the angle and set the angle to 30 We do still need to increment the rotation angle but that s why the code has the operator to subtract a value from the rotation angle rather than set the angle to that value By not using Rotate we can manipul
244. es of still frames of a movie www allitebooks com 16 1 3 2 CHAPTER 1 Getting to know Unity Listing 1 1 Code template for a basic script component using UnityEngine using System Collections E9 Include namespaces for Unity and Mono classes public class HelloWorld MonoBehaviour ae The syntax for inheritance youd Start 4 do something once a Put code in here that runs once void Update do something every frame AL Put code in here that runs every frame This is what the file contains when you create a new C script the minimal boilerplate code that defines a valid Unity component Unity has a script template tucked away in the bowels of the application and when you create a new script it copies that template and renames the class to match the name of the file which is HelloWorld cs in my case There are also empty shells for Start and Update because those are the two most common places to call your custom code from although I tend to adjust the whitespace around those functions a tad because the template isn t quite how I like the whitespace and I m finicky about that To create a script select C Script from the Create menu that you access either under the Assets menu note that Assets and GameObjects both have listings for Cre ate but they re different menus or by right clicking in the Project view Type in a name for the new script such as HelloWorld As explained
245. etely exchanged places the func tion swaps which audio source is considered active and inactive Great We ve completed the background music for our game s audio system FMOD a tool for game audio The audio system in Unity is powered by FMOD a popular audio programming library The library is available at www fmod org but it s already integrated into Unity Unity has many features of FMOD integrated although it lacks the library s most advanced features you can visit their website to learn about those features Such advanced audio features are offered through FMOD Studio a plug in that adds more functionality to Unity but the examples in this chapter will stick to the function ality built into Unity That core functionality comprises the most important features fora game s audio system Most game developers have their audio needs served quite well by this core functionality but the plug in is useful for those wishing to get even more intricate with their game s audio 10 5 Summary In this chapter you ve learned that Sound effects should be uncompressed audio and music should be compressed but use the WAV format for both because Unity applies compression to imported audio Audio clips can be 2D sounds that always play the same or 3D sounds that react to the listener s position The volume of sound effects is easily adjusted globally using Unity s Audio Listener You can set volume on indi
246. ettings pop up can affect the settings of the game Open WanderingAL cs and add the code from the next listing Listing 6 10 Event listener added to WanderingAl ublic const float baseSpeed 3 0f ee r j Dy Base speed that is adjusted void Awake by the speed setting Messenger lt float gt AddListener GameEvent SPEED CHANGED OnSpeedChanged void OnDestroy Messenger lt float gt RemoveListener GameEvent SPEED CHANGED OnSpeedChanged private void OnSpeedChanged float value speed baseSpeed value DS Method that was declared in listener for event SPEED_CHANGED Awake and OnDestroy add and remove respectively an event listener here too but the methods have a value this time That value is used to set the speed of the wan dering Al TIP The code in the previous section just used a generic event but this mes saging system can pass a value along with the message Supporting a value in the listener is as simple as adding a type definition note the lt float gt added to the listener command Now make the same changes in FPSInput cs to affect the speed of the player The code in the next listing is almost exactly the same as that in listing 6 10 except that the player has a different number for baseSpeed Listing 6 11 Event listener added to FPSinput public const float baseSpeed 6 0f LY er This value is changed from listing 6 10 void Awake Messenger lt float gt AddListener GameEvent
247. ew Snowing THE wans and floor organized under TIP Empty game objects can be used to organize the an empty object scene in this way By linking visible objects to a root object their Hierarchy list can be collapsed Be warned before linking any child objects to it you want to position the empty root object at 0 0 0 to avoid any positioning oddities later What iS GameObject All scene objects are instances of the class GameObject similar to how all script com ponents inherit from the class MonoBehaviour This fact was more explicit with the empty object actually named GameObject but is still true regardless of whether the object is named Floor Camera or Player GameObject is really just a container for a bunch of components The main purpose of GameObject is so that MonoBehaviour has something to attach to What exactly the object is in the scene depends on what components have been added to that GameObject Cube objects have a Cube component Sphere objects have a Sphere component and so on Once the outer walls are in place create some inner walls to navigate around Position the inner walls however you like the idea is to create some hallways and obstacles to walk around once you write code for movement Now the scene has a room in it but without any lights the player won t be able to see any of it Let s take care of that next 2 2 2 Lights and cameras Typically you light a 3D scene with a directional light and the
248. ew project in 2D mode but this is still important to know about and worth double checking Select the camera in Hier archy to show its settings in the Inspector and then look for the Projection setting see figure 5 5 For 3D graphics the setting should be Perspective but for 2D graphics the camera projection should be Orthographic DEFINITION Orthographic is the term for a flat camera view that has no per spective apparent This is the opposite of a Perspective camera where closer objects appear larger and lines recede into the distance Although the Projection mode is the most important camera setting for 2D graphics there are a few other settings for us to adjust as well Next we ll look at Size that set ting is under Projection The camera s orthographic size determines the size of the camera view from the center of the screen up to the top of the screen In other words set Size to half the pixel dimensions of the screen you want If you later set the resolu tion of the deployed game to the same pixel dimensions you ll get pixel perfect graphics inspector MaE M Main Camera ori v Tag MainCamera MainCamera Layer Default YA Transform T Position xio y 0 z 100 Background color Rotation x0 Yo Z0 Scale xi hae zf1 Y amp M Camera d amp Clear Flags Perspective Orthographic Background E 7 projection lt Culling Mask gt Projection a gt Size 3 84 Figure 5 5 Camera size Clipping
249. f a skybox comes in DEFINITION A skybox is a cube surrounding the camera with pictures of the sky on each side No matter what direction the camera is facing it s looking at a picture of the sky Properly implementing a skybox can be tricky figure 4 9 shows a diagram of how a sky box works There are a number of rendering tricks needed so that the skybox will appear as a distant background Fortunately Unity already takes care of all that for you New scenes actually come with a very simple skybox already assigned This is why the sky has a gradient from light to dark blue rather than being a flat dark blue If you open the lighting window Window gt Lighting the first setting is Skybox and the slot for that setting says Default This setting is in the Environment Lighting panel this window has a number of settings panels related to the advanced lighting system in Unity but for now we only care about the first setting a The skybox functionality needed Render behind everything else in the scene Stay centered on the camera so that it will seem too far away for the player s movements to affect it Full brightness with no shading applied to avoid any lighting differences Figure 4 9 between sides of the cube Diagram of a skybox 4 4 2 Generating sky visuals using texture images 81 Just like the brick textures earlier skybox images can be obtained from a variety of web sites Search for skybox textures f
250. f almost any other game development tool out there This chapter will focus on the first six platforms listed because those platforms are of pri mary interest to the majority of people exploring Unity but keep in mind how many options are available to you To see all these platforms open the Build Settings window That s the window you used in the previous chapter to add scenes to be loaded to access it choose File gt Build Settings In chapter 11 you only cared about the list at the top but now you want to pay attention to the buttons at the bottom see figure 12 1 You ll notice a lot of space taken up by the list of platforms the currently active platform is indicated with the Unity icon Select platforms in this list and then click the Switch Platform button 278 12 1 CHAPTER 12 Deploying your game to players devices 600 Build Settings M Startup unity w Levell unity w uni The list of all platforms oa that Unity can build Scenes listed for an app for Select a loading this is the platform to switch to list from Chapter II Platform a ee Web Player y A PC Mac amp Linux Standalone fe PC Mac amp Linux Standalone lt Target Platform Architecture Development Build Autoconnect Profiler Script Debugging Open settings for the app These settings include the app s name Click this button to actually switch to the selected platform O WARNING switching platforms could
251. f the audio software available this section looks at two major sound editing tools other examples beyond this list include Logic Able ton and Reason Pro Tools This audio software boasts many useful features and is considered the industry stan dard by countless music producers and audio engineers It s frequently used for all sorts of professional audio work including game development www avid com US products family Pro Tools Audacity Although nowhere near as useful for professional audio work Audacity is a handy sound editor for small scale audio work like preparing short sound files to use as sound effects in a game This is a popular choice for those looking for open source sound editing software http audacity sourceforge net appendix G Modeling a bench in Blender In chapters 2 and 4 we looked at creating levels with large flat walls and floors But what about more detailed objects What if you want say interesting furniture in the room You can accomplish that by building 3D models in external 3D art apps Recall the definition from the introduction to chapter 4 3D models are the mesh objects in the game that is the three dimensional shapes In this appendix Tl show you how to create a mesh object of a simple bench see figure C 1 While appendix B lists a number of 3D art tools we ll use Blender for this exer cise because it s open source and thus accessible to all readers You ll create a mesh ob
252. f the shaders YF FRVTFYLIT FY Alpha Blended Premultiply ui under the Particles submenu As Multiply Unlit Multiply Double VertexLit Blended Legacy Shaders shown in figure 4 23 in this case we want Additive Soft This will make the particles appear to be hazy and Figure 4 23 Setting the shader for the fire particle material Additive Multiply brighten the scene just like a fire DEFINITION Additive is a shader that adds the color of the particle to the color behind it as opposed to replacing the pixels This makes the pixels brighter and makes black on the particle turn invisible The opposite is Multiply which makes everything darker these shaders have the same visual effect as the Additive and Multiply layer effects in Photoshop 90 CHAPTER 4 Developing graphics for your game With the fire material assigned to the fire particle effect it ll now look like the effect shown earlier in figure 4 18 This looks like a pretty convincing jet of flame but the effect doesn t only work when sitting still next let s attach it to an object that moves around 4 6 3 Attaching particle effects to 3D objects Create a sphere remember GameObject gt 3D Object gt Sphere Create a new script called BackAndForth as shown in the following listing and attach it to the new sphere Listing 4 1 Moving an object back and forth along a straight path using UnityEngine using System Collections public class BackA
253. files into the same directory as the appli cation every time you build your game You can easily automate such tasks by pro gramming them in a script that will execute after the build process completes First create a new folder in the Project view and name that folder Editor any scripts that affect Unity s editor and that includes the build process must go in the Editor folder Create a new script in that folder rename it TestPostBuild and write the fol lowing code in it using UnityEngine using Una eynGatorr using UnatyEdaror Callbacks public Static class Test PostBuild Post ProcessBuild public static void OnPostprocessBuild BuildTarget target string pathToBuiltProject Debug rog build location pathToburleProjecu The directive PostProcessBuild tells the script to run the function that s immedi ately after it That function will receive the location of the built app you could then use that location with the various filesystem commands provided by C For now the file path is being printed to the console to test that the script works The application will appear in the location you chose double click it to run it like any other program Congrats that was easy Building applications is a snap but the pro cess can be customized in a number of ways let s look at how to adjust the build 280 CHAPTER 12 Deploying your game to players devices inspector M PlayerSettings Set
254. fore now you re downloading an image The next listing contains code for the new ImagesManager Create a new script and enter that code Listing 9 13 Creating ImagesManager to retrieve and store images using UnityEngine using System Collections using System Collections Generic using System public class ImagesManager MonoBehaviour IGameManager public ManagerStatus status get private set private NetworkService _network ak Variable to store downloaded image private Texture2D _webImage public void Startup NetworkService service Debug Log Images manager starting network service status ManagerStatus Started 214 Check if CHAPTER 9 Connecting your game to the internet public void GetWebImage Action lt Texture2D gt callback i if bI LL ihe imag Ea if _webImage null is already stored 9 3 2 StartCoroutine _network DownloadImage callback else llback bI i ca ack _webImage A Invoke callback right away don t download if there s a stored image The most interesting part of this code is GetWebImage everything else in this script consists of standard properties and methods that implement the manager interface When GetWebImage is called it ll return via a callback function the web image First it ll check if _webImage already has a stored image if not it ll invoke the network call to download the image If webImage already
255. freys engraved and printed maps for government and other offi cial bodies and produced a wide range of commercial maps and atlases especially of North America His work as a mapmaker sparked an interest in local dress customs of the lands he surveyed which are brilliantly displayed in this four volume collection Fascination with faraway lands and travel for pleasure were relatively new pheno mena in the late eighteenth century and collections such as this one were popular introducing both the tourist as well as the armchair traveler to the inhabitants of other countries The diversity of the drawings in Jeffreys volumes speaks vividly of the uniqueness and individuality of the world s nations some 200 years ago Dress codes have changed since then and the diversity by region and country so rich at the time has faded away It is now hard to tell the inhabitant of one continent apart from another Perhaps trying to view it optimistically we have traded a cultural and visual diversity for a more varied personal life or a more varied and interesting intellectual and technical life At a time when it is hard to tell one computer book from another Manning cele brates the inventiveness and initiative of the computer business with book covers based on the rich diversity of regional life of two centuries ago brought back to life by Jeffreys pictures Part l First steps I time to take your first steps in using Unity If you don t know
256. ftware engineers refer to this principle as separation of concerns 130 CHAPTER 6 Putting a 2D GUI in a 3D game OnClick event panel near Lo vouaste the bottom of settings _ onClick Editor And UlController OnOpenSettings Drag an object in the scene to the object slot then choose Press the button to add aikani ef a as iti the ment an entry in the panel a Figure 6 12 The OnClick panel toward the bottom of the button settings Now drag objects to component slots in order to wire them up Drag the score label the text object we created before to the UIController s text slot The code in UICon troller sets the text displayed on that label Currently the code displays a timer to test the text display that will be changed to the score later Next add an OnClick entry to the button to drag the controller object onto Select the button to see its settings in the Inspector Toward the bottom you should see an OnClick panel initially that panel is empty but as you can see in figure 6 12 you can click the button to add an entry to that panel Each entry defines a single function that gets called when that button is clicked the listing has both a slot for an object and a menu for the function to call Drag the controller object to the object slot and then look for UIController in the menu select OnOpenSettings in that section Responding to other mouse events OnClick is the only event that the butt
257. g all files in the project and messages from the code respectively Navigate folders on the left then double click the Car example scene Figure 1 9 Parts of the interface in Unity This is just the default layout in Unity all of the various views are in tabs and can be moved around or resized docking in different places on the screen Later you can play around with customizing the layout but for now the default layout is the best way to understand what all the views do Scene view Game view and the Toolbar The most prominent part of the interface is the Scene view in the middle This is where you can see what the game world looks like and move objects around Mesh objects in the scene appear as well the mesh object defined in a moment You can also see a number of other objects in the scene represented by various icons and col ored lines cameras lights audio sources collision regions and so forth Note that the view you re seeing here isn t the same as the view in the running game you re able to look around the scene at will without being constrained to the game s view DEFINITION A mesh object is a visual object in 3D space Visuals in 3D are con structed out of lots of connected lines and shapes hence the word mesh The Game view isn t a separate part of the screen but rather another tab located right next to Scene look for tabs at the top left of views A couple of places in the interface have multiple tabs
258. g at the sides of the screen you ll see the Hierarchy tab on the left and the Inspector on the right see figure 1 12 Hierarchy is a list view with the name of every 1 2 4 How to use Unity 13 inspector M 4000 Figure 1 12 Editor screenshot cropped to show the Hierarchy and Inspector tabs object in the scene listed with the names nested together according to their hierarchy linkages in the scene Basically it s a way of selecting objects by name instead of hunt ing them down and clicking them within Scene The Hierarchy linkages group objects together visually grouping them like folders and allowing you to move the entire group together The Inspector shows you information about the currently selected object Select an object and the Inspector is then filled with information about that object The infor mation shown is pretty much a list of components and you can even attach or remove components from objects All game objects have at least one component Transform so you ll always at least see information about positioning and rotation in the Inspec tor Many times objects will have several components listed here including scripts attached to that object The Project and Console tabs At the bottom of the screen you ll see Project and Console see figure 1 13 As with Scene and View these aren t two separate portions of the screen but rather tabs that you can switch between Project shows all the assets a
259. g doesn t do anything by itself region 10S Di limport Internal private static extern float TestNumber Refer to function in the iOS code Ditimpert Internal private static extern string TestString string test endregion iOS public static float TestNumber float val Of 292 CHAPTER 12 Deploying your game to players devices if Application platform RuntimePlatform IPhonePlayer val TestNumber 7 ae Call this if platform return val is IPhonePlayer public static string TestString string test string val if Application platform RuntimePlatform IPhonePlayer val TestString test return val First note that the static Initialize function creates a permanent object in the scene so that you don t have to do it manually in the editor You haven t previously seen code to create an object from scratch because it s a lot simpler to use a prefab in most cases but in this case it s cleaner to create the object in code so that you can use the plug in script without editing the scene The main wizardry going on here involves the DLLImport and static extern com mands Those commands tell Unity to link up to functions in the native code you pro vide Then you can use those referenced functions in this script s methods with a check to make sure the code is running on iPhone iOS Next you ll use these plug in functions to test them Create a new scr
260. g right away usually you want to keep this setting off for short sound clips to ensure that they load completely before they play Because the imported clips are short sound effects you should leave Load In Background off Finally the most important settings are Load Type and Compression Format Com pression Format controls the formatting of the audio data that s stored As discussed in the previous section music should be compressed choose Vorbis it s the name of a compressed audio format in that case Short sound clips don t need to be com pressed so choose PCM Pulse Code Modulation the technical term for the raw sam pled sound wave for these clips The third setting ADPCM is a variation on PCM and occasionally results in slightly better sound quality Load Type controls how the data from the file will be loaded by the computer Because computers have limited memory and audio files can be large sometimes you want the audio to play while it s streaming into memory saving the computer from needing to have the entire file loaded at once But there s a bit of computing overhead when streaming audio like this so audio plays fastest when it s loaded into memory first Even then you can choose whether the loaded audio data will be in compressed form or if it will be decompressed for faster playback Because these sound clips are short they don t need to stream and can be set to Decompress On Load At this point the sound eff
261. ge the player s inventory Let s set up the code structure for that Setting up player and inventory managers The general idea here is to split up all the data management into separate well defined modules that each manages its own area of responsibility We re going to cre ate separate modules to maintain player state in PlayerManager things like the player s health and maintain the inventory list in InventoryManager These data managers will behave like the Model in MVC the Controller is an invisible object in most scenes it wasn t needed here but recall SceneController in previous chapters and the rest of the scene is analogous to the View Managing inventory data and game state 179 There will be a higher level manager of managers that keeps track of all the sepa rate modules Besides keeping a list of all the various managers this higher level man ager will control the lifecycle of the various managers especially initializing them at the start All the other scripts in the game will be able to access these centralized modules by going through the main manager Specifically other code can use a number of static properties in the main manager in order to connect with the specific module desired Design patterns for accessing centralized shared modules Over the years a variety of design patterns have emerged to solve the problem of con necting parts of a program to centralized modules that are shared throughout t
262. gers between different scenes but you still don t have any success or failure conditions within the level Completing a level by reaching the exit To handle level completion you ll put an object in the scene for the player to touch and that object will inform MissionManager when the player reaches the objective This will involve the UI responding to a message about level completion so add another GameEvent see the following listing 266 CHAPTER 11 Putting the parts together into a complete game Listing 11 19 Level Complete added to GameEvent cs public static class GameEvent public const string HEALTH UPDATED HEALTH UPDATED public const string LEVEL COMPLETE LEVEL COMPLETE Now add a new method to MissionManager in order to keep track of mission objec tives and broadcast the new event message see the next listing Listing 11 20 Objective method in MissionManager public void ReachObjective could have logic to handle multiple objectives Messenger Broadcast GameEvent LEVEL COMPLETE Adjust the UIController script to respond to that event as shown in the next listing Listing 11 21 New event listener in UlController SerializeField private Text levelEnding void Awake Messenger AddListener GameEvent HEALTH UPDATED OnHealthUpdated Messenger AddListener GameEvent LEVEL COMPLETE OnLevelComplete void OnDestroy Messenger RemoveListener GameEvent HEALTH UPDAT
263. gine how a modern single page web application works as opposed to old school web development based on web pages generated server side The familiarity of this approach can be misleading for experienced web developers Video games often have much more stringent performance requirements than web applications and these differences can affect design decisions WARNING Time scales can be vastly different between web apps and video games Half a second can seem like a short wait for updating a website but pausing even just a fraction of that time can be excruciating in the middle of a high intensity action game The concept of fast is definitely relative to the situation Online games usually connect to a server specifically intended for that game for learning purposes however we ll connect to some freely available internet data sources including both weather data and images we can download The last section of this chapter does require you to set up a custom web server that section is optional because of that requirement although I ll explain an easy way to do it with open source software The plan for this chapter is to go over multiple uses of HTTP requests so that you can learn how they work within Unity 1 Set up an outdoor scene in particular build a sky that can react to the weather data 2 Write code to request weather data from the internet 3 Parse the response and then modify the scene based on the data 9 1 9 1
264. h of a second so multiplying the speed value by deltaTime will scale the speed value on different computers Now the movement speed will be the same on all computers But the movement script is still not quite done when you move around the room you can pass through walls so we need to adjust the code further to prevent that Moving the CharacterController for collision detection Directly changing the object s transform doesn t apply collision detection so the char acter will pass through walls To apply collision detection what we want to do instead is use CharacterController CharacterController is a component that makes the object move more like a character in a game including colliding with walls Recall that back when we set up the player we attached a CharacterController so now we ll use that component with the movement code in FPSInput see the following listing Listing 2 11 Moving CharacterController instead of Transform private CharacterController c charController eo Variable for referencing void Start the CharacterController _charController GetComponent lt CharacterController gt ae Access other void Update float deltaX Input GetAxis Horizontal speed components attached to the same object float deltaZ Input GetAxis Vertical speed Limit diagonal movement Vector3 movement new Vector3 deltax 0 deltaZ to the same speed as movement Vector3 ClampMagnitude movement spe
265. hat function encapsulates the multiple adjustments made to the scene I ve already explained what SetFloat is doing so we won t go over that again and the last line adjusts the intensity of the light Now play the scene to watch the code running You ll see what figure 9 2 depicts over a couple of seconds you ll see the scene transition from a sunny day to dark and overcast WARNING One unexpected quirk about Unity is that the Blend change on the material is permanent Unity resets objects in the scene when the game stops running but assets that were linked directly from the Project view such as the skybox material are changed permanently This only happens within Unity s editor changes don t carry over between plays after the game is deployed outside the editor and thus can result in frustrating bugs if you for get about it It s pretty cool watching the scene transition from sunny to overcast But this was all just a setup for the actual goal having the weather in the game sync up to real world weather conditions For that we need to start downloading weather data from the internet Sunny before transition Overcast after transition Figure 9 2 Before and after scene transition from sunny to overcast 9 2 Downloading weather data from an internet service 201 Downloading weather data from an internet service Now that we have the outdoors scene set up we can write code that will download weather data and m
266. hat s Inside e Program characters that run jump and interact e Build code architectures that manage the game s state e Connect your games to the internet to download live data e Deploy games to platforms including web and mobile e Covers Unity version 5 Youll need to know how to program in C or a similar OO language No previous Unity experience or game development knowledge is assumed Joe Hocking is a software engineer specializing in interactive media development He works for Synapse Games and teaches classes in game development at Columbia College Chicago To download their free eBook in PDF ePub and Kindle formats owners of this book should visit manning com UnityinAction 44 99 Can 51 99 INCLUDING eBOOK c Joe Hocking wastes none of your time and gets you coding fast 2 From the Foreword by Jesse Schell author of The Art of Game Design Gets you up and running in no time 2 Sergio Arbeo codecantor CC The text is clear and concise and the examples are outstanding Dan Kacenjar Sr Wolters Kluwer CC All the roadblocks evaporated and I took my game from concept to build in short order Philip Taffet SOHOsoft LLC ISBN 13 978 1l bl7292 32 3 gt 1l 617292 32 3 ISBN 10 X l ii 9178 1617 2 9232
267. haviour this time responding when the object is clicked 104 5 2 3 5 3 5 3 1 CHAPTER 5 Building a Memory game using Unity s new 2D functionality on Play the game and watch messages appear in the console But this only prints to the console for testing we want the card to be revealed Revealing the card on click Rewrite the code to match what s shown in the next listing the code won t run quite yet but don t worry Listing 5 2 Script that hides the back when the card is clicked using UnityEngine using System Collections Variable that appears ublic class MemoryCard MonoBehaviour j A l in the Inspector SerializeField private GameObject cardBack Only run deactivate code if the ublic void OnMouseDown cae ae P 04 a object is currently active visible if cardBack activeSelf cardBack SetActive false HS Set the object to inactive invisible There are two key additions to the script a reference to an object in the scene and the SetActive method that deactivates that object The first part the reference to an object in the scene is similar to what we ve done in previous chapters mark the variable as serialized and then drag the object from Hierarchy over to the variable in the Inspec tor With the object reference set the code will now affect the object in the scene The second key addition to the code is the SetActive command That command will deactivate any GameObje
268. he ones shown in table 4 2 Table 4 2 2D image file formats supported by Unity File type Pros and cons PNG Commonly used on the web Lossless compression has an alpha channel JPG Commonly used on the web Lossy compression no alpha channel GIF Commonly used on the web Lossy compression no alpha channel Technically the loss isn t from compression rather data is lost when the image is converted to 8 bit Ultimately it amounts to the same thing BMP Default image format on Windows No compression no alpha channel TGA Commonly used for 3D graphics obscure everywhere else No or lossless compression has an alpha channel TIFF Commonly used for digital photography and publishing No or lossless compression no alpha channel PICT Default image format on old Macs Lossy compression no alpha channel PSD Native file format for Photoshop No compression has an alpha channel The main reason to use this file format would be the advantage of using Photoshop files directly DEFINITION The alpha channelis used to store transparency information in an image The visible colors come in three channels of information Red Green and Blue Alpha is an additional channel of information that isn t visi ble but controls the visibility of the image Although Unity will accept any of the images shown in table 4 2 to import and use as a texture the various file formats vary considerably in what features they support T
269. he code is written in MonoDevelop the code isn t actually run there The IDE is pretty much a fancy text editor and the code is run when you hit Play within Unity Printing to the console Hello World All right you already have an empty script in the project but you also need an object in the scene to attach the script to Recall figure 1 1 depicting how a component sys tem works a script is a component so it needs to be set as one of the components on an object Select GameObject gt Create Empty and a blank GameObject will appear in the Hierarchy list Now drag the script from the Project view over to the Hierarchy view and drop it on the empty GameObject As shown in figure 1 15 Unity will highlight 18 CHAPTER 1 Getting to know Unity Main Camera Directional Light GameObject roy Favorites all Materials all Models All Prefabs All Scripts HelloWorld MonoScript HelloWorld Figure 1 15 How to link a script to a GameObject valid places to drop the script and dropping it on the GameObject will attach the script to that object To verify that the script is attached to the object select the object and look at the Inspector view You should see two components listed the Transform component that s the basic position rotation scale component all objects have and that can t be removed and below that your script NOTE Eventually this action of dragging objects from one place
270. he mouse MouseDown is the moment when the mouse button is physically pressed and MouseUp is the moment when the mouse button is released You can see that this code tints the sprite when the mouse hovers over it and scales the sprite when it s clicked on In both cases you can see that the change in color or scale happens when the mouse interaction begins and then the property returns to default either white or scale 1 when the mouse interaction ends For scaling the code uses the standard transform component that all GameObjects have For tint though the code uses the SpriteRenderer component that sprite objects have the sprite is set to a color that s defined in Unity s editor through a public variable In addition to returning the scale to 1 SendMessage is called when the mouse is released SendMessage calls the function of the given name in all components of that GameObject Here the target object for the message as well as the message to send are both defined by serialized variables This way the same UIButton compo nent can be used for all sorts of buttons with the target of different buttons set to dif ferent objects in the Inspector Normally when doing object oriented programming in a strongly typed language like C you need to know the type of a target object in order to communicate with that object for example to call a public method of the object like calling target Object SendMessage itself But scripts f
271. he particle system To complete the flaming 4 7 Summary 91 sphere find Simulation Space in the particle system settings it s in the top panel of figure 4 20 and switch from Local to World NOTE In this script the object moves back and forth in a straight line but video games commonly have objects moving around complex paths Unity comes with support for complex navigation and paths see https docs unity3d com Manual Navigation html to read about it I m sure that at this point you re itching to apply your own ideas and add more con tent to this sample game You should do that you could create more art assets or even test your skills by bringing in shooting mechanics developed in chapter 3 In the next chapter we ll switch gears to a different game genre and start over with a new game Even though future chapters will switch to different game genres everything from these first four chapters will still apply and will be useful Summary In this chapter you ve learned that Art asset is the term for all individual graphics Whiteboxing is a useful first step for level designers to block out spaces Textures are 2D images displayed on the surface of 3D models 3D models are created outside Unity and imported as FBX files Particle systems are used to create many visual effects fire smoke water and so on Part 2 Getting comfortable Y built your first game prototypes in Unity so now you re re
272. he player to shoot into the scene Create static targets that react to being hit Make the targets wander around Spawn the wandering targets automatically ao A OO N P Enable the targets enemies to shoot fireballs at the player NOTE This chapter s project assumes you already have a first person move ment demo to build on We created a movement demo in chapter 2 but if you skipped to this chapter then you will need to download the sample files for chapter 2 Shooting via raycasts The first new feature to introduce into the 3D demo is shooting Looking around and moving are certainly crucial features for a first person shooter but its not a game until players can affect the simulation and apply their skills Shooting in 3D games can be implemented with a few different approaches and one of the most important approaches is raycasting What is raycasting As the name indicates raycasting is when you cast a ray into the scene Clear right Well okay so what exactly is a ray DEFINITION A rayis an imaginary or invisible line in the scene that starts at some origin point and extends out in a specific direction 48 3 1 2 CHAPTER 3 Adding enemies and projectiles to the 3D game Raycasting is when you create a ray A ray projected and then determine what intersects through a 3D scene that ray figure 3 1 illustrates the concept Consider what happens when you fire a bullet from a gun the bullet starts at the
273. he pro gram For example the Singleton pattern was enshrined in the original Gang of Four book about design patterns But that pattern has fallen out of favor with many software engineers so they use alternative patterns like service locator and dependency injection In my code use a compromise between the simplicity of static variables and the flexibility of a service locator This design leaves the code simple to use while also allowing for swapping in different modules For example requesting InventoryManager using a singleton will always refer to the exact same class and thus will tightly couple your code to that class on the other hand requesting Inventory from a service locator leaves the option to return either InventoryManager or DifferentInventoryManager Sometimes it s handy to be able to switch between a number of slightly different versions of the same module deploying the game on different platforms for example In order for the main manager to reference other modules in a consistent way these modules must all inherit properties from a common base We re going to do that with an interface many programming languages including C allow you to define a sort of blueprint that other classes need to follow Both PlayerManager and Inventory Manager will implement a common interface called IGameManager in this case and then the main Managers object can treat both PlayerManager and InventoryManager as type IGameManager
274. he same speed value of 6 would be applied every time At 30 fps the rate of movement would be 180 units second and the movement at 60 fps would be 360 units second For most games movement speed that varies like this would be bad news The solution is to adjust the movement code to make it frame rate independent That means the speed of movement is not dependent on the frame rate of the game The way to achieve this is by not applying the same speed value at every frame rate Instead scale the speed value higher or lower depending on how quickly the com puter runs This is achieved by multiplying the speed value by another value called deltaTime as shown in the next listing 42 2 5 3 Transform the movement vector from CHAPTER 2 Building a demo that puts you in 3D space Listing 2 10 Frame rate independent movement using deltaTime void Update float deltaX Input GetAxis Horizontal speed float deltaZ Input GetAxis Vertical speed transform Translate deltaxX Time deltaTime 0 deltaZ Time deltaTime That was a simple change The Time class has a number of properties and methods useful for timing and one of those properties is deltaTime Because we know that delta means the amount of change that means deltaTime is the amount of change in time Specifically deltaTime is the amount of time between frames The time between frames varies at different frame rates for example 30 fps is a deltaTime of 1 30t
275. hey were downloaded but those images aren t ideal for use as textures Although they re certainly tileable the important aspect of why we re using these images they aren t the right size and they re the wrong file for mat Textures should be sized in powers of 2 For reasons of technical efficiency graphics chips like to handle textures in sizes that are 2N 4 8 16 32 64 128 256 78 4 3 3 CHAPTER 4 Developing graphics for your game A folder in your computer E VOownioaa BrickLargeBare003 2 png Project view in Unity Assets Textures BrickLargeBa A BrickRound0067 st Figure 4 6 Drag images from outside Unity to import them into the Project view 512 1024 2048 the next number is 4096 but at that point the image is too big to use as a texture In your image editor Photoshop GIMP or whatever refer to appendix B scale the downloaded image to 256x256 and save it as a PNG Now drag the files from their location in the computer into the Project view in Unity This will copy the files into your Unity project see figure 4 6 at which point they re imported as textures and can be used in the 3D scene If dragging the file over would be awkward you could instead right click in Project and select Import New Asset to get a file picker TIP Organizing your assets into separate folders is probably a good idea as your projects start to get more complex in the Project view create
276. his update should work invisibly and the game still works the same That adjustment was easy but the next one will be harder BRING OVER THE Al ENEMY Besides the NetworkServices adjustments from chapter 9 you also need the AI enemy from chapter 3 Implementing enemy characters involved a bunch of scripts and art assets So you need to import all those assets First copy over these scripts remember WanderingAI and ReactivelTarget were behaviors for the AI enemy Fireball was the projectile fired the enemy attacks the PlayerCharacter component and SceneController handles spawning enemies PlayerCharacter cs SceneController cs WanderingAl cs ReactiveTarget cs Fireball cs Similarly get the Flame material Fireball prefab and Enemy prefab by dragging those files in If you got the enemy from chapter 10 instead of 3 you also need the added fire particle material After copying over all the required assets the links between assets will probably be broken so you ll need to relink everything in order to get them to work In particular scripts are probably not correctly connected to the prefabs For example the Enemy prefab has two missing scripts in the Inspector so click the circle button indicated in figure 11 2 to choose WanderingAI and ReactiveTarget from the list of scripts vy O M Gcripp Click the circle button that s Script o just to the right of the script slot Figure 11 2 Linking a script to a compone
277. hoose None from the list With the new project for this chapter created and set for 2D we can start putting our images into the scene 5 1 2 Displaying 2D images aka sprites Drag all the image files into the Project view to import them make sure the images are imported as sprites and not textures This is automatic if the editor is set to 2D Setting everything up for 2D graphics 99 Select an asset to see its import settings in the Inspector Now drag the table_top sprite our background image up from the Project view into the empty scene and then save the scene As with mesh objects in the Inspector there s a Transform com ponent for the sprite type 0 0 5 to position the background image TIP Another import setting to take note of is Pixels To Units Because Unity was previously a 3D engine that recently had 2D graphics grafted in one unit in Unity isn t necessarily one pixel in the image You could set the Pixels To Units setting to 1 1 but I recommend leaving it at the default of 100 1 because the physics engine doesn t work properly at 1 1 and the default is better for compatibility with others code Animated sprites Although we re going to use only still images for this project 2D games commonly have animated sprites Animated sprites are created by drawing each of the frames of the animation and then displaying the frames in sequence within Unity The multiple frames can be imported as separate images
278. iable to 9 this time because that value needs to be bigger once the code starts scaling it which will be soon The adjusted code should look like the following listing Listing 2 3 Horizontal rotation not yet responding to the mouse public RotationAxes axes RotationAxes MouseXAndY Italicized code was already in script it s public float sensitivityHor 9 0f shown here for reference bS Declare a variable for void Update the speed of rotation if axes RotationAxes MouseX transform Rotate 0 sensitivityHor 0 EJ Put the Rotate command here so that it runs every frame If you play the script now the view will spin around just like before only a lot faster because the Y rotation is 9 instead of 3 The next step is to make the rotation react to mouse movement so let s introduce a new method Input GetAxis The Input class has a bunch of methods for handling input devices such as the mouse and the method GetAxis returns numbers correlated to the movement of the mouse posi tive or negative depending on the direction of movement GetAxis takes the name of the axis desired as a parameter and the horizontal axis is called Mouse X If you multiply the rotation speed by the axis value the rotation will respond to mouse movement The speed will scale according to mouse movement scaling down to zero or even reversing direction The Rotate command now looks like the next listing Listing 2 4 Rota
279. icVolume value if musiclSource null E t ps Adjust volume of the musiclSource volume musicVolume p AudioSource directly public bool musicMute get if musiclSource null return musiclSource mute return false ae Default value in case the set AudioSource is missing if musiclSource null musiclSource mute value public void Startup NetworkService service Debug Log Audio manager starting AL Italicized code was already in script shown here for reference _network service musiclSource ignoreListenerVolume true These properties tell the AudioSource musiclSource ignoreListenerPause true to ignore AudioListener volume soundVolume 1f musicVolume 1f status ManagerStatus Started The key to this code is realizing you can adjust the volume of an AudioSource directly even though that audio source is ignoring the global volume defined in Audio Listener There are properties for both volume and mute that manipulate the individ ual music source The Startup method initializes the music source with both ignoreListener Volume and ignoreListenerPause turned on As the names suggest those properties cause the audio source to ignore the global volume setting on AudioListener 242 10 4 3 CHAPTER 10 Playing audio sound effects and music You can hit Play now to verify that the music is no longer affected by the existing volume control Now let
280. ically a separate application even though it s bundled along with Unity In a similar manner developers rely on an array of external tools to do work not internal to Unity This isn t to say that Unity is lacking capabilities that it ought to have Rather the game development process is so complex and multifaceted that any well designed piece of software with a clear focus and clean separation of concerns will inevitably limit itself to being good at a limited subset of the process In this case Unity con centrates on being the glue and the engine that brings together all the content of a game and makes it function Creating all that content is done with other tools let s take a look at several categories of software that could be useful to you Programming tools We ve already looked at MonoDevelop the most significant programming tool used alongside Unity But there are a handful of other programming tools to be aware of as you ll see in this section Visual Studio As mentioned in chapter 1 although Unity comes with MonoDevelop and you can use that IDE on both Windows and Mac on Windows you could also choose to use Visual Studio Recently Microsoft acquired SyntaxTree a company that has been improving the integration of Visual Studio http unityvs com 304 B 1 2 B 1 3 B 1 4 B 2 B 2 1 3D art applications 305 Xcode Xcode is the programming environment provided by Apple in particular an IDE but also in
281. if the screen changes size for example if the game is played on different monitors The easiest way to understand what I m talking about is to see it in action Select the image object and look over at the Inspector Anchor settings see figure 6 10 will appear right below the transform component By default UI elements have their anchor set to Center but you want to set the anchor to Top Left for this image figure 6 10 shows how to adjust that using the Anchor Presets Change the gear button s anchor as well Set it to Top Right for this object click the top right Anchor Preset Now try scaling the window left and right click and drag on the side of the Scene view Thanks to the anchors the UI objects will stay in their v E Rect Transform Anchor Presets center Pos X Pos Y Pos Z Shift Also set pivot Alt Also set position 69 873 l 50 97 10 mm left center right stretch to open the entire Anchor presets menu Width Heigt 100 100 gt Anchors Pivot x 05 l i 0 5 Rotation xio hat z 0 Scale E KIE zfi middle You can type in exact numbers for the anchor point but usually the presets work best For example press this button to set a top right anchor Click the Anchor button it looks like a target bottom middle Stretch presets affect the image size as well as position stretch Figure 6 10 How to adjust anchor settings 128 6 3 Pa Include Ul syst
282. igure lined up in the middle of the pop up Set the text to Speed so that it can be a label for the slider The input field is for typing in text and Text is shown in the box before the player types something else 134 CHAPTER 6 Putting a 2D GUI in a 3D game Input controls on the pop up The close button is in the top corner while a text label was placed just over the slider a text InputField a numerical Slider Figure 6 16 Input controls added to the pop up window set this value to Name You can leave the options Content Type and Line Type at their defaults if desired you can use Content Type to restrict typing to things like only let ters or only numbers whereas you can use Line Type to switch from a single line to multiline text WARNING You won t be able to click the slider if the text label covers it Make sure the text object appears under the slider by placing it above the slider in the Hierarchy As for the slider itself several settings appear toward the bottom of the component inspector Min Value is set to 0 by default leave that Max Value defaults to 1 but make it 2 for this example Similarly both Value and Whole Numbers can be left at their defaults Value controls the starting value of the slider and Whole Numbers con strains itto 0 1 2 rather than decimal values a constraint we don t want And that wraps up all the objects Now you need to write the code that the objects are linked to add
283. ike UV Blank box Box covered in wrapping paper Wrapping paper 4 7 7 7 AS r Texture coordinates define i points and shapes on the wrapping paper that i correlate to sides of the pox NE Numbers in the coordinates are labeled UV instead of XY 7 7 Figure C 8 Wrapping paper makes a good analogy for how texture coordinates work Texture mapping the model 313 Select bottom edges Choose Mark Seam Now the unfolded shape will split at the selected edges Select edges outside legs Figure C 9 Seam edges along the bottom of the bench and along the legs unwrapping there are a lot of essentially synonymous terms surrounding texture map ping so try not to get confused Traditionally the process of texture mapping has been wickedly complicated but fortunately Blender provides tools to make the process fairly simple First you define seams on the model if you think further about wrapping around a box or better yet think about the other direction unfolding a box you ll realize that not every part of a 3D shape can remain seamless when unfolded into two dimensions There will have to be seams in the 3D form where the sides come apart Blender enables you to select edges and declare them as seams Switch to Edge Selection mode see the buttons in figure C 4 and select edges along the outside of the bottom of the bench Now select Mesh gt Edges gt Mark Seam
284. ilding the application 279 Adjusting Player Settings setting the game s name and icon 280 Platform dependent compilation 281 12 2 Building for the web 282 Unity Player vs HTML5 WebGL 282 Building the Unity file and a test web page 252 Communicating with JavaScript in the browser 283 12 9 12 4 CONTENTS xiii Building for mobile apps iOS and Android 285 Setting up the build tools 286 Texture compression 289 Developing plug ins 290 Summary 298 afterword 299 appendix A appendix B appendix C appendix D Scene navigation and keyboard shortcuts 302 External tools used alongside Unity 304 Modeling a bench in Blender 308 Online learning resources 316 index 319 foreword I started programming games in 1982 It wasn t easy We had no internet Resources were limited to a handful of mostly terrible books and magazines that offered fascinat ing but confusing code fragments and as for game engines well there weren t any Coding games was a massive uphill battle How I envy you reader holding the power of this book in your hands The Unity engine has done so much to open game programming to so many people Unity has managed to strike an excellent balance by being a powerful professional game engine that s still affordable and approachable for someone just getting started Approachable that is with the right guidance I once spent time in a circus troupe run by a magician He was kind enough to t
285. ile FileStream stream File Create _ filename at the file BinaryFormatter formatter new BinaryFormatter path formatter Serialize stream gamestate stream Close A Serialize the Dictionary as contents of the created file public void LoadGameState if File Exists filename E Only continue to Debug Log No saved game ee load if the file exists Dictionary to put DENS a loaded data in Dictionary lt string object gt gamestate BinaryFormatter formatter new BinaryFormatter FileStream stream File Open filename FileMode Open gamestate formatter Deserialize stream as Dictionary lt string object gt stream Close Managers Inventory UpdateData Dictionary lt string int gt gamestate inventory ao Managers Player UpdateData int gamestate health int gamestate maxHealth Managers Mission UpdateData int gamestate curLevel int gamestate maxLevel Managers Mission RestartCurrent Update managers with deserialized data 272 CHAPTER 11 Putting the parts together into a complete game During Startup the full file path is constructed using Application persistent DataPath a location Unity provides to store data in The exact file path differs on dif ferent platforms but Unity abstracts it behind this static variable incidentally this path includes both Company Name and Product Name from Player Settings so adjust those if needed
286. iled explanation This chapter s project is a demo of an action RPG In this sort of game the camera is placed high and looks down sharply see fig ure 11 1 and the character is controlled by clicking the mouse where you want to go you may be familiar with the game Diablo which is an action RPG like this Save Game I m switching to yet another game Load Game genre so that we can squeeze in Figure 11 1 Screenshot of the top down viewpoint one more genre before the end of the book In full the project in this chapter will be the biggest game yet It ll feature the following A top down view with point and click movement The ability to click on devices to operate them Scattered items you can collect Inventory that s displayed in a UI window Enemies wandering around the level The ability to save the game and restore your progress Three levels that must be completed in sequence Whevw that s a lot to pack in good thing this is almost the last chapter Building an action RPG by repurposing projects We ll develop the action RPG demo by building on the project from chapter 8 Copy that project s folder and open the copy in Unity to start working Or if you skipped directly to this chapter download the sample project for chapter 8 in order to build on that The reason we re building on the chapter 8 project is that it s the closest to our goal for this chapter and thus will require the le
287. ill handle both jumping and falling Specifically this code will have gravity pulling the player down at all times but occasionally an upward jolt will be applied when the player jumps Before we write this code let s add a few raised platforms to the scene There s cur rently nothing to jump on or fall off of Create a couple more cube objects and then modify their positions and scale to give the player platforms to jump on In the sample project I added two cubes and used these settings Position 5 75 5 and Scale 4 1 5 4 Position 1 1 5 5 5 and Scale 4 3 4 Figure 7 8 shows the raised platforms Position I 1 5 5 5 Scale 4 3 4 _ Figure 7 8 A couple of raised platforms added to the sparse scene Position 5 75 5 Y lt Scale 4 1 5 4 Implementing the jump action 153 7 3 1 Applying vertical speed and acceleration As mentioned when we first started writing the RelativeMovement script in listing 7 2 the movement values are calculated in separate steps and added to the movement vec tor progressively The next listing adds vertical movement to the existing vector Listing 7 4 Adding vertical movement to the RelativeMovement script public float jumpSpeed 15 0f public float gravity 9 8f public float terminalVelocity 10 0f public float minFall 1 5f private float _vertSpeed hid Initialize the vertical speed void Start to the minimum falling speed at _vertSpeed minFall
288. imations on the character model will be played back according to the movement scripts you ll write Of course the very first thing you need to do before any of those steps is turn on the animation system Select the player model in the Project view to see its Import settings in the Inspector Select the Animations tab and make sure Import Animation is checked Then go to the Rig tab and switch Animation Type from Generic to Human oid this isa humanoid character naturally Note that this last menu also has a Legacy setting Generic and Humanoid are both settings within the umbrella term Mecanim Explaining Unity s Mecanim animation system Unity has a sophisticated system for managing animations on models called Mecanim Mecanim is based on skeletal animation the style of animation defined in this chapter The special name Mecanim identifies the newer more advanced anima tion system that was recently added to Unity as a replacement for the older animation system The older system is still around identified as Legacy animation but it may be phased out in a future version of Unity at which point Mecanim will simply be the animation system Although the animations we re going to use are all included in the same FBX file as our character model one of the major advantages of Mecanim s approach is that you 160 7 4 1 CHAPTER 7 Creating a third person 3D game player movement and animation continued can apply animations from
289. implemented in any class that implements this interface The status property tells the rest of the code whether this module has completed its initialization The purpose of Startup is to handle initial ization of the manager so initialization tasks happen there and the function sets the manager s status Notice that the property is of type ManagerStatus that s an enum we haven t writ ten yet so create the script ManagerStatus cs see the next listing Listing 8 10 ManagerStatus possible states for IGameManager status public enum ManagerStatus Shutdown Initializing Started This is another file with barely any code in it This time we re listing the different pos sible states that managers can be in thereby enforcing that the status property will always be one of these listed values Now that IGameManager is written we can implement it in other scripts Listings 8 11 and 8 12 contain code for PlayerManager and InventoryManager Listing 8 11 InventoryManager using UnityEngine g yang Import new data structures using System Collections used in listing 8 14 using System Collections Generic i a running startup tasks go here Managing inventory data and game state 181 public class InventoryManager MonoBehaviour IGameManager public ManagerStatus status get private set A Property can be read from anywhere but only public void Startup sae i set within this script
290. in the folder Plugins iOS in the Project view Create TestPlugin h and TestPlugin mm there in the h file write the code from the following listing Listing 12 6 TestPlugin h header for iOS code import lt Foundation Foundation h gt interface TestObject NSObject NSString status end Look for an explanation about iOS programming to understand what this header is doing explaining iOS programming is beyond this introductory book Write the code from the next listing in the mm file Listing 12 7 TestPlugin mm implementation import TestPlugin h implementation TestObject end NSString CreateNSString const char string if string return NSString stringWithUTF8String string else return NSString stringWithUTF8String char MakeStringCopy const char string if string NULL return NULL 294 CHAPTER 12 Deploying your game to players devices char res char malloc strlen string 1 strcpy res string return res extern C const char TestString const char string NSString oldString CreateNSString string NSString newString oldString uppercaseString return MakeStringCopy newString UTF8String float TestNumber return arc4random 100 100 0 Again a detailed explanation of this code is a bit beyond this book Note that many of the string functions are there to convert between how Unity represents string d
291. in Unity especially mobile games that took advantage 95 96 5 1 CHAPTER 5 Building a Memory game using Unity s new 2D functionality of Unity s cross platform nature In prior versions of Unity game developers required a third party framework such as 2D Toolkit from Unikron Software to emulate 2D graphics within Unity s 3D scenes Eventually the core editor and game engine were modified to incorporate 2D graphics and this chapter will teach you about that newer functionality The 2D workflow in Unity is more or less the same as the workflow to develop a 3D game import art assets drag them into a scene and write scripts to attach to the objects The primary kind of art asset in 2D graphics is called a sprite DEFINITION Sprites are 2D images displayed directly on the screen as opposed to images displayed on the surface of 3D models that is textures You can import 2D images into Unity as sprites in much the same way you can import images as textures see chapter 4 Technically these sprites will be objects in 3D space but they ll be flat surfaces all oriented along the Z axis Because they ll all face the same direction you can point the camera straight at the sprites and players will only be able to discern their movements along the X and Y axes that is two dimensions In chapter 2 we discussed the coordinate axes having three dimensions adds a Z axis perpendicular to the X and Y axes you were already familiar with
292. in the two string variables intro synth and loop The remainder of the added code calls commands for loading and playing music or in the last added method stopping the music The Resources Load command loads the named asset from the Resources folder taking into account that the files are placed in the Music subfolder within Resources A generic object is returned by that command but the object can be converted to a more specific type in this case an AudioClip using the as keyword The loaded audio clip is then passed into the PlayMusic method This function sets the clip in the AudioSource and then calls Play As I explained earlier sound effects are better implemented using PlayOneShot but setting the clip in the AudioSource is a more robust approach for music allowing you to stop or pause the playing music STEP 4 ADD MUSIC CONTROLS TO THE UI The new music playback methods in AudioManager won t do anything unless they re called from elsewhere Let s add more buttons to the audio UI that will play different music when pressed Here again are the steps enumerated with little explanation refer back to chapter 6 if needed Change the pop up s width to 350 to fit more buttons Create a new UI button and parent it to the pop up Set the button s width to 100 and position to 0 20 Expand the button s hierarchy to select the text label and set that to Level Music Repeat these steps twice more to create two additi
293. including the texture while applying basic dark and light across the surface For skyboxes there s a differ Inspector ent shader Click the menu in G order to see the drop down list mE Shader Skybox 6 Sided see figure 4 11 of all the avail Shader ic EEO able shaders Move down to the property as Skybox section and choose 6 Ol a Rieg EE 4 r i icles a Sided in the submenu E V 6 Sided gt P Cubemap Sprites E With this shader active the Skybox Procedural U z P Unli amp material now has six large texture shader in i the menu ae Legacy Shaders i slots instead of just the small Albedo texture slot that the Figure 4 11 The drop down menu of available shaders 82 CHAPTER 4 Developing graphics for your game Skybox images from 93i de up down front back left right P i Figure 4 12 Six sides of a skybox images for top bottom front back left and right standard shader had These six texture slots correspond to the six sides of a cube so these images should match up at the edges in order to appear seamless For example figure 4 12 shows the images for the sunny skybox Import the skybox images into Unity the same way you brought in the brick tex tures drag the files into the Project view or right click in Project and select Import New Asset There s one subtle import setting to change click the imported texture to see its properties in the Inspector an
294. ing sim Frame rendered return to Step 1 ilar to but in a different context Figure 3 5 Basic Al cyclical process of moving from shooting forward and avoiding obstacles Seeing obstacles with a raycast As you saw in the introduction to this chapter raycasting is a technique that s useful for a number of tasks within 3D simulations One easily grasped task was shooting but another place raycasting can be useful is for scanning around the scene Given that scanning around the scene is a step in AI code that means raycasting is used in AI code Earlier you created a ray that originated at the camera because that s where the player was looking from this time you ll create a ray that originates at the enemy The first ray shot out through the center of the screen but this time the ray will shoot for ward in front of the character figure 3 6 illustrates this Then just like the shooting code used RaycastHit information to determine whether anything was hit and where the AI code will use RaycastHit information to determine whether anything is in front of the enemy and if so how far away Basic wandering AI 57 One difference between raycasting for R shooting and raycasting for AI is the radius of the ray detected against For shooting the ray was treated as infinitely thin but for AI the ray will be treated as having a large cross section in terms of the code this means using the method Sphe
295. ing 2D graphics and chapters 5 and 6 focus on 2D graphics it originated as a 3D game engine and continues to have strong 3D graphics features Many 3D artists work with at least one of the software packages described in this section Maya Maya is a 3D art and animation package with deep roots in moviemaking Maya s fea ture set covers almost every task that comes up for 3D artists from crafting beautiful cinematic animations to making efficient game ready models 3D animation done in Maya such as a character walking can be exported over to Unity www autodesk com products autodesk maya overview 306 B 2 2 B 2 3 B 3 B 3 1 B 3 2 B 3 3 B 4 APPENDIX B External tools used alongside Unity 3ds Max The other widely used 3D art and animation package 3ds Max offers an almost identi cal feature set and is quite comparable in workflow to Maya 3ds Max runs only on Windows whereas other tools including Maya are cross platform but it s used just as often in the game industry www autodesk com products autodesk 3ds max overview Blender Though not as commonly used in the game industry as either 3ds Max or Maya Blender is also comparable to those other applications Blender also covers almost all 3D art tasks and best of all Blender is open source Given that it s available for free on all platforms Blender is the only 3D art application that s assumed to be available by this book www blender org
296. ing the enemy The other two lines added are PlayOneShot methods That method causes an audio source to play a given audio clip Add those methods inside the target condi tional in order to play sounds when different objects are hit NOTE You could set the clip in the AudioSource and call Play to play the clip Multiple sounds would cut each other off though so we used Play OneShot instead Replace PlayOneShot with this code and shoot a bunch rapidly to see er hear the problem soundSource clip hitEnemySound soundSource Play All right play the game and shoot around You now have several different sound effects in the game These same basic steps can be used to add all sorts of sound effects A robust sound system in a game requires a lot more than just a bunch of dis connected sounds though at a minimum all games should offer volume control You ll implement that control next through a central audio module Audio control interface Continuing the code architecture established in previous chapters you re going to create an AudioManager Recall that the Managers object has a master list of various code modules used by the game such as a manager for the player s inventory This time you ll create an audio manager to stick into the list This central audio module will allow you to modulate the volume of audio in the game and even mute it Initially you ll only worry about sound effects but in later sections you ll ex
297. ion resulting in a realistic falling movement Jump ing will happen in a natural arc as the character s upward speed gradually reduces to 0 and it starts falling instead Finally the code makes sure the downward speed doesn t exceed terminal velocity Note that the operator is less than and not greater than because downward is a negative speed value Then after the big if statement assign the calculated vertical speed to the Y axis of the movement vector And that s all you need for realistic vertical movement By applying a constant downward acceleration when the character isn t on the ground and adjusting the speed appropriately when the character is on the ground the code creates nice falling behavior But this all depends on detecting the ground correctly and there s a subtle glitch we need to fix Modifying the ground detection to handle edges and slopes As explained in the previous section the isGrounded property of Character Controller indicates whether the bottom of the character controller collided with anything in the last frame Although this approach to detecting the ground works the majority of the time you ll probably notice that the character seems to float in the air while stepping off edges That s because the collision area of the character is a sur rounding capsule you can see it when you select the character object and the bot tom of this capsule will still be in contact with the ground when
298. ion technologies as well as techniques to compensate for lag For example Unity uses the RakNet networking library through a system called remote procedure calls RPCs The cutting edge for networked action games is a complex topic that goes beyond the scope of this book You can look up more information on your own starting here http docs unity3d com Manual NetworkReferenceGuide html Now that you know how to get numerical and string data from the internet let s do the same thing with an image Adding a networked billboard Although the responses from a web API are almost always text strings formatted in XML or JSON many other sorts of data are transferred over the internet Besides text data the most common kind of data requested is images Unity s WWW object can be used to download images too You re going to learn about this task by creating a billboard that displays an image downloaded from the internet You need to code two steps downloading an image to display and applying that image to the billboard object Then as a third step you ll improve the code so that the image will be stored to use on multiple billboards Loading images from the internet First let s write the code to down load an image You re going to download some public domain landscape photography see fig ure 9 5 to test with The down loaded image won t be visible on the billboard yet Pll show you a script to display the image in the next
299. iour private Camera _camera Access other components void Start a attached to the same object _camera GetComponent lt Camera gt void Update S Respond to the mouse button if Input GetMouseButtonDown 0 ss Vector3 point new Vector3 _camera pixelWidth 2 _camera pixelHeight 2 0 a Ray ray _camera ScreenPointToRay point RaycastHit hit Create the ray at if Physics Raycast ray out hit that position using Debug Log Hit hit point ScreenPointToRay AL The raycast fills a referenced variable with information Retrieve coordinates where the ray hit You should note a number of things in this code listing First the camera component is retrieved in Start just like the CharacterController in the previous chapter Then the rest of the code is put in Update because it needs to check the mouse over and over repeatedly as opposed to just one time The method Input GetMouse ButtonDown returns true or false depending on whether the mouse has been clicked so putting that command in a conditional means the enclosed code runs only when the mouse has been clicked You want to shoot when the player clicks the mouse hence the conditional check of the mouse button A vector is created to define the screen coordinates for the ray remember that a vector is several related numbers stored together The camera s pixelWidth and pixelHeight values give you the size of the
300. ipt called MobileTestObject create an empty object in the scene and then attach the script see the next listing to the object Listing 12 5 Using the plug in from MobileTestObject using UnityEngine using System Collections public class MobileTestObject MonoBehaviour private string message Initialize the plug in void Awake ie at the beginning TestPlugin Initialize al 8 8 Use this for initialization void Start _message START TestPlugin TestString This Is A CEST Update is called once per frame void Update Make sure the user touched the screen if Input touchCount 0 return Respond to touch input Touch touch Input GetTouch 0 a if touch phase TouchPhase Began Building for mobile apps iOS and Android 293 _message TOUCH TestPlugin TestNumber Display a message in the void OnGUI a corner of the screen GUI Label new Rect 10 10 200 20 _message The script in this listing initializes the plug in object and then calls plug in methods in response to touch input Once this is running on the device you ll see the test mes sage in the corner change whenever you tap the screen The final thing left to do is to write the native code that TestPlugin references Code on iOS devices is written using Objective C and or C so we need both a h header file and a mm implementation file As described earlier they need to go
301. irection as the character semirandom transform Rotate 0 angle 0 new direction The listing added a couple of variables to represent the speed of movement and from how far away to react to obstacles Then a Translate method was added in the Update method in order to move forward continuously including the use of deltaTime for frame rate independent movement In Update you ll also see ray casting code that looks a lot like the shooting script from earlier again the same tech nique of raycasting is being used here to see instead of shoot The ray is created using the enemy s position and direction instead of using the camera 58 3 3 3 CHAPTER 3 Adding enemies and projectiles to the 3D game As explained earlier the raycasting calculation was done using the method Physics SphereCast This method takes a radius parameter to determine how far around the ray to detect intersections but in every other respect it s exactly the same as Physics Raycast This similarity includes how the command fills in hit information checks for intersections just like before and uses the distance property to be sure to react only when the enemy gets near an obstacle as opposed to a wall across the room When the enemy has a nearby obstacle right in front of it the code rotates the character a semi random amount toward a new direction I say semi random because the values are constrained to minimum and maximum values tha
302. is task than just this involves rotation Diagramming how movement is programmed Animating an object such as making it spin boils down to moving it a small amount every frame with the frames playing over and over By themselves transforms apply instantly as opposed to visibly moving over time But applying the transforms over and over causes the object to visibly move just like a series of still drawings in a flipbook Figure 2 11 diagrams how this works Recall that script components have an Update method that runs every frame To spin the cube add code inside Update that rotates the cube a small amount This code will run over and over every frame Sounds pretty simple right Frame 1 Frame 2 Frame 3 Frame 4 oO ZN Rotate cube Rotate cube Rotate cube by 15 degrees by 15 degrees by 15 degrees ee Figure 2 11 The appearance of movement cyclical process of transforming between still pictures 2 3 2 Making things move a script that applies transforms 31 Writing code to implement the diagram Now let s put in action the concepts just discussed Create a new C script remember it s in the Create submenu of the Assets menu name it Spin and write in the code from the following listing don t forget to save the file after typing in it Listing 2 1 Making the object spin using UnityEngine using System Collections public class Spin MonoBehaviour ublic float speed 3 0f j 7 DI Decla
303. isplayed over the 3D scene rather than displaying the images as part of the scene The positioning of UI elements also has some special tricks because of the needs of a display that may change on different screens Creating a canvas for the interface One of the most fundamental and nonobvious aspects of how the UI system works is that all images must be attached to a canvas object TIP Canvasis a special kind of object that Unity renders as the UI for a game Open the GameObject menu to see the various kinds of objects you can create in the UI category choose Canvas A canvas object will appear in the scene it may be clearer to rename the object HUD Canvas This object represents the entire extent of the screen and it s huge relative to the 3D scene because it scales one pixel of the screen to one unit in the scene WARNING When you create a canvas object an EventSystem object is auto matically created too That object is required for UI interaction but you can otherwise ignore it Switch to 2D view mode refer to figure 6 4 and double click the canvas in the Hierar chy in order to zoom out and view it fully The 2D view mode is automatic when the entire project is 2D but in a 3D project this toggle must be clicked to switch between 124 6 2 2 CHAPTER 6 Putting a 2D GUI in a 3D game 2D view mode Switch to this view when working in 2D including the Ul Canvas object displayed in the Scene view If you see the col
304. isting 5 4 New public methods in MemoryCard cs SerializeField private SceneController controller private int _id Added getter function an public int id S idiom common in languages get return _id like C and Java Public method that other scripts can public void SetCard int id Sprite image use to pass new sprites to this object id id GetComponent lt SpriteRenderer gt sprite image LI SpriteRenderer code line just like in the deleted example code The primary change from previous listings is that we re now setting the sprite image in SetCard instead of Start Because that s a public method that takes a sprite as a parameter you can call this function from other scripts and set the image on this object Note that SetCard also takes an ID number as a parameter and the code stores that number Although we don t need the ID quite yet soon we ll write code that compares cards for matches and that comparison will rely on the IDs of the cards NOTE Depending on what programming languages you ve used in the past you may not be familiar with the concept of getters and setters Long story short those are functions that run when you attempt to access the property associated with them for example retrieving the value of card id There are multiple reasons to use getters and setters but in this case the id property is read only because there s only a function to get the value and not
305. isual editor instead of hardcoding every value The second line to examine from listing 2 1 is the Rotate method That s inside Update so that the command runs every frame Rotate is a method of the Trans form class so it s called with dot notation through the transform component of this object as in most object oriented languages this transform is implied if you type v c M Spin Scrip mE Script Espn o Speed B 4 Figure 2 12 The Inspector displaying a public variable declared in the script 32 2 3 3 CHAPTER 2 Building a demo that puts you in 3D space Roll Pitch Yaw Figure 2 13 Illustration of pitch yaw and roll rotation of an aircraft transform The transform is rotated by speed degrees every frame resulting in a smooth spinning movement But why are the parameters to Rotate listed as 0 speed 0 as opposed to say speed 0 0 Recall that there are three axes in 3D space labeled X Y and Z It s fairly intuitive to understand how these axes relate to positions and movements but these axes can also be used to describe rotations Aeronautics describes rotations in a similar way so programmers working with 3D graphics often use a set of terms borrowed from aero nautics pitch yaw and roll Figure 2 13 illustrates what these terms mean pitch is rotation around the X axis yaw is rotation around the Y axis and roll is rotation around the Z axis Given that we can describe rotations ar
306. it s not standing on the ground but it ll also push away from the point of collision because it needs to move the capsule away from the platform it s hitting Thus the code will detect collisions with the character controller and respond to those collisions by nudging away The following listing adjusts the vertical movement with everything we just discussed Listing 7 5 Using raycasting to detect the ground private ControllerColliderHit contact A Needed to store collision bool hitGround false data between functions Check if the RaycastHit hit player is falling Ns if _vertSpeed lt 0 amp amp Physics Raycast transform position Vector3 down out hit float check an charController height charController radius 1 9f The distance to check hitGround hit distance lt check a against extend slightly beyond the bottom of the capsule if hitGround if Input GetButtonDown Jump _vertSpeed jumpSpeed else _vertSpeed minFall else _vertSpeed gravity 5 Time deltaTime if _vertSpeed lt terminalVelocity _vertSpeed terminalVelocity LA Instead of using isGrounded check the raycasting result Respond slightly Raycasting didn t detect differently depending on ground but Me capsule whether the character is Tf _charCont roller isGrounded IS touching the ground facing the contact point L Vector3 Dot movement _contact normal lt 0 movement _
307. its position along with the character but will rotate independently of the character 146 CHAPTER 7 Creating a third person 3D game player movement and animation First place the camera where you want it to be relative to the player I went with position 0 3 5 3 75 to put the camera above and behind the character reset rota tion to 0 0 0 if needed Then create a script called OrbitCamera see the next list ing Attach the script component to the camera and then drag the player character into the Target slot of the script Now you can play the scene to see the camera code in action Listing 7 1 Camera script for rotating around a target while looking at it using UnityEngine using System Collections Serialized reference to the public aaa GED TG Gens re MonoBehaviour S object to orbit around SerializeField private Transform target public float rotSpeed 1 5f private fl at rotY private Vectors offset void Start Store the starting position _rotY transform eulerAngles y offset between the camera _offset target position transform position a and the target void LateUpdate l l Either rotate the camera float horInput Input GetAxis Horizontal i A slowly using arrow keys if horInput 0 hori i _rotY horInput rotSpeed or rotate quickly else a with the mouse _rotY Input GetAxis Mouse X rotSpeed 3 Maintain the starting offset shifted
308. ityEngine using System Collections nE 7 Erori De or Declare a method with the pu 1c Class OLOr angevevice Onobenavilour Ps same name as the door script public void Operate ao Color random new Color Random Range 0f 1f Random Range 0f 1f Random Range 0Of 1f Get Component lt Renderer gt material color random The color is set in the material attached to the object To start with declare the same function name as the door script used Operate is the function name that the device operator script uses so we need to use that name in order for it to be triggered Inside this function the code assigns a random color to the object s material remember color isn t an attribute of the object itself but rather the object has a material and that material can have a color NOTE Although the color is defined with Red Blue and Green components as is standard in most computer graphics the values in Unity s Color object vary between 0 and 1 instead of 0 and 255 as is common in most places including Unity s color picker UI All right so we ve gone over one approach to interacting with devices in the game and have even implemented a couple of different devices to demonstrate Another way of interacting with items is by bumping into them so let s go over that next Interacting with objects by bumping into them In the previous section devices were operated by keyboard input from the player bu
309. ityEngine using System Collections This script needs a public class RelativeMovement MonoBehaviour reference to the object SerializeField private Transform target to move relative to void Update fo Vector3 movement Vectors ZeEro Start with vector float horInput Input GetAxis Horizontal Onik handie movement while 0 0 0 and add float vertInput Input GetAxis Vertical y a arrow keys are pressed movement if horInput 0 vertInput 0 components movement x horiInput progressively movement z vertInput NNS l p Keep the initial rotation to restore a after finishing with the target object Transform movement Quaternion tmp target rotation direction from Local target eulerAngles new Vector3 0 target eulerAngles y 0 to Global coordinates movement target TransformDirection movement target rotation tmp transform rotation Quaternion LookRotation movement LookRotation calculates a quaternion facing in that direction The code in this listing starts the same way as listing 7 1 did with a serialized variable for target Just as the previous script needed a reference to the object itd orbit around this script needs a reference to the object it ll move relative to Then we get to the Update function The first line of the function declares a Vector3 value of 0 0 0 It s important to create a zeroed vector and fill in the values later rather than simply create
310. ject in Blender and export that out to an art asset that works with Unity TIP Modeling is a huge topic but we ll cover only a handful of modeling functions that will allow you to create the bench If you want to keep learn ing more about modeling after this chapter look to some of the many books and tutorials on the subject to start with look at the learning resources on www blender org WARNING I used Blender 2 67 so the explanations and screenshots come from that version of the software Newer versions of Blender are released frequently and there may be slight changes to the placement of buttons or names of commands Figure C 1 Diagram of the simple bench you re going to model 308 C 1 Building the mesh geometry 309 The default camera delete this A default cube The default light delete this Figure C 2 The initial default screen in Blender NN The toolbar settings for this viewport Building the mesh geometry Launch Blender the initial default screen looks like figure C 2 with a cube in the middle of the scene Use the middle mouse button to manipulate the camera view click and drag to tumble Shift with click drag to pan and Control with click drag to zoom Blender starts out in Object mode which as the name Weight Paint Texture Paint Switch to Edit mode instead implies is when you manipulate entire objects moving them een around the scene To edit a sin emits ind of Object
311. ject you build it simply adds audio capabilities on top of an existing game demo All of the examples in this chapter are built on top of the FPS created in chapter 3 and you could download that sample project but you re free to use whatever game demo you d like Once you have an existing game demo copied to use for this chapter you can tackle the first step importing sound effects Importing sound effects Before you can play any sounds you obviously need to import the sound files into your Unity project First you ll collect sound clips in the desired file format and then you ll bring the files into Unity and adjust them for your purposes Supported file formats Much as you saw with art assets in chapter 4 Unity supports a variety of audio formats with different pros and cons Table 10 1 lists the audio file formats that Unity supports Table 10 1 Audio file formats supported by Unity File type Pros and cons WAV Default audio format on Windows Uncompressed sound file AIF Default audio format on Mac Uncompressed sound file MP3 Compressed sound file sacrifices a bit of quality for much smaller files OGG Compressed sound file sacrifices a bit of quality for much smaller files 224 CHAPTER 10 Playing audio sound effects and music Table 10 1 Audio file formats supported by Unity continued File type Pros and cons MOD Music tracker file format A specialized kind of efficient digital music XM Music tracke
312. k if _webImage null StartCoroutine _ network DownloadImage Texture2D image gt Store _webImage image downloaded callback webImage o image Ws J AL Callback is used in lambda function instead of sent directly to NetworkService else callback _webImage The main change was in the function passed to NetworkService DownloadImage Previously the code was passing through the same callback method from WebLoading Banner After the change though the callback sent to NetworkService was a separate lambda function declared on the spot that called the method from WebLoading Banner Take note of the syntax to declare a lambda method gt Making the callback a separate function made it possible to do more than call the method in WebLoadingBanner specifically the lambda function also stores a local copy of the downloaded image Thus GetWebImage only has to download the image the first time all subsequent calls will use the locally stored image Because this optimization applies to subsequent calls the effect will be noticeable only on multiple billboards Let s duplicate the billboard object so that there will be a second billboard in the scene Select the billboard object hit Duplicate look under the Edit menu or right click and move the duplicate over for example change the X position to 18 Now play the game and watch what happens When you operate the first billboard there will be a
313. k script using UnityEngine using System Collections public class MouseLook MonoBehaviour public enum RotationAxes MouseXAndY 0 MousexX 1 MouseY 2 public RotationAxes axes RotationAxes MouseXAndY public float sensitivityHor 9 0f public float sensitivityVert 9 0f public float minimumVert 45 0f public float maximumVert 45 0f private float rotationxX 0 void Stare Rigidbody body GetComponent lt Rigidbody gt if body null body freezeRotation true void Update if axes RotationAxes MouseX transform Rotate 0 Input GetAxis Mouse X sensitivityHor 0 else if axes RotationAxes MouseyY rotationx Input GetAxis Mouse Y sensitivityVert _rotationxX Mathf Clamp _rotationX minimumVert maximumVert float rotationY transform localEulerAngles y transform localEulerAngles new Vector3 _ rotationxX rotationY 0 else _rotationx Input GetAxis Mouse Y sensitivityVert _rotationxX Mathf Clamp _rotationX minimumVert maximumVert float delta Input GetAxis Mouse X sensitivityHor float rotationYy transform localEulerAngles y delta transform localEulerAngles new Vector3 _ rotationxX rotationY 0 40 2 5 2 5 1 CHAPTER 2 Building a demo that puts you in 3D space When you run the new script you re able to look around in all directions while mov ing the mouse Great But you re still stuck in one
314. ke HTTP requests to get XML data from a server Chapter 10 teaches how to program audio functionality Unity has great support for both short sound effects and long music tracks both sorts of audio are crucial for almost all video games XXil ABOUT THIS BOOK Chapter 11 walks you through bringing together pieces from different chapters into a single game In addition you ll learn how to program point and click controls and how to save the player s game Chapter 12 goes over building the final app with deployment to multiple plat forms like desktop web and mobile Unity is wonderfully platform agnostic enabling you to create games for every major gaming platform There are also four appendixes with additional information about scene naviga tion external tools Blender and learning resources Code conventions requirements and downloads All the source code in the book whether in code listings or snippets is in a fixed width font like this which sets it off from the surrounding text In most listings the code is annotated to point out key concepts and numbered bullets are sometimes used in the text to provide additional information about the code The code is format ted so that it fits within the available page space in the book by adding line breaks and using indentation carefully The only software required is Unity this book uses Unity 5 0 which is the latest version as I write this Certain chapters do occasionally
315. kybox iki of the textures e Wrap Mode images pen ARR from Repeat to Clamp Figure 4 13 Correct faint edge lines by adjusting the Wrap mode 4 5 4 5 1 Working with custom 3D models 83 Woohoo you ve learned how to create sky visuals for your scene A skybox is an ele gant way to create the illusion of a vast atmosphere surrounding the player The next step in polishing the visuals in your level is to create more complex 3D models Working with custom 3D models In the previous sections we looked at applying textures to the large flat walls and floors of the level But what about more detailed objects What if we want say interest ing furniture in the room We can accomplish that by building 3D models in external 3D art apps Recall the definition from the introduction to this chapter 3D models are the mesh objects in the game that is the three dimensional shapes Well we re going to import a 3D mesh of a simple bench Applications widely used for modeling 3D This includes both the 3D mesh geometry objects include Autodesk s Maya and 3ds Max and a texture applied to the mesh Those are both expensive commercial tools so the sample for this chapter uses the open source app Blender The sample download includes a blend file that you can use figure 4 14 depicts the bench model in Blender If you re interested in learning how to model your own objects you ll find an exercise in appendix C about modeling this ben
316. l free to rearrange most of the scene but there are several essential game elements that you must keep the player object that s tagged Player the floor object set to the Ground layer and the objective object Controller HUD Canvas and EventSystem TIP By default the lighting system regenerates the lightmaps when the level is loaded But this only works while you are editing the level lightmaps won t be generated when loading levels while the game is running As you did in chapter 9 you can turn off Continuous Baking in the lighting window Win dow gt Lighting and then click Build to bake lightmaps remember don t touch the Scene folder that s created You also need to adjust MissionManager to load the new levels Change maxLevel to 3 by changing the call UpdateData 0 1 to UpdateData 0 3 Now play the game and you ll start on Level initially reach the level objective and you ll move on to the next level Incidentally you can also save on a later level to see that the game will restore that progress Exercise Integrating audio into the full game Chapter 10 was all about implementing audio in Unity didn t explain how to integrate that into this chapter s project but at this point you should understand how encour age you to practice your skills by integrating the audio functionality from the previous chapter into this chapter s project Here s a hint change the key to toggle the audio settings pop up so
317. l make the entire thing a prefab Create a cube object at Position 18 1 0 Select the Is Trigger option of the Box Collider turn off Cast Receive Shadows in Mesh Renderer and set the object to the Ignore Raycast layer Create a new material called objective make it bright green and set the shader to Unlit gt Color for a flat bright look Next create the script Objective Trigger shown in the next listing and attach that script to the objective object Listing 11 22 Code for ObjectiveTrigger to put on objective objects using UnityEngine using System Collections public class ObjectiveTrigger MonoBehaviour Call the new objective void OnTriggerEnter Collider other method in MissionManager Managers Mission ReachObjective a Drag this object from the Hierarchy into Project view to turn it into a prefab in future levels you could put the prefab in the scene Now play the game and go reach the objective The completion message shows when you beat the level Next let s have a failure message show when you lose 268 CHAPTER 11 Putting the parts together into a complete game 11 2 3 Losing the level when caught by enemies The failure condition will be when the player runs out of health because of the enemy attacking First add another GameEvent public const string LEVEL FAILED LEVEL FAILED Now adjust PlayerManager to broadcast this message when health drops to O as shown in the next listing
318. l of that code was for calculating the movement direction as a vector The final line of code applies that movement direction to the character by converting the Vector3 into a Quaternion using Quaternion LookDirection and assigning that value Try running the game now to see what happens Smoothly rotating interpolating by using Lerp Currently the character s rotation snaps instantly to different facings but it d look better if the character smoothly rotated to different facings We can do so using a mathematical operation called Lerp First add this variable to the script DUubltewrloae CsOrspeed 11s 0r Then replace the existing transform rotation line at the end of listing 7 2 with the following code Quaternion direction Quaternion LookRotation movement eranstorm rotacion Ouatrerni on erp transtorm rotation direction rotSpeed Time deltaTime Now instead of snapping directly to the LookRotation value that value is used indirectly as the target direction to rotate toward The Quaternion Lerp method smoothly rotates between the current and target rotations with the third parameter controlling how quickly to rotate Incidentally the term for smoothly changing between values is interpolate you can interpolate between two of any kind of value not just rotation values Lerp is a quasi acronym for linear interpolation and Unity provides Lerp methods for vectors and float values too to i
319. l readers and between readers and the author can take place It is not a commitment to any specific amount of participation on the part of the author whose contribution to the forum remains voluntary and unpaid We sug gest you try asking the author some challenging questions lest his interest stray ABOUT THIS BOOK Xxiii The Author Online forum and the archives of previous discussions will be accessi ble from the publisher s website as long as the book is in print About the author Joseph Hocking is a software engineer living in Chicago specializing in interactive media development He works for Synapse Games as a developer of web and mobile games such as the recently released Tyrant Unleashed He also teaches classes in game development at Columbia College Chicago and his website is www newarteest com About the cover illustration The figure on the cover of Unity in Action is captioned Habit of the Master of Ceremo nies of the Grand Signior The Grand Signior was another name for a sultan of the Ottoman Empire The illustration is taken from Thomas Jefferys A Collection of the Dresses of Different Nations Ancient and Modern 4 volumes London published between 1757 and 1772 The title page states that these are hand colored copperplate engravings heightened with gum arabic Thomas Jefferys 1719 1771 was called Geographer to King George HI An English cartographer who was the leading map supplier of his day Jef
320. lVersionControlSystemSupport html A third weakness has to do with working with prefabs Prefabs are a concept specific to Unity and are explained in chapter 3 for now all you need to know is that prefabs are a flexible approach to visually defining interactive objects The concept of prefabs is both powerful and unique to Unity and yes it s tied into Unity s component system but it can be surprisingly awkward to edit prefabs Considering prefabs are such a use ful and central part of working with Unity I hope that future versions improve the workflow for editing prefabs Example games built with Unity You ve heard about the pros and cons of Unity but you might still need convincing that the development tools in Unity can give first rate results Visit the Unity gallery at http unity3d com showcase gallery to see a constantly updated list of hundreds of games and simulations developed using Unity This section explores just a handful of games showcasing a number of genres and deployment platforms DESKTOP WINDOWS MAC LINUX Because the editor runs on the same platform deployment to Windows or Mac is often the most straightforward target platform Here are a couple of examples of desktop games in different genres Guns of Icarus Online figure 1 2 a first person shooter devel oped by Muse Games Figure 1 2 Guns of Icarus Online CHAPTER 1 Getting to know Unity Gone Home figure 1 3 an exploration adventur
321. laced later to demonstrate the technique First add the code from the following listing to the MemoryCard script Listing 5 3 Test code to demonstrate changing the sprite image Reference to the Sprite SerializeField private Sprite image lt asset that will be loaded void Start GetComponent lt SpriteRenderer gt sprite image i P j AL Set the sprite for this SpriteRenderer component After you save this script the new image variable will appear in the Inspector because it has been set as serialized Drag a sprite up from the Project view pick one of the card images and not the same as the image already in the scene and drop it on the Image slot Now run the scene and you ll see the new image on the card The key to understanding this code is to know about the SpriteRenderer component Sprite asset displayed You ll notice in figure 5 7 that the card back on this Sprite object object has just two components the standard Y Elw Sprite Renderer g Transform component on all objects in the EE a scene and a new component called Sprite Color 2 Renderer This component makes it a sprite object and determines which sprite asset will Color that tints this Sprite object be displayed Note that the first property in aaua Winnie aii a the component is called Sprite and links to Figure 5 7 A sprite object in the scene one of the sprites in the Project view the has the SpriteRenderer component property can b
322. later in the chapter see figure 1 15 you ll click and drag this script file onto an object in the scene Double click the script and it ll automatically be opened in another program called Mono Develop discussed next Using MonoDevelop the cross platform IDE Programming isn t done within Unity exactly but rather code exists as separate files that you point Unity to Script files can be created within Unity but you still need to use some text editor or IDE to write all the code within those initially empty files Unity comes bundled with MonoDevelop an open source cross platform IDE for C figure 1 14 shows what it looks like You can visit www monodevelop com to learn more about this software but the version to use is the version bundled along with Unity rather than a version downloaded from their website because some modifications were made to the base software in order to better integrate it with Unity NOTE MonoDevelop organizes files into groupings called a solution Unity automatically generates a solution that has all the script files so you usually don t need to worry about that Because C originated as a Microsoft product you may be wondering if you can use Visual Studio to do programming for Unity The short answer is yes you can Support 1 3 3 Getting up and running with Unity programming 17 Don t hit the Run button within MonoDevelop Script files open as tabs in the main viewing hit Play in Unity to
323. lculation of delta is the amount that rota tion should change That amount of change is then added to the current rotation angle to get the desired new rotation angle Finally both angles vertical and horizontal are used to create a new vector that s assigned to the transform component s angle property Disallow physics rotation on the player Although this doesn t matter quite yet for this project in most modern FPS games there s a complex physics simulation affecting everything in the scene This will cause objects to bounce and tumble around this behavior looks and works great for most objects but the player s rotation needs to be solely controlled by the mouse and not affected by the physics simulation For that reason mouse input scripts usually set the EreezeRotation property on the player s Rigidbody Add this Start method to the MouseLook script void Start 4 Rigidbody body GerComponentr Rigidboedy if body null 7 body freezeRotation true Check if this component exists A Rigidbody is an additional component an object can have The physics simulation acts on Rigidbodies and manipulates objects they re attached to Script component for looking around MouseLook 39 In case you ve gotten lost on where to make the various changes and additions we ve gone over the next listing has the full finished script Alternatively download the example project Listing 2 7 The finished MouseLoo
324. led list youd Start ae Much of this listing is Vector3 startPos originalCard transform position context to show where Declare an integer the additions go array with a pair l numbers 0 0 1 1 2 2 3 3 numbers ShuffleArray numbers i of IDs for all ss AL Call a function that will shuffle four card sprites Dr Gne i Oe 4 gnaler i 7 the elements of the array for int j 0 j lt gridRows j MemoryCard card if i 0 amp amp j 0 card originalCard else card Instantiate originalCard as MemoryCard int index j gridCols i int id numbers index card Saeed esd AL Retrieve IDs from the shuffled list instead of random numbers float posX offsetX i startPos x float posY offsetY j startPos y card transform position new Vector3 posX posY startPos z private int ShuffleArray int numbers int newArray numbers Clone as int for int i 0 i lt newArray Length i Here s an implementation of the Knuth shuffle algorithm 110 5 4 CHAPTER 5 Building a Memory game using Unity s new 2D functionality int tmp newArray i int r Random Range i newArray Length newArray i newArrayl r newArrayl r tmp return newArray Now when you hit Play the grid of cards will be a shuffled assortment that reveals exactly two of each card image The array of cards was run through the
325. llboard without image Billboard with downloaded image Figure 9 6 The billboard object before and after displaying the downloaded image new cube and then place it in the middle of the scene at something like Position 0 1 5 5 and Scale 5 3 5 see figure 9 6 You re going to create a device that operates just like the color changing monitor in chapter 8 Copy the DeviceOperator script and put it on the player As you may recall that script will operate nearby devices when the Fire3 button is pressed which is defined in the project s input settings as the left Command key Also create a script for the billboard device called WebLoadingBillboard put that script on the billboard object and enter the code from the next listing Listing 9 15 WebLoadingBillboard device script using UnityEngine using System Collections public class WebLoadingBillboard MonoBehaviour Call the method in public void Operate ImagesManager Managers Images GetWebImage OnWebImage Downloaded private void OnWebImage Texture2D image image is applied l l a to the material GetComponent lt Renderer gt material mainTexture image in the callback This code does two primary things it calls ImagesManager GetWebImage when the device is operated and it applies the image from the callback function Textures are applied to materials so you can change the texture in the material that s on the bill board Figure 9 6 shows what the
326. loaded from scratch TIP You can mark specific objects to exclude from the default memory flush when a level is loaded Unity provides the DontDestroyOnLoad method to keep an object around in multiple scenes we ll use this method on parts of the code architecture in later chapters Another game successfully completed Well completed is a relative term you could always implement more features but everything from the initial plan is done Many of the concepts from this 2D game apply to 3D games as well especially the checking of game state and loading levels Time to switch gears yet again and move away from this Memory game and on to new projects 118 CHAPTER 5 Building a Memory game using Unity s new 2D functionality 5 6 Summary In this chapter you ve learned that Displaying 2D graphics in Unity uses an orthographic camera For pixel perfect graphics the camera size should be half the screen height Clicking on sprites requires that you first assign 2D colliders to them New images for the sprites can be loaded programmatically UI text can be made using 3D text objects Loading levels resets the scene Putting a 2D GUI in a 3D game This chapter covers Comparing old pre Unity 4 6 and new GUI systems Creating a canvas for the interface Positioning Ul elements using anchor points Adding interactivity to the UI buttons sliders and SO On Broadcasting and listening for events from the UI In this
327. lowing listing Listing 9 5 Making HTTP requests in NetworkService using UnityEngine using System Collections using System public class NetworkService URL to send request to private const string xmlApi ay http api openweathermap org data 2 5 weather g Chicago us amp mode xml1 private bool IsResponseValid WWW www aoe if www error null Check for errors in the response Debug Log bad connection return false else if string IsNullOrEmpty www text Debug Log bad data return false else all good return true private IEnumerator CallAPI string url Action lt string gt callback WWW new WWW url AE en bees eee oe AO HTTP request sent by Pause while Pa l creating a WWW object downloading if IsResponseValid www Break out of the Sf EE Delegate can be called just ine i like the original function coroutine if error callback www text a 6 public IEnumerator GetWeatherXML Action lt string gt callback return CallAPI xmlApi callback a yield cascades through coroutine methods that call each other Downloading weather data from an internet service 205 Remember the code design explained earlier WeatherManager will tell Network Service to go fetch data Thus all this code doesn t actually run yet you re setting up code that will be called by WeatherManager a bit later To explore this code listing let s start at the bottom and w
328. lso our responsibility to conserve the resources of our planet Manning books are printed on paper that is at least 15 percent recycled and processed without elemental chlorine Di Manning Publications Co Development editor Dan Maharry 20 Baldwin Road Technical development editor Scott Chaussee PO Box 761 Copyeditor Elizabeth Welch Shelter Island NY 11964 Proofreader Melody Dolab Technical proofreader Christopher Haupt Typesetter Marija Tudor Cover designer Marija Tudor ISBN 9781617292323 Printed in the United States of America 12345678 9 10 EBM 20 19 18 17 16 15 www allitebooks com brief contents PART 1 FIRST STEPS csssssccsnssscccnssssccesssceccnssssccassssscensssessnsssees l 1 Getting to know Unity 3 2 Building a demo that puts you in 3D space 21 3 Adding enemies and projectiles to the 3D game 46 4 Developing graphics for your game 69 PART 2 GETTING COMFORTABLE ccccccccccccccccccccccccccccccscccccces 93 5 Building a Memory game using Unity s new 2D functionality 95 Putting a 2D GUI in a 35D game 119 7 Creating a third person 3D game player movement and animation 140 8 Adding interactive devices and items within the game 167 PART 3 STRONG FINISH ssssssssssssssssesesececsosssssssssossososssossooo 193 9 Connecting your game to the internet 195 10 Playing audio sound effects and music 222 1i Putting the parts together into a complete game 246 12 Deploying your game to players device
329. lt button object has a text object as its child this button doesn t need a text label so delete the text object Roughly position the UI elements into their corners In the next section we ll make the positions exact for now just drag the objects until they re pretty much in position Click and drag the image object to the top left of the canvas the button goes in the top right TIP As noted in chapter 5 you use the Rect tool in 2D mode I described it as a single manipulation tool that encompasses all three transforms Move Rotate and Scale These operations have to be separate tools in 3D but are combined in 2D because that s one less dimension to worry about In 2D mode this tool is selected automatically or you can click the button in the top left corner of Unity At the moment the images are both blank If you select a UI object and look at the Inspector you should see a Source Image slot near the top of the image component As shown in figure 6 6 drag over sprites remember not textures from the Project I Drag Sprite from v 1M Image Script i i Proje derunt Cno o U 3 2 and the image will S I tti Color A appear on the UI element ource Image setting Rae eT il Set Native Size l 3 Click Set Native Size to resize the image correctly Figure 6 6 Assign 2D sprites to the Image property of UI elements 126 CHAPTER 6 Putting a 2D GUI in a 3D game v M Text Script
330. lts The new UI system works in retained mode so the graphics are laid out once and then drawn every frame without needing to be continually redefined In this system graphics for the UI are placed in Unity s editor This provides two advantages over the immediate mode UI 1 you can see what the UI looks like while placing UI elements and 2 this system makes it straightforward to customize the UI with your own images To use this system you re going to import images and then drag objects into the scene Next let s plan how this UI will look Planning the layout The HUD for most games is only a few different UI controls repeated over and over That means this project doesn t need to be a terribly complex UI in order for you to learn how to build a game s UI You re going to put a score display and a settings button in the corners of the screen see figure 6 2 over the main game view The settings button will bring up a pop up window and that window will have both a text field and a slider For this example those input controls will be used for setting the player s name and movement speed but ultimately those UI elements could control any settings rel evant to your game Well that plan was pretty simple The next step is bringing in the images that are needed Importing UI images This UI requires some images to display for things like buttons The UI is built from 2D images like the graphics in chapter 5 so you ll follow th
331. ly a list of fea tures with no programming required which is a misleading view that won t teach people what they need to know in order to produce commercial titles Though it s true that you can click together a fairly elaborate prototype using preexisting components even without a programmer involved which is itself a pretty big feat rigorous pro gramming is required to move beyond an interesting prototype to a polished game for release How to use Unity The previous section talked a lot about the productivity benefits from Unity s visual editor so let s go over what the interface looks like and how it operates If you haven t done so already down Figure 1 8 The Golf Club load the program from www unity3d com and install it on your computer be sure to include Example Project if that s unchecked in the installer After you install it launch Unity to start exploring the interface You probably want an example to look at so open the included example project a new installation should open the example project automatically but you can also select File gt Open Project to open it manually The example project is installed in the shared user directory which is something like C Users Public Documents Unity Projects on Windows or Users Shared Unity on Mac OS You may also need to open the example scene so double click the Car scene file highlighted in figure 1 9 scene files have the Unity cube icon th
332. meManager public interface IGameManager ManagerStatus status get void Startup NetworkService service The code in this listing adds a reference to NetworkService so also be sure to copy over that additional script drag the file from its location in the chapter 9 project remember a Unity project is a folder on your disc so get the file from there and drop it in the new project Now modify Managers cs to work with the changed inter face see the following listing Listing 11 2 Changing a bit of code in the Managers script private IEnumerator StartupManagers NetworkService network new NetworkService A The adjustments are at the beginning of this method foreach IGameManager manager in startSequence manager Startup network Building an action RPG by repurposing projects 249 Finally adjust both InventoryManager and PlayerManager to reflect the changed interface The next listing shows the modified code from InventoryManager Player Manager needs the same code modifications but with different names Listing 11 3 Adjusting InventoryManager to reflect GameManager private NetworkService _network public void Startup NetworkService service Debug Log Inventory manager starting Same adjustments in both network service managers but change names items new Diclionaryestring int gt Once all the minor code changes are in everything should still act as before T
333. ments the rotation value based on input controls This code looks at two different input controls horizontal arrow keys and horizontal mouse move ment so a conditional is used to switch between them The code checks if horizontal arrow keys are being pressed if they are then it uses that input but if not it checks the mouse By checking the two inputs separately the code can rotate at different speeds for each type of input Next the code positions the camera based on the position of the target and the rotation value The transform position line is probably the biggest aha in this code because it provides some crucial math that you haven t seen before in previous chapters Multiplying a position vector by a quaternion note that the rotation angle was converted to a quaternion using Quaternion Euler results in a position that s shifted over according to that rotation This rotated position vector is then added as the offset from the character s position in order to calculate the position for the cam era Figure 7 7 illustrates the steps of the calculation and provides a detailed break down of this rather conceptually dense line of code Multiply the offset vector by a quaternion to get the rotated offset position transform position target position rotation _offset Then determine the position for the camera by subtracting the rotated offset from the target s position I Define a position to u
334. mes with other tools or built other kinds 1 1 1 1 1 CHAPTER 1 Getting to know Unity of software like desktop applications or websites Creating a video game isn t funda mentally different from writing any other kind of software it s mostly a difference of degree For example a video game is a lot more interactive than most websites and thus involves very different sorts of code but the skills and processes involved in creat ing both are similar If you ve already cleared the first hurdle on your path to learning game development having learned the fundamentals of programming software then your next step is to pick up some game development tools and translate that program ming knowledge into the realm of gaming Unity is a great choice of game develop ment environment to work with A warning about terminology This book is about programming in Unity and is therefore primarily of interest to coders Although many other resources discuss other aspects of game development and Unity this is a book where programming takes front and center Incidentally note that the word developer has a possibly unfamiliar meaning in the context of game development developer is a synonym for programmer in disciplines like web development but in game development the word developer refers to anyone who works on a game with programmer being a specific role within that Other kinds of game developers are artists and designers but this book will fo
335. moving a component in the Inspector ES Cat 30 2 3 2 3 1 CHAPTER 2 Building a demo that puts you in 3D space this menu you ll find Character Controller select that option As the name implies this component will allow the object to behave like a character You need to complete one last step to set up the player object attaching the cam era As mentioned in the earlier section on floors and walls objects can be dragged onto each other in the Hierarchy view Drag the camera object onto the player capsule to attach the camera to the player Now position the camera so that it ll look like the player s eyes I suggest a position of 0 0 5 0 If necessary reset the camera s rotation to 0 0 O this will be off if you rotated the capsule You ve created all the objects needed for this scene What remains is writing code to move the player object Making things move a script that applies transforms To have the player walk around the scene you ll write movement scripts attached to the player Remember components are modular bits of functionality that you add to objects and scripts are a kind of component Eventually those scripts will respond to keyboard and mouse input but first just make the player spin in place This beginning will teach you how to apply transforms in code Remember that the three transforms are Translate Rotate and Scale spinning an object means changing the rotation But there s more to know about th
336. mple Unity asked the web series Extra Credits a great series about 299 300 AFTERWORD game development to do some videos about starting in game dev and you ll find those videos here http unity3d com learn tutorials modules beginner your first game Game design The entire Extra Credits series goes way beyond this handful of videos sponsored by Unity It covers a lot of ground but mostly focuses on the discipline of game design DEFINITION Game design is the process of defining a game by creating its goals rules and challenges Game design is not to be confused with visual design which is designing appearance not function this is a common mistake because the average person is most familiar with design in the context of graphic design DEFINITION One of the most central parts of game design is crafting game mechanics these are individual actions or systems of actions within a game The mechanics in a game are often set up by its rules whereas the challenges in a game generally come from applying the mechanics to specific situations For example walking around the game is a mechanic whereas a maze is a kind of challenge based on that mechanic Thinking about game design can be tricky for newcomers to game development On the one hand the most successful and satisfying to create games are built with interesting and innovative game mechanics On the other hand worrying too much about the design of your firs
337. mputer you re already using NOTE Open up any project to work with in this section Seriously any Unity project will work in fact I strongly suggest using a different project in every sec tion to drive home the fact that Unity can build any project to any platform Start by building for the desktop Windows Mac and Linux 279 12 1 1 Building the application First choose File gt Build Settings to open the Build Settings window By default the current platform will be set to PC Mac and Linux but if that isn t current select the correct platform from the list and click Switch Platform On the right side of the window you ll notice the Target Platform menu This menu lets you choose between Windows PC Mac OS X and Linux All three are treated as one platform in the list on the left side but these are very different plat forms so choose the correct one Once you ve chosen your desktop platform click Build A file dialog pops up allowing you to choose where the built application will go Change to a safe location if necessary the default location is usually within the Unity project which isn t a great place to put builds Then the build process starts this could take a while for a big project but the build process should be fast for the tiny demos we ve been making Custom post build script Although the basic build process works fine in most situations you may want a series of steps to be taken Such as moving help
338. musicVolume while _activeMusic volume gt 0 _activeMusic volume scaledRate Time deltaTime _inactiveMusic volume scaledRate Time deltaTime yield return null bI This yield statement pauses for one frame AudioSource temp _activeMusic AL Temporary variable to use while in ive and _inactive _activeMusic 1nactiveMusic swapping active _activeMusic volume _musicVolume _AmactiveMusic temp _inactiveMusic Stop _crossFading false public void StopMusic _activeMusic Stop _inactiveMusic Stop The first addition is a variable for the second music source While keeping the first AudioSource object duplicate that object make sure the settings are the same select Loop and then drag the new object into this Inspector slot The code also defines AudioSource variables active and inactive but those are private variables used within the code and not exposed in the Inspector Specifically those variables define which of the two audio sources is considered active or inactive at any given time The code now calls a coroutine when playing new music This coroutine sets the new music playing on one AudioSource while the old music keeps playing on the old Summary 245 audio source Then the coroutine incrementally increases the volume of the new music while incrementally decreasing the volume of the old music Once the cross fading is complete that is the volumes have compl
339. my wan der around Code for wandering around is pretty much the simplest example of AI 56 3 3 1 3 3 2 CHAPTER 3 Adding enemies and projectiles to the 3D game artificial intelligence AI refers to computer controlled entities In this case the entity is an enemy in a game but it could also be a robot in the real world or a voice that plays chess for example Diagramming how basic Al works There are a number of different approaches to AI seriously artificial intelligence is a major area of research for computer scientists but for our purposes we ll stick with a simple approach As you become more experienced and your games get more sophis ticated you ll probably want to explore various approaches to AI Figure 3 5 depicts the basic pro cess Every frame the AI code will scan around its environment to Step 1 determine whether it needs to react i Move forward a little bit If an obstacle appears in its way the enemy turns to face a different direction Regardless of whether the enemy needs to turn it will always Step 2 move forward steadily Thus the Raycast forward to look enemy will ping pong around the for obstacles room always moving forward and turning to avoid walls The actual code will look pretty Step 3 familiar because it moves enemies Turn away from obstacles forward using the same commands as moving the player forward The Step 4 Tinea AI code will also use raycast
340. n a series of point lights First start with a directional light the scene probably already has one by default but if not then create one by choosing GameObject gt Light and selecting Directional Light Types of lights You can create several types of light sources defined by how and where they project light rays The three main types are point spot and directional 28 CHAPTER 2 Building a demo that puts you in 3D space continued Point lights are a kind of light source where all the light rays originate from a single point and project out in all directions like a lightbulb in the real world The light is brighter up close because the light rays are bunched up Spot lights are a kind of light source where all the light rays originate from a single point but only project out in a limited cone No spotlights are used in the current project but these lights are commonly used to highlight parts of a level Directional lights are a kind of light source where all the light rays are parallel and project evenly lighting everything in the scene the same way This is like the sun in the real world The position of a directional light doesn t affect the light cast from it only the rota tion the light source is facing so technically you could place that light anywhere in the scene I recommend placing it high above the room so that it intuitively feels like the sun and so that it s out of the way when you re manipulating the rest
341. nManagersProgress int numReady int numModules float progress float numReady numModules progressBar value progress Update the slider to show loading progress private void OnManagersStarted Managers Mission GoToNext ae Load the next scene once managers have started Next link the Slider object to the slot in the Inspector One last thing to do in prepa ration is add the two scenes to Build Settings Building the app will be the topic of the next chapter so for now choose File gt Build Settings to see and adjust the list of scenes Click the Add Current button to add a scene to the list load both scenes and do this for each NOTE You need to add the scenes to Build Settings so that they can be loaded If you don t Unity won t know what scenes are available You didn t need to do this in chapter 5 because you weren t actually switching levels you were reloading the current scene Now you can launch the game by hitting Play from the Startup scene The Game Managers object will be shared in both scenes WARNING Because the managers are loaded in the Startup scene you always need to launch the game from that scene You could remember to always open that scene before hitting Play but there s a script on the Unify wiki that will automatically switch to a set scene when you click Play http wiki unity3d com index php SceneAutoLoader This structural change handles the sharing of game mana
342. nal and can support gameplay At a mini mum the player can walk around the scene think of the demo from chapter 2 In this way you can test to make sure the level is coming together well for example are the rooms the right size for this game before investing a lot of time and energy in detailed work If something is off say you realize the spaces need to be bigger then its much easier to change and retest while you re at the stage of whiteboxing Moreover being able to play the under construction level is a huge morale boost Don t discount this benefit building all the visuals for a scene can take a great deal of time and it can start to feel like a slog if you have to wait a long time before you can experience any of that work in the game Whiteboxing builds a complete if primi tive level right away and it s exciting to then play the game as it continually improves All right so you understand why levels start with whiteboxing now let s actually build a level Drawing a floor plan for the level Building a level on the computer follows designing the level on paper We re not going to get into a huge discussion about level design just as chapter 2 noted about game design level design which is a subset of game design is a large discipline that could fill up an entire book by itself For our pur poses we re going to draw a basic level with Wall Player start little design going into the plan in order to give u
343. name of the copies I also created ore health and key these names must be exact because they ll be used in code later on Also create separate materials for each item in order to give them distinct colors I did light blue energy dark gray ore pink health and yellow key TIP Rather than a name like we ve done here items in more complex games often have an identifier used to look up further data For example one item might be assigned id 301 and id 301 correlates to such and such display name image description and so forth 178 8 3 8 3 1 CHAPTER 8 Adding interactive devices and items within the game Now make prefabs of the items so that you can clone them throughout the level In chapter 3 I explained that dragging an object from the Hierarchy view down to the Project view will turn that object into a prefab do that for all four items NOTE The object s name will turn blue in the Hierarchy list blue names indi cate objects that are instances of a prefab Right click a prefab instance to pick Select Prefab and select the prefab that the object is an instance of Drag out instances of the prefabs and place the items in open areas of the level even drag out multiple copies of the same item to test with Play the game and run into items to collect them That s pretty neat but at the moment nothing happens when you collect an item We re going to start keeping track of the items collected to do that we need to
344. nates had two numbers one along each The ae A axis 3D coordinates have a three numbers X Y Z imagine this line sticking straight ss into and out of the page Horizontal axis labeled X Figure 2 4 Coordinates along the X Y and Z axes define a 3D point Two axes give you 2D coordinates with all points in the same plane Three axes are used to define 3D space Because the X axis goes along the page horizontally and the Y axis goes along the page vertically we now imagine a third axis that sticks straight into and out of the page perpendicular to both the X and Y axes Figure 2 4 depicts the X Y and Z axes for 3D coordinate space Everything that has a specific position in the scene will have XYZ coordinates position of the player placement of a wall and so forth In Unity s Scene view you can see these three axes displayed and in the Inspector you can type in the three numbers to position an object Not only will you write code to position objects using these three number coordinates but you can also define movements as a distance to move along each axis Left handed vs right handed coordinates The positive and negative direction of each axis is arbitrary and the coordinates still work no matter which direction the axes point You simply need to stay consistent within a given 3D graphics tool animation tool game development tool and so forth But in almost all cases X goes A to the right and Y g
345. ncludes tablets The two most widely used mobile computing platforms are iOS from Apple and Android from Google Setting up the build process for mobile apps is more complicated than either desktop or web builds so this is an optional section optional as in only read through it and not actually do the steps ll still write as if you re working along but you d have to buy a developer license for iOS and install all the developer tools for Android WARNING Mobile devices are undergoing so much innovation that the exact build process is likely to be slightly different by the time you read this The high level concepts are probably still true but you should look at up to date documentation online for an exact rundown on the commands to execute and buttons to push For starters here are the doc pages from Apple and Google https developer apple com library ios documentation IDEs Conceptual AppDistributionGuide Introduction Introduction html http developer android com tools building index html Touch input Input on mobile devices works differently than on the desktop or the web Mobile input is done by touching the screen rather than with the mouse and keyboard Unity has input functionality for handling touches including code like Input touchCount and Input GetTouch You may want to use these commands to write platform specific code on mobile devic es Handling input that way can be a hassle though so a number of cod
346. nd choose Physics gt Rigidbody In the component that s added deselect Use Gravity see figure 3 12 so that the fireball won t be pulled down due to gravity Play now and fireballs are destroyed when they hit something T a Rigidbody Because the fireball emitting code aa pd sos rag runs whenever there isn t already a Angular Drag fireball in the scene the enemy will A a Is Kinematic Uncheck shoot more fireballs at the player yee ae m es l this value Now there s just one more bit colision Detection TE gt Constraints remaining for shooting at the player making the player react to Figure 3 12 Turn off gravity in the Rigidbody being hit component Damaging the player Earlier you created a PlayerCharacter script but left it empty Now you ll write code to have it react to being hit as the following listing shows Listing 3 13 Player that can take damage using UnityEngine using System Collections public class PlayerCharacter MonoBehaviour private int _health void Start d Initialize the health value _health 5 a public void Hurt int damage Decrement the player s health _health damage a Debug Log Health health The listing defines a field for the player s health and reduces the health on command In later chapters we ll go over text displays to show information on the screen but for now we can just display information about the
347. nd closing on keypress 168 170 inventory data displaying in UI 186 188 List vs Dictionary 184 186 managers for 178 184 restoring player health by consuming health packs 190 191 using key on locked doors 188 190 setting values using sliders and input fields 133 135 UIController 129 130 internet connected games billboard caching downloaded images 216 217 displaying images 214 216 loading images from internet 212 214 general discussion 195 197 outdoor scene generating sky visuals using skybox 197 198 setting up atmosphere con trolled by code 198 200 posting data to web server overview 217 218 sending post requests 218 220 server side code in PHP 220 weather data service callbacks 205 206 cascading coroutine methods 205 changing scene based on data 210 212 coroutines overview 203 204 HTTP requests 204 205 overview 201 203 206 207 parsing JSON 209 210 parsing XML 207 209 interpolation 150 inventory data displaying in UI 186 188 List vs Dictionary 184 186 managers for 178 184 restoring player health by con suming health packs 190 191 using key on locked doors 188 190 iOS build tools for 286 288 developing plug ins for 291 294 iIween 317 J JavaScript C vs 14 15 communicating with 283 285 JPG format 76 JSON JavaScript Object Notation 209 210 jumping action applying vertical speed and acceleration 153 154 ground detection 154 158 setting up scene 152 153 K keyboard input collision dete
348. nd especially Dan Maharry helped me throughout this undertaking and the book is much stronger for their feedback My sincere thanks also to the many others who worked with me during the development and production of the book My writing benefited from the scrutiny of reviewers every step of the way Thanks to Alex Lucas Craig Hoffman Dan Kacenjar Joshua Frederick Luca Campobasso Mark Elston Philip Taffet Ren van den Berg Sergio Arbeo Rodriguez Shiloh Mor ris and Victor M Perez Special thanks to the notable review work by technical deve lopment editor Scott Chaussee and by technical proofreader Christopher Haupt And I also want to thank Jesse Schell for writing the foreword to my book Next I d like to recognize the people who ve made my experience with Unity a fruit ful one That of course starts with Unity Technologies the company that makes Unity the game engine I owe a debt to the community at gamedev stackexchange com I visit that QA site almost daily to learn from others and to answer questions And the big gest push for me to use Unity came from Alex Reeve my boss at Synapse Games Simi larly I ve picked up tricks and techniques from my coworkers and they all show up in the code I write Finally I want to thank my wife Virginia for her support during the time I was writ ing the book Until I started working on it I never really understood how much a book project takes over your life and affects everyone aro
349. nd increase tiling in the material try numbers like 8 or 9 in one or both direc tions so that the image won t be stretched in an ugly way Once the ground and walls are taken care of it s time to address the sky Generating sky visuals using a skybox Start by importing the skybox images as you did in chapter 4 go to www 93i1 de to down load skybox images This time get the images for the DarkStormy set in addition to TropicalSunnyDay the sky will be more complex in this project Import these textures into the Project view and as explained in chapter 4 set their Wrap Mode to Clamp Now create a new material to use for this skybox At the top of the settings for this material click the Shader menu in order to see the drop down list with all the avail able shaders Move down to the Skybox section and choose 6 Sided in that submenu With this shader active the material now has six texture slots instead of only the small Albedo texture slot that the standard shader had Drag the SunnyDay skybox images to the texture slots of the new material The names of the images correspond to the texture slot to assign them to top front and so on Once all six textures are linked up you can use this new material as the skybox for the scene Assign this skybox material in the Lighting window Window gt Lighting Assign the material for your skybox to the Skybox slot at the top of the window either drag the material over or click the little ci
350. nd the JSON parser for example There are certainly many more useful scripts you can find here http wiki unity3d com index php Scripts UNITY PATTERNS The library of scripts here isn t nearly as extensive as at the Unify wiki but there s some useful code to look through along with some illuminating tutorials http unitypatterns com ITWEEN As mentioned briefly in chapters 3 and 8 a kind of motion effect commonly used in games is referred to as a tween This is a kind of movement where a single code com mand can set an object moving to a target over a certain amount of time Tweening functionality can be added to Unity via a number of libraries and here s one good option http itween pixelplacement com index php 318 APPENDIX C Online learning resources PRIME 31 Unity provides deployment to mobile platforms like 10S and Android but the actual platform specific features are limited to core features You can add a lot of more spe cific features through plug ins and prime 31 has many such plug ins https prime31 com PLAY GAMES SERVICES FROM GOOGLE On iOS Unity has GameCenter integration built in so that your games can have plat form native leaderboards and achievements The equivalent system on Android is called Google Play Games although this isn t built into Unity Google maintains a plug in https github com playgameservices play games plugin for unity FMOD STUDIO The audio functionality built int
351. ndForth MonoBehaviour public float speed 3 0f public float maxZ 16 0f public float minZ 16 0f These are the positions the a object moves between Which direction is the ae object currently moving in Private int direction 1 void Update transform Translate 0 0 direction speed Time d eltaTime bool bounced false if transform position z gt maxZ transform position z lt minz direction direction LS Make an extra bounced true Toggle the direction back and forth movement this I frame if the object if bounced switched directions transform Translate 0 0 direction speed Time deltaTime Run this script and the sphere glides back and forth in the central corridor of the level Now you can make the particle system a child of the sphere and the fire will move with the sphere Just like with the walls of the level in the Hierarchy view drag the particle object onto the sphere object WARNING You usually have to reset the position of an object after making it the child of another object For example we want the particle system at 0 0 0 this is relative to the parent Unity will preserve the placement of an object from before it was linked as a child Now the particle system moves along with the sphere the fire isn t deflecting from the movement though which looks unnatural That s because by default particles move correctly only in the local space of t
352. ne Although the scene is defined using XYZ coordinates the actual display on your monitor is a 2D grid of colored pixels Thus in order to display the 3D scene the computer needs to calculate the color of all the pixels in the 2D grid running that algorithm is referred to as rendering Inside OnGUI the code defines 2D coordinates for the display shifted slightly to account for the size of the label and then calls GUI Label That method displays a text label because the string passed to the label is an asterisk you end up with that 3 2 3 2 1 Scripting reactive targets 53 character displayed in the center of the screen Now it s much easier to aim in our nascent FPS game Listing 3 3 also added some cursor settings to the Start method All that s hap pening is that the values are being set for cursor visibility and locking The script will work perfectly fine if you omit the cursor values but these settings make first person controls work a bit more smoothly The mouse cursor will stay in the center of the screen and to avoid cluttering the view it will turn invisible and will only reappear when you hit Esc WARNING Always remember that you can hit Esc to unlock the mouse cursor While the mouse cursor is locked it s impossible to click the Play button and stop the game That wraps up the first person shooting code well that wraps up the player s end of the interaction anyway but we still need to take ca
353. nent method public class RelativeMovement MonoBehaviour public float moveSpeed 6 0f l Here s a pattern you ve seen in access to other components void Start at _charController GetComponent lt CharacterController gt void Update Overwrite the existing X and Z a lines to apply movement speed horInput moveSpeed movement z vertInput moveSpeed Ne movement Vector3 ClampMagnitude movement moveSpeed N X Remember to always multiply ase movements by deltaTime to make movement Time deltaTime them frame rate independent _charController Move movement If you play the game now you can see the character stuck in a T pose moving around in the scene Pretty much the entirety of this listing is code you ve already seen before so I ll just review everything briefly First there s a RequireComponent method at the top of the code As explained in chapter 2 RequireComponent will force Unity to make sure the GameObject has 152 1 3 CHAPTER 7 Creating a third person 3D game player movement and animation a component of the type passed into the command This line is optional you don t have to require it but without this component the script will have errors Next there s a movement value declared followed by getting this script a reference to the character controller As you ll recall from previous chapters GetComponent returns other components a
354. new Rect posxX posY width height already in script shown Equip item here for reference Managers Inventory EquipItem item Start of j new code jf item lt health if GUI Button new Rect posx posY height buffer width height Use Health Managers Inventory ConsumeItem health Managers Player ChangeHealth 25 Run the contained code if the button is clicked posX width buffer The new ConsumeItem method is pretty much the reverse of AddItem it checks for an item in the inventory and decrements if the item is found It has responses to a couple of tricky cases such as if the item count decrements to 0 The UI code calls this new inventory method and it calls the ChangeHealth method that PlayerManager has had from the beginning If you collect some health items and then use them you ll see health messages appear in the console And there you go multiple examples of how to use inventory items 8 5 Summary In this chapter you ve learned that Both keypresses and collision triggers can be used to operate devices Objects with physics enabled can respond to collision forces or trigger volumes Complex game state is managed via special objects that can be accessed globally Collections of objects can be organized in List or Dictionary data structures Tracking the equip state of items can be used to affect other parts of the game Part 3 Strong finish
355. ng but it won t cause errors either the code for Android plug ins will only compile when Unity is set to the Android platform In particular note the calls to AndroidJNI That s the system within Unity for con necting to native Android The other possibly confusing word that appears is Activity 296 CHAPTER 12 Deploying your game to players devices in Android apps an activity is an app process Unity is an activity of the Android app so the plug in code needs access to that activity to pass it around when needed Finally you need the native Android code Whereas iOS code is written in lan guages like Objective C and C Android is programmed in Java But we can t simply provide the raw Java code for the plug in the plug in must be a JAR packaged from the Java code Here again the details of Android programming are out of scope for a Unity intro but for reference the following listing shows an Ant build file replace paths with locations on your computer especially notice Unity s classes jar to use when building Android plug ins and listing 12 10 shows the Java code for the plug in being used Listing 12 9 Script build xml that generates a JAR from the Java code lt xml version 1 0 encoding UTF 8 gt lt project name TestPlugindJava gt lt Change this in order to match your configuration gt lt property name sdk dir value LOCATION OF ANDROID SDK gt s lt property name target value android 18 g
356. ng in order to work with health in that manager Listing 11 4 Adjusting PlayerCharacter to use health in PlayerManager using UnityEngine using System Collections public class PlayerCharacter MonoBehaviour Use the value in PlayerManager public void Hurt int damage instead of the variable in Managers Player ChangeHealth damage a PlayerCharacter At this point you have a game demo with pieces assembled from multiple previous projects An enemy character has been added to the scene making the game more threatening But the controls and viewpoint are still from the third person movement demo so let s implement point and click controls for an action RPG Programming point and click controls movement and devices This demo needs a top down view and mouse control of the player s movement refer back to figure 11 1 Currently the camera responds to the mouse whereas the player responds to the keyboard that is what was programmed in chapter 7 which is the reverse of what you want in this chapter In addition you ll modify the color changing monitor so that devices are operated by clicking on them In both cases the existing code isn t terribly far from what you need you ll make adjustments to both the move ment and device scripts Building an action RPG by repurposing projects 251 TOP DOWN VIEW OF THE SCENE First you ll raise the camera to 8 Y to position it for an overhead view You ll also adjust Orbi
357. ng music involves the same series of steps as UI sound effects did background music is also 2D sound without a source within the scene so we re going to go through all the steps again 1 Import audio clips 2 Set up an AudioSource for AudioManager to use 3 Write code to play the audio clips in AudioManager 4 Add music controls to the UI Each step will be modified slightly to work with music instead of sound effects Let s look at the first step STEP 1 IMPORT AUDIO CLIPS Obtain some music by downloading or recording tracks For the sample project I went to www freesound org and downloaded the following public domain music loops loop by Xythe Ville Nousiainen Intro Synth by noirenex 238 CHAPTER 10 Playing audio sound effects and music Drag the files into Unity to import them and then adjust their import settings in the Inspector As explained earlier audio clips for music generally have different settings than audio clips for sound effects First the audio format should be set to Vorbis for compressed audio Remember compressed audio will have a significantly smaller file size Compression also degrades the audio quality slightly but that slight degradation is an acceptable trade off for long music clips set Quality to 50 in the slider that appears The next import setting to adjust is Load Type Again music should stream from the disc rather than being loaded completely Choose Streaming from the
358. nifest xml Unity creates a basic manifest file if you don t provide one but you could provide one manually by putting it in Plugins Android alongside the plug in JAR When an Android app is built Unity puts the generated manifest file in the Temp folder at StagingArea AndroidManifest xml copy that file to manually edit it the downloaded code includes a sample manifest file Similarly there s a folder called res where you can put resources like custom icons you could create res in the Android plugins folder 298 12 4 CHAPTER 12 Deploying your game to players devices The JAR file generated by that build script goes in Plugins Android people often put the entire Java project here for clarity but technically only the JAR matters Now build the game and then the message will change whenever you tap the screen Also like the iOS plug in an Android plug in could use UnityPlayer UnitySendMessage to communicate with the object in the scene the Java code would need to import Unity s Android Player library JAR I know I glossed over a lot in developing Android JARs but that s because the pro cess is both too complicated and changes frequently If you become advanced enough to develop plug ins for your Android games you re going to have to look up docu mentation on Android s developer website CONGRATULATIONS YOU VE REACHED THE END Congratulations you now know the steps for deploying a Unity game to mobile de
359. nly because we ll be going through every line to understand all the con cepts in detail This project is a first person demo in order to keep the art require ments simple because you can t see yourself it s fine for you to be a cylindrical shape with a camera on top Now you just need to understand how 3D coordinates work and it will be easy to place everything in the visual editor Understanding 3D coordinate space If you think about the simple plan we re starting with there are three aspects to it a room a view and controls All of those items rely on you understanding how positions and movements are represented in 3D computer simulations and if you re new to working with 3D graphics you might not already know that stuff It all boils down to numbers that indicate points in space and the way those num bers correlate to the space is through coordinate axes If you think back to math class you ve probably seen and used X and Y axes see figure 2 3 for assigning coordinates to points on the page which is referred to as a Cartesian coordinate system Vertical axis Coordinates that define the point s usually labeled Y position The numbers are each No distance along one axis X Y 6 5 eee Horizontal axis labeled X Figure 2 3 Coordinates along the X and Y axes define a 2D point 24 CHAPTER 2 Building a demo that puts you in 3D space Vertical axis labeled Y ee 6 f 5 Where 2D coordi
360. nt 250 11 1 2 CHAPTER 11 Putting the parts together into a complete game Similarly check the Fireball prefab and relink that script if needed Once you re through with the scripts check the links to materials and textures Now add SceneController cs to the controller object and drag the Enemy prefab onto that component s Enemy slot in the Inspector You may need to drag the Fireball prefab onto the Enemy s script component select the Enemy prefab and look at Wan deringAI in the Inspector Also attach PlayerCharacter cs to the player object so that enemies will attack the player Play the game and you ll see the enemy wandering around The enemy shoots fire balls at the player although it won t do much damage select the Fireball prefab and set its Damage value to 10 NOTE Currently the enemy isn t particularly good at tracking down and hit ting the player In this case I d start by giving the enemy a wider field of vision using the dot product approach from chapter 8 Ultimately though you ll spend a lot of time polishing a game and that includes iterating on the behavior of enemies Polishing a game to make it more fun though crucial for a game to be released isn t something you ll do in this book The other issue is that when you wrote this code in chapter 3 the player s health was an ad hoc thing for testing Now the game has an actual PlayerManager so modify Player Character according to the next listi
361. nt will be a trigger volume just like the door trigger in chapter 8 You need to create a new cube object position the object off to one side of the scene set the collider to Trigger and apply a semitransparent material like you did in the previ ous chapter remember set the material s Rendering Mode Figure 9 7 shows the checkpoint object with a green semitransparent material applied Now that the trigger object is in the scene let s write the code that it invokes Tracking current weather sending post requests The code that s invoked by the checkpoint object will cascade through several scripts As with the code for downloading data the code for sending data will involve WeatherManager telling NetworkService to make the request while NetworkService handles the details of HTTP communication The next listing shows the adjustments you need to make to NetworkService Listing 9 17 Adjusting NetworkService to post data ae pe const string localApi http localhost ch9 api php server side script change this if needed private IEnumerator CallAPI string url Hashtable args Action lt string gt callback WWW www T Added arguments to CallAPI parameters Posting data to a web server 219 if args null www new WWW url else WWWForm form new WWWForm foreach DictionaryEntry arg in args form AddField arg Key ToString arg Value ToString Send arguments along with _ WWW using WWWFo
362. nteraction is programmed with a standard series of steps that s the same for all UI elements 1 Create a UI object in the scene the button created in the previous section 2 Write a script to call when the UI is operated 3 Attach that script to an object in the scene 4 Link UI elements such as buttons to the object with that script To follow these steps first we need to create a controller object to link to the button Create a script called UIController shown in the following listing and drag that script onto the controller object in the scene Listing 6 3 UlController script used to program buttons using UnityEngine using UnityEngine UI LS using System Collections Import UI code framework public class UIController MonoBehaviour SerializeField private Text scoreLabel Reference Text object in void Update scene to set text property scoreLabel text Time realtimeSinceStartup ToString public void OnOpenSettings Debug Log open settings AL Method called by settings button TIP You might be wondering why we need separate objects for Scene Controller and UIController Indeed this scene is so simple that you could have one controller handling both the 3D scene and the UI As the game gets more complex though it ll become increasingly useful for the 3D scene and the UI to be separate modules communicating indirectly This notion extends well beyond games to software in general so
363. nterpolate positions colors or anything Quaternions also have a closely related alternative method for interpolation called Slerp for spherical linear interpolation For slower turns Slerp rotations may look better than Lerp 7 2 2 Limit diagonal movement to the same movement speed as movement along an axis Programming camera relative movement controls 151 Currently the character is rotating in place without moving in the next section we ll add code for moving the character around NOTE Because sideways facing uses the same keyboard controls as orbiting the camera the character will slowly rotate while the movement direction points sideways This doubling up of the controls is desired behavior in this project Moving forward in that direction As you ll recall from chapter 2 in order to move the player around the scene we need to add a character controller component to the player object Select the character and then choose Components gt Physics gt Character Controller In the Inspector you should slightly reduce the controller s radius to 4 but otherwise the default settings are all fine for this character model The next listing shows what you need to add in the RelativeMovement script Listing 7 3 Adding code to change the player s position using UnityEngine using System Collections The surrounding lines are context for placing the RequireComponent typeof CharacterController A RequireCompo
364. ntory Figure 11 4 The UI for this chapter s project 7 Set the Text object s anchor to top left and position 100 40 s Type Health as the text on the label 9 Create an image connected to that canvas GameObject gt UI gt Image 10 Name the new object Inventory Popup 11 Assign the pop up sprite to the image s Source Image 12 Set Image Type to Sliced and select Fill Center 13 Position the pop up image at 0 0 and scale the pop up to 250 width 150 height NOTE Recall how to switch between viewing the 3D scene and the 2D inter face toggle 2D view mode and double click either the Canvas or the Building to zoom to that object Now you have the Health label in the corner and the large blue pop up window in the center Let s program these parts first before getting deeper into the UI functionality The interface code will use the same Messenger system from chapter 6 so copy over the Messenger script Then create a GameEvent script see the following listing Listing 11 10 GameEvent script to use with this Messenger system public static class GameEvent public const string HEALTH UPDATED HEALTH UPDATED For now only one event is defined over the course of this chapter you ll add a few more events Broadcast this event from PlayerManager cs shown in the next listing Listing 11 11 Broadcasting the health event from PlayerManager cs public void ChangeHealth int value Set listener for health update event
365. o Unity works well for simply playing back recordings but can be limited for advanced sound design work FMOD Studio is an advanced sound design tool that has a free to use but not necessarily publish Unity plug in Scroll down to find it in their Downloads page www fmod org download PROBUILDER AND PROTOTYPE ProBuilder and Prototype are add ons that enable powerful level editing within Unity ProBuilder costs money for professional features like flexible texturing but Prototype is free and ideal for use in the white boxing workflow from chapter 4 www protoolsforunity3d com prototype FPS CONTROL FPS Control is a suite of tools and code designed to ease the creation of FPS first person shooter games This framework grew out of a popular series of video tutorials www fpscontrol com features index Symbols lt gt syntax 206 Numerics 2D images memory game card objects buidling from sprites 102 103 instantiating grid of cards 107 109 loading images programmatically 104 105 responding to clicks 103 104 revealing card 104 setting image from SceneController 105 107 shuffling cards 109 110 sprites 98 100 switching camera to 2D mode 101 102 textures applying 78 80 file formats 76 77 importing files 77 78 overview 75 76 2D sound 227 3D art tools 305 306 3D models defined 141 file formats 83 84 importing and exporting 84 86 overview 83 3D scenery floor plans 73 74 laying out primitive
366. o the web This refers to games that run within a web browser and can thus be played over the internet Unity Player vs HTML5 WebGL Previously Unity had to deploy web builds in a form that plays within a custom browser plug in This has long been necessary because 3D graphics aren t built in for web browsers In the last few years though a standard has emerged for 3D graphics on the web called WebGL Technically WebGL is separate from HTML5 although the two terms are related and are often used interchangeably Unity 5 has added WebGL to the platforms list of the Build window and future ver sions may even make it the new main avenue for doing web builds In part these changes in Unity s web build are being driven by strategic decisions made within Unity the company These changes are also being driven by pushes from browser makers who are moving away from custom plug ins and embracing HTML5 WebGL as the way to do interactive web applications including games Regardless of the form of the final built app the process for doing a web build is almost exactly the same for both a web player and WebGL The following sections will describe the process for the web player so you should also use that platform The text will mention spots where the code you write differs slightly for WebGL Building the Unity file and a test web page Open a different project again this is to emphasize how any project will work and open the Build Settings
367. oM A public void OnSoundToggle A property of AudioManager Managers Audio soundMute Managers Audio soundMute public void OnSoundValue float volume Managers Audio soundVolume volume a This slider will adjust the volume property of AudioManager This script has two methods that affect the properties of AudioManager OnSound Toggle sets the soundMute property and OnSoundValue sets the soundVolume property As usual link in the SettingsPopup script by dragging it onto the Settings Popup object in the UI Then in order to call the functions from the button and slider link the pop up object to interaction events in those controls In the Inspector for the button look for the panel labeled OnClick Click the button to add a new entry to this event Drag Audio control interface 235 Settings Popup to the object slot in the new entry and then look for SettingsPopup in the menu select OnSoundToggle to make the button call that function The method used to link the function applies to the slider as well First look for the interaction event in a panel of the slider s settings in this case the panel is called OnValueChanged Click the button to add a new entry and then drag Settings Popup to the object slot In the function menu find the SettingsPopup script and then choose OnSoundVolume under Dynamic Float WARNING Remember to choose the function under Dynamic Float and not Static Parameter Although the
368. ode architecture to manage data for the collected inventory Finally you ll program inter faces to make use of the inventory for gameplay such as requiring a key to open a door WARNING Previous chapters were relatively self contained and didn t techni cally require projects from earlier chapters but this time some of the code listings make edits to scripts from chapter 7 If you skipped directly to this chapter download the sample project for chapter 7 in order to build on that The example project will have these devices and items strewn about the level ran domly A polished game would have a lot of careful design behind the placement of items but there s no need to carefully plan out a level that only tests functionality Even so though the placement of objects will be haphazard the chapter opening bul lets lay out the order in which we ll implement things As usual the explanations build up the code step by step but if you want to see all the finished code in one place you can download the sample project Creating doors and other devices Although levels in games mostly consist of static walls and scenery they also usually incorporate a lot of functional devices as well I m talking about objects that the player can interact with and operate things like lights that turn on or a fan that starts turn ing The specific devices can vary a lot and are mostly limited only by your imagina tion but they almost all use the s
369. odify the scene based on that data This task will provide a good example of retrieving data using HTTP requests A web service for free weather data is OpenWeatherMap you ll use their API application programming interface a way to access their service using code commands instead of a graphical interface located at http openweathermap org api DEFINITION A web service or web API is a server connected to the internet that returns data upon request There s no technical difference between a web API and a website a website is a web service that happens to return the data for a web page and browsers interpret HTML data as a visible document The code you ll write will be structured around the same Managers architecture from chapter 8 This time you ll have a WeatherManager class that gets initialized from the central manager of managers WeatherManager will be in charge of retrieving and stor ing weather data but to do so it ll need the ability to communicate with the internet To accomplish that you ll create a utility class called NetworkService Network Service will handle the details of connecting to the internet and making HTTP requests WeatherManager can then tell NetworkService to make those requests and pass back the response Figure 9 3 shows how this code structure will operate For this to work obviously WeatherManager will need to have access to the NetworkService object You re going to address this by creating the object in M
370. oes up what SEPE Y axis differs between different tools is nel ant pee ae whether Z goes into or comes axis out of the page These two direc tions are referred to as left handed or right handed as this figure shows if you point your thumb along the X axis and your index finger along the Y axis then your middle finger points along the Zaxis Right handed coordinates The Z axis points in a different direction on the left hand versus the right hand 2 2 2 2 1 Begin the project place objects in the scene 25 Unity uses a left handed coordinate system as do many 3D art applications Many other tools use right handed coordinate systems OpenGL for example so don t get confused if you ever see different coordinate directions Now that you have a plan in mind for this project and you know how coordinates are used to position objects in 3D space it s time to start building the scene Begin the project place objects in the scene All right lets create and place objects in the scene First you ll set up all the static scenery the floor and walls Then you ll place lights around the scene and position the camera Last you ll create the object that will be the player the object to which you ll attach scripts to walk around the scene Figure 2 5 shows what the editor will look like with everything in place Chapter 1 showed how to create a new project in Unity so you ll do that now Remember Choose
371. oesn t require such constant connectivity modern video games 195 196 CHAPTER 9 Connecting your game to the internet usually incorporate features like reporting scores to a global list of high scores Unity provides support for such networking so we ll be going over those features Unity supports multiple approaches to network communication since different approaches are better suited to different needs However this chapter will mostly cover the most general sort of internet communication issuing HTTP requests What are HTTP requests assume most readers know what HTTP requests are but here s a quick primer just in case HTTP is a communication protocol for sending requests to and receiving responses from web servers For example when you click a link on a web page your browser the client sends out a request to a specific address and then that server responds with the new page HTTP requests can be set to a variety of methods in particular either GET or POST to retrieve or to send data HTTP requests are reliable and that s why the majority of the internet is built around them The requests themselves as well as the infrastructure for handling such requests are designed to be robust and handle a wide range of failures in the network In an online game built around HTTP requests the game developed in Unity is essen tially a thick client that communicates with the server in an Ajax style As a good com parison ima
372. of the scene Rotate this light and watch the effect on the room I recommend rotating it slightly on both the X and Y axes to get a good effect You can see an Intensity setting when you look in the Inspector see figure 2 8 As the name implies that setting controls the brightness of the light If this were the only light it d have to be more intense but because you ll add a bunch of point lights as well this directional light can be pretty dim like 0 6 Intensity As for point lights create several using the same menu and place them around the room in dark spots in order to make sure all the walls are lit You don t want too many performance will degrade if the game has lots of lights but one near each corner should be fine I suggest raising them to the tops of the walls plus one placed high above the scene like a Y of 18 to give some variety to the light in the room Note that point lights have a setting for Range added to the Inspector see figure 2 9 This con trols how far away the light reaches whereas directional lights cast light evenly throughout the entire scene point lights are brighter when an object is closer The point lights lower to the floor should have a range around 18 but the light placed high up should have a range of around 40 in order to reach the entire room The other kind of object needed in order for the player to see the scene is a cam era but the empty scene already came with a main camera so yo
373. oks in the scene for an object with the Player tag so assign this tag to the player object Tag is a drop down menu at the top of the Inspector you can define custom tags as well but several tags are defined by default including Player Select the player object to edit it and then select the Player tag Now that BaseDevice is programmed you can modify ColorChangeDevice to inherit from that script The following listing shows the new code Listing 11 8 Adjusting ColorChangeDevice to inherit from BaseDevice using UnityEngine using System Collections Inherit BaseDevice instead AS of MonoBehaviour public class ColorChangeDevice BaseDevice public override void Operate Color random new Color Random Range 0f 1f Random Range 0f 1f Random Range 0Of 1f GetComponent lt Renderer gt material color random Because this script inherits from BaseDevice instead of MonoBehaviour it gets the mouse control functionality Then it overrides the empty Operate method to pro gram the color changing behavior Now the device will operate when you click on it Also remove the player s Device Operator script component because that script operates devices using the control key This new device input brings up an issue with the movement controls currently the movement target is set any time the mouse clicks but you don t want to set the movement target when clicking on devices You can fix this issue by using layers
374. ol ume according to the slider 236 CHAPTER 10 Playing audio sound effects and music 10 3 3 Playing Ul sounds 10 4 You re going to make another addition to AudioManager now to allow the UI to play sounds when buttons are clicked This task is more involved than it seems at first owing to Unity s need for an AudioSource When sound effects issued from objects in the scene it was fairly obvious where to attach the AudioSource But UI sound effects aren t part of the scene so you ll set up a special AudioSource just for AudioManager to use when there isn t any other audio source Create a new empty GameObject and parent it to the main Game Managers object this new object is going to have an AudioSource used by AudioManager so call the new object Audio Add an AudioSource component to this object leave the Spatial Blend setting at 2D this time because the UI doesn t have any specific position in the scene and then add the code shown in the next listing to use this source in AudioManager Listing 10 7 Play sound effects in AudioManager SerializeField private AudioSource soundSource a Variable slot in the Inspector to reference the new audio source public void PlaySound AudioClip clip soundSource PlayOneShot clip ies seins ce di have any other source A new variable slot will appear in the Inspector drag the Audio object onto this slot Now add the UI sound effect to the pop up script see the following
375. on a stack of boxes in the scene Unity has physics simulation built in so we didn t have to write much code That simulation can cause objects to move around in response to collisions but another possible response is firing trigger events so let s use those trig ger events to control the door Triggering the door with a pressure plate Whereas previously the door was operated by a keypress this time the door will open and close in response to the character colliding with another object in the scene Cre ate yet another door and place it in another wall gap I duplicated the previous door and moved the new door to 2 5 1 5 17 Now create a new cube to use for the trigger object and select the Is Trigger check box for the collider this step was illustrated when making the fireball in chapter 3 In addition set the object to the Ignore Ray cast layer the top right corner of the Inspector has a Layer menu Finally you should turn off shadow casting from this object remember this setting is under Mesh Ren derer when you select the object WARNING These tiny steps are easy to miss but very important to use an object as a trigger be sure to turn on Is Trigger In the Inspector look for the check box in the Collider component Also change the layer to Ignore Ray cast so that the trigger object won t show up in raycasting NOTE When trigger objects were first introduced in chapter 3 the object needed to have a Rigidbody com
376. on component exposes but Ul elements can respond to a number of different interactions To go beyond the default interactions use an EventTrigger component Add a new component to the button object and look for the Event section of the com ponent s menu Select EventTrigger from that menu Although the button s OnClick responded only to a full click the mouse button being pressed down and then released let s try responding to the mouse button being pressed down but not released Perform the same steps as for OnClick only responding to a different event First add another method to UlController public void OnPointerDown Debug Log pointer down Now click Add New Event Type to add a new type to the EventTrigger component Choose Pointer Down for the event This will create an empty panel for that event just like OnClick had Click the button to add an event listing drag the controller object to this entry and select OnPointerDown in the menu There you go Play the game and click the button to output debug messages in the console Again the code is currently random output in order to test the button s functionality What we want to do is open a settings pop up so let s create that pop up window next 6 3 2 Programming interactivity in the UI 131 Change the pop up v EI M image Scrip The Set Native Size button image from Simple Source Image Elpopup o only applies to Simple and to Sliced Col
377. on mouse and yes a three button mouse works fine on Mac OSX Transforming objects is also done through three main maneuvers and the three scene navigation moves are analogous to the three transforms Translate Rotate and Scale figure 1 11 demonstrates the transforms on a cube When you select an object in the scene you can then move it around the mathe matically accurate technical term is translate rotate the object or scale how big it is Relating back to scene navigation Move is when you Translate the camera Orbit is when you Rotate the camera and Zoom is when you Scale the camera Besides the buttons on the Toolbar you can switch between these functions by pressing W E or R on the keyboard When you activate a transform you ll notice a set of color coded arrows or circles appears over the object in the scene this is the Transform gizmo and you can click and drag this gizmo to apply the transformation There s also a fourth tool next to the transform buttons Called the Rect tool it s designed for use with 2D graphics This one tool combines movement rotation and scaling These operations have to be separate tools in 3D but are combined in 2D because there s one less dimension to worry about Unity has a host of other keyboard shortcuts for speeding up a variety of tasks Refer to appendix A to learn about them And with that on to the remaining sections of the interface The Hierarchy tab and the Inspector Lookin
378. onal buttons Position one at 105 20 and the other at 105 20 so they appear on either side vn Oo OF A W N P Change the first text label to Intro Music and the last text label to No Music 240 10 4 2 CHAPTER 10 Playing audio sound effects and music Now the pop up has three buttons for playing different music Write a method shown in the following listing in SettingsPopup that will be linked to each button Listing 10 10 Adding music controls to SettingsPopup public void OnPlayMusic int selector Managers Audio PlaySound sound A This method gets a number parameter from the button switch selector case 1 Managers Audio PlayIntroMusic break case 2 Managers Audio PlayLevelMusic break default Managers Audio StopMusic break os Call a different music function in AudioManager for each button Note that the function takes an int parameter this time normally button methods don t have a parameter and are simply triggered by the button In this case we need to distinguish between the three buttons so the buttons will each send a different number Go through the typical steps to connect a button to this code add an entry to the OnClick panel in the Inspector drag the pop up to the object slot and choose the appropriate function from the menu This time there will be a text box for typing in a number because OnPlayMusic takes a number for a parameter Type 1 for Intro Mu
379. ook for Rigid body under the Physics menu Create a new cube object and then add a Rigidbody component to it Create sev eral such cubes and position them in a neat stack For example in the sample down load I created five boxes and stacked them into two tiers see figure 8 3 The boxes are now ready to react to physics forces To have the player apply a force to the boxes make the small addition shown in the following listing to the Relative Movement script this is one of the scripts written in the previous chapter that s on the player Listing 8 5 Adding physics force to the RelativeMovement script oo Pa Amount of force to apply public float pushForce 3 0f void OnControllerColliderHit ControllerColliderHit hit _contact hit Check if the collided JS object has a Rigidbody to Rigidbody body hit collider attachedRigidbody receive physics forces 174 8 2 2 CHAPTER 8 Adding interactive devices and items within the game if body null amp amp body isKinematic body velocity hit moveDirection pushForce bF Apply velocity to the physics body There s not a ton to explain about this code whenever the player collides with some thing check if the collided object has a Rigidbody component If so apply a velocity to that Rigidbody Play the game and then run into the pile of boxes you should see them scatter around realistically And that s all you had to do to activate physics simulation
380. op of the screen The items will be displayed using icons so we need to import those images into the project Unity handles assets in a special way if those assets are in a folder called Resources TIP Assets placed into the Resources folder can be loaded in code using the method Resources Load Otherwise assets can only be placed in scenes through Unity s editor Figure 8 8 shows the four icon images along with Assets Resources Icons health key Figure 8 8 Image assets for a equipment icons placed inside the it a new script called BasicUI see the next listing Resources folder the directory structure showing where to put those images Create a folder called Resources and then create a folder called Icons inside it The icons are all set up so create a new empty GameObject named Controller and then assign Listing 8 18 BasicUl displays the inventory using UnityEngine using System Collections using System Collections Generic 188 CHAPTER 8 Adding interactive devices and items within the game public class BasicUI MonoBehaviour void OnGUI int posx 10 int posy 10 int width 100 g int height 30 ag fy plan int buffer 10 y Pty List lt string gt itemList Managers Inventory GetItemList if itemList Count 0 GUI Box new Rect posxX posY width height No Items The method that loads assets from the Resources folder 8 4 2 foreach string item in itemList
381. operate the animations from the movement script Writing code that operates the animator Finally you ll add methods to the RelativeMovement script As explained earlier most of the work of setting up animation states is done in the animation controller only a small amount of code is needed to operate a rich and fluid animation system see the following listing Listing 7 6 Code for setting values in the Animator component private Animator _animator a Added inside the Start function animator GetComponent lt Animators gt _animator SetFloat Speed movement sqrMagnitude a if hitGround Just below the if statement if Input GetButtonDown Jump for horizontal movement _vertSpeed jumpSpeed 166 CHAPTER 7 Creating a third person 3D game player movement and animation else _vertSpeed 0 1f animator SetBool Jumping false else _vertSpeed gravity 5 Time deltaTime if _vertSpeed lt terminalVelocity _vertSpeed terminalVelocity ie if contact l null _animator SetBool Jumping true Don t trigger this value right at the beginning of the level if _charController isGrounded 1 9 if Vector3 Dot movement _contact normal lt 0 movement Contact normal moveSpeed else movement _contact normal moveSpeed Again much of this listing is repeated from previous listings the animation code is a handful of lines int
382. or C is replaced by a check box Material J None Material for Fill Center Image Type Sliced Fill Center o Figure 6 13 Settings for the image component including Image Type Creating a pop up window The UI has a button to open a pop up window but there s no pop up yet That will be a new image object along with several controls such as buttons and sliders attached to that object The first step is to create a new image so choose GameObject gt UI gt Image Just as before the new image has a slot in the Inspector called Source Image Drag a sprite to that slot to set this image This time use the sprite called popup Ordinarily the sprite is stretched over the entire image object this was how the score and gear images worked and you clicked the Set Native Size button to resize the object to the size of the image This behavior is the default for image objects but the pop up will do something different As you can see in figure 6 13 the image component has an Image Type setting This setting defaults to Simple which was the correct image type earlier For the pop up though set Image Type to Sliced DEFINITION A sliced image is split up into nine sections that scale differently from one another By scaling the edges of the image separately from the mid dle you ensure that the image can scale to any size you want while it main tains its sharp and crisp edges In other development tools these kinds of images oft
383. or UI elements may have lots of different types of targets so Unity provides the SendMessage method to communicate specific messages with a target object even if you don t know exactly what type of object it is WARNING Using SendMessage is less efficient for the CPU than calling pub lic methods on known types that is using object SendMessage Method versus component Method so only use SendMessage when it s a big win in terms of making the code simpler to understand and work with As a gen eral rule of thumb that will only be the case if there could be lots of different types of objects receiving the message in situations like that the inflexibility of inheritance or even interfaces will hinder the game development process and discourage experimentation With this code written wire up the public variables in the button s Inspector The highlight color can be set to whatever you d like although the default cyan looks pretty good on a blue button Meanwhile put the SceneController object in the tar get object slot and then type Restart as the message 5 5 2 Restart button 117 If you play the game now there s a Reset button in the top right corner that changes color in response to the mouse and it makes a slight visual pop when clicked on But an error message was emitted when you clicked the button in the con sole you ll see an error about there not being a receiver for the Restart message That s be
384. or example I obtained several great skyboxes from www 931 de including the TropicalSunny Day set Once this skybox is applied to the scene you will see something like figure 4 10 As with other textures sky Figure 4 10 Scene with background pictures of the sky box images are first assigned to a material and that gets used in the scene Let s examine how to create a new skybox material Creating a new skybox material First create a new material as usual either right click and Create or choose Create from the Assets menu and select it to see settings in the Inspector Next you need to change the shader used by this material The top of the material settings has a Shader menu see figure 4 11 In section 4 3 we pretty much ignored this menu because the default works fine for most standard texturing but a skybox requires a special shader DEFINITION A shader is a short program that outlines instructions for how to draw a surface including whether to use any textures The computer uses these instructions to calculate the pixels when rendering the image The most common shader takes the color of the material and darkens it according to the light but shaders can also be used for all sorts of visual effects Every material has a shader that controls it you could kind of think of a material as an instance of a shader New materials are set to the Standard shader by default This shader displays the color of the material
385. or the latter Materials and animations aren t as directly relatable to the real world Instead both are abstract packets of information that layer onto 3D models For example materials were already introduced in a basic sense in chapter 3 Understanding art assets 71 DEFINITION A material is a packet of information that defines the surface properties of any 3D object that the material is attached to These surface properties can include color shininess and even subtle roughness Continuing the art analogy you can think of a material as the media clay brass mar ble and so on that the sculpture is made of Similarly an animation is also an abstract layer of information that s attached to a visible object DEFINITION An animation is a packet of information that defines movement of the associated object Because these movements can be defined indepen dently from the object itself they can be used in a mix and match way with multiple objects For a concrete example think about a character walking around The overall position of the character is handled by the game s code for example the movement scripts you wrote in chapter 2 But the detailed movements of feet hitting the ground arms swinging and hips rotating are an animation sequence that s being played back that animation sequence is an art asset To help you understand how animations and 3D models relate to each other let s make an analogy to puppeteering the 3
386. ored arrows of the manipulator that means the Rect tool is It is scaled very large because I unit in the NOT on That button is scene pixel in the top left corner on the Ul of Unity you will see blue dots on every The borders of the corner of a 2D object canvas scale to match the game s screen Figure 6 4 A blank canvas object in the Scene view the UI and the main scene To return to viewing the 3D scene toggle the 2D view mode off and then double click the building to zoom to that object TIP Don t forget this tip from chapter 4 across the top of the Scene view s pane are buttons that control what s visible so look for the Effects button to turn off the skybox The canvas has a number of settings that you can adjust First is the Render Mode option leave this at the default setting but you should know what the three possible settings mean Screen Space Overlay Renders the UI as 2D graphics on top of the camera view this is the default setting Screen Space Camera Also renders the UI on top of the camera view but UI ele ments can rotate for perspective effects World Space Places the canvas object within the scene as if the UI were part of the 3D scene The two modes besides the initial default can sometimes be useful for specific effects but are slightly more complicated The other important setting is Pixel Perfect This setting causes the rendering to subtly adjust the po
387. ork our way up WRITING COROUTINE METHODS THAT CASCADE THROUGH EACH OTHER GetWeatherXML is the coroutine method that outside code can use to tell Network Service to make an HTTP request Notice that this function has IEnumerator for its return type methods used in coroutines must have IEnumerator declared as the return type It might look odd at first that GetWeatherXML doesn t have a yield statement Coroutines are paused by the yield statement which implies that every coroutine must yield somewhere It turns out that the yielding can cascade through multiple methods If the initial coroutine method itself calls another method and that other method yields part of the way through then the coroutine will pause inside that sec ond method and resume there Thus the yield statement in CallAPI pauses the coroutine that was started in GetWeatherXML figure 9 4 shows this code flow The next potential head scratcher is the callback parameter of type Action UNDERSTANDING HOW THE CALLBACK WORKS When the coroutine is started the method is called with a parameter called callback and callback has the type Action But what is an Action DEFINITION The type Action is a delegate C has a few approaches to dele gates but this one is the simplest Delegates are references to some other method function They allow you to store the function or rather a pointer to the function in a variable and to pass that function as a parameter to
388. osing levels 268 269 overview 261 262 player progress beating game by complet ing levels 273 275 saving and loading 269 273 point and click controls movement code 251 253 operating devices using mouse 253 255 overview 250 255 top down view of scene 251 S scene navigation 302 303 Scene view 10 11 SceneController 61 62 scenery changing based on data 210 212 floor plans 73 74 laying out primitives 74 75 object placement 25 27 outdoor scenes generating sky visuals using skybox 197 198 setting up atmosphere con trolled by code 198 200 whiteboxing 72 73 scoring memory game comparing revealed cards 111 displaying score text 112 114 hiding mismatched cards 111 112 overview 110 111 Screen Space 124 screen space ambient occlusion See SSAO ScreenPointToRay method 48 50 script components 15 16 SendMessage method 285 291 serialization 210 270 service locator 179 shaders 81 198 shadows 144 145 shooting Al enemies 56 59 via instantiating objects creating projectile prefabs 64 65 damaging player 67 68 overview 63 68 shooting projectiles 65 67 via raycasts overview 47 48 ScreenPointToRay method 48 50 visual indicators for aiming 50 53 reactive targets alerting target to being hit 54 55 determining hits 53 54 spawning enemy prefabs instantiation from invisible SceneController 61 62 overview 60 61 INDEX sideloading 289 skeletal animation 158 160 sky visuals 80 83 197 198 skybox 80 Slerp 15
389. other FBX files to a character For example all of the human enemies can share a single set of animations This has a number of advantages including keeping all your data organized models can go in one folder whereas ani mations go in another folder as well as saving time spent animating each separate character Click the Apply button at the bottom of the Inspector in order to lock these settings onto the imported model and then continue defining animation clips WARNING You may notice a warning not an error in the console that says conversion warning spine3 is between humanoid transforms That specific warning isn t a cause for worry it indicates that the skeleton in the imported model has extra bones beyond the skeleton that Mecanim expects Defining animation clips in the imported model The first step in setting up animations for our character is defining the various anima tion clips that ll be played If you think about a lifelike character different movements can happen at different times sometimes the player is running around sometimes the player is jumping on platforms and sometimes the character is just standing there with its arms down Each of these movements is a separate clip that can play individually Often imported animations come as a single long clip that can be cut up into shorter individual animations To split up the animation clips first select the Anima tions tab in the Inspector You ll see a
390. ould be reset to essentially nothing The character isn t falling 154 7 3 2 CHAPTER 7 Creating a third person 3D game player movement and animation while on the ground so obviously its vertical speed is 0 if the character then steps off a ledge we re going to get a nice natural looking motion because the falling speed will accelerate from nothing NOTE Well not exactly 0 we re actually setting the vertical speed to minFall a slight downward movement so that the character will always be pressing down against the ground while running around horizontally There needs to be some downward force in order to run up and down on uneven terrain The exception to this grounded speed value is if the jump button is clicked In that case the vertical speed should be set to a high number The if statement checks Get ButtonDown a new input function that works much like GetAxis does returning the state of the indicated input control And much like Horizontal and Vertical input axes the exact key assigned to Jump is defined by going to Input settings under Edit gt Project Settings the default key assignment is Space that is the spacebar Getting back to the larger if condition if the character is not on the ground then the vertical speed should be constantly reduced by gravity Note that this code doesn t simply set the speed value but rather decrements it this way it s not a constant speed but rather a downward accelerat
391. ound players will see the world from their character s point of view and the player can control the character using the mouse and keyboard All the interesting complexity of a complete game can be stripped away for now in order I Set up the boundaries of the room First create the floor then the outer walls and then place the inner walls 2 Players need to be able to see the room Put some lights around the room and place the camera that will be the player s view 3 Create the primitive shape for the player Attach the camera to the top of this so that as this object moves the camera moves with it 4 Write movement scripts for the player First write code to rotate with the mouse then write code to move with keyboard Figure 2 2 Roadmap for the 3D demo 2 1 2 Before you start 23 to concentrate on the core mechanic moving around in a 3D space Figure 2 2 depicts the roadmap for this project basically laying out the mental checklist I built in my head Set up the room create the floor outer walls and inner walls Place the lights and camera Create the player object including attaching the camera on top b amp b U N P Write movement scripts rotate with the mouse and move with the keyboard Don t be scared off by everything in this roadmap It sounds like there s a lot in this chapter but Unity makes it easy The upcoming sections about movement scripts are so extensive o
392. ound the X Y and Z axes that means the three parameters for Rotate are X Y and Z rotation Because we only want the player to spin around sideways as opposed to tilting up and down there should only be a number given for the Y rotation and just 0 for X and Z rotation Hopefully you can guess what will happen if you change the parameters to speed 0 0 and then play it try that now There s one other subtle point to understand about rotations and 3D coordinate axes embodied in an optional fourth parameter to the Rotate method Local vs global coordinate space By default the Rotate method operates on what are called local coordinates The other kind of coordinates you could use are global You tell the method whether to use local or global coordinates using an optional fourth parameter by writing either Space Self or Space World like so Rotate 0 speed 0 Space World 2 4 Script component for looking around MouseLook 33 Global coordinate axes Local coordinate axes Note that these axes are aligned to the tilted object but are out of alignment with the global coordinates Figure 2 14 Local vs global coordinate axes Refer back to the explanation about 3D coordinate space and ponder these ques tions Where is 0 0 0 located What direction is the X axis pointed in Can the coordinate system itself move around It turns out that every single object has its own origin point as well as its own dir
393. ove when clicking on the color changing monitor Great the point and click controls are complete One more thing to bring into this project from previous projects is the improved UI Replacing the old GUI with a new interface Chapter 8 used Unity s old immediate mode GUI because that approach was simpler to code But the UI from chapter 8 doesn t look as nice as the one from chapter 6 so let s bring over that interface system The newer UI is more visually polished than the old GUI figure 11 4 shows the interface you re going to create First you ll set up the UI graphics Once the UI images are all in the scene you can attach scripts to the UI objects I ll list the steps involved without going into detail if you need a refresher refer back to chapter 6 1 Import popup png as a sprite choose Texture Type 2 In the Sprite Editor set a 12 pixel border on all sides remember to apply changes Create a canvas in the scene GameObject gt UI gt Canvas Choose the Pixel Perfect setting of the canvas Optional Name the object HUD Canvas and switch to 2D view mode ao a Q Create a Text object connected to that canvas GameObject gt UI gt Text 256 CHAPTER 11 Putting the parts together into a complete game UI as viewed in the editor UI while playing the game There are four sets of text labels and icons set up in the editor but during play they can change appearance or be hidden depending on your inve
394. owing listing Listing 9 3 Initial script for WeatherManager using UnityEngine using System Collections using System Collections Generic public class WeatherManager MonoBehaviour IGameManager public ManagerStatus status get private set Add cloud value here listing 9 8 private NetworkService _network public void Startup NetworkService service Debug Log Weather manager starting _network service pS Store the injected status ManagerStatus Started NetworkService object This initial pass at WeatherManager doesn t really do anything For now it s just the minimum amount that IGameManager requires that the class implements declare the status property from the interface as well as implement the Startup function You ll fill in this empty framework over the next few sections Finally copy over Manag ers from chapter 8 and adjust it to start up WeatherManager see the next listing Listing 9 4 Managers cs adjusted to initialize WeatherManager using UnityEngine using System Collections using System Collections Generic Require the new manager a instead of player and inventory RequireComponent typeof WeatherManager public class Managers MonoBehaviour public static WeatherManager Weather get private set private List lt IGameManager gt startSequence void Awake Weather GetComponent lt WeatherManager gt _startSequence new List lt IGameManager
395. own animations For our purposes though the settings should be Body Orientation Center Of Mass and Center Of Mass in that order Now click Apply and you ve added an idle animation clip to your character Do the same for two more clips walk starts at frame 144 and ends at 169 and run starts at 171 and ends at 190 All the other settings should be the same as for idle because they re also animation loops The fourth animation clip is jump and the settings for that clip differ a bit First this isn t a loop but rather a still pose so don t select Loop Time Set the Start and End to 190 5 and 191 this is a single frame pose but Unity requires that Start and End be different The animation preview below won t look quite right because of these tricky numbers but this pose will look fine in the game 162 7 4 2 CHAPTER 7 Creating a third person 3D game player movement and animation Click Apply to confirm the new animation clips and then move on to the next step creating the animation controller Creating the animator controller for these animations The next step is to create the animator controller for this character This step allows us to set up animation states and create transitions between those states Various ani mation clips are played during different animation states and then our scripts will cause the controller to shift between animation states This might seem like an odd bit of indirection putting the abs
396. p corner of the component select Copy Component from one object and then Paste As New on the other Add this component but don t assign event listeners because that s done in the InventoryPopup code And that completes the inventory UI Play the game to watch the inventory pop up respond when you collect items and click buttons We re now finished assembling parts from previous projects next I ll explain how to build a more expansive game from this beginning Developing the overarching game structure Now that you have a functioning action RPG demo we re going to build the overarch ing structure of this game By that I mean the overall flow of the game through multiple levels and progressing through the game by beating levels What we got from chapter 8 s project was a single level but the roadmap for this chapter specified three levels Doing this will involve decoupling the scene even further from the Managers back end so you ll broadcast messages about the managers just as PlayerManager broad casts health updates Create a new script called StartupEvent listing 11 15 define 262 11 2 1 CHAPTER 11 Putting the parts together into a complete game these events in a separate script because these events go with the reusable Managers system whereas GameEvent is specific to the game Listing 11 15 The StartupEvent script public static class StartupEvent public const string MANAGERS STARTED MANAGERS STARTED
397. p into nine sections Close the editor win dow and apply the changes Now that the sprite has the nine sections defined the sliced image will work correctly and the Image component settings will show Fill Center make sure that setting is on Click and drag the blue indicators in the corner of the image to scale it switch to the Rect tool described in chapter 5 if you don t see any scale indicators The border sections will maintain Figure 6 15 Sliced image scaled to dimensions of the their size while the center portion pop up scales Because the border sections maintain their size a sliced image can be scaled to any size and still have crisp edges This is perfect for UI elements different windows may be different sizes but should still look the same For this pop up enter a width of 250 and a height of 200 to make it look like figure 6 15 also center it on position 0 0 0 TIP How UI images stack on top of each other is determined by their order in the Hierarchy view In the Hierarchy list drag the pop up object above other UI objects always staying attached to the canvas of course Now move the pop up around within the Scene view you can see how images overlap the pop up window Finally drag the pop up to the bottom of the canvas hierarchy so that it will display on top of everything else The pop up object is set up now so write some code for it Create a script called Set tingsPopup see the next listing and
398. parse JSON data We ve been getting XML from the OpenWeatherMap API but as it happens they can also send the same data formatted as JSON To do that modify NetworkService according to the next listing Listing 9 9 Making NetworkService request JSON instead of XML private const string jsonApi http api openweathermap org data 2 5 weather q Chicago us The URL is slightly public IEnumerator GetWeatherJSON Action lt string gt callback different this time return CallAPI jsonApi callback This is pretty much the same as the code to download XML data except that the URL is slightly different The data returned from this request has the same values but it s formatted differently This time we re looking for a chunk like clouds all 40 There wasn t a ton of additional code required this time That s because we set up the code for requests into nicely parceled separate functions so every subsequent 210 9 2 4 CHAPTER 9 Connecting your game to the internet HTTP request will be easy to add Nice Now let s modify WeatherManager to request JSON data instead of XML see the following listing Listing 9 10 Modifying WeatherManager to request JSON instead using MiniJSON bg Be sure to add needed public void Startup NetworkService service e e tare nen Debug Log Weather manager starting Network _network service request StartCoroutine _network GetWeatherJSON OnJSONDataLoaded
399. place looking around as if mounted on a turret The next step is moving around the scene Keyboard input component first person controls Looking around in response to mouse input is an important part of first person con trols but you re only halfway there The player also needs to move in response to key board input Let s write a keyboard controls component to complement the mouse controls component create a new C script called FPSInput and attach that to the player alongside the MouseLook script For the moment set the MouseLook compo nent to horizontal rotation only TIP The keyboard and mouse controls explained here are split up into sepa rate scripts You don t have to structure the code this way and you could have everything bundled into a single player controls script but a component sys tem such as the one in Unity tends to be most flexible and thus most useful when you have functionality split into several smaller components The code you wrote in the previous section affected rotation only but now we ll change the object s position instead As shown in listing 2 8 refer back to the rotation code from before we added mouse input type that into FPSInput but change Rotate to Translate When you hit Play the view slides up instead of spinning around ry changing the parameter values to see how the movement changes in par ticular try swapping the first and second numbers after experimenting with th
400. plained before drag image files into the Project view or choose Assets gt Import New Asset Just like with 3D models textures aren t applied to particle sys Figure 4 21 The image used for fire tems directly you add the texture to a material and apply that particles material to the particle system Create a new material and then select it to see its properties in the Inspector Drag the fire image from Project up to the texture slot That linked the fire texture to the fire material so now you want to apply the material to the particle system Figure 4 22 shows how to do this select the particle system expand Renderer at the bottom of the settings and drag the material onto the Material slot Render Mode Billboard Normal Direction 1 l l Material e ceo LE iMate rial Sort Mode Sorting Fudge Cast Shadows Receive Shadows Max Particle Size Assets Materials BrickLargeBa BrickRoundd MARTES As you did for the skybox material you fire_particle Shader Partiches Addinve Sof 0000 Particle Textur Standard Standard Specular setup need to change the shader for a parti cle material Click the Shader menu near the top of the material settings to Tiling Offset Gul Soft Particles Nature Particles Additive Soft Skybox Alpha Blended Sprites see the list of available shaders Instead of the standard default a material for particles needs one o
401. player s health using debug messages Now we need to go back to the Fireball script to call the player s Hurt method Replace the debug line in the Fireball script with player Hurt damage to tell the player they ve been hit And that s the final bit of code we needed 68 3 6 CHAPTER 3 Adding enemies and projectiles to the 3D game Whew that was a pretty intense chapter with lots of code being introduced Between the previous chapter and this one you now have most of the functionality in place for a first person shooter Summary In this chapter you ve learned that A ray is an imaginary line projected into the scene For both shooting and sensing obstacles do a raycast with that line Making a character wander around involves basic AI New objects are spawned by instantiating prefabs Coroutines are used to spread out functions over time 4 1 Developing graphics for your game This chapter covers Understanding art assets Understanding whiteboxing Using 2D images in Unity Importing custom 3D models Building particle effects We ve been focusing mostly on how the game functions and not as much on how the game looks That was no accident this book is mostly about programming games in Unity Still it s important to understand how to work on and improve the visuals Before we get back to the book s main focus on coding different parts of the game let s spend a chapter learning about game art so
402. ponent added Rigidbody wasn t required for the trigger this time because the trigger would be responding to the player versus colliding with a wall the earlier situation In order for triggers to work either the trigger or the object entering the trigger need to have Unity s physics system enabled a Rigidbody component fulfills this require ment but so does the player s CharacterController Position and scale the trigger object so that it both encompasses the door and sur rounds an area around the door I used Position 2 5 1 5 17 same as the door and Scale 7 5 3 6 Additionally you may want to assign a semitransparent material to the object so that you can visually distinguish trigger volumes from solid objects Create a new material using the Assets menu and select the new material in the Project view Looking at the Inspector the top setting is Rendering Mode currently set to the default value of Opaque select Transparent in this menu Interacting with objects by bumping into them 175 Box with a semitransparent material surrounding the door it triggers Figure 8 4 Trigger volume surrounding the door it will trigger Now click its color swatch to bring up the Color Picker window Pick green in the main part of the window and lower the alpha using the bottom slider Drag this material from Project onto the object figure 8 4 shows the trigger with this material DEFINITION Triggers are often referred to as volumes ra
403. ponent in the Inspector like the Enemy Prefab slot in the Scene Controller component Click the enemy prefab in the Project view and the Inspector 66 CHAPTER 3 Adding enemies and projectiles to the 3D game will show that object s components as if Y G M Wandering Al Script g you d selected an object in the scene Script Speed E Although the earlier warning about E aie ENGE interface awkwardness often applies Fireball Prefab when editing prefabs the interface makes it easy to adjust components on the object and that s all we re doing As Drag the pretab itor shown in figure 3 11 drag up the fire f Project view to a slot ball prefab from Project onto the Fire mO in the Inspector ball Prefab slot in the Inspector again just as you did with SceneController Figure 3 11 Drag the fireball prefab from Project Now the enemy will fire at the player up to the Fireball Prefab slot in the Inspector when the player is directly ahead of it well try to fire the bright orange sphere appears in front of the enemy but it just sits there because we haven t written its script yet Let s do that now The next listing shows the code for the Fireball script Listing 3 12 Fireball script that reacts to collisions using UnityEngine using System Collections public class Fireball MonoBehaviour public float speed 10 0f public int damage 1 void Update transform Translate 0 0 sp
404. poses graphics on top of the view of world The concept of a HUD originated with military jets so that pilots could see crucial information without having to look down Similarly a GUI superimposed on the game view is referred to as the HUD This chapter will show how to build the game s HUD using the latest UI tools in Unity As you saw in chapter 5 Unity provides multiple ways to create UI displays This chap ter demonstrates the new UI system available with Unity 4 6 and later I ll also discuss the previous UI system and the advantages of the new system To learn about the UI tools in Unity you ll build on top of the first person shooter FPS project from chapter 3 The project in this chapter will involve these steps Planning the interface Placing UI elements on the display Programming interactions with the UI elements Making the GUI respond to events in the scene o FF OQO N P Making the scene respond to actions on the GUI NOTE This chapter is largely independent of the project you build on top of it just adds a graphical interface on top of an existing game demo All the examples in this chapter are built on top of the FPS created in chapter 3 and you could download that sample project but you re free to use whatever game demo you d like 6 1 6 1 1 Before you start writing code 121 Copy the project from chapter 3 and open the copy to start working on this chapter As usual the art assets you need are in
405. position of h hen fli dj ss Point of the gun and then flies forward in a intersection straight line until it hits something Origin of the ray i e where A ray is analogous to the path of the imagine a gun the ray hit bullet and raycasting is analogous Figure 3 1 A ray is an imaginary line and raycasting to firing the bullet and seeing is finding where that line intersects where it hits As you can imagine the math behind raycasting often gets complicated Not only is it tricky to calculate the intersection of a line with a 3D plane but you need to do that for all polygons of all mesh objects in the scene remember a mesh object is a 3D visual constructed from lots of connected lines and shapes Fortunately Unity han dles the difficult math behind raycasting but you still have to worry about higher level concerns like where the ray is being cast from and why In this project the answer to the latter question why is to simulate a bullet being fired into the scene For a first person shooter the ray generally starts at the camera position and then extends out through the center of the camera view In other words you re checking for objects straight in front of the camera Unity provides commands to make that task simple Let s take a look at these commands Using the command ScreenPointToRay for shooting You ll implement shooting by projecting a ray that starts at the camera and extends forward through the center of
406. previous button we actu ally want this text label so select the text and type Close in the text field and set Color to white In the Hierarchy view drag this button onto the pop up object so that it will be a child of the pop up window And as a final touch of polish adjust the but ton transition to a Fade Duration value of 01 and a darker Normal Color setting of 110 110 110 255 To make the button close the pop up it needs an OnClick entry click the button on the button s OnClick panel drag the pop up window into the object slot and choose Close from the function list Now play the game and this button will close the pop up window The pop up window has been added to the HUD The window is currently blank though so let s add some controls to it next Setting values using sliders and input fields Adding some controls to the settings pop up involves two main steps like the buttons we made earlier You create UI elements attached to the canvas and link those objects to a script The input controls we need are a slider and a text field and there will be a static text label to identify the slider Choose GameObject gt UI gt Text to create the text object GameObject gt UI gt InputField to create the text field and GameObject gt UI gt Slider to create the slider object see figure 6 16 Make all three objects children of the pop up by dragging them in the Hierarchy view and then position them as indicated in the f
407. ps for 160 162 overview 165 skeletal animation 158 160 defined 71 with Mecanim 86 sprite 99 Animator view 164 anonymous functions 216 API application programming interface 201 artificial intelligence See AI Assault Android Cactus 8 AssetBundles 216 assets 60 atlas 100 atmosphere controlled by code 198 200 Audacity 225 307 audio 2D vs 3D sound 227 background music controlling volume separately 240 242 fading between songs 242 overview 236 237 playing music loops 237 240 control interface AudioManager 230 232 playing sounds 236 volume control UI 232 235 sound effects importing files 225 226 looping sound 228 229 overview 226 228 supported formats 223 225 triggering from code 229 230 tools for 307 AudioClip component 226 227 AudioListener component 226 227 AudioManager component 230 AudioMixer 228 INDEX AudioSource component 226 229 236 238 Awake method 183 background music controlling volume separately 240 242 fading between songs 242 overview 236 237 playing music loops 237 240 Bad Piggies 8 baking shadows 145 Blender 75 84 building mesh geometry 309 311 texture mapping model 312 BMP format 76 broadcast messenger system 136 bumping into objects collecting scattered items 176 178 overview 172 173 physics enabled obstacles 173 174 pressure plate 174 176 C C vs JavaScript 14 15 cache 216 callbacks 205 206 camera camera relative movement controls changing character position 1
408. r Program in order to sell your iOS game in the App Store Apple s developer program costs 99 year enroll at https developer apple com programs Once Xcode is installed go back to Unity and switch to iOS You need to adjust the Player settings for the 10S app remember open Build Settings and click Player Set tings You should already be on the iOS tab of the Player settings but click the iPhone icon tab if needed Scroll down to Other Settings and then look for Identification Bun dle Identifier needs to be adjusted so that Apple will correctly identify the app NOTE Both iOS and Android use Bundle Identifier the same way so that set ting is important on both platforms The identifier should follow the same convention as that for any code package all lowercase in the form com companyname productname Another important setting that applies to both 10S and Android is Bundle Version this is the version number of the app Most of the settings beyond that are platform specific though for example recently 10S added a short version number that will be visible to players separate from the main bundle version There s also a setting for Scripting Backend Mono was always used before but the new IL2CPP back end can support platform updates like 64 bit binaries Now click Build in Unity Select the location for the built files and that ll generate an Xcode project in that location The Xcode project that results can be modified
409. r abstraction on top of what the audio system is doing obviously the actual listener is the player of the game but much like how the position of the AudioListener AudioClip AudioSource Figure 10 2 Diagram of the three things you control in Unity s audio system 228 10 2 2 CHAPTER 10 Playing audio sound effects and music audio source gives the position that the sound is projected from the position of the audio listener gives the position that the sound is heard from Advanced sound control using Audio Mixers Audio Mixers are a new feature added in Unity 5 Rather than playing audio clips direct ly audio mixers enable you to process audio signals and apply various effects to your clips Learn more about AudioMixer in Unity s documentation for example watch this tutorial video https unity3d com learn tutorials modules beginner 5 pre order beta audiomixer and audiomixer groups Although both audio clips and AudioSource components have to be assigned an AudioListener component is already on the default camera when you create a new scene Typically you want 3D sounds to react to the position of the viewer Assigning a looping sound All right now let s set our first sound in Unity The audio clips were already imported and the default camera has an AudioListener component so we only need to assign an AudioSource component We re going to put a crackling fire sound on the Enemy prefab the enemy character
410. r file format A specialized kind of efficient digital music The primary consideration differentiating audio files is the compression applied Compression reduces the file s size but accomplishes that by throwing out a bit of information in the file Audio compression is clever about only throwing out the least important information so that the compressed sound still sounds good Nevertheless it s a small loss of quality so you should choose uncompressed audio when the sound clip is short and thus wouldn t be a large file Longer sound clips especially music should use compressed audio because the audio clip would be prohibitively large oth erwise Unity adds a small wrinkle to this decision though TIP Although music should be compressed in the final game Unity can com press the audio after you ve imported the file Thus when developing a game in Unity you usually want to use uncompressed file formats even for lengthy music as opposed to importing compressed audio How digital audio works In general audio files store the waveform that ll be created in the speakers when the sound plays Sound is a series of waves that travel through the air and different sounds are made with different sizes and frequencies of sound waves Audio files record these waves by sampling the wave repeatedly at short time intervals and saving the state of the wave at each sample Recordings that sample the wave more frequently get a more acc
411. rcle button next to the slot Hit Play and you should see something like figure 9 1 198 9 1 2 CHAPTER 9 Connecting your game to the internet Figure 9 1 Scene with background pictures of the sky Great now you have an outdoors scene A skybox is an elegant way to create the illu sion of a vast atmosphere surrounding the player But the skybox shader built into Unity does have one significant limitation the images can never change resulting in a sky that appears completely static We ll address that limitation by creating a new cus tom shader Setting up an atmosphere that s controlled by code The images in the TropicalSunnyDay set look great for a sunny day but what if we want to transition between sunny and overcast weather This will require a second set of sky images some pictures of a cloudy sky so we need a new shader for the skybox As explained in chapter 4 a shader is a short program with instructions for how to render the image That implies that you can program new shaders and that is in fact the case We re going to create a new shader that takes two sets of skybox images and transitions between them Fortunately a shader for this purpose already exists in the Unify Community wiki s collection of scripts http wiki unity3d com index php title SkyboxBlended In Unity create a new shader script go to the Create menu just like when you cre ate a new C script but select Shader instead Name the asset Sky
412. rd if _firstRevealed null Store card objects in one of the two _firstRevealed card card variables depending on if the Compare the else first variable is already occupied IDs of the two _secondRevealed card revealed cards Debug Log Match firstRevealed id _secondRevealed id The listing stores the revealed cards in one of the two card variables depending on whether the first variable is already occupied If the first variable is empty then fill it if it s already occupied fill the second variable and check the card IDs for a match The debug statement prints either true or false in the console At the moment the code doesn t respond to matches it only checks for them Now let s program the response 5 4 2 Hiding mismatched cards We ll use coroutines again because the reaction to mismatched cards should pause to allow the player to see the cards Refer back to chapter 3 for a full explanation of coroutines long story short using a coroutine will allow us to pause when checking for a match The next listing shows more code for you to add to SceneController 112 5 4 3 CHAPTER 5 Building a Memory game using Unity s new 2D functionality Listing 5 11 SceneController which either scores matches or hides missed matches private int score 0 Another variable to add to the list public void CardRevealed MemoryCard card near the top of SceneController if _firstRevealed
413. rd input Defining and manipulating both 3D positions and rota tions are thoroughly explained Chapter 3 turns the movement demo into a first person shooter teaching you ray casting and basic AI Raycasting shooting a line into the scene and seeing what inter sects is a useful operation for all sorts of games Chapter 4 covers art asset importing and creation This is the one chapter of the book that does not focus on code because every project needs basic models and textures Chapter 5 teaches you how to create a 2D game in Unity Although Unity started exclusively for 3D graphics there s now excellent support for 2D graphics Chapter 6 introduces you to the latest GUI functionality in Unity Every game needs a UI and the latest versions of Unity feature an improved system for creating user interfaces Chapter 7 shows how to create another movement demo in 3D only seen from the third person this time Implementing third person controls will demonstrate a number of key 3D math operations and you ll learn how to work with an animated character Chapter 8 goes over how to implement interactive devices and items within your game The player will have a number of ways of operating these devices including touching them directly touching triggers within the game or pressing a button on the controller Chapter 9 covers how to communicate with the internet You ll learn how to send and receive data using standard internet technologies li
414. rder to respond to the collision data anywhere else in the script that data must be stored in an external variable That s all the method is doing here storing the colli sion data in contact so that this data can be used within the Update method Now the errors are corrected around platform edges and on slopes Go ahead and play to test it out by stepping over edges and jumping onto the steep slope This move ment demo is almost complete The character is moving around the scene correctly so only one thing remains animating the character out of the T pose Setting up animations on the player character Besides the more complex shape defined by mesh geometry a humanoid character needs animations In chapter 4 you learned that an animation is a packet of informa tion that defines movement of the associated 3D object The concrete example I gave was of a character walking around and that situation is exactly what you re going to be doing now The character is going to run around the scene so you ll assign animations that make the arms and legs swing back and forth Figure 7 11 shows what itll look like when the character has an animation playing while it moves around the scene A good analogy with which to understand 3D animation is to think about puppe teering 3D models are the puppets the animator is the puppeteer and an animation is a recording of the puppets movements Animations can be created with a few dif ferent approaches mo
415. re a public variable void Update for the speed of rotation transform Rotate 0 speed 0 a A Put the Rotate command here so that it runs every frame To add the script component to the player object drag the script up from the Project view and drop it onto Player in the Hierarchy view Now hit Play and you ll see the view spin around you ve written code to make an object move This code is pretty much the default template for a new script plus two new added lines so let s examine what those two lines do First there s the variable for speed added toward the top of the class definition There are two reasons for defining the rotation speed as a variable one is the stan dard no magic numbers programming rule and the second reason is specific to how Unity displays public variables Unity does something handy with public variables in script components as described in the following tip TIP Public variables are exposed in the Inspector so that you can adjust the component s values after adding a component to a game object This is referred to as serializing the value because Unity saves the modified state of the variable Figure 2 12 shows what the script component looks like in the Inspector You can type in a new number and then the script will use that value instead of the default value defined in the code This is a handy way to adjust settings for the component on dif ferent objects working within the v
416. re limited to one megabyte and are only intended to save a handful of values Create the script DataManager see the next listing WARNING You can t access the filesystem in a web game This is a security fea ture that means a web game can t save a local file To save data for web games post the data to your server Listing 11 28 New script for DataManager using UnityEngine using System Collections using System Collections Generic Handling the player s progression through the game 271 using System Runtime Serialization Formatters Binary using System I1O public class DataManager MonoBehaviour IGameManager public ManagerStatus status get private set private string filename private NetworkService _network public void Startup NetworkService service Debug Log Data manager starting _network service Construct full path Pa to the game dat file _filename Path Combine Application persistentDataPath game dat status ManagerStatus Started public void SaveGameState Dictionary lt string object gt gamestate new Dictionary lt string Dictionary obyects 5 that will be gamestate Add inventory Managers Inventory GetData serialized gamestate Add health Managers Player health gamestate Add maxHealth Managers Player maxHealth gamestate Add curLevel Managers Mission curLevel gamestate Add maxLevel Managers Mission maxLevel Create a f
417. re of targets Scripting reactive targets Being able to shoot is all well and good but at the moment players don t have any thing to shoot at We re going to create a target object and give it a script that will respond to being hit Or rather we ll slightly modify the shooting code to notify the target when hit and then the script on the target will react when notified Determining what was hit First you need to create a new object to shoot at Create a new cube object Game Object gt 3D Object gt Cube and then scale it up vertically by setting the Y scale to 2 and leaving X and Z at 1 Position the new object at 0 1 0 to put it on the floor in the middle of the room and name the object Enemy Create a new script called Reac tiveTarget and attach that to the newly created box Soon you ll write code for this script but leave it at the default for now you re only creating the script file because the next code listing requires it to exist in order to compile Go back to RayShooter cs and modify the raycasting code according to the following listing Run the new code and shoot the new target debug messages appear in the console instead of sphere indicators in the scene Listing 3 4 Detecting whether the target object was hit _ ETRE c t hit Retrieve the object 1 YS1CS KayCas ray ou 1 S the ray hit GameObject hitObject hit transform gameObject ReactiveTarget target hitObject GetComponent lt ReactiveTarget gt
418. re until we adjust the code devices were operated by pressing a button Instead they should operate when clicked on To do this you ll first create a base script that all devices will inherit from the base script will have the mouse con trol and devices will inherit that Create a new script called BaseDevice and write the code from the following listing Listing 11 7 BaseDevice script that operates when clicked on using UnityEngine using System Collections public class BaseDevice MonoBehaviour public float radius 3 5f 254 CHAPTER 11 Putting the parts together into a complete game Function that void OnMouseDown runs when Transform player GameObject FindWithTag Player transform clicked if Vector3 Distance player position transform position lt radius Vector3 direction transform position player position if Vector3 Dot player forward direction gt 5f O t e a D9 Call Operate if player is nearby and facing virtual marks a method that l l aA inheritance can override public virtual void Operate behavior of the specific device Most of this code happens inside OnMouseDown because MonoBehaviour calls that method when the object is clicked on First it checks the distance to the player and then it uses dot product to see if the player is facing the device Operate is an empty shell to be filled in by devices that inherit this script NOTE This code lo
419. re used to be an older legacy particle system and the newer system had a special name Shuriken At this point the legacy particle system is entirely phased out so the separate name is no longer necessary To begin create a new particle system and watch the default effect play From the GameObject menu choose Particle System and you ll see basic white puffballs spraying upward from the new object Or rather you ll see particles spraying upward while you have the object selected when you select a particle system the particle playback panel is displayed in the corner of the screen and indicates how much time has elapsed see figure 4 19 The default effect looks pretty neat already but let s go through the extensive list of parameters you can use to customize the effect Adjusting parameters on the default effect 87 Figure 4 18 Fire effect created using a particle system Pause or reset the particle effect playing in the scene Click and drag the label Playback Time to play back and forth Figure 4 19 Playback panel for a particle system Figure 4 20 shows the entire list of settings for a particle system We re not going to go through every single setting in that list instead we ll look at the settings relevant to making the fire effect Once you understand how a few of the settings work the rest should be fairly self explanatory Each of the settings labels is in fact a whole informa tion panel Ini
420. reCast a instead of Raycast The reason for this Every frame the Al character difference is that bullets are tiny whereas to projects a ray in front of it in order to detect obstacles Here the character is facing check for obstacles in front of the character we need to account for the width of the a wall so the raycast will character detect a close obstacle Create a new script called WanderingAI Figure 3 6 Using raycasting to see attach that to the target object alongside obstacles the ReactiveTarget script and write the code from the next listing Play the scene now and you should see the enemy wandering around the room you can still shoot the target and it reacts the same way as before Listing 3 7 Basic WanderingAl script using UnityEngine using System Collections Values for the speed of movement and public class WanderingAI MonoBehaviour a how far away to react to obstacles public float speed 3 0f public float obstacleRange 5 0f Move forward void Update continuously every frame transform Translate 0 0 speed Time deltaTime a regardless of turning Do raycasting with Ray ray new Ray transform position transform forward m a circumference RaycastHit hit around the ray se if Physics SphereCast ray 0 75f out hit A ray at the same position if hit distance lt obstacleRange and pointing the same Turn toward a float angle Random Range 110 110 d
421. rise or Ad Hoc Deployment walk you through Sign and package application for distribution outside of the 105 App Store the process Figure 12 4 Distribute archived iOS apps from the Organizer window the top is set to 10S Device and not the simulator some build options are grayed out if this is wrong Once the provisioning profiles are set you re ready to build the app From the Product menu choose either Run or Archive There are a lot of options in the Prod uct menu including the tantalizingly named Build but for our purposes the two options that are useful are either Run or Archive Build generates executable files but doesn t bundle them for iOS whereas Run will test the application on an iPhone connected to the computer with a USB cable a Archive will create an application package that can be sent to other registered devices what Apple refers to as ad hoc distribution Archive doesn t create the app package directly but rather creates a bundle in an inter mediate stage between the raw code files and an IPA The created archive will be listed in Xcode s Organizer window in that window click the Distribute button in order to generate an IPA file from the archive Figure 12 4 shows this process after you click Dis tribute you ll be asked if you want to distribute the app on the store or ad hoc If you choose ad hoc distribution you ll end up with an IPA file that can be sent to testers You could send the fil
422. rm www new WWW url form a WWWForm automatically changes the request from GET to POST yield return www Calls modified because of changed public IEnumerator GetWeatherXML Action lt string gt callback parameters return CallAPI xmlApi null callback public IEnumerator GetWeatherJSON Action lt string gt callback return CallAPI jsonApi null callback public IEnumerator LogWeather string name float cloudValue Action lt string gt callback Hashtable args new Hashtable args Add message name args Add cloud_ value cloudValue args Add timestamp DateTime UtcNow Ticks bI Define a table of arguments to send Send timestamp along return CallAPI localApi args callback with the cloudiness First notice that CallAPI has a new parameter This is a table of arguments to send along with the HTTP request Within CallAPI a WWWForm object may be created according to that table of arguments Normally WWW sends a GET request but WWWForm will change it to a POST request to send data All the other changes in the code react to that central change for example modifying GetWhatever code because of the CallAPI parameters The next listing shows what you need to add in WeatherManager Listing 9 18 Adding code to WeatherManager that sends data public void LogWeather string name StartCoroutine _network LogWeather name cloudValue OnLogged privat
423. roid click the Android icon tab to override the default compression Adjusting texture compression is an important optimization detail on Android The topic of the next section is important for both iOS and Android developing native plug ins Developing plug ins Unity has a huge amount of functionality built in but that functionality is mostly lim ited to features common across all platforms Taking advantage of platform specific toolkits such as Play Game Services on Android often requires add on plug ins for Unity TIP A variety of premade mobile plug ins are available for iOS and Android specific features appendix D lists a few places to get mobile plug ins These plug ins operate in the manner described in this section except that the plug in code is already written for you The process for communicating back and forth with native plug ins is similar to the process for communicating with the browser On the Unity side of things there are special commands that call functions within the plug in On the plug in s side the Building for mobile apps iOS and Android 291 plug in can use SendMessage to send a message to an object in Unity s scene The exact code looks different on different platforms but the general idea is always the same WARNING Just as with the initial build process the process for developing mobile plug ins tends to change frequently not the Unity end of the pro cess but the native code part
424. rs Player health Managers Player maxHealth healthLabel text message Attach this script to the Controller object and remove BasicUI Also create an InventoryPopup script add an empty public Refresh method for now the rest will 258 CHAPTER 11 Putting the parts together into a complete game be filled in later and attach it to the pop up window the Image object Now you can drag the pop up to the reference slot in the Controller s component also link the health label to the Controller The health label changes when you get hurt or use health packs and pressing M toggles the pop up window One last detail to adjust is that currently clicking on the pop up window causes the player to move just as with devices you don t want to set the target position when the UI has been clicked on Make the adjustment shown in the next listing to PointClickMovement Listing 11 13 Checking the UI in PointClickMovement using UnityEngine EventSystems void Update Vectors movement Vector3 zero if Input GetMouseButton 0 amp amp EventSystem current IsPointerOverGameObject Note that the conditional checks whether or not the mouse is on the UI That com pletes the overall structure of the interface so now let s deal with the inventory pop up specifically IMPLEMENTING THE INVENTORY POP UP The pop up window is currently blank but it should display the player s inventory depicted in figure 11 5 These
425. rs shouldn t dismiss this development envi ronment mistaking it for some click together game creator with limited pro gramming capability The editor is especially helpful for doing rapid iteration honing the game through cycles of prototyping and testing You can adjust objects in the editor and move things around even while the game is running Plus Unity allows you to customize the editor itself by writing scripts that add new features and menus to the interface Besides the editor s significant productivity advantages the other main strength of Unity s toolset is a high degree of cross platform support Not only is Unity multiplat form in terms of the deployment targets you can deploy to the PC web mobile or consoles but it s multiplatform in terms of the development tools you can develop the game on Windows or Mac OS This platform agnostic nature is largely because Unity started as Mac only software and was later ported to Windows The first version launched in 2005 but now Unity is up to its fifth major version with lots of minor updates released frequently Initially Unity supported only Mac for both developing and deployment but within a few months Unity had been updated to work on Win dows as well Successive versions gradually added more deployment platforms such as a cross platform web player in 2006 iPhone in 2008 Android in 2010 and even game consoles like Xbox and PlayStation Most recently they ve added deplo
426. rt code and so on in the fa a ie 3334343343444 Figure 1 13 Editor screenshot cropped to show the Project and Console tabs 14 1 3 CHAPTER 1 Getting to know Unity project Specifically on the left side of the view is a listing of the directories in the project when you select a directory the right side of the view shows the individual files in that directory The directory listing in Project is similar to the list view in Hierarchy but whereas Hierarchy shows objects in the scene Project shows files that aren t con tained within any specific scene including scene files when you save a scene it shows up in Project TIP Project view mirrors the Assets directory on disk but you generally shouldn t move or delete files directly by going to the Assets folder If you do those things within the Project view Unity will keep in sync with that folder The Console is the place where messages from the code show up Some of these mes sages will be debug output that you placed deliberately but Unity also emits error messages if it encounters problems in the script you wrote Getting up and running with Unity programming Now let s look at how the process of programming works in Unity Although art assets can be laid out in the visual editor you need to write code to control them and make the game interactive Unity supports a few programming languages in particular JavaScript and C There are pros and cons to bo
427. rtical speed and acceleration 153 154 ground detection 154 158 setting up scene 152 153 orbiting camera around character 145 148 overview 140 142 this keyword 177 TIFF format 76 tileable images 77 Time class 42 tools 2D image editors 306 3D art 305 306 audio 307 programming 304 305 touch input 285 touchCount property 285 transforming defined 43 Translate method 41 57 58 triggers 175 tutorials Learn Unity3D 316 317 Maya LT guide 317 script reference 316 StackExchange 317 Unity manual 316 Unity3D Student 316 326 tweening 170 Tyrant Unleashed 8 U UI user interface 112 186 188 UIController 129 130 Unity advantages 4 6 C vs JavaScript 14 15 Console tab 13 14 disadvantages 6 7 example games built with console 8 9 desktop 7 8 mobile 8 Game view 10 11 Hello World example 17 Hierarchy tab 12 13 history of 5 Inspector in 12 13 interface 9 10 mouse and keyboard usage 11 12 Project tab 13 14 Scene view 10 11 script components 15 16 toolbar in 10 11 using MonoDevelop 16 17 Unity Player 282 INDEX Unity3D Student 316 UnitySend Message method 294 298 unwrapping 312 Update method 15 30 user interface See UI using statements 183 UV unwrapping 313 V variables 31 VCS version control system 305 vectors 37 vertical rotation 35 40 visual indicators 50 53 Visual Studio 17 304 Vorbis format 226 238 W WAV format 223 weather data service callbacks 205 206 cas
428. run the o area Multiple script files can be open at once Solution view shows all script files in the project Document Outline may not be showing by default Select it veid ig EF charinmi ber iaire trad wik om af under View gt Pads J siren and then drag the tab ar A to where you want it Figure 1 14 Parts of the interface in MonoDevelop tools are available from www unityvs com but I generally prefer MonoDevelop mostly because Visual Studio only runs on Windows and using that IDE would tie your work flow to Windows That s not necessarily a bad thing and if you re already using Visual Studio to do programming then you could keep using it and not have any problems following along with this book beyond this introductory chapter I m not going to talk about the IDE Tying your workflow to Windows though would run counter to one of the biggest advantages of using Unity and doing so could prove problematic if you need to work with Mac based developers on your team and or if you want to deploy your game to iOS Although C originated as a Microsoft product and thus only worked on Windows with the NET Framework C has now become an open lan guage standard and there s a significant cross platform framework Mono Unity uses Mono for its programming backbone and using MonoDevelop allows you to keep the entire development workflow cross platform Always keep in mind that although t
429. ryPopup MonoBehaviour SerializeField private Image itemIcons Arrays to reference four SerializeField private Text itemLabels images and text labels SerializeField private Text curlItemLabel SerializeField private Button equipButton SerializeField private Button useButton private string _curlItem public void Refresh List lt string gt itemList Managers Inventory GetItemList ie j I JL h i i i int len itemIcons Lengt Check inventory list while for int i 0 i lt len i looni ooping through all Ul images if i lt itemList Count a ping 8 itemIcons i gameObject SetActive true itemLabels i gameObject SetActive true Load sprite from string item itemList i Resources aw Sprite sprite Resources Load lt Sprite gt Icons item itemIcons i sprite sprite Resize image wa itemIcons i SetNativeSize to native size of the sprite int count Managers Inventory GetItemCount item string message x count if item Managers Inventory equippedItem H 7 z message Equipped n message A Label may say Equipped itemLabels i text message in addition to item count 260 CHAPTER 11 Putting the parts together into a complete game EventTrigger Entry entry new EventTrigger Entry entry eventID EventTriggerType PointerClick a Enable clicki entry callback AddListener BaseEventData data gt be Sarees Lambda function to Pa OnI
430. s Let s go over a messaging system to accomplish that TIP C does have a built in system for handling events so you might wonder why we don t use that Well the built in event system enforces targeted mes sages whereas we want a broadcast messenger system A targeted system requires the code to know exactly where messages originate from broadcasts can originate from anywhere Integrating an event system To alert the UI of actions in the scene we re going to make use of a broadcast messen ger system Although Unity doesn t have this feature built in a great script for this purpose exists online Among the resources listed in appendix D is the Unify commu nity wiki this is a repository of free code contributed by other developers Their mes senger system is great for providing a decoupled way of communicating events to the rest of the program When some code broadcasts a message that code doesn t need to know anything about the listeners allowing for a great deal of flexibility in switching around or adding objects Create a script called Messenger and paste in the code from this page on Unify http wiki unity3d com index php CSharpMessenger_Extended Then you also need to create a script called GameEvent see the following listing Listing 6 7 GameEvent script to use with Messenger public static class GameEvent public const string ENEMY HIT ENEMY HIT public const string SPEED CHANGED SPEED CHANGED
431. s This is pretty great if you want the player to fly around the scene but what if you want the player walking around on the ground Adjusting components for walking instead of flying Now that collision detection is working the script can have gravity and the player will stay down against the floor Declare a gravity variable and then use that gravity value for the Y axis as shown in the next listing 44 CHAPTER 2 Building a demo that puts you in 3D space Listing 2 12 Adding gravity to the movement code public float gravity 9 8f void Update Ne e Weekeus Clamieonitudei aj Use the gravity value movemen ecCtCOr3 ampMagnituae movement Spee i Pa instead of just 0 movement y gravity Now there s a constant downward force on the player but it s not always pointed straight down because the player object can tilt up and down with the mouse Fortu nately everything we need to fix that is already in place so we just need to make some minor adjustments to how components are set up on the player First set the Mouse Look component on the player object to horizontal rotation only Next add the MouseLook component to the camera object and set that one to vertical rotation only That s right you re going to have two different objects responding to the mouse Because the player object now only rotates horizontally there s no longer any problem with the downward force of gravity being tilted The camera obj
432. s 276 www allitebooks com www allitebooks com contents foreword xv preface xvi acknowledgments xix about this book xx PART 1 FIRST STEPS 0000 080800808888H8HH8HH8H8H8H8HHHHHH888H8888888888O88888EC888 l Getting to know Unity 3 1 1 Why is Unity so great 4 Unity s strengths and advantages 4 Downsides to be aware of 6 Example games built with Unity 7 1 2 Howto use Unity 9 Scene view Game view and the Toolbar 10 Using the mouse and keyboard 11 The Hierarchy tab and the Inspector 12 The Project and Console tabs 13 1 53 Getting up and running with Unity programming 14 How code runs in Unity script components 15 Using MonoDevelop the cross platform IDE 16 Printing to the console Hello World 17 1 4 Summary 20 www allitebooks com Vill CONTENTS Building a demo that puts you in 3D space 21 2 1 Before you start 22 Planning the project 22 Understanding 3D coordinate space 23 2 2 Begin the project place objects in the scene 25 The scenery floor outer walls inner walls 25 Lights and cameras 27 The player s collider and viewpoint 29 2 3 Making things move a script that applies transforms 30 Diagramming how movement is programmed 30 Writing code to implement the diagram 31 Local vs global coordinate space 32 2 4 Script component for looking around MouseLook 33 Horizontal rotation that tracks mouse movement 35 Vertical rotation with limits 35 Horizontal and vertical rotation
433. s 74 75 whiteboxing 72 73 3D sound 227 3D space demo 3D coordinate space 23 25 keyboard input collision detection 42 43 overview 40 responding to key presses 40 41 setting rate of movement 41 42 MouseLook script component horizontal and vertical rota tion together 38 40 horizontal rotation 35 overview 33 35 vertical rotation 35 37 movement local vs global coordinate space 32 33 overview 30 32 object placement capsule collider 29 30 lights and cameras 27 29 scenery 25 27 planning project 22 23 walking instead of flying 43 45 3DS format 83 3ds Max 306 319 A Action keyword 206 action RPG example adding GUI 255 261 assembling assets from multi ple projects 248 250 overarching game structure completing levels 265 267 controlling mission flow and levels 262 265 losing levels 268 269 overview 261 262 player progress beating game by complet ing levels 273 275 saving and loading 269 273 point and click controls movement code 251 253 operating devices using mouse 253 255 overview 250 255 top down view of scene 251 Action type 205 AddComponentMenu method 44 additives 89 ADPCM 226 AI artificial intelligence overview 56 58 tracking character s state 58 59 AIF format 223 Ajax 196 alpha channel 76 320 anchor points 127 128 Android build tools for 288 289 developing plug ins for 294 298 SDK 305 AndroidManifest xml file 297 animation character controller for 162 165 defining cli
434. s a target to work toward Figure 4 1 is a top down drawing of a simple layout with four rooms connected by a central hallway That s all we need for a plan right now a bunch of separated areas and interior walls to place In a real game your plan would be more extensive and include things like enemies and items You could practice whiteboxing by Figure 4 1 Floor plan for the level four rooms building this floor plan or you could draw and a central corridor 74 4 2 3 CHAPTER 4 Developing graphics for your game your own simple level to practice that step too The specifics of the room layout mat ters little for this exercise The important thing for our purposes is to have a floor plan drawn so that we can move forward with the next step Laying out primitives according to the plan Building the whitebox level in accordance with the drawn floor plan involves position ing and scaling a bunch of blank boxes to be the walls in the diagram As described in section 2 2 1 select GameObject gt 3D Object gt Cube to create a blank box that you can position and scale as needed NOTE It isn t required but instead of cube objects you may want to use the QuadsBox object in the project download This object is a cube constructed of six separate pieces to give you more flexibility when applying materials Whether or not you use this object depends on your desired workflow for example I don t bother with Qua
435. s and shrinks while it moves The default is off turn this on and click the arrow to set a curve that quickly grows from 0 and then slowly shrinks back to 0 as illustrated here Rotation over Lifetime The particle rotates while it moves The default is off turn this on and set Random Between to 80 and 80 to make different particles rotate in different directions se eeeeeeerfeeeeece lt Farticle System Curves 10 Renderer Set what each particle looks like You could even set this to a mesh but leave it as Billboard and drag in a new material explained shortly Add points to the curve by double clicking or right click and select Add Key Figure 4 20 The Inspector displays settings for a particle system pointing out settings for the fire effect Adjust parameters of the particle system as indicated in figure 4 20 and it ll look more like a jet of flame Applying a new texture for fire Now the particle system looks more like a jet of flame but the effect still needs the particles to look like flame not white blobs That requires importing a new image into Unity Figure 4 21 depicts the image I painted I made an orange dot and used the Creating effects using particle systems 89 Smudge tool to draw out the tendrils of flame and then I drew the same thing in yellow Whether you use this image from the sample project draw your own or download a similar one you need to import the image file into Unity As ex
436. s called as soon as the object becomes active In other words Start will be called once as soon as you hit Play in the editor Once you ve added the log command to your script be sure to save the script hit Play in Unity and switch to the Console view You ll see the message Hello World appear Congratulations you ve written your first Unity script In later chapters the code will be more elaborate of course but this is an important first step Hello World steps in brief Let s reiterate and summarize the steps from the last several pages 1 Create a new project 2 Create a new C script 3 Create an empty GameObject 4 Drag the script onto the object 5 Add the log command to the script 6 Press Play You could now save the scene that would create a unity file with the Unity icon The scene file is a snapshot of everything currently loaded in the game so that you can reload this scene later It s hardly worth saving this scene because it s so simple just a single empty GameObject but if you don t save the scene then you ll find it empty again when you come back to the project after quitting Unity Errors in the script To see how Unity indicates errors purposely put a typo in the HelloWorld script For example if you type an extra parenthesis symbol this error message will appear in the Console with a red error icon console Clear Collapse Clear on Play Error Pause ow Assets
437. s collecting a second Health item you ll see both copies listed instead of aggregating all items of the same type refer to figure 8 6 Depending on your game you may want the inventory to track each item separately but in most games the inventory should aggregate multiple copies of the same item It s possible to accomplish this using List but it s done more naturally and efficiently using Dictionary instead DEFINITION Dictionary is another collection data structure provided by C Entries in the dictionary are accessed by an identifier or key rather than by their position in the list This is similar to a hash table but more flexible because the keys can be literally any type for example Return the entry for this GameObject Change the code in InventoryManager to use Dictionary instead of List Replace everything from listing 8 14 with the code from the following listing Listing 8 16 Dictionary of items in InventoryManager Private Diclionary lt string ints items LS Dictionary is declared with two public void Startup types the key and the value Debug Log Inventory manager starting items new Dictionary lt string int gt status ManagerStatus Started private void DisplayItems string itemDisplay Items foreach KeyValuePair lt string int gt item in _ items itemDisplay item Key item Value Debug Log itemDisplay public void AddItem string
438. s first step Now all we do is drag the object down from the Hierarchy view and drop it in the Project E neran view this will automatically save the object as aie Directional light a prefab see figure 3 7 Back in the Hierar Drag the object i i gt Floor from Hierarchy view chy view the original objects name will turn gt Player into Project view to 5 Point light blue to signify that it s now linked to a pre Point light create a prefab l Point light fab If you wanted to edit the prefab further Point light i Point light Project such as by adding new components you d make those changes on the object in the scene and then select GameObject gt Apply Changes To Prefab But we don t want the a aero ly object in the scene anymore we re going to Enemy Fear leet spawn the prefab not use the instance already in the scene so delete the ERAT Figure 3 7 Drag objects from Hierarchy to object now Project in order to create prefabs Spawning enemy prefabs 61 WARNING The interface for working with prefabs is somewhat awkward and the relationship between prefabs and their instances in scenes can be brittle For example you often have to drag a prefab into a scene to edit it and then delete the object once you re done editing In the first chapter I mentioned this as a downside to Unity and I hope the workflow with prefabs improves in future versions of Unity Now we have the actual pref
439. s in the targets array Because we have only one door that we want to control with this trigger type 1 in the array s Size field and then drag that door into the target slot With all of this done play the game and watch what happens to the door when the player walks toward and away from it It ll open and close automatically as the player enters and leaves the trigger volume That s another great way to put interactivity into levels But this trigger volume approach doesn t only work with devices like doors you can also use this approach to make collectible items Collecting items scattered around the level Many games include items that can be picked up by the player These items include equipment health packs and power ups The basic mechanism of colliding with items Interacting with objects by bumping into them 177 to pick them up is simple most of the complicated stuff happens after items are picked up but we ll get to that a bit later Create a sphere object and place it hovering at about waist height in an open area of the scene Make the object small like Scale 5 5 5 but otherwise prepare it like you did with the large trigger volume Select the Is Trigger setting in the collider set the object to the Ignore Raycast layer and then create a new material to give the object a distinct color Because the object is small you don t want to make it semitransparent this time so don t turn down the alpha slider at all
440. se as 2 Multiply the offset position 3 Subtract from the player s the offset for the camera with a quaternion to get the position to figure out where rotated offset position to offset relative to the player Offset Position p f a b rs 6 Final Camera e z Position e Player s Position Figure 7 7 The steps for calculating the camera s position 148 1 2 CHAPTER 7 Creating a third person 3D game player movement and animation NOTE The more mathematically astute among you may be thinking Hmm that transforming between coordinate systems thing in chapter 2 can t we do that here too The answer is yes we could transform the offset position using a rotated coordinate system to get the rotated offset But that d require setting up the rotated coordinate system first and it s more straightforward not to need that step Finally the code uses the LookAt method to point the camera at the target this function points one object not just cameras at another object The rotation value calculated before was used to position the camera at the correct angle around the tar get but in that step the camera was only positioned and not rotated Thus without the final LookAt line the camera position would orbit around the character but wouldn t necessarily be looking at it Go ahead and comment out that line to see what happens The camera has its script for orbiting around the player character next up is cod
441. se to the event First notice the Awake and OnDestroy methods Much like Start and Update every MonoBehaviour automatically responds when the object awakes or is removed A listener gets added and removed in Awake OnDestroy This listener is part of the broadcast messaging system and it calls OnEnemyHit when that message is received OnEnemyHit increments the score and then puts that value in the score display The event listeners are set up in the UI code so now we need to broadcast that message whenever an enemy is hit The code to respond to hits is in RayShooter cs so emit the message as shown in the following listing Listing 6 9 Broadcast event message from RayShooter if target null Message broadcast added sR ToHi e Cor JET REA ETORTEN wa to hit response Messenger Broadcast GameEvent ENEMY HIT else 138 6 4 3 CHAPTER 6 Putting a 2D GUI in a 3D game Play the game after adding that message and watch the score display when you shoot an enemy You should see the count going up every time you make a hit That covers sending messages from the 3D game to the 2D interface but we also want an example going in the other direction Broadcasting and listening for events from the HUD In the previous section an event was broadcast from the scene and received by the HUD In a similar way UI controls can broadcast a message that both players and ene mies listen for In this way the s
442. set that you can see and manipulate by opening the Animator view This is another view just like Scene or Project shown in figure 7 16 except this view isn t open by default Select Animator from the Window menu be careful not to get confused with the Animation window that s a separate selection from Animator The node network displayed here is whichever animator controller is currently selected or the animator controller on the selected character The Animator Controller as it v P M Animator 2 Uncheck Root Motion appears in the Project view Contre i player which will move the player a Re object around the scene animations but not ours nega along with the animation a Culling Mode That is desirable for some player Figure 7 15 Animator controller and Animator component Setting up animations on the player character 163 A series of number or Boolean values can be created here to control the animations The currently active state transitions between states on the graph when these values change sl Peart O RER EEC Each node on the graph is an animation state The named animation clip plays when the controller is in that state The orange node is the default animation state before any transitions happen The lines connecting nodes are transitions Transitions have a direction for transitioning from A to B Figure 7 16 The Animator view with our completed animator controller TIP Rememb
443. set it Lastly note that the code has a variable for the controller even as SceneController starts cloning card objects to fill the scene the card objects also need a reference back to the controller to call its public methods As usual when the code references objects in the scene drag the controller object in Unity s editor to the variable slot in the Inspector Do this once for this single card and all of the copies to come later will have the reference as well With that additional code now in MemoryCard write the code from the next list ing in SceneController 5 3 3 Displaying the various card images 107 Listing 5 5 First pass at SceneController for the Memory game using UnityEngine using System Collections l Reference for the public class SceneController MonoBehaviour A wees a card in the scene SerializeField private MemoryCard originalCard SerializeField private Sprite images An array for references void Start to the sprite assets int id Random Range 0 images Length originalCard SetCard id images id j ps Call the public method we added to MemoryCard For now this is a short snip Tne mhont Y C M Scene Controller Script ga yP y Script le SceneController pet to demonstrate the con array elements Original Card o cept of manipulating cards Fone 4 from SceneController Most Element 0 idiamond symbol of this should already be Drag sprite a
444. setting smoother surfaces are more shiny to 0 Finally having adjusted everything as needed you can put the bench in the scene Drag the model up from the Project view This image relates to the model using texture coordinates To understand the concept of texture coordinates refer to appendix C Figure 4 16 The 2D image for the bench texture 86 4 6 CHAPTER 4 Developing graphics for your game Figure 4 17 The imported bench in the level and place it in one room of the level as you drag the mouse you should see it in the scene Once you drop it in place you should see something like figure 4 17 Congrat ulations you created a textured model for the level NOTE We re not going to do it in this chapter but typically you d also replace the whitebox geometry with models created in an external tool The new geometry might look essentially identical but you ll have much more flexibility to set UVs for the texture Animating characters with Mecanim The model we created is static sitting still where placed You can also animate in Blender and then play the animation in Unity The process of creating 3D animation is long and involved but this isn t a book about animation so we re not going to discuss that here As had already been mentioned for modeling there are a lot of existing resources if you want to learn more about 3D animation But be warned it is a huge topic There s a reason animator is
445. shing a rendering loop It s tempting to immediately start building the scene in Unity especially with such a simple in concept project But it s always a good idea to pause at the beginning and plan out what you re going to do and this is especially important right now because you re new to the process Before you start Unity makes it easy for a newcomer to get started but let s go over a couple of points before you build the complete scene Even when working with a tool as flexible as Unity you do need to have some sense of the goal you re working toward You also need a grasp of how 3D coordinates operate or you could get lost as soon as you try to position an object in the scene Planning the project Before you start programming anything you always want to pause and ask yourself So what am I building here Game design is a huge topic unto itself with many impressively large books focused on how to design a game Fortunately for our pur poses you only need a brief outline of this simple demo in mind in order to develop a basic learning project These initial projects won t be terribly complex designs anyway in order to avoid distracting you from learning programming concepts you can and should worry about higher level design issues after you ve mastered the fundamen tals of game development For this first project you ll build a basic FPS first person shooter scene There will be a room to navigate ar
446. sic 2 for Level Music and anything else for No Music I went with 0 The switch statement in OnMusic plays intro music or level music depending on the number or stops the music as a default if the number isn t 1 or 2 When you press the music buttons while the game is playing you ll hear the music Great The code is loading the audio clips from the Resources folder Music plays effi ciently although there are still two bits of polish we ll add separate music volume con trol and cross fading when changing the music Controlling music volume separately The game already has volume control and currently that affects the music too Most games have separate volume controls for sound effects and music though so let s tackle that now The first step is to tell the music AudioSources to ignore settings on AudioListener We want volume and mute on the global AudioListener to continue to affect all sound effects but we don t want this volume to apply to music Listing 10 10 includes code to tell the music source to ignore the volume on AudioListener The code in the follow ing listing also adds volume control and mute for music so add it to AudioManager Background music 241 Listing 10 11 Controlling music volume separately in AudioManager private float _musicVolume Private variable that won t be public float musicVolume accessed directly only through get the property s getter return _musicVolume set _mus
447. simi lar to how a tag was set on the player objects can be set to different layers and the 11 1 3 Building an action RPG by repurposing projects 255 code can check for that Adjust PointClickMovement to check for the object s layer see the next listing Listing 11 9 Adjusting mouse click code in PointClickMovement Ray ray Camera main ScreenPointToRay Input mousePosition RaycastHit mouseHit if Physics Raycast ray out mouseHit GameObject hitObject mouseHit transform gameObject Added code the if hitObject layer LayerMask NameToLayer Ground rest is reference _targetPos mouseHit point _curSpeed moveSpeed This listing adds a conditional inside the mouse click code to see if the clicked object is on the Ground layer Layers like Tags is a drop down menu at the top of the Inspector click it to see the options Also like tags several layers are already defined by default You want to create a new layer so choose Edit Layers in the menu Type Ground in an empty layer slot probably slot 8 NameToLayer in the code converts names into layer numbers so that you can say the name instead of the number Now that the Ground layer has been added to the menu set ground objects to the Ground layer that means the floor of the building along with the ramps and plat forms that the player can walk on Select those objects and then select Ground in the Layers menu Play the game and you won t m
448. sion 289 290 multi platform 276 278 web communicating with Java Script in browser 283 285 test web page for 282 283 Unity Player vs HTML5 WebGL 282 deserialization 210 desktop deployment adjusting Player settings 280 281 building application 279 example games built for 7 8 platform dependent compilation 281 282 Destroy method 55 63 177 Diablo game 247 Dictionary objects 184 186 directional lights 28 DLLImport command 292 DontDestroyOnLoad method 117 doors facing before opening 170 171 opening and closing on keypress 168 170 triggering with pressure plate 174 176 using key on locked 188 190 dot product 157 DXF format 83 dynamic strings 135 E editor modes 98 effects attaching to 3D objects 90 default effect 87 88 fire texture 88 90 overview 86 87 enemies Al overview 56 58 tracking character s state 58 59 reactive targets alerting target to being hit 54 55 INDEX determining hits 53 54 shooting via instantiating objects creating projectile prefabs 64 65 damaging player 67 68 overview 63 68 shooting projectiles 65 67 shooting via raycasts overview 47 48 ScreenPointToRay method 48 50 visual indicators for aiming 50 53 spawning prefabs instantiation from invisible SceneController 61 62 overview 60 61 Enlighten 200 errors in Animator view 164 in console 19 ETC Ericsson Texture Compression 290 Euler angles 37 events HUD 138 139 EventIrigger component 261 Extensible M
449. sition images so that they re always perfectly crisp and sharp as opposed to blurring them when positioned between pixels Go ahead and select that check box Now the HUD canvas is set up but it s still blank and needs sprites Buttons images and text labels The canvas object defines an area to display as the UI but it still requires sprites to dis play If you refer back to the UI mockup in figure 6 2 there s an image of the block enemy in the top left corner text displaying the score next to that and a gear shaped Setting up the GUI display 125 e Directional light Canvas object bearer Point light Point light Point light Point light Point light Image object Y HUD Canvas Image child of Canvas in EventSystem the Hierarchy Figure 6 5 Canvas with an image linked in the Hierarchy view button in the top right corner Accordingly in the UI section of the GameObject menu are options to create an image text or button Create one of each UI elements need to be a child of the canvas object in order to display correctly Unity does this automatically but remember that as usual you can drag objects around the Hierarchy view see figure 6 5 to make parent child linkages Objects within the canvas can be parented together for positioning purposes just like any other objects in the scene For example you may want to drag the text object onto the image so that the text will move with the image Similarly the defau
450. ssets T Se S Element 2 E square symbol Sn onto array elements familiar to you for exam Element 3 ple in Unity s editor drag Figure 5 8 The filled in array of sprites the card object to the vari able slot in the Inspector but the array of images is new As shown in figure 5 8 in the Inspector you can set the number of elements Type in 4 for the array length and then drag the sprites for card images onto the array slots Now these sprites can be accessed in the array like any other object reference Incidentally we used the Random Range method in chapter 3 so hopefully you recall that The exact boundary values didn t matter there but this time it s important to note that the minimum value is inclusive and may be returned whereas the return value is always below the maximum Hit Play to run this new code You ll see different images being applied to the revealed card each time you run the scene The next step is to create a whole grid of cards instead of just one Instantiating a grid of cards SceneController already has a reference to the card object so now you ll use the Instantiate method see the next listing to clone the object numerous times like spawning objects in chapter 3 Listing 5 6 Cloning the card eight times and positioning in a grid using UnityEngine using System Collections Values for how many grid public class SceneController MonoBehaviour spaces to make and how public con
451. st character animation in modern games certainly all the ani mations on this chapter s character uses a technique called skeletal animation DEFINITION Skeletal animation is a kind of animation where a series of bones are set up inside the model and then the bones are moved around during the animation When a bone moves the model s surface linked to that bone moves along with it The character is now moving its arms and legs instead of sliding around in a T pose 1 lt Figure 7 11 Character moving around with a run animation playing Setting up animations on the player character 159 Bone invisible in Unity Visible mesh The arm bone was moved and the arm mesh moved with it Figure 7 12 Skeletal animation of a humanoid character As the name implies skeletal animation makes the most intuitive sense when simulat ing the skeleton inside a character figure 7 12 illustrates this but the skeleton is an abstraction that s useful any time you want a model to bend and flex while still having a definite structure to how it moves for example a tentacle that waves around Although the bones move rigidly the model surface around the bones can bend and flex Achieving the result illustrated in figure 7 11 involves several steps first define ani mation clips in the imported file then set up the controller to play those animation clips and finally incorporate that animation controller in your code The an
452. st int gridRows 2 ae far apart to place them keep Z the same 108 CHAPTER 5 Building a Memory game using Unity s new 2D functionality public const int gridCols 4 public const float offsetX 2f public const float offsetY 2 5f SerializeField private MemoryCard originalCard SerializeField private Sprite images void Start 4 a Vector3 startPos originalCard transform position Nested loops to define both The position of for int i 0 i lt oridCole i the a card all fon ee a a he K ree os al columns and rows of the grid other cards will be MemoryCard card offset from here if i 0 amp amp j 0 aa A container reference for either E E the original card or the copies else card Instantiate originalCard as MemoryCard int id Random Range 0 images Length card SetCard id images id j ea float posX offsetX i startPos x you only need to float posY offsetY j startPos y offset X and Y i i card transform position new Vector3 posxX posY startPos z Although this script is much longer than the previous listing there s not a lot to explain because most of the additions are straightforward variable declarations and math The oddest bit of this code is probably the if else statement that begins if i 0 amp amp j 0 What that conditional does is either choose the original card object for the first grid slot or clone the card obj
453. standard short cuts Move rotate and scale the walls to form a perimeter around the floor as shown in figure 2 5 Experiment with different numbers for example 1 4 50 for scale or use the transform tools first seen in section 1 2 2 remember that the mathematical term for moving and rotating in 3D space is transform TIP Also recall the navigation controls so that you can view the scene from different angles or zoom out for a bird s eye view If you ever get lost in the scene press F to reset the view on the currently selected object The exact transform values the walls end up with will vary depending on how you rotate and scale the cubes in order to fit and on how the objects are linked together in the Hierarchy view For example in figure 2 7 the walls are all children of an empty Begin the project place objects in the scene 27 root object so that the Hierarchy list will look organized If Hierarchy _ you need an example to copy working values from down ae Loa load the sample project and refer to the walls there Y Building Floor TIP Drag objects on top of each other in the Hierarchy Outer Wall view to establish linkages Objects that have other Outer Wall objects attached are referred to as parent objects Outer Wall attached to other objects are referred to as children Outer Wall When the parent object is moved or rotated or scaled Figure2 7 The Hierarchy the child objects are transformed along with it V
454. steps You need to delete the default light and then turn on textures in the viewport see figure C 12 To delete the light first switch back to Object mode in order to select it using the same menu you used to switch to Edit mode Press X to delete a selected object delete the camera while you re at it Finally go to the Viewport Shading menu to switch to Texture Now you can see the finished bench with texture applied Go ahead and save the model now Blender will save the file with the blend exten sion using the native file format for Blender Use the native file format to work in so that all the features of Blender will be preserved correctly but later you ll have to export the model to a different file format for importing into Unity Note that the tex ture image isn t actually saved in the model file what s saved is a reference to the image but you still need the image file that s being referenced D 1 appendix D Online learning resources This book is designed to be a complete introduction to game development in Unity but there s a lot more to learn beyond this introduction There are lots of great resources online you can use to go further after finishing this book Additional tutorials Many sites exist that provide directed information on a variety of topics within Unity Several of these are even provided officially by the company behind Unity UNITY MANUAL This is the comprehensive user manual provided by
455. steps will create the UI objects 1 Create four images and parent them to the pop up that is drag objects in the Hierarchy Create four text labels and parent them to the pop up Position all the images at 0 Y and X values 75 25 25 and 75 Position the text labels at 50 Y and X values 75 25 25 and 75 Set the text not the anchor to Center alignment Bottom vertical align and Height 60 6 In Resources set all inventory icons as Sprite instead of Textures ao W N 4 Text objects 4 Image objects 2 Button objects I Text object Figure 11 5 Diagram of the inventory Ul Building an action RPG by repurposing projects 259 7 Drag these sprites to the Source Image slot of the Image objects also set Native Size 8 Enter x2 for all the text labels 9 Add another text label and two buttons all parented to the pop up 10 Position this text label at 120 55 and set Right alignment 11 Type Energy for the text on this label 12 Set both buttons to Width 60 then Position at 50 Y and X values 0 or 70 13 Type Equip on one button and Use on the other These are the visual elements for the inventory pop up next is the code Write the contents of the following listing into the InventoryPopup script Listing 11 14 Full script for InventoryPopup using UnityEngine using UnityEngine UI using UnityEngine EventSystems using System Collections using System Collections Generic public class Invento
456. t lt property name unity androidplayer jarfile value Applications Unity Unity app Contents PlaybackEngines AndroidPlayer development bin classes jar gt lt Source directory gt lt property name source dir value LOCATION OF THIS PROJECT Assets Plugins Android TestPlugin gt lt Output directory for class files gt lt property name output dir value LOCATION OF THIS PROJECT Assets Plugins Android TestPlugin classes gt lt Name of the jar to be created Please note that the name should match the name of the class and the name placed in the AndroidManifest xml gt lt property name output jarfile value TestPlugin jar gt lt Creates the output directories if they don t exist yet gt lt target name dirs depends message gt lt echo gt Creating output directory output dir lt echo gt lt mkdir dir output dir gt lt target gt lt Compiles this project s java files into class files gt lt target name compile depends dirs description Compiles project s java files into class files s gt s lt javac encoding ascii target 1 6 debug true destdir output dir verbose verbose includeantruntime false gt lt sre path source dir gt lt Cclasspath gt lt pathelement location sdk dir platforms target android jar gt lt pathelement location unity androidplayer jarfile gt lt classpath gt lt javac gt lt targe
457. t that s not the only way players can interact with items in the level Another very straightforward approach is to respond to collisions with the player Unity handles most of that for you by having collision detection and physics built into the game engine Unity will detect collisions for you but you still need to program the object to respond 8 2 1 Interacting with objects by bumping into them 173 Each box has a RigidBody component Their positions are 4 2 5 23 4 2 5 l2 42 5 l 4 2 1 5 I9 4 2 1 5 7 Figure 8 3 Stack of five boxes to collide with We ll go over three collision responses that are useful for games Push away and fall over Trigger a device in the level Disappear on contact for item pickups Colliding with physics enabled obstacles To start we re going to create a pile of boxes and then cause the pile to collapse when the player runs into it Although the physics calculations involved are complicated Unity has all of that built in and will scatter the boxes in a realistic way for us By default Unity doesn t use its physics simulation to move objects around That can be enabled by adding a Rigidbody component to the object This concept was first discussed back in chapter 3 because the enemy s fireballs also needed a Rigidbody component As I explained in that chapter Unity s physics system will act only on objects that have a Rigidbody component Click Add Component and l
458. t game can distract you from other aspects of game devel opment like learning how to program a game You re better off starting out by aping the design of existing games remember I m only talking about starting out cloning existing games is great for initial practice but eventually you ll have enough skills and experience to branch out further That said any successful game developer should be curious about game design There are lots of ways to learn more about game design you already know about the Extra Credits videos but here are some other websites www gamasutra com www lostgarden com www sloperama com There are also a number of great books on the subject such as the following Game Design Workshop Third Edition by Tracy Fullerton A K Peters CRC Press 2014 A Theory of Fun for Game Design Second Edition by Raph Koster O Reilly Media 2013 The Art of Game Design Second Edition by Jesse Schell A K Peters CRC Press 2014 Marketing your game 301 Marketing your game In the Extra Credits videos the fourth video is about marketing your game Sometimes game developers put off thinking about marketing They only want to think about building the game and not marketing it but that attitude will probably result in a failed game The best game in the world still won t be successful if nobody knows about it The word marketing often evokes thoughts of ads and if you have the budget then running ads
459. t gt Building for mobile apps iOS and Android 297 lt target name build jar depends compile s gt s lt zip zipfile output jarfile basedir S output dir gt lt target gt lt target name clean post jar gt lt echo gt Removing post build jar clean lt echo gt lt delete dir S output dir gt lt target gt lt target name clean description Removes output files created by other targets gt lt delete dir S output dir verbose verbose gt lt target gt lt target name message gt lt echo gt Android Ant Build for Unity Android Plugin lt echo gt lt echo gt message Displays this message lt echo gt lt echo gt clean Removes output files created by other targets lt echo gt lt echo gt compile Compiles java files into class files lt echo gt lt echo gt build jar Compiles class files into jar file lt echo gt lt target gt lt project gt Listing 12 10 TestPlugin java that compiles into a JAR package com companyname testplugin public class TestPlugin private static int number 0 public static int getNumber number return number public static String getString String message return message toLowerCase Android s manifest and resources folder It wasn t required for this simple test plug in but Android plug ins often must edit the manifest file All Android apps are controlled by a main configuration file called Android Ma
460. t install it on a device You can get the APK file onto an Android phone by downloading the file from the web or by transfer ring the file via a USB cable connected to your computer an approach referred to as sideloading The details of how to transfer files onto your phone vary for every device but once there it can be installed using a file manager app I don t know why file man agers aren t built into Android but you can install one for free from the Play Store Navigate to your APK file within the file manager and then install the app As you can see the basic build process for Android is a lot simpler than the build process for 10S Unfortunately the process of customizing the build and implement ing plug ins is more complicated than with iOS you ll learn how in section 12 3 3 Before that let s talk about texture compression Texture compression Assets can add a lot of file size to an app and this certainly includes textures To reduce their file size you can compress assets in some way mobile apps in particular need to be careful about using too much space so these apps apply compression to their textures A variety of methods exist to compress images with different pros and cons to each method Because of these pros and cons you may need to adjust how Unity compresses the textures It s essential to manage texture compression on mobile devices but technically textures are often compressed on other platforms too But yo
461. t leave it at default for now while we work on a few other parts of the fireball object So that it appears like a fireball and not just a gray sphere we re going to give the object a bright orange color Surface properties such as color are controlled using materials DEFINITION A material is a packet of information that defines the surface properties of any 3D object that the material is attached to These surface properties can include color shininess and even subtle roughness Choose Assets gt Create gt Material Name the new material something like Flame Select the material in the Project view in order to see the material s properties in the Inspector As figure 3 10 shows click the color swatch labeled Albedo that s a techni cal term that refers to the main color of a surface Clicking that will bring up a color picker in its own window slide both the rainbow colored bar on the right side and main picking area to set the color to orange We re also going to brighten up the material to make it look more like fire Adjust the Emission value one of the other attributes in the Inspector It defaults to 0 so type in 3 to brighten up the material Inspector 2 Flame Shader Standard z Rendering Mode Main Maps Smoothness Normal Map Height Map Occlusion Emission A Matail Mack Click the color swatch to bring up color picker E Adjust hue on the right si
462. t level reached Application LoadLevel name a Developing the overarching game structure 263 else Debug Log Last level For the most part there s nothing unusual going on in this listing but note the Load Level method near the end although I mentioned that method before in chapter 5 it wasn t important until now That s Unity s method for loading a scene file in chapter 5 you used it to reload the one scene in the game but you can load any scene by passing in the name of the scene file Attach this script to the Game Managers object in the scene Also add a new compo nent to the Managers script see the following listing Listing 11 17 Adding a new component to the Managers script RequireComponent typeof MissionManager public class Managers MonoBehaviour public static PlayerManager Player get private set public static InventoryManager Inventory get private set public static MissionManager Mission get private set void Awake DontDestroyOnLoad gameObject Unity s command to persist Player GetComponent lt PlayerManager gt j an object between scenes Inventory GetComponent lt InventoryManager gt Mission GetComponent lt MissionManagers gt _startSequence new List lt IGameManager gt _startSequence Add Player _startSequence Add Inventory _startSequence Add Mission StartCoroutine StartupManagers private IEnumer
463. t make sense for this situation Specifically we use the method Random Range that Unity provides for obtaining a random value between constraints In this case the constraints were just slightly beyond an exact left or right turn allowing the character to turn suffi ciently to avoid obstacles Tracking the character s state One oddity of the current behavior is that the enemy keeps moving forward after fall ing over from being hit That s because right now the Translate method runs every frame no matter what Let s make small adjustments to the code in order to keep track of whether or not the character is alive or to put it in another more technical way we want to track the alive state of the character Having the code keep track of and respond differently to the current state of the object is a common code pattern in many areas of programming not just AI More sophisticated implementations of this approach are referred to as state machines or possibly even finite state machines DEFINITION finite state machine FSM is a code structure in which the current state of the object is tracked well defined transitions exist between states and the code behaves differently based on the state We re not going to implement a full FSM but it s no coincidence that a common place to see the initials FSM is in discussions of AI A full FSM would have many states for all the different behaviors of a sophisticated AI but in this b
464. tCamera to remove mouse controls from the camera and only use arrow keys see the following listing Listing 11 5 Adjusting OrbitCamera to remove mouse controls Reverse the direction void LateUpdate S kom belore rogy Input GetAxis Horizontal rotSpeed Quaternion rotation Ouaternion fuler 0 rotY 0j Lranslorm position target position rotation ofisec transform LookAt target The camera s Near Far clipping planes As long as you re adjusting the camera want to point out the Near Far clipping planes These settings never came up before because the defaults are fine but you may need to adjust these in some future project Select the camera in the scene and look for the Clipping Planes section in the Inspec tor both Near and Far are numbers you l type here These values define near and far boundaries within which meshes are rendered polygons closer than the Near clipping plane or farther than the Far clipping plane aren t drawn You want the Near Far clipping planes as close together as possible while still being far enough apart to render everything in your scene When those planes are too far apart Near is too close or Far is too far the rendering algorithm can no longer tell which polygons are closer This results in a characteristic rendering error called z fighting as in the Z axis for depth where polygons flicker on top of each other With the camera raised even higher the view
465. te and Scale tools that we used in 3D in 2D mode we use a single manipulation tool called the Rect Tool In 2D mode this tool is selected automatically or you can click the rightmost navigation but ton in the top left corner of Unity With this tool active click and drag objects to do all three operations move rotate scale in two dimensions 5 2 2 Building a card object and making tt react to clicks 103 Card back is a child of the card front sprite Hierarchy inspector is P E E Lise v Position slightly in front Tag Untagged Layer Defaut of the parent sprite Main Camera i Y Memory Card YA Transform a card_back_ Position x 0 y o _ z o1 Remember this is the Rotation XO YO ZO ag Scale xi fl zi local position relative v El M Snrita Renderer w to the parent Figure 5 6 Hierarchy linking and position for the card back sprite With the card back in place as depicted in figure 5 6 the graphics are in place for a reactive card that can be revealed Mouse input code In order to respond when the player clicks on them the card sprites need to have a collider component New sprites don t have a collider by default so they can t be clicked on We re going to attach a collider to the root card object but not to the card back so that only the card front and not the card back will receive mouse clicks To do this select the root card object in Hierarchy
466. te command adjusted to respond to the mouse transform Rotate 0 Input GetAxis Mouse X sensitivityHor 0 n Note the use of GetAxis to get mouse input Hit Play and then move the mouse around As you move the mouse from side to side the view will rotate from side to side That s pretty cool The next step is to rotate ver tically instead of horizontally 2 4 2 Vertical rotation with limits For horizontal rotation we ve been using the Rotate method but we ll take a differ ent approach with vertical rotation Although that method is convenient for applying www allitebooks com 36 CHAPTER 2 Building a demo that puts you in 3D space transforms it s also kind of inflexible It s only useful for incrementing the rotation without limit which was fine for horizontal rotation but vertical rotation needs limits on how much the view can tilt up or down The following listing shows the vertical rotation code for MouseLook a detailed explanation of the code will come right after Listing 2 5 Vertical rotation for MouseLook Declare variables used public float sensitivityHor 9 0f for vertical rotation public float sensitivityVert 9 0f public float minimumVert 45 0f public float maximumVert 45 0f i Declare a private variable for the vertical angle private float rotationxX 0 Increment the ical angle b void Update vertical angle based on the mouse if axes RotationAx
467. tem item OM eee trigger differently for each item EventTrigger trigger itemIcons i GetComponent lt EventTrigger gt ee RE Ye trigger delegates Add entry function to EventTrigger Display currently selected item trigger delegates Clear j g Ig J re Clear listener to refresh from clean slate else itemIcons i gameObject SetActive false itemLabels i gameObject SetActive false Hide this image text if no item to display if itemList Contains curItem I TASA Spe ee renee Hide buttons if no item selected if _curItem null g curItemLabel gameObject SetActive false equipButton gameObject SetActive false useButton gameObject SetActive false ae else curItemLabel gameObject SetActive true equipButton gameObject SetActive true if _curItem health useButton gameObject SetActive true ro ee ee or nea item useButton gameObject SetActive false c rItemLabel text Jcurlceme ss y Function called by mouse click listener public void OnItem string item a C rItem item Refresh S Refresh inventory display after making changes public void OnEquip Managers Inventory EquipItem _curItem Refresh public void OnUse Managers Inventory ConsumeItem _curItem if _curItem health Managers Player ChangeHealth 25 Refresh 11 2 Developing the overarching game struct
468. tend the Audio Manager to handle music as well Setting up the central AudioManager The first step in setting up AudioManager is to put in place the Managers code frame work From the chapter 9 project copy over IGameManager ManagerStatus and NetworkService we won t change them Remember that IGameManager is the inter face that all managers must implement whereas ManagerStatus is an enum that IGameManager uses NetworkService provides calls to the internet and won t be used in this chapter Audio control interface 231 NOTE Unity will probably issue a warning because NetworkService is assigned but not used You can just ignore Unity s warning we want to enable the code framework to access the internet even though we don t use that functionality in this chapter Also copy over the Managers file which will be adjusted for the new AudioManager Leave it be for now or comment out the erroneous sections if the sight of compiler errors drives you crazy Create a new script called AudioManager that the Managers code can refer to see the following listing Listing 10 2 Skeleton code for AudioManager using UnityEngine using System Collections using System Collections Generic public class AudioManager MonoBehaviour IGameManager public ManagerStatus status get private set private NetworkService _network Add volume controls here listing 10 4 public void Startup NetworkService service Debug Log
469. tensity Cn Bounce Intensity _ _ ai Shadow Type Soft Shadows KI Strength k Select the Directional light Resolution and turn on Soft Shadows Figure 7 5 Before and after casting shadows from the directional light 7 1 3 Adjusting the camera view for third person 145 DEFINITION Lighimaps are textures applied to the level geometry with pic tures of the shadows baked into the texture image DEFINITION Drawing shadows onto a model s texture is referred to as baking the shadows Because these images are generated ahead of time rather than while the game is run ning they can be very elaborate and realistic On the downside because the shadows are generated ahead of time they won t move Thus lightmaps are great to use for static level geometry but they aren t useful for dynamic objects like characters Light maps are generated automatically rather than being painted by hand The computer calculates how the lights in the scene will illuminate the level while subtle darkness builds up in corners In Unity the system for rendering lightmaps is called Enlighten so you can look up that keyword in Unity s manual Whether or not to use real time shadows or lightmaps isn t an all or Shadows are projected from this mesh nothing choice You can set the Culling Mask property on a light so that real Y L M Mesh Renderer y i Cast Shadows Receive Shadows time shadows are used only for certain
470. ter We take shadows for granted in the real world but shadows aren t guaranteed in the game s virtual world Fortunately Unity can handle this detail and shadows are turned on for the default light that comes with new scenes Select the directional light in your scene and then look in the Inspector for the Shadow Type option That setting shown in figure 7 5 is already on Soft Shadows for the default light but notice the menu also has a No Shadows option That s all you need to do to set up shadows in this project but there s a lot more you should know about shadows in games Calculating the shadows in a scene is a par ticularly time consuming part of computer graphics so games often cut corners and fake things in various ways in order to achieve the visual look desired The kind of shadow cast from the character is referred to as real time shadow because the shadow is calculated while the game is running and moves around with moving objects A per fectly realistic lighting setup would have all objects casting and receiving shadows in real time but in order for the shadow calculations to run fast enough real time shad ows are limited in how the shadows look or which lights can even cast shadows Note that only the directional light is casting shadows in this scene Another common way of handling shadows in games is with a technique called lightmapping d by s J Y o Migh pa Type Directional Baking Color ee In
471. terial and apply the new material to the object figure 4 7 illustrates the maneuver Try that now with the texture for the floor Besides that convenience method of automatically creating materials the proper way to create a material is through the Create submenu of the Assets menu the new asset will appear in the Project view Now select the material to show its properties in the Inspector you ll see something like figure 4 8 and drag a texture to the main tex ture slot the setting is called Albedo that s a technical term for the base color and the texture slot is the square to the side of the panel Meanwhile drag the material up from Project onto an object in the scene to apply the material to that object Try these steps now with the texture for the wall create a new material drag the wall texture into this material and drag the material onto a wall in the scene You should now see the stone and brick images appearing on the surface of the floor and wall objects but the images look rather stretched out and blurry What s happening is the single image is being stretched out to cover the entire floor What you want instead is for the image to repeat a few times over the floor surface You can set this using the Tiling property of the material select the material in Project and Inspector 3 BrickLargeBareO032 Shader Standard Rendering Mode Opaque Assets Textures Main Maps _ Ba aie
472. th both that direction vector and the forward direction of the player When the dot product is close to 1 specifically this code checks greater than 5 that means the two vectors are close to pointing in the same direction With this adjustment made the door won t open and close when the player faces away from it even if the player is close And this same approach to operating devices can be used with any sort of device To demonstrate that flexibility let s create another example device Operating a color changing monitor We ve created a door that opens and closes but that same device operating logic can be used with any sort of device We re going to create another device that s operated in the same way this time we ll create a color changing display on the wall 172 The numbers are RGB values that range from 0 to 8 2 CHAPTER 8 Adding interactive devices and items within the game Create a new cube and place it so that one side is barely sticking out of the wall For exam ple I went with Position 10 9 1 5 5 Now create a new script called ColorChangeDevice and attach that script shown in the next listing to the wall display Now run up to the wall moni tor and hit the same operate key as used with the door you should see the display change color as figure 8 2 illustrates Figure 8 2 Color changing display embedded in the wall Listing 8 4 Script for a device that changes color using Un
473. th choices but you ll be using C throughout this book Why choose C over JavaScript All of the code listings in this book use C because it has a number of advantages over JavaScript and fewer disadvantages especially for professional developers it s certainly the language use at work One benefit is that C is strongly typed whereas JavaScript is not Now there are lots of arguments among experienced programmers about whether or not dynamic typ ing is abetter approach for say web development but programming for certain gaming platforms such as iOS often benefits from or even requires static typing Unity has even added the directive pragma strict to force static typing within JavaScript Although technically this works it breaks one of the bedrock principles of how Java Script operates and if you re going to do that then you re better off using a language that s intrinsically strongly typed This is just one example of how JavaScript within Unity isn t quite the same as Java Script elsewhere JavaScript in Unity is certainly similar to JavaScript in web browsers but there are lots of differences in how the language works in each context Many developers refer to the language in Unity as UnityScript aname that indicates similarity to but separateness from JavaScript This similar but different state can create issues for programmers both in terms of bringing in knowledge about JavaScript from outside Uni
474. th that file format as well With this decision made it s time to bring some images into Unity and apply them to the blank scene Importing an image file Let s start creating preparing the textures we ll use The images used to texture levels are usually tileable so that they can be repeated across large surfaces like the floor DEFINITION A tileable image sometimes referred to as a seamless tile is an image where opposite edges match up when placed side by side This way the image can be repeated without any visible seams between the repeats The concept for 3D texturing is just like wallpapers on web pages You can obtain tileable images in sev eral different ways such as manipulat ing photographs or even painting them by hand Tutorials and explana tions of these techniques can be found in a variety of books and websites but we don t want to get bogged down with that right now Instead let s grab a cou ple of tileable images from one of the many websites that offer a catalog of such images for 3D artists to use For i Figure 4 5 Seamlessly tiling stone and brick example I obtained a couple of images images obtained from CGTextures com from www cgtextures com see figure 4 5 to apply to the walls and floor of the level find a couple of images you think look good for the floor and walls Download the images you want and prepare them for use as textures Technically you could use the images directly as t
475. that approach certainly will work But Unity includes a Sprite Packer that will pack together multiple sprites automatically To use this feature enable Sprite Packer in Editor settings found under Edit gt Project Settings Now write a name in Packing Tag option when looking at the Import settings of a sprite image Unity will pack together sprites with the same packing tag into one atlas For more information look at Unity s documentation http docs unity3d com Manual SpritePacker html 5 1 3 Setting everything up for 2D graphics 101 Switching the camera to 2D mode Now let s adjust settings on the main camera in the scene You might think that because the Scene view is set to 2D what you see in Unity is what you ll see in the game Somewhat non intuitively though that isn t the case WARNING Whether or not the Scene view is set to 2D has nothing to do with the camera view in the running game It turns out that regardless of whether the Scene view is set to 2D mode the camera in the game is set independently This can be handy in many situations so that you can toggle the Scene view back to 3D in order to work on certain effects within the scene This disconnect does mean that what you see in Unity isn t necessarily what you see in the game and it can be easy for beginners to forget this The most important camera setting to adjust is Projection The camera projection is probably already correct because you created the n
476. that wanders around NOTE Because the enemy will sound like it s on fire you might want to give it a particle system so that it looks like it s on fire You can copy over the particle system created in chapter 4 by making the particle object into a prefab and then choosing Export Package from the Asset menu Alternatively you could redo the steps from chapter 4 here to create a new particle object from scratch drag the Enemy prefab into the scene to edit it and then choose GameObject gt Apply Changes To Prefab Usually you need to drag a prefab into the scene in order to edit it but you can edit the prefab asset directly when you re just adding a component onto the object Select the Enemy prefab so that its properties appear in the Inspector Now add a new com ponent choose Audio gt Audio Source An AudioSource component will appear in the Inspector Tell the audio source what sound clip to play Drag an audio file from the Project view up to the Audio Clip slot in the Inspector we re going to use the fireplace sound effect for this example refer to figure 10 3 Skip down a bit in the settings and select both Play On Awake and Looping of course make sure that Mute isn t checked Play On Awake tells the audio source to begin playing as soon as the scene starts in the next section you ll learn how to trig ger sounds manually while the scene is running Looping tells the audio source to keep playing continuously repea
477. the methods shown in the following listing to SettingsPopup cs Listing 6 6 SettingsPopup methods for the pop up s input controls public void OnSubmitName string name Debug Log name AL This will trigger when the user types in the input field public void OnSpeedValue float speed Debug Log Speed speed ae This will trigger when the user adjusts the slider Great there are methods for the controls to use Starting with the input field in set tings you ll see an End Edit panel events listed here are triggered when the user fin ishes typing Add an entry to this panel drag the pop up to the object slot and choose OnSubmitName in the function list WARNING Be sure to select the function in the End Edit panel s top section Dynamic String and not the bottom section Static Parameters The OnSubmitName function appears in both sections but selecting it under Updating the game by responding to events 135 Static Parameters will send only a single string defined ahead of time dynamic string refers to whatever value is typed in the input field Follow these same steps for the slider look for the event panel toward the end of the component settings in this case the panel is OnValueChanged click to add an entry drag in the settings pop up and choose OnSpeedValue in the list of dynamic value functions Now both of the input controls are connected to code in the pop up s script Play th
478. the player steps off the edge of the platform Figure 7 9 illustrates the problem This won t do at all Similarly if the character stands on a slope the current ground detection will cause problematic behavior Try it now by creating a sloped block against the raised platforms Create a new cube object and set its transform values to Position 1 5 1 5 5 Rotation 0 0 25 Scale 1 4 4 Implementing the jump action 155 but the collision capsule around the character is still touching the platform edge As a result the player The character has completel aie appears to be floating in the air stepped off the platform Figure 7 9 Diagram showing the character controller capsule touching the platform edge If you jump onto the slope from the ground you ll find that you can jump again from midway up the slope and thereby ascend to the top That s because the slope does touch the bottom of the capsule obliquely and the code currently considers any colli sion on the bottom to be solid footing Again this won t do the character should slide back down not have solid footing to jump from NOTE Sliding back down is only desired on steep slopes On shallow slopes such as uneven ground we want the player to run around unaffected If you want one to test on make a shallow ramp by creating a cube and set it to Posi tion 5 25 25 25 Rotation 0 90 75 Scale 1 6 3 All these problems have the same root cause che
479. the sample download With those files set up you re ready to start building the game s UI Before you start writing code To start building the HUD you first need to understand how the UI system works Unity provides multiple approaches to building a game s HUD so we need to go over how those systems work Then we can briefly plan the UI and prepare the art assets that we ll need Immediate mode GUI or advanced 2D interface From its first version Unity came with an immediate mode GUI system and that sys tem makes it easy to put a clickable button on the screen Listing 6 1 shows the code to do that simply attach this script to any object in the scene For another example of immediate mode UI recall the target cursor displayed in chapter 3 This GUI system is entirely based on code with no work in Unity s editor DEFINITION Immediate mode refers to explicitly issuing draw commands every frame versus a system where you define all the visuals once and then for every frame the system knows what to draw without you having to tell it again The latter approach is called retained mode Listing 6 1 Example of a button using the immediate mode GUI using UnityEngine using System Collections Function called every frame i after everything else renders public class BasicUI MonoBehaviour void OnGUI if GUI Button new Rect 10 10 40 20 Test Debug Log Test button Parameters position X pos
480. the view Projecting a ray through the center of the camera View is a special case of an action referred to as mouse picking DEFINITION Mouse picking is the action of picking out the spot in the 3D scene directly under the mouse cursor Unity provides the method ScreenPointToRay to perform this action Figure 3 2 illustrates what happens The method creates a ray that starts at the camera and projects The camera is the origin The screen of this ray similar to the 1 i e the camera s window gun previously Lo into the 3D scene Figure 3 2 ScreenPointToRay projects a ray from the camera through the given screen coordinates Ray projects from the camera through this point on the screen The middle of the screen is half its width and height Shooting via raycasts 49 at an angle passing through the given screen coordinates Usually the coordinates of the mouse position are used for mouse picking but for first person shooting the center of the screen is used Once you have a ray it can be passed to the method Physics Raycast to perform raycasting using that ray Let s write some code that uses the methods we just discussed In Unity create a new C script attach that script to the camera not the player object and then write the code from the next listing in it Listing 3 1 RayShooter script to attach to the camera using UnityEngine using System Collections public class RayShooter MonoBehav
481. their texture compression has to aim for the lowest common denominator To be more specific all iOS devices use PowerVR GPUs thus 10S apps can use the optimized PVR texture compression Some Android devices also use PowerVR chips but they just as frequently use Adreno chips from Qualcomm Mali GPUs from ARM or other options As a result Android apps generally rely on Ericsson Texture Com pression ETC a compression algorithm supported by all Android devices Unfortu nately ETC ETC1 anyway the successor under development is ETC2 doesn t support alpha transparency so images with alpha transparency can t be compressed using that algorithm Unity recompresses images when you switch platforms On Android Unity gets around the transparent image limitation by converting images with transparency to 16 bit instead of compressing them Converting images to 16 bit does lower their file size but it does so at the cost of reducing image quality Because of this on Android you sometimes need to manually reset the compression of individual images deter mining image by image which ones need transparency versus which ones can have ETC better image quality and no transparency and deciding which transparent images need reduced file size versus which ones can be made uncompressed If you need to adjust compression on a texture adjust the settings shown in figure 12 6 Change Texture Type to Advanced in order to access those settings and set And
482. ther than objects in order to conceptually differentiate solid objects from objects you can move through Play the game now and you can freely move through the trigger volume Unity still registers collisions with the object but those collisions don t affect the player s move ment anymore To react to the collisions we need to write code Specifically we want this trigger to control the door Create a new script called Device Trigger see the fol lowing listing Listing 8 6 Code for a trigger that controls a device using UnityEngine using System Collections bli 1 Wau canes MEE E List of target objects that pu 1C Class evicelrigger onobenaviour A this trigger will activate SerializeField private GameObject targets void OnTriggerEnter Collider other LS OnTriggerEnter is called foreach GameObject target in targets when another object enters target SendMessage Activate the trigger volume void OnTriggerExit Collider other LS whereas OnTriggerExit is foreach GameObject target in targets called when an object leaves target SendMessage Deactivate the trigger volume 176 8 2 3 CHAPTER 8 Adding interactive devices and items within the game This listing defines an array of target objects for the trigger even though it ll only be a list of one most of the time it s possible to have multiple devices controlled by a single trigger Loop through the array of targets to send
483. thod in MissionManager public void Startup NetworkService service Debug Log Mission manager starting _network service Modify this line using the new method UpdateData 0 1 A 270 CHAPTER 11 Putting the parts together into a complete game status ManagerStatus Started public void UpdateData int curLevel int maxLevel this curLevel curLevel this maxLevel maxLevel Listing 11 27 UpdateData method in InventoryManager public void Startup NetworkService service Debug Log Inventory manager starting _network service Pa Initialize an empty list UpdateData new Dictionary lt string int gt status ManagerStatus Started public void UpdateData Dictionary lt string int gt items _items items Need getter in a order to save data public Dictionary lt string int gt GetData recurnh _ items Now that the various managers all have UpdateData methods the data can be saved from a new code module Saving the data will involve a procedure referred to as serial izing the data DEFINITION Serialize means to encode a batch of data into a form that can be stored You ll save the game as binary data but note that C is also fully capable of saving text files For example the JSON strings you worked with in chapter 9 were data serialized as text Previous chapters used PlayerPrefs but in this project you re going to save a local file PlayerPrefs a
484. tially only the first information panel is expanded the rest of the panels are collapsed Click on the setting label to expand that information panel TIP Many of the settings are controlled by a curve displayed at the bottom of the Inspector That curve represents how the value changes over time the left side of the graph is when the particle first appears the right side is when the particle is gone the bottom is a value of 0 and the top is the maximum value Drag points around the graph and double click or right click on the curve to insert new points 88 4 6 2 CHAPTER 4 Developing graphics for your game Looping The particle system keeps playing forever leave default inspector ae Y Particle System Lifetime How long the particle exists reduce to 3 Speed How fast the particle is moving reduce to I Size How big the particle is leave default Rotation The orientation of the particle click the arrow menu to change to Between Constants set to 0 and 180 Color Tint the particles We want a dim orange like RGB values 182 101 58 Local simulation space is fine for a still particle system but World may be better for a system that s moving Emission How quickly particles are emitted leave default Shape The shape of the area emitted from The default is a wide cone but we want a small box to make a tight jet of flame set Box all numbers 0 2 Size over Lifetime The particle grow
485. ting the audio clip when playback is over 10 2 3 Playing sound effects 229 v c M Audio Source The AudioClip AudioClip fireplace to play Output None Audio Mixer Group Mute nae ine m Should this audio pass Listener ect Sean teceeeneee play as soon as the Play On Awake scene starts Loop Spatial Blend can set Priority this audio source to Volume either 2D or 3D aa Should the playback loop Stereo Pan a io Spatial Blend 2D 3 Reverb Zone Mix 1 k Y 3D Sound Settings Figure 10 3 Settings for the AudioSource component You want this audio source to project 3D sounds As explained earlier 3D sounds have a distinct position within the scene That aspect of the audio source is adjusted using the Spatial Blend setting That setting is a slider between 2D and 3D set it to 3D for this audio source Now play the game and make sure your speakers are turned on You can hear a crackling fire coming from the enemy and the sound becomes faint if you move away because you used a 3D audio source Triggering sound effects from code Setting the AudioSource component to play automatically is handy for some looping sounds but for the majority of sound effects you ll want to trigger the sound with code commands That approach still requires an AudioSource component but now the audio source will only play sound clips when told to by the program instead of auto matically all the time Add
486. traction of a con troller between our code and the actual playing of animations You may be familiar with systems where you directly play animations from your code indeed the old Leg acy animation system worked in exactly that way with calls like Play idle But this indirection enables us to share animations between models rather than only being able to play animations that are internal to this model In this chapter we won t take advantage of this ability but keep in mind that it can be helpful when you re working on a larger project You can obtain your animations from several sources including multiple animators or you can buy individual animations from stores online such as Unity s Asset Store Begin by creating a new animator controller asset Assets gt Create gt Animator Con troller not Animation a different sort of asset In the Project view you ll see an icon with a funny looking network of lines on it see figure 7 15 rename this asset to player Select the character in the scene and you ll notice this object has a compo nent called Animator any model that can be animated has this component in addi tion to the Transform component and whatever else you ve added The Animator component has a Controller slot for you to link a specific animator controller so drag and drop your new controller asset and be sure to uncheck Root Motion The animator controller is a tree of connected nodes hence the icon on that as
487. troller Drag that script onto the empty object and then write the following listing in that script Listing 9 1 WeatherController script that transitions from sunny to overcast using UnityEngine using System Collections Reference the material in Project public class WeatherController MonoBehaviour Aa view not only objects in the scene SerializeField private Material sky SerializeField private Light sun private float fullinvensity private float cloudVvalue Of T Initial intensity of the light is void Start A considered full intensity _fullintensity sun intensity void Update SetOvercast _cloudValue _CloudValue 005f Increment the value every frame ea for a continuous transition Adjust both the material s Blend a value and the light s intensity private void SetOvercast float value sky setFloat Blend value sun intensity fullIntensity _fullIntensity value Pll point out a number of things in this code but the key new method is Set Float which appears almost at the bottom Everything up to that point should be fairly famil iar but that one is new The method sets a number value on the material Which value specifically is the first parameter to that method In this case the material has a prop erty called Blend note that material properties in code start with an underscore As for the rest of the code a few variables are defined inclu
488. ts because these are two of the most important activities you ll do in Unity s visual editor they re so impor tant that they get their own section following this one The right side of the Toolbar is where you ll find drop down menus for layouts and layers As mentioned earlier the layout of Unity s interface is flexible so the Layouts menu allows you to switch between layouts As for the Layers menu that s advanced functionality that you can ignore for now layers will be mentioned in future chapters Using the mouse and keyboard Scene navigation is primarily done using the mouse along with a few modifier keys used to modify what the mouse is doing The three main navigation maneuvers are 12 1 2 3 CHAPTER 1 Getting to know Unity Translate Rotate Scale Figure 1 11 Applying the three transforms Translate Rotate and Scale The lighter lines are the previous state of the object before it was transformed Move Orbit and Zoom The specific mouse movements for each are described in appendix A at the end of this book because they vary depending on what mouse you re using Basically the three different movements involve clicking and dragging while holding down some combination of Alt or Option on Mac and Ctrl Spend a few min utes moving around in the scene to understand what Move Orbit and Zoom do TIP Although Unity can be used with one or two button mice I highly rec ommend getting a three butt
489. ttached to the given object and if the object to search on isn t explicitly defined then it s assumed to be this GetComponent that is the same object as this script Movement values are assigned based on the input controls This was in the previous listing too the change here is that we also account for the movement speed Multiply both movement axes by the movement speed and then use Vector3 Clamp Magnitude to limit the vector s magnitude to the movement speed the clamp is needed because otherwise diagonal movement would have a greater magnitude than movement directly along an axis picture the sides and hypotenuse of a right triangle Finally at the end we multiply the movement values by deltaTime in order to get frame rate independent movement recall that frame rate independent means the character moves at the same speed on different computers with different frame rates Pass the movement values to CharacterController Move to make the movement This handles all the horizontal movement next let s take care of vertical movement Implementing the jump action In the previous section we wrote code to make the character run around on the ground In the chapter introduction though I also mentioned making the character jump so let s do that now Most third person games do have a control for jumping And even if they don t they almost always have vertical movement from the character falling off ledges Our code w
490. ttons is drawn using GUI Button instead That method creates a button that executes the code inside the if statement when clicked With all the needed code in place select the requireKey option in Device Trigger and then play the game Try running into the trigger volume before equipping a key nothing happens Now collect a key and click the button to equip it running into the trigger volume opens the door Just for fun you could puta key at Position 11 5 14 to add a simple gameplay chal lenge to see if you can figure out how to reach the key Whether or not you try that let s move on to using health packs Restoring the player s health by consuming health packs Using items to restore the player s health is another generally useful example That requires two code changes a new method in InventoryManager and a new button in the UI see listings 8 22 and 8 23 respectively Listing 8 22 New method in InventoryManager public bool ConsumeItem string name a Check if the item is in inventory if _items ContainsKey name _items name if _items name 0 _items Remove name ne neoe CC emery tt the count goes to 0 Summary 191 else l Debug Log cannot consume name a Response if that item isnt in inventory return false DisplayItems return true Listing 8 23 Adding a health item to Basic Ul foreach string item in itemList Italicized code was if GUI Button
491. ty and in terms of applying programming knowledge gained by working in Unity 13 1 Getting up and running with Unity programming 15 Let s walk through an example of writing and running some code Launch Unity and create a new project choose File gt New Project to open the New Project window Type a name for the project and then choose where you want to save it Realize that a Unity project is simply a directory full of various asset and settings files so save the project anywhere on your computer Click Create Project and then Unity will briefly disap pear while it sets up the project directory WARNING Unity projects remember which version of Unity they were created in and will issue a warning if you attempt to open them in a different version Sometimes it doesn t matter for example just ignore the warning if it appears while opening this book s sample downloads but sometimes you will want to back up your project before opening it When Unity reappears you ll be looking at a blank project Next let s discuss how your programs get executed in Unity How code runs in Unity script components All code execution in Unity starts from code files linked to an object in the scene Ulti mately it s all part of the component system described earlier game objects are built up as a collection of components and that collection can include scripts to execute NOTE Unity refers to the code files as scripts using a definition
492. u don t have to pay as much attention to compression on other platforms for various reasons the chief rea son is that the platform is more technologically mature On mobile devices you need to pay closer attention to texture compression because the devices are touchier about this detail Unity compresses textures for you in most development tools you need to compress images yourself but in Unity you generally import uncompressed images and then Unity applies image compression in the import settings for the image see figure 12 6 Click the Android Change from Texture icon to see settings to Advanced for Filter Mode for this platform advanced texture Aniso Level Oo compression settings Default siol l4 _ Override for Android Max Size Tr Override settings Format Compressed for Android to Compression Quality Normal change compression on this image Figure 12 6 Texture compression settings in the Inspector 290 12 3 3 CHAPTER 12 Deploying your game to players devices These compression settings are the default and you may need to adjust them for spe cific images In particular image compression is trickier on Android This is mostly due to the fragmentation of Android devices because all iOS devices use pretty much the same video hardware iOS apps can have texture compression optimized for their graphics chips the GPU Android apps don t enjoy the same uniformity of hardware so
493. u ll use that If you The remaining settings don t Y a MLight e e now These settings include hs al i ets bea the color of the light shadows seed E raa ee k ntensity 06 brightness from 0 cast by the light and even Bounce intensity lt a silhouette projection IOF COMPLETE HAKK Shadow T think of the Bat signal A _ C Figure 2 8 Directional light settings in the Inspector 2 2 3 Begin the project place objects in the scene 29 Y y MLight Here is where you control Type a Other than Range a4 1 aT light range with the same the settings for units as position and scale Range 40 KE perk Color _ 4 If you see an error about Intensity OO P ms directional lights Bounce Intensity Oooo i realtime not supported just ignore it or switch Shadow Type Baking to Mixed Figure 2 9 Point light settings in the Inspector ever need to create new cameras such as for split screen views in multiplayer games Camera is another choice in the same GameObject menu as Cube and Lights The camera will be positioned around the top of the player so that the view appears to be the player s eyes The player s collider and viewpoint For this project a simple primitive shape will do to represent the player In the GameObject menu remember hover over 3D Object to expand the menu click Cap sule Unity creates a cylindrical shape with rounded
494. ump Jumping is true None Jump to Idle Jumping is false None In addition to these menu based settings there s a complex visual interface shown in figure 7 18 just above the Condition setting This graph allows you to visually adjust the length in time of a transition The default transition time looks fine for both tran sitions between Idle and Run but all of the transitions to and from Jump should be shorter so that the character will snap faster between the jump animation The shaded area of the graph indicates how long the transition takes to see more detail use Alt left click to pan across the graph and Alt right click to scale it these are the same controls as navigating in the Scene view Use the arrows on top of the shaded area to shrink it to under 4 milliseconds for all three Jump transitions Finally you can perfect the animation network by selecting the animation nodes one at a time and adjusting the ordering of transitions The Inspector will show a list of all transitions to and from that node you can drag items in the list their drag han dles are the icon on the left side to reorder them Make sure the Jump transition is on top for both the Idle and Run nodes so that the Jump transition has priority over the other transitions While you re looking at these settings you can also change the playback speed if the animation looks too slow Run looks better at 1 5 speed The animation controller is set up so now we can
495. und you Thank you so much for your love and encouragement www allitebooks com about this book This is a book about programming games in Unity Think of it as an intro to Unity for experienced programmers The goal of this book is straightforward to take people who have some programming experience but no experience with Unity and teach them how to develop a game using Unity The best way of teaching development is through example projects with students learning by doing and that s the approach this book takes I ll present topics as steps toward building sample games and you ll be encouraged to build these games in Unity while exploring the book We ll go through a selection of different projects every few chapters rather than one monolithic project developed over the entire book sometimes other books take the one monolithic project approach but that can make it hard to jump into the middle if the early chapters aren t relevant to you This book will have more rigorous programming content than most Unity books especially beginners books Unity is often portrayed as a list of features with no pro gramming required which is a misleading view that won t teach people what they need to know in order to produce commercial titles If you don t already know how to program a computer I suggest going to a resource like Codecademy first the com puter programming lessons at Khan Academy work well too and then come back to
496. urate recording of the wave changing over time there s less gap between changes But more frequent samples mean more data to save resulting in a larger file Compressed sound files reduce the file size through a number of tricks including tossing out data at sound frequencies that aren t noticeable to listeners Music trackers are a special type of sequencer software used to create music Where as traditional audio files store the raw waveform for the sound sequencers store some thing more akin to sheet music the tracker file is a sequence of notes with information like intensity and pitch stored with each note These notes consist of little wave forms but the total amount of data stored is reduced because the same note is used repeatedly throughout the sequence Music composed this way can be efficient but this is a fairly specialized sort of audio Because Unity will compress the audio after it s been imported you should always choose either WAV or AIF file format You ll probably need to adjust the import set 10 1 2 Importing sound effects 225 tings differently for short sound effects and longer music in particular to tell Unity when to apply compression but the original files should always be uncompressed There are various ways to create sound files for example appendix B mentions tools like Audacity that can record sounds from a microphone but for our purposes we ll download some sounds from one of the man
497. ure 261 7 Inventory Popup Script Lj 4 Set the length Script of the array ne Item Icons Size 4c CS An array defined by Element 0 the script component Element 1 5 l Expand the array Element 2 Drag Image objects by clicking the arrow Element 3 Ti item Icon Image a to these slots Figure 11 6 Arrays displayed in the Inspector Whew that was a long script With this programmed it s time to link together every thing in the interface The script component now has the various object references including the two arrays expand both arrays and set to a length of 4 see figure 11 6 Drag the four images to the icons array and drag the four text labels to the labels array NOTE If you aren t sure which object is linked where they all look the same click the slot in the Inspector to see that object highlighted in the Hierarchy view Similarly slots in the component reference the text label and buttons at the bottom of the pop up After linking those objects you ll add OnClick listeners for both buttons Link these events to the pop up object and choose either OnEquip or OnUse as appropriate Finally add an EventTrigger component to all four of the item images The Inven toryPopup script modifies this component on each icon so they better have this com ponent You ll find EventTrigger under Add Component gt Event it may be more convenient to copy paste the component by clicking the little gear button in the to
498. use for one second and then destroy the sphere that sequence sets up a temporary visual indicator Listing 3 2 gave you indicators to mark where the ray hits But you also want an aiming spot in the center of the screen so that s done in the next listing Listing 3 3 Visual indicator for aiming void Start _camera GetComponent lt Camera gt Cursor lockState CursorLockMode Locked Hide the mouse cursor at Cursor visible false the center of the screen void OnGUI int size 12 float x pixelWidth 2 si 4 a ee ree The command GUI Label float posY camera pixelHeight 2 size 2 di isplays text on screen GUI Label new Rect posX posY size size a Another new method has been added to the RayShooter class called OnGUI Unity comes with both a basic and more advanced user interface UI system because the basic system has a lot of limitations we ll build a more flexible advanced UI in future chapters but for now it s much easier to display a point in the center of the screen using the basic UI Much like Start and Update every MonoBehaviour automati cally responds to an OnGUI method That function runs every frame right after the 3D scene is rendered resulting in everything drawn during OnGUI appearing on top of the 3D scene imagine stickers applied to a painting of a landscape DEFINITION ender is the action of the computer drawing the pixels of the 3D sce
499. ut anything in front of it The first line of the coroutine function makes the object tip over As discussed in chapter 2 rotations can be defined as an angle around each of the three coordinate axes X Y and Z Because we don t want the object to rotate side to side at all leave Y and Z as 0 and assign an angle to the X rotation NOTE The transform is applied instantly but you may prefer seeing the movement when objects topple over Once you start looking beyond this book for more advanced topics you might want to look up tweens systems used to make objects move smoothly over time The second line of the method uses the yield keyword that s so significant to corou tines pausing the function there and returning the number of seconds to wait before resuming Finally the game object destroys itself in the last line of the function Destroy this gameObject is called after the wait time just like the code called Destroy sphere before WARNING Be sure to call Destroy on this gameObject and not simply this Don t get confused between the two this only refers to this script com ponent whereas this gameObject refers to the object the script is attached to The target now reacts to being shot great But it doesn t do anything else on its own so let s add more behavior to make this target a proper enemy character Basic wandering Al A static target isn t terribly interesting so let s write code that ll make the ene
500. uts are W E R and T those buttons activate the transform tools Translate Rotate and Scale refer back to chapter 1 if you don t recall what the transform tools do as well as the 2D Rect tool Because those keys are right next to each other it s common to leave your left hand on those keys while your right hand operates the mouse In addition to the transform tools there are a number of keyboard shortcuts table A 2 lists many useful keyboard shortcuts in Unity Table A 2 Useful keyboard shortcuts Keystroke Function W Translate move the selected object E Rotate rotate the selected object R Scale resize the selected object T Rect tool manipulate 2D objects F Focus view on the selected object V Snap to vertices Ctrl Command Shift N New GameObject Ctrl Command P Play game Ctri Command R Refresh project Ctrl Command 1 Set current window to Scene view Ctrl Command 2 Set to Game view Ctri Command 3 Set to Inspector view Ctrl Command 4 Set to Hierarchy view Ctrl Command 5 Set to Project view Ctri Command 6 Set to Animation view Unity responds to a number of other keyboard shortcuts as well but they get increas ingly obscure the further down the list we get B 1 B 1 1 appendix B External tools used alongside Unity Developing a game using Unity relies on a variety of external software tools for tak ing care of various tasks In chapter 1 we already discussed one external tool MonoDevelop is techn
501. vices The basic build process for all platforms is simple just a single button but customizing the app on various platforms can get complicated Now you re ready to get out there and build your own games Summary In this chapter you ve learned that Unity can build executable applications for a huge variety of platforms includ ing desktop computers mobile devices and websites A host of settings can be applied to builds including details like the icon for the app and the name that appears Web games can interact with the web page they re embedded in allowing for all kinds of interesting web apps Unity supports custom plug ins in order to extend its functionality afterword At this point you know everything you need to know in order to build a complete game using Unity everything from a programming standpoint that is a top notch game needs fantastic art and sounds too But success as a game developer involves a lot more than technical skills Let s face it learning Unity isn t your end goal Your goal is to create successful games and Unity is just a tool granted a very good tool to get you to that goal Beyond the technical skills to implement everything in the game you need an additional intangible attribute grit I m talking about the doggedness and confi dence to keep working on a challenging project and see it through to the end what I sometimes refer to as finishing ability There
502. vidual audio sources that play music You can fade background music in and out by setting the volume on individual audio sources Putting the parts together into a complete game This chapter covers Assembling objects and code from other projects Programming point and click controls Upgrading the UI from the old to a new system Loading new levels in response to objectives Setting up win loss conditions Saving and loading the player s progress The project in this chapter will tie together everything from previous chapters Most chapters have been pretty self contained and there was never any end to end look at the entire game I ll walk you through pulling together pieces that had been intro duced separately so that you know how to build a complete game out of all the pieces Pll also discuss the encompassing structure of the game including switching levels and especially ending the game for example Game Overwhen you die Success when you reach the exit And Ill show you how to save the game because saving the player s progress becomes increasingly important as the game grows in size 246 11 1 Building an action RPG by repurposing projects 247 WARNING Much of this chapter will use tasks that were explained in detail in previous chapters so ll move through steps quickly If certain steps confuse you refer to the relevant previous chapter for example chapter 6 about the UI for a more deta
503. ving in the wrong direction but when facing away from the edge we want to add to the previous horizontal movement in order to keep the forward momentum away from the edge The movement vector s facing relative to the point of collision can be determined using the dot product DEFINITION The dot product is one kind of mathematical operation that can be done on two vectors Long story short the dot product of two vectors ranges between l1 and 1 with 1 meaning they point in exactly the same direction and 1 when they point in exactly opposite directions Don t confuse dot product and cross product the cross product is a different but also com monly seen vector math operation 158 1 4 CHAPTER 7 Creating a third person 3D game player movement and animation Vector3 includes a Dot function to calculate the dot product of two given vectors If we calculate the dot product between the movement vector and the collision normal that will return a negative number when the two directions face away from each other and a positive number when the movement and the collision face the same direction Finally the very end of listing 7 5 adds a new method to the script In the previous code we were checking the collision normal but where did that information come from It turns out that collisions with the character controller are reported through a callback function called OnControllerColliderHit that MonoBehaviour provides in o
504. with the techniques you ll learn this proj ect is a great way to learn about several fundamental concepts in 3D simulations For example shooting games are a great way to teach raycasting In a bit we ll get into the specifics of what raycasting is but for now you just need to know that it s a tool that s useful for many different tasks in 3D simulations Although raycasting is useful in a wide variety of situations it happens that using raycasting makes the most intuitive sense for shooting Creating wandering targets to shoot at gives us a great excuse to explore code for computer controlled characters as well as use techniques for sending messages and spawning objects In fact this wandering behavior is another place that raycasting is valuable so we re already going to be looking at a different application of the tech nique after having first learned it with shooting Similarly the approach to sending messages that s demonstrated in this project is also useful elsewhere In future chap ters you ll see other applications for these techniques and even within this one proj ect we ll go over alternative situations Ultimately we ll approach this project one new feature at a time with the game always playable at every step but also always feeling like there s a missing part to work on next This roadmap breaks down the steps into small understandable changes with only one new feature added in each step Write code enabling t
505. wo factors in particular are important for 2D images imported as textures how is the image compressed and does it have an alpha channel The alpha channel is a straightforward consideration because the alpha channel is used often in 3D graphics it s better when the image has an alpha channel Image compression is a slightly more complicated consideration but it boils down to lossy compression is bad both no compression and lossless compression preserve the image quality whereas lossy compression reduces the image quality hence the term lossy as part of reducing the file size 4 3 2 Texture the scene with 2D images 77 Between these two considerations the two file formats I recommend for Unity tex tures are either PNG or TGA Targas TGA used to be the favorite file format for tex turing 3D graphics before PNG had become widely used on the internet these days PNG is almost equivalent technologically but is much more widespread because it s useful both on the web and as a texture PSD is also commonly recommended for Unity textures because it s an advanced file format and it s convenient that the same file you work on in Photoshop also works in Unity But I tend to prefer keeping work files separate from finished files that are exported over to Unity this same mind set comes up again later with 3D models The upshot is that all the images I provide in the example projects are PNG and I recommend that you work wi
506. y Particle system An orderly mechanism for creating and controlling large numbers of small moving objects Many visual effects are done this way such as fire smoke or spraying water Creating art for a new game generally starts with either 2D images or 3D models because those assets form a base on which everything else relies As the names imply 2D images are the foundation of 2D graphics whereas 3D models are the foundation of 3D graphics Specifically 2D images are flat pictures even if you have no previous familiarity with game art you re probably already familiar with 2D images from the graphics used on websites Three dimensional models on the other hand may be unfamiliar to a newcomer so I m providing the following definition DEFINITION A modelis a 3D virtual object In chapter 1 you were introduced to the term mesh object 3D model is practically a synonym The terms are fre quently used interchangeably but mesh object strictly refers to the geometry of the 3D object the connected lines and shapes whereas model is a bit more ambiguous and often includes other attributes of the object The next two types of assets on the list are materials and animations Unlike 2D images and 3D models materials and animations don t do anything in isolation and are much harder for newcomers to understand Two dimensional images and 3D models are eas ily understood through real world analogs paintings for the former sculptures f
507. y audio as 2D sounds or 3D sounds Things like music should be 2D sounds but using 3D sounds for most sound effects will create immersive audio in the scene As an analogy imagine a room in the real world The room has a stereo playing a CD If a man comes into the room he hears it clearly When he leaves the room he hears it more quietly and eventually not at all Similarly if we move the stereo around the room he ll hear the music changing volume as it moves As figure 10 2 illustrates in this analogy the CD is an AudioClip the stereo is an AudioSource and the man is the AudioListener The first of the three different parts is an Audio Clip That refers to the actual sound file that we imported in the last section This raw waveform data is the founda tion for everything else the audio system does but audio clips don t do anything by themselves The next kind of object is an Audio Source This is the object that plays audio clips This is an abstraction over what the audio system is actually doing but it s a useful abstraction that makes 3D sounds easier to understand A 3D sound played from a spe cific audio source is located at the position of that audio source 2D sounds also must be played from an audio source but the location doesn t matter The third kind of object involved in Unity s audio system is an Audio Listener As the name implies this is the object that hears sounds projected from audio sources This is anothe
508. y free sound websites We re going to use a number of clips downloaded from www freesound org and get the clips in WAV file format WARNING Free sounds are offered under a variety of licensing schemes so always make sure that you re allowed to use the sound clip in the way you intend For example many free sounds are for noncommercial use only The sample project uses the following public domain sound effects of course you can choose to download your own sounds look for a 0 license listed on the side thump by hy96 ding by Daphne_in_Wonderland swish bamboo pole by ra_gun fireplace by leosalom Once you have the sound files to use in your game the next step is to import the sounds into Unity Importing audio files After gathering together some audio files you need to bring them into Unity Just as you did with art assets in chapter 4 you have to import audio assets into the project before they can be used in the game The actual mechanics of importing files are simple and are the same as with other assets drag the files from their location on the computer to the Project view within Unity create a folder called Sound FX to drag the files into Well that was easy But just like other assets there are import settings shown in figure 10 1 to adjust in the Inspector Leave Force To Mono unchecked That refers to mono versus stereo sound often sounds are recorded in stereo where ther
509. y know most objects will ignore the message Once the code is written you can attach this script to the player object Now you can open and close the door by standing near it and pressing the key There s one little detail we can fix Currently it doesn t matter which way the player is facing as long as the player is close enough But we could also adjust the script to only operate devices the player is facing so let s do that Recall from chapter 7 that you can calculate the dot product for checking facing That s a mathematical opera tion done on a pair of vectors that returns a range between l and 1 with 1 meaning they point in exactly the same direction and 1 when they point in exactly opposite directions The next listing shows the new code in the DeviceOperator script Listing 8 3 Adjusting DeviceOperator to only operate devices that the player is facing foreach Collider hitCollider in hitColliders Vector3 direction hitCollider transform position transform position if Vector3 Dot transform forward direction gt 5f hitCollider SendMessage Operate N SendMessageOptions DontRequireReceiver Only send the message when facing the right direction To use the dot product we first determine the direction to check against That would be the direction from the player to the object make a direction vector by subtracting the position of the player from the position of the object Then call Vector3 Dot wi
510. yment to WebGL the new framework for 3D graphics in web browsers Few game engines sup port as many deployment targets as Unity and none make deploying to multiple plat forms so simple Meanwhile in addition to these main strengths a third and subtler benefit comes from the modular component system used to construct game objects In a component www allitebooks com 1 1 2 CHAPTER 1 Getting to know Unity INHERITANCE COMPONENT SYSTEM Mobile enemy Mobile Shooter Stationary shooter Enemy Enemy component Enemy component component Mobile enemy Mobile shooter Motion component Motion Shooter component Shooter component component The mix and match components Stationary shooter K The separate inheritance branches for mobile and stationary enemies need separate duplicated shooter enable a single shooter component classes Every behavior change and new to be added anywhere it s needed enemy type requires a lot of refactoring on both mobile and stationary enemies Figure 1 1 Inheritance vs components system components are mix and match packets of functionality and objects are built up as a collection of components rather than as a strict hierarchy of classes In other words a component system is a different and usually more flexible approach to doing object oriented programming where game objects are constructed through composition rather than inheritance Figure 1 1 diagrams an example

Downloading - All IT eBooks

Contents

Download Pdf Manuals

Related Search

Related Contents