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Documentation of Bridge Condition Using QuickTime Virtual Reality

1. Research Documentation of Bridge Condition Using QuickTime Virtual Reality Report NMO4STR 05 Prepared by New Mexico State University Department of Civil Engineering Box 30001 MSC 3CE Las Cruces NM 88003 8001 July 2006 Prepared for New Mexico Department of Transportation Research Bureau 7500B Pan American Freeway NE Albuquerque NM 87109 In Cooperation with The US Department of Transportation Federal Highway Administration NMO4STR O5 4 Title and Subtitle 5 Report Date Documentation of Bridge Condition using QuickTime Virtual Reality a 7 Author s 8 Performing Organization Report No David Jauregui Kenneth White Wesley Cook Hyunsik Moon 9 Performing Organization Name and Address 10 Work Unit No TRAIS New Mexico State University Department of Civil Engineering Box 30001 MSC 3CE Las Cruces NM 88003 8001 CO 4416 12 Sponsoring Agency Name and Address 13 Type of Report and Period Covered NMDOT Research Bureau 7500B Pan American Freeway NE 14 Sponsoring Agency Code PO Box 94690 Albuquerque NM 87199 4690 15 Supplementary Notes Will Dooley Bridge Engineer FHWA New Mexico Division Jimmy Camp Bridge Engineer NMDOT Rais Rizvi Research Engineer NMDOT Virgil Valdez Research Analyst NMDOT 11 Contract or Grant No 16 Abstract In bridge inspection the condition rating assigned to a structural component represents the outcome of a subjective comparison of
2. The different panels involved in creating a panorama are described in the following sections Setup Panel 1 The Setup Panel will automatically activate after clicking OK as just described 2 Select Multiple images in the Source Format menu 3 Choose PLUG IN Image File in the Acquire From menu 4 Click on the Setup button next to the Acquire From field 5 Under Source Rotation select 90 degrees and click on OK to return to the setup panel 6 Set the Node Sweep to the desired angle of panoramic rotation this angle varies from 90 to 360 degrees or a custom setting may be used For this example choose 180 7 Set Max Frames equal to the number of indentions on the detent disc for this example specify 18 This allows for 9 pictures to be stitched together for an 180 panorama 8 The Lens Params Length should be adjusted manually to 27 mm to match the camera Highlight the number already in the space and then type in 27 The vertical degree will automatically change Do not adjust the F O V in the Lens Params 9 Set Image Size to Auto This is satisfactory in most cases otherwise set it equal to the pixel size of the image sensor 1 e 1200x1600 for the Olympus C 5069 It may be necessary to select Custom Size and enter the size in manually as just described 10 At this point the screen should look like FIGURE A11 40 s Untitled 1 Panorama t Setup Ic Acquire de Stitch E Blend Q Hot Spots o Compo
3. Background Hodes compose Preview General Definition Name Mesa Scene Orientation lr y Master Size 1600 1200 Playback Size 1600x1200 Scene Boundary Dimensions 70 4 fi 00 Feet Y Scale 1 10 1Inch 2 10 Iv Background Grid Divisions la IV Active v Node Grid Divisions E IV Active FIGURE A18 Scene Setup Panel Screen of VR Worx Background Panel The Background Panel is used to set up the scenario for the scenes In FIGURE A19 two bridge decks have been sketched one representing the northbound bridge and the other the southbound d Background Hodes sd Compose a Preview E uL ms mig Layer n a FIGURE A19 Scene Background Panel Screen of VR Worx 48 1 Click on the Background tab 2 Click on the Tools and choose the square that is highlighted in the darker grey 3 Go to the paint bucket and click on the colors a set of colors will come out Choose a color and then sketch on the grid the sketch should be filled in with the chosen color 4 At this point the Background panel should look like the FIGURE A19 5 You can also draw the background picture by using some other software and save it as an image file e g jpeg The picture can subsequently be imported to the Background panel using the Add button This is useful when a more complicated background picture is needed The background picture 1s meant for organizational purposes and should be
4. Mesa East folder in the lesson CD Save all your work in mov and prx files You will need these files when you create the scene NOTE this completes the appendix related to panoramic creation 46 APPENDIX D SCENE CREATION CREATING A SCENE A scene is a set of panoramas still pictures web pages etc that are linked together and accessed from a single movie In scene mode it is possible to see many views of a panorama In order to make a scene there needs to be two or more panoramas or items to link together You can use the panorama movie files you already created or the movie files stored in folder Mesa Scene of your lesson CD To get started open VR Worx 2 5 select Create a Scene and click OK as shown in FIGURE A17 Welcome to The VR Worx v2 5 2 t Create a Panorama LUN TUE MULTINODE SCENE le Create a Scene Open an existing project Don t show this dialog at startup Cancel FIGURE A17 Scene Project Options Screen of VR Worx Setup Panel The Setup Panel is where you define the scene boundary background grid node grid and general definitions see FIGURE A18 1 Go to the Setup screen in the Name field change the name to Mesa Scene 2 Choose 0 degrees for Orientation 3 Change the Master Size and the Playback Size to 1600 x 1200 4 Choose 70 x 100 for the Scene Boundary 5 Activate the Background Grid and Node Grid choose 8 Divisions for both 47 Untitled 1 Scene setup 3
5. improve routine bridge inspections one of which is the collection and management of inspection data In this section an approach using QuickTime Virtual Reality QTVR is described for recording bridge inspection data at a high level of photographic detail High resolution photography also provides an excellent management tool for the review of inspection reports by supervisors Virtual reality technology has been previously used to create virtual worlds of various settings such as art museums archaeological sites city attractions and natural surroundings to name a few There are many other ways in which QTVR has been employed however prior to this application for bridge inspection little has been done to address a specific engineering problem In QTVR photographic images are moved from the flat two dimensional world into a more immersive three dimensional environment complete with interactive components 9 Thus this technology provides the capability for an inspector or engineer to explore and examine a bridge s physical condition as if he she were actually in the field with the simple use of a computer mouse in lieu of virtual reality equipment such as goggles headsets or gloves 9 The amount of equipment needed for a virtual reality system is not extensive a basic system excluding a laptop computer should include a high resolution digital camera a camera tripod panoramic tripod heads and virtual reality computer software A
6. a series of individual photographs are taken and later merged into a single panorama through a stitching process discussed later At first the photography should focus on producing global panoramas of the bridge from both elevation and cross section viewpoints as outlined below e end spans horizontal sweep of span elevation from the abutment to the adjacent interior pier from each side of bridge width and horizontal sweep of cross section in the direction of the abutment from the interior pier and vice versa e interior spans horizontal sweep of span elevation between interior piers from both sides of bridge width and horizontal sweep of cross section from one interior pier to the other e overall bridge horizontal sweep of bridge elevation between abutments from both sides of bridge width Based on the recommendations given above the photography of a three span bridge for example would involve a total of 14 global panoramas 1 e four panoramas per span plus two panoramas of the whole bridge as shown in Figure 1 Abutment jueunnqy FIGURE 1 Camera Stations for Global Panoramas of Three Span Bridge Afterward local areas of the bridge having damage and or deterioration should be identified with the assistance of an experienced bridge inspector or professional engineer and photographed If the bridge is in pristine condition pictures should be taken of deterioration prone
7. all directions up to 360 degrees The vertical angle of view depends on the viewing range of the camera lens and thus wide angle lens cameras such as the Olympus C 5060 are advantageous Cubic panoramas combine multi row images and add the capability to pan vertically up to 180 degrees overhead and or underneath the focal point of the camera lens in a spherical environment There are various software programs available for creating virtual reality panoramas a few of which include 11 Apple s QuickTimeVR Authoring Studio VR Toolbox s The VR Worx PhotoVista Virtual Tour Maker iPLX s software amp Panoweaver Realviz Stitcher and Helmut Dersch s Panotools The latter two stitching programs may be used to create both cylindrical and cubic panoramas while the other programs listed are capable of only cylindrical panoramas A brief discussion of cylindrical and cubic panorama creation using the VR Worx and Realviz Stitcher programs respectively is provided in the following paragraphs The VR Worx software is an IBM PC based program which can create cylindrical panoramas of varying horizontal sweeps ranging from a partial 90 to a full 360 using the Kaidan Kiwi Panoramic Head mentioned earlier Single row images must overlap by at least 30 in order for stitching to work some programs require up to 60 Figure 2 a shows the general way in which a cylindrical panorama is created while Figure 2 b shows a sample panoramic i
8. altered as desired Nodes Panel The Nodes Panel see FIGURE A20 is where you add your source movies link the nodes and view your newly created links To add a node you must already have a movie file or single picture saved C Documents and Settings qtvr My Documents ZHIYONGWesa lsceneWesa Scene srx 4 Setup E Background Nodes s Compose a Preview Actions Mesa South mov FIGURE A20 Scene Nodes Panel Screen of VR Worx 49 Select the Nodes tab Press the Add button navigate to the folder where you stored your movie files or still pictures and select the movie or picture desired For this example go to the Mesa Scene folder in your lesson CD Add the Mesa_North mov file first which will make sure this movie file will be the initial node then add the other five movie files The files will automatically appear as icons on the grid The icons can be moved around on the grid and placed wherever desired to match the actual bridge In this example place the movies at the locations shown in FIGURE A20 Select the double sided arrow icon click on a node and drag the pointer on top of another node without releasing the left button of the mouse Benefits of using the double sided arrow are that 1t creates two hot spots one to get to the linked node and another to return to the original node Connect the nodes as shown in FIGURE A20 If the one sided arrow 1s used then it will only go to the linked node and
9. can be changed if desired however it is best if the file name appears initially when added to the Node Panel This name will appear in the item identification display in the movie controller e Tip 2 use a background that shows an overview of panoramic shots similar to the image created in step 5 of the Background Panel procedure or create an opening scene including the structure number deck substructure superstructure and report to link the scene to the indicated links as hotspots This helps the final product to be user friendly and well organized 51 Adding Hot Spots Hot spots are special areas within your movie that can be utilized as links to other movies and QuickTime resources as well as displaying text in the movie controller Each double sided arrow you defined in the Nodes Panel automatically creates a hot spot in both images the arrow connects Each one sided arrow automatically creates a hot spot in the original image where the arrow originates The main problem that comes up with the hot spots is the placement of the link they are all on top of each other in the images It 1s necessary to separate each link reshape them into smaller sizes and place on the panorama Not all the pictures will have a hot spot If the head of the arrow is touching an object then it will not have a hot spot The return key in the QuickTime Player will be needed to get back to the previous panorama The following steps describe the
10. list of suitable hardware and software products is provided below 10 e Olympus C 5060 Digital Camera with wide angle lens including memory cards Kaidan Slik Master Classic Tripod Kaidan Kiwi Panoramic Tripod Head with QuickTilt Leveler Kaidan QuickPan III System spherical camera bracket with universal camera mount and rotator configuration VR Toolbox The VR Worx panoramic software Realviz Stitcher panoramic software QTVR DOCUMENTATION PROCEDURES The virtual reality documentation process consists of three basic steps 1 planning and taking of photographs 2 creation of panoramas and 3 rendering of virtual reality records with hot spots These steps are discussed in detail in the following sections for different bridge inspection projects with reference to the equipment listed earlier A step by step manual suitable for the training of bridge inspectors 1s provided in the appendix of this report along with a lesson CD which provides hardware and software lessons for using QTVR The lesson CD also contains QTVR files for 12 bridges in New Mexico PLANNING AND TAKING OF PHOTOGRAPHS The time invested in planning the fieldwork will greatly improve the efficiency of the photography as well as the overall image quality The photography plan should primarily indicate the locations to setup the camera at the bridge site camera stations may be limited at some bridges due to accessibility and obstructions From each camera station
11. o o ooooo 53 Scene Nodes Preview Panel of VR WorX oooo oo o 29 Menu Bar of QuickTime Player oooooooooo 54 vi LIST OF APPENDICES Page APPENDIX A EQUIPMENT REQUIREMENTS 22 BASIC EQUIPNIBIND p asa 227 CAMERA SETUP uscar iaa UE Ro EHE Be ns RR AUR ROS dom de 22 PC CUMS EE E EEE E EE oia E E E E E EE E ENE 22 APEE corra pr 22 Mannal T OCUS asii cc o iii 24 PICAS OUT AR AA AA AA eS 25 Using the Remote and the Timer lis Ai 27 Preparing the Camera for the Timer 00 060s 21 Preparing the Camera for the Remote 22e 28 TRIPOD SETUP sitiar ect aga nibns uou ee ee ee tio 28 Detent Disc Installation in KiWi Head o ooooooooo oo 20 Attaching Camera to Tripod Head 0 0 cece ees 31 APPENDIX B PHOTOGRAPHY PROCEDURES 33 PREPARING FOR THE FIELD i2 pex Dir era is eas e 33 WHERE TO TAKE PICTURES 240 34 HOW TO TAKE PICTURES dj p ERE paladio ea 35 ADVANCED PHOTOGRAPHY eee Ie 36 APPENDIX C PANORAMIC CREATION e 38 TRANSFERRING PICTURES FROM THE CAMERA 38 CREATING A PANORAMA sseee hh 39 Selup Paneb acorralado cda omi dd 40 ACUS Panel 32d dide bar esie e da redire Ear ssi hd dett Bp 4 o cya eae tuce m datas Mb ecc du e I E db Ub pce 43 Dione ect ue DR deb Au iet ees o RUE deb A de adit m du pA d 44 HOoLUSDOLUS Panieh 45 ida A ida 44 COMPOS AMG Ul soport
12. of damage and or deterioration such as 3 4 collision damage concrete spalls cracks and delaminations with possibly exposed rebar corroded steel fatigue cracks malfunctioning or damaged bearing devices member section loss and scour and undermining Based on these field observations condition ratings are assigned using the rating system given in Table 1 to describe the general condition of each bridge subsection 1 e deck superstructure and substructure As shown in the table there are ten condition states ranging from FAILED to FAIR to EXCELLENT Handwritten notes sketches measurements and or photographs are utilized to document the bridge condition and support the assigned condition states TABLE 1 Standard Condition Rating System 5 Condition State Description of and Rating Condition State Not Applicable N B Excellent 9 B Very Good 8 no problems noted Good 7 U some minor problems Satisfactory 6 10 structural elements show some minor deterioration all primary structural elements are sound but may have minor section loss cracking spalling or scour Fair 5 E SP Poor 4 advanced section loss deterioration spalling or scour present section loss deterioration spalling or scour have seriously affected primary structural members local failures possible fatigue cracks in steel or shear cracks in concrete may be present advanced deterioration of primary structural members fatigue cr
13. process for adding hot spots 1 Double click on the node to be edited in the Nodes panel For this example double click on the Mesa_North mov node The Node Browse menu will come up 2 Click on the Hot Spot tab 3 Click on the zoom out button at the lower left corner of the panorama until the panorama is minimized or using the mouse pan through the scene to find the hot spots 4 Some hot spots will be on top of each other Separate the hot spots and modify by location shape or color In this example place the hotspots as shown in FIGURE A22 5 Click on the Preview tab in the Node Browser and adjust the panorama so it looks like FIGURE A23 Then click the Set button in the Initial View setting to the left of the preview area When complete click on OK 6 Repeat steps through 5 above for each node until all the hot spots are defined 22 Node Browser Properties Hot Spots Preview Ik L1 Q Aute m 210 Manual E Aj Row Column PES i Node Browser Properties Hot Spots Preview Name Mesa_North mow ID 001 Pan Tilt Zoom Initial set Go Name y fat ai eee FIGURE A23 Scene Nodes Preview Panel of VR Worx Panoramas or individual pictures can be added as hot spots When adding single shots it is best to use pictures in the gif or jpeg format Compose Panel 1 Under File gt save your work 2 Click on the Compose tab 3 Click on the B
14. that are needed e Tip 2 creating a folder for each set of panoramic views and one folder for defects helps with organization The pictures are now in an album Move the cursor to the upper left corner to Menu and double click This will bring you to the main menu Go to the Browse icon and click This menu has tools for editing pictures and copying files Copy the album with the pictures and paste the album file to My Documents see FIGURE A9 Close the Camedia Master file Other software may also be used to transfer pictures as specified by its associated instruction manual 38 mm liz ff Hy Camera LU Emm My Albums A Ag A i Ava dk e Facing asst ANTANA a nege akelad imager FIGURE A9 Transfer Images Screen of Camedia Master CREATING A PANORAMA To demonstrate how to create panoramas and scenes using VR Worx the file folder Mesa Bridge will be used The Mesa Bridge is a three span bridge across a roadway All the example pictures and files in this instruction can be found in the lesson CD To begin launch the VR Worx 2 5 from the desktop Then select Create a Panorama from the pop up menu and press OK as shown in FIGURE A10 Welcome to The VR Worx v2 5 7 Create a Panorama AN OBA i C Create an Object PANOR A C Create a Scene C Open an existing project Don t show this dialog at startup Cancel FIGURE A10 Project Options Screen in VR Worx 39
15. the member s current physical condition to its as built condition This evaluation is made with the aid of the various definitions of structural condition provided in the Recording and Coding Guide published by the Federal Highway Administration FHWA and based on National Bridge Inspection Standards NBIS Since a condition rating is usually assigned based on a visual assessment of the bridge by inspectors with varying levels of training experience and background the evaluation is quite biased and photographic support is needed QuickTime Virtual Reality QTVR provides the capability of generating and managing an interactive high resolution photographic record that allows bridge engineers detailed visual access to the physical condition of the bridge components in electronic format This digital record of the bridge provides inspectors engineers and supervisory staff a very useful tool for planning conducting and reviewing the results of a field inspection In this report the equipment and procedures for using QTVR for documenting bridge condition is provided 17 Key Words 18 Distribution Statement Virtual reality bridge inspection condition rating photography Available from NMDOT Research Bureau 19 Security Classification 20 Security Class 21 No of Pages 22 Price of this report of this page Unclassified Unclassified 55 Form DOT F 1700 7 8 72 DOCUMENTATION OF BRIDGE CONDITION USING QUICKTIME VIRTUAL REALITY b
16. to a linked panorama As the inspector navigates the panorama a directional indicator on the active node marker follows the inspector s line of sight to show the position and viewing orientation of the panorama along with an audio description This particular capability may prove quite useful to acquaint the inspector with the bridge structure and site prior to an inspection As indicated earlier consistent and uniform field inspections depend greatly on the experience and training of the inspection teams The detailed high resolution photographic records will allow supervisors 17 to quickly review each inspection without personally visiting every structure Supervisors will also be able to review inspections with the field crews to improve the quality of the final reports to better determine when critical damage or deterioration has occurred Bridge inspector training courses that cover visual inspection could benefit greatly from virtual reality technology In order to fulfill NBIS training requirements inspectors must complete a comprehensive training course based on the Bridge Inspector s Training Manual 4 These courses are offered by various agencies and cover general topics such as bridge mechanics bridge materials bridge types and components fundamentals of bridge inspection and bridge inspection reporting Also covered in depth are the inspection and evaluation of bridge decks timber concrete and steel superstructures fractu
17. to the Stitch tab and fix any corrections that need to be made Then repeat steps 1 and 2 given above Hot Spots Panel Hot spots are not needed at this point and are better left when creating the scene which will be covered in APPENDIX D Compose Panel l 2 Click on the Compose tab Select the Set button in the Compression panel adjust the quality to High in the pop up menu and click OK Choose 24 bit million in the Color depth option in the Compression panel Choose 7x24 in the Tile Array option in the Dicing panel Leave all the checkboxes in Additional track panel unchecked Click on the Build button At this point the screen should look like FIGURE A15 44 Untitled 1 Panorama seup C Acquire stitch a Blend Q Hotspots Y Compose Preview Actions Composition Presets Click to choose a preset j M Compression Set Codec Build Hints Photo JPEG Target Size 5120 Quality Medium 50 Color Depth 24 bit Millions y Dicing Tile Array 124 v Optimal Scaling IV Optimize for Web Delivery Additional Tracks Create Web Preview Image Track Optiot Create Quarter Resolution Image Track Create Half Resolution Image Track View Angles Pan Tilt Zoom Initia 900 foo faz 2 Minimum 00 E 4 E no qd Maximum ficou 2 ra sso g poer FIGURE A15 Compose Panel Screen of VR Worx Preview Panel 1 Click o
18. Buttons 16 CONCLUSIONS AND RECOMMENDATIONS Virtual reality can favorably contribute to bridge inspection practice in several possible ways First of all inspectors will often review information given in past reports to determine the type and severity of previously observed damage and or deterioration to prepare for an upcoming bridge inspection Design drawings field sketches and or still photographs are also reviewed to further aid the inspector Following the inspection the observed bridge condition is then evaluated relative to that previously recorded to determine if there are any changes This comparison may be troublesome due to the written format and limited amount of photographic documentation given in a typical inspection report It is important to note that the NBIS requires photographs of only the side elevation of the bridge and the top of the roadway 2 In a virtual reality system notes and photographs can be integrated into an interactive and more realistic visual environment to aid in tracking changes from inspection to inspection Another powerful feature of this technology is that design drawings overhead maps and or audio recordings can be integrated into the virtual reality record using programs such as those developed by Squamish Media Group 15 In such an application clickable node markers may be overlaid on the bridge drawing or map at different reference points Clicking on a node marker then transports the inspector
19. ET function highlighted with green letters Press p select OFF e twice and the main screen will reappear Using the Remote and the Timer In order to get the best picture quality either the self timer or the camera remote control should be used when taking the pictures options are provided below The remote control may be more convenient because the self timer has to be reset for each picture however it is left to the user to decide which is preferred Preparing the Camera for the Timer l 2 2 4 Hold down the self timer remote control button N UB Turn the control dial continuing to hold V a Select Press the shutter button to start self timing shooting 27 Procedures for setting up the camera for both 5 The self timer is automatically cancelled after every photograph follow steps 1 4 for subsequent photographs Preparing the Camera for the Remote 1 Hold down the self timer remote control button 37 UB 2 Turn the control dial continuing to hold V 3 Select gt 4 Point the remote control device at the remote control receiver on the camera the range of the remote control ranges from 3 m 9 8 ft to 5 m 16 4 ft as shown in Figure A4 5 Press the shutter button on the remote control device The self timer remote control lamp blinks for about two seconds before taking the picture Repeat steps 4 and 5 for subsequent pictures FIGURE A4 Distance Range from Re
20. RUE hao atada 16 View of Olympus C 3060 from a Top b Back and c Front 14 23 a Mode Dial and b Control Dial of the OLYMPUS C 5060 14 24 Setting of MF for Olympus C 5060 14 oooooooooooo o 25 Distance Range from Remote Control to Olympus C 5060 14 28 Panoramic Tripod Head Components a QuickTilt Leveler and BIKI e 5 LO MA A 29 Disassembly of Kiwi Head 76 o o ooooooooocoooooomo 30 Reassembly of Kiwi Head 76 o o o ooooooooomo ooo 31 Spall with Exposed Rebar at Abutment a Poor and b High QUA BIGUES 25 esas d So koe E EE ei 36 Transfer Images Screen of Camedia Master o o ooooo o 39 Project Options Screen in VR Worx o oooooooooooo ooo 39 Setup Panel Screen in VR WO srt A Ai 4 Acquire Panel Screen of VR Worx o o oooooooommoo oo 41 Import Images Screen of VR Worx o oooooooocoooooo 42 Stuten Panel Screen OF VER WO id pec op Er aa dra 43 Compose Panel Screen of VR WorX o o o oooooooocooooo o 45 Preview Panel Screen of VR Worx o o o oooooooooooo oo 45 Scene Project Options Screen of VR Worx o o ooooooo 47 Scene Setup Panel Screen of VR Worx o o o oooooooo ooo 48 Scene Background Panel Screen of VR Worx o o 48 Scene Nodes Panel Screen of VR WorX o o ooooooooooo 49 Scene Nodes Property Panel Screen of VR Worx 51 Scene Nodes Hot Spot Panel of VR Worx
21. VR Worx 3 From the Look in menu find the folder where the image files are For this example locate the Mesa Mesa North folder in the lesson CD 4 Next select the images that are needed Selecting one of the 9 images and then clicking on the Add 9 button will add the next 9 pictures If there are images not associated with the panorama stored in the same folder you can hold down the Ctrl key and click on all the images needed and then click the Add button 5 At this point the files will appear in the lower display box Make sure all the images were added in order before clicking the Done button The pictures selected will be automatically downloaded into the image slots If the pictures are not already vertical in the slots they can be rotated by the Rotate or Rotate All button When this function is used it will ask for 90 90 or 180 degrees It 1s important to note that the order of the pictures needs to be in the clockwise direction Otherwise the order of the pictures needs to be reversed and this can be done by clicking the Reverse button 42 Stitch Panel The Stitch Panel shown in FIGURE A14 is where the alignment of each image is made Untitled 1 Panorama 4 Setup Acquire dy Stitch 4 Blend Actions Build Tools de Tolerance Options Correction FIGURE A14 Stitch Panel Screen of VR Worx 1 Click on the Stitch tab 2 Click on the Build button The software will then superim
22. acks in steel or shear cracks in concrete may be present or scour may have removed substructure support major deterioration or section loss present in critical structural members or obvious vertical or horizontal movement affecting structure stability Serious 3 Critical 2 Imminent Failure 1 Failure 0 0 out of service beyond corrective action no description of condition state given by NBIS CORE ELEMENT GUIDE In lieu of the NBIS rating system given in Table 1 many state highway departments in the U S are now using the AASHTO Guide for Commonly Recognized CoRe Elements 6 which provides more quantitative definitions of the various bridge condition states This guide breaks down the deck superstructure and substructure into individual elements as defined by CoRe element descriptions and a rating ranging from five to one with one being the best is assigned to each element based on its condition For example a condition state of four in the AASHTO CoRe Guide 6 for a concrete deck or slab with or without coated reinforcement represents the case where patched areas and or spalls delaminations exist and the combined area of distress is between ten and 25 of the total deck surface area The same condition state has a different meaning for prestressed concrete girder stringer or floor beam element s of a superstructure For this type of CoRe element a condition state of four represents the following situation Del
23. ad 16 Once the new detent disc is in place the horizontal bracket may be reassembled Reverse the disassembly inserting the axle into the bearing and plate see FIGURE A7 a Check that the detent disc remained in place and all components are flush with each other Thread the friction cap onto the axle until the washer is compressed slightly and friction drag feels adequate Take care not to over tighten the friction cap as it will interfere with rotation of the tripod head if too much friction is created Turn the knob until the knob lines up with one of the flats on the interior screw see FIGURE A7 b Tighten the knob so that the friction cap stays in place 30 a b FIGURE A7 Reassembly of KiWi Head 16 Attaching Camera to Tripod Head The following steps describe the procedure for attaching the camera to the tripod head l 2 Slide the vertical bracket onto the horizontal bracket as shown in FIGURE AS b Temporarily tighten the purple clamping knob Attach the panoramic tripod head to the tripod by placing the panoramic tripod head on the tripod and tightening the lower mounting screw To ensure that the camera s nodal point is in alignment with the panoramic head locate the tick mark labeled with a 30 on the silver scale located on the horizontal bracket Place the vertical bracket on the horizontal bracket at nodal point 30 this point should be marked for future use Tighten th
24. ado aio ee an kat paso sido 44 Preview Panel AAA AAA CREE UD ACA COE Ua Rd 45 APPENDIX D SCENE CREATION eene 47 CREATING A SCENE surcos eae aes WE Rees OH ee Re eee a 47 AN EA teat are eo c nda de dr oe ah ae ac acu dd Rt 4 Backeround Patel oae Seid Ave ra ad aida enacts ai 48 IN OG SPA Ls se tints ons auch Eo A edu cur S a a ee ad db End Gr tur 49 Adding LIGESDODS usaras Seo M SEE e eds SD OC d Cade ys 52 Composer AIM I a ud E ENA 53 Preview Panel id AAA Ada 54 THEOUICKRTIME PLAYER session sottile 9e ctt ti e son Ria esee ie 54 Vil BACKGROUND NATIONAL BRIDGE INSPECTION STANDARDS Since the early 1970s the safety inspection of bridges has been regulated by the National Bridge Inspection Standards NBIS These standards set national policy for bridge inspection practice in matters such as inspection and rating procedures frequency of inspections qualifications of inspectors and inspection report formats 1 For the most part the type of inspection performed to satisfy NBIS regulations 1s routine inspection which 1s described as Regularly scheduled inspections consisting of observations and or measurements needed to determine the physical and functional condition of the bridge to identify any changes from initial or previously recorded conditions and to ensure that the structure continues to satisfy present service requirements 2 In a routine inspection the bridge is visually examined for evidence
25. ally placed into a workspace and roughly adjusted before the software can perform the automated stitching To illustrate this process Figure 3 b shows four separate images one at 45 two at zero and one at a 45 degree pitch which have been placed in the stitching workspace at the start of development of a cubic panorama of a steel truss bridge RENDERING OF VIRTUAL REALITY RECORDS WITH HOT SPOTS Once the stitching process is complete the cylindrical and or cubic panoramas are rendered to an output file for viewing on the Apple QuickTime player There are several choices in compression and playback settings for the rendered panoramas for which the reader should refer to the virtual reality software manual One especially important setting to be aware of 1s the output size of the panorama which has a direct affect on playback performance In the final virtual reality record hot spots are used to bring together the rendered panoramas and discrete photographs of local areas prone to or with existing damage and or deterioration Generally speaking hot spots are user defined links that connect 1 separate panoramas and or 2 a panorama to a single picture a nodal map defines the interaction between a single panorama and its associated links Once linked the panoramas and or photographs will form a network of visual records about the bridge which may be reviewed at the discretion of the inspector Written explanations along with design drawings an
26. alternative format contact the NMDOT Research Bureau 7500B Pan American Freeway Albuquerque NM 87109 P O Box 94690 Albuquerque NM 87199 4690 or by telephone 505 841 9145 DISCLAIMER This report presents the results of research conducted by the author s and does not necessarily reflect the views of the New Mexico Department of Transportation or the Department of Transportation Federal Highway Administration This report does not constitute a standard or specification ABSTRACT In bridge inspection the condition rating assigned to a structural component represents the outcome of a subjective comparison of the member s current physical condition to its as built condition This evaluation is made with the aid of the various definitions of structural condition provided in the Recording and Coding Guide published by the Federal Highway Administration FHWA and based on National Bridge Inspection Standards NBIS Since a condition rating is usually assigned based on a visual assessment of the bridge by inspectors with varying levels of training experience and background the evaluation is quite biased and photographic support is needed QuickTime Virtual Reality QTVR provides the capability of generating and managing an interactive high resolution photographic record that allows bridge engineers detailed visual access to the physical condition of the bridge components in electronic format This digital record of the
27. aminations spalls and corrosion of non prestressed reinforcement are prevalent There may also be exposure and deterioration of the prestress system manifested by loss of bond broken strands or wire failed anchorages etc There is sufficient concern to warrant an analysis to ascertain the impact on the strength and or serviceability of either the element or the bridge 6 As shown in this comparison the AASHTO CoRe Guide provides descriptions of condition states that are more quantitative and element specific than those given in the NBIS rating system Another important difference of note is that there are ten NBIS condition states see Table 1 which rate from zero to nine with the higher number being the best condition Both of these procedures however primarily utilize visual evaluation of the bridge components and are very subjective As a result the quality of the reported field inspection depends upon the training experience and dedication of the inspection teams Consistent and uniform inspections are difficult to achieve as shown by Phares et al 7 FHWA BRIDGE INSPECTION STUDIES A series of studies related to highway bridge inspection were completed by the Federal Highway Administration FHWA In one study Rolander et al S surveyed 42 state highway departments 72 county highway departments in the state of Iowa and six bridge inspection contractors Two important findings from the survey were 1 visual inspection wa
28. an image to appear on film in digital photography the same principles apply The longer the 36 shutter is open the more exposure In dark areas the shutter speed should be slower because more light is required for a clear image to appear on the film The reverse is true in lighted areas since less exposure time is needed Shutter speed also controls the brightness of colors Camera mode A allows a built it light sensor to choose the best shutter speed for each picture At variable shutter speeds the colors generated while facing out from under a structure would be different than those generated while facing an abutment for example Furthermore objects such as girders and piers would appear much darker and less defined when facing out toward lighter objects As the pictures are stitched together the color and contrast differences become noticeable in the panoramas However by setting the shutter speed to a constant during the photography the colors and contrast of the bridge features will match each other more closely This process for setting the shutter speed is described below 1 Level the camera and set on mode A 2 On mode A determine the best shutter speed before taking the pictures The viewing screen will show the shutter speed as a fraction The smaller the fraction the faster the shutter speed 1 e 1 250 is faster than 1 50 By rotating the camera around on the KiWi Head the light sensor will determine the appropriate s
29. areas such as bearing locations and interior piers below an expansion joint Local photographs of existing and or potential problem areas may be integrated into the global panoramic images to further establish a baseline for future condition assessment In general proper photographic procedures should be followed by the inspector to acquire the 1mages needed for the virtual reality record A good quality tripod with a tiltable head and adjustable legs such as the Kaidan Slik Master Classic should be used in order to withstand and adapt to the bridge environment Many features of a bridge require the use of the pan and tilt adjustment which allows the inspector to view under the superstructure as well as pan horizontally The camera should be oriented vertically on the panoramic tripod head so that the captured photos have a portrait orientation Having the camera in portrait orientation fills the viewing area as much as possible however the angle of view in the horizontal direction is reduced compared to landscape orientation Thus more pictures need to be taken in order to cover the panoramic area being photographed Care should be taken to position the tripod head such that the individual pictures representing the middle region of the panoramic area are level and centered In order to reduce errors due to parallax the camera should be positioned on the tripod head so that it rotates horizontally about the focal point of the lens Parallax is corr
30. be originally taken in tif format Later conversion can be made to other formats such as jpeg or gif using the Camedia Master Software or another software such as Paint This allows for smaller file sizes while still maintaining quality pictures The step by step procedure for adjusting pixel resolution is as follows 1 With the camera dial mode in A press ON this puts the camera in DRIVE mode 2 When in DRIVE mode press from the Arrow Pad 3 The CAMERA tab will be highlighted press Do get to the PICTURE tab 4 When in the PICTURE tab press p get to RECORD mode then 5 to find IMAGE APPLICATION 5 Scroll down to TIFF and press once more Use Do select 640 x 480 pixels higher resolution can be used if desired The 1024 x 768 and 1280 x 960 options offer higher quality resolutions which are acceptable 1f only a few pictures are needed The zoom in feature is also more useful at these resolutions The optimum resolution considering the size and number of pictures is 1600 x 1200 6 Press O times to select application and to exit It is necessary to save the completed settings or the camera will default to the manufacturer s settings when the camera is turned off Settings will also reset when the battery is removed The step by step procedure for saving settings 1s as follows 26 6 Press AS button Press f DRIVE will be lighter color Press Esc times to get to the SETUP tab Press p the ALL RES
31. bridge provides inspectors engineers and supervisory staff a very useful tool for planning conducting and reviewing the results of a field inspection In this report the equipment and procedures for using QTVR for documenting bridge condition are described 11 ACKNOWLEDGEMENTS The NMSU research team would like to acknowledge the advice and review provided by Mr Jimmy Camp State Bridge Engineer NMDOT and Mr Wil Dooley Bridge Engineer FHWA New Mexico Division during development of this technology for bridge inspection The guidance provided by Mr Rais Rizvi Research Engineer NMDOT is also appreciated We also acknowledge the contributions of the NMSU Bridge Inspection personnel that helped develop and implement the technology including Dr Samuel P Maggard Mr George Baca Ms Amanda White and Mr Robert Fierro iii METRIC CONVERSION FACTORS PAGE APPROXIMATE CONVERSIONS TO SI UNITS LENGTH AREA VOLUME iones ms Y mes NOTE volumes greater than 1000 L shall be shown in m MASS SYMBOL Z 3 in m ft m yd m ac ha mi km short tons 2000 Ib megagrams or 0 907 Mg or t metric ton TEMPERATURE exact degrees 5 F 32 9 F Fahrenheit Celsius yx or F 32 1 8 ILLUMINATION r FORCE and PRESSURE or STRESS TABLE OF CONTENTS Page BACKGROUND 24212 uar uen io s iria odia I National Bridge Inspection Standards o o o oooooooooo
32. cracks spalls delamination leaching water and or rust stains rust scour erosion settlement undermining or any other specific or general defect 34 on or relevant to the structure in the Bridge Inspection Report The panoramas and single shots will later be linked to create the final virtual reality tour of the bridge HOW TO TAKE PICTURES At the bridge site check that all applicable procedures have been followed and settings are in order to ensure quality pictures Make sure the camera is level before taking pictures and do not re level once picture taking at a station has begun otherwise panoramic creation may be a problem If the camera or tripod is bumped or is not level start over after re leveling the camera and redo all pictures The following recommendations are given to improve the quality of the pictures l Determine the best possible lighting for the background and foreground of a specific bridge feature or defect Shadows may bring out the third dimension in a two dimensional image which can be a good thing if it defines a defect Avoid direct sunlight as it creates a glare on the photograph Limit lighting changes in a set of panoramic shots On mode A the shutter speed can change since it is light sensitive Cloud movement may also become a factor To avoid overexposed photographs press the Erase button also called the AEL button facing the darker areas of the photographed region This sets the shutt
33. d maps may be included to fully describe the view within the virtual bridge environment and or the specific bridge feature under observation The amount of office time spent in the development of a virtual bridge record will depend on several factors such as 1 the number and type of panoramas 2 the number of hot spots or links and 3 the amount of miscellaneous material such as local pictures text descriptors design drawings and or maps included in the record 14 Figure 4 shows a sample QTVR movie of a steel I girder bridge The movie screen has three distinct areas the header image and footer area l 10 Steel Bridge mov 0X Header File Edit Movie QTY Window Help area Image area a APT 3 X eg an Hot spot Advance in Westward direction towards Abutment 1 Footer Rd v o o009 Q area FIGURE 4 Virtual Reality Record of Steel Girder Bridge Showing Screen Areas The header area of the screen displays the name of the bridge inspection project in this case I 10 Steel Bridge and also contains the menu bar for the Apple QuickTime player Below the header the image area of the screen displays the cylindrical and or cubic panoramas Using the computer mouse 1 e clicking and holding the left button and dragging the mouse the inspector may navigate the panoramic area at his her discretion User defined hot spots appear as transparent outlined regions within the image area which link the active panorama to oth
34. e purple clamping knob Attach the camera to the captive camera knob 1 e the outermost knob on the highest vertical bracket which is located on the horizontal slide scale on the vertical bracket Tighten the captive camera knob Align the camera to the 92 5 marking on the outward facing scale or the 17 5 marking on the inside scale near the leveling bubbles This point should also be marked These steps should place the camera over the central axis of the friction cap 31 7 Level the twin axis bubble leveler This can be achieved by using the tripod handle to get the bubbles as close to the middle as possible The three circular fine adjusters on the Quick Tilt leveler located on the panoramic tripod head can then be used to perform the fine leveling adjustments to the tripod head Rotate the KiWi Head and assembly in 90 intervals to check how level the apparatus 1s fine level if needed 8 Level camera with a bubble leveler Permanently attach or set bubble leveler on camera to ensure the camera is level It is important to note that any type of pitch on the camera or an unleveled camera will result in poor horizontal stitching along the vertical plane NOTE this completes the appendix related to equipment requirements 32 APPENDIX B PHOTOGRAPHY PROCEDURES The camera and tripod settings for taking pictures have just been described Panoramas of varying angles will be required in different situations but will commonly range
35. ected by simply repositioning the camera so that the effect 1s minimized The panoramic tripod heads mentioned earlier have a graduated horizontal rotation scale and a detent mechanism to provide click stops when rotating the camera in equal angle increments Detect discs are available with two to 22 stops which correspond to horizontal angle increments of 180 and about 15 7 degrees respectively The number of stops used depends on the lens size of the camera or the lens equivalent in 35 mm format for a digital camera and should provide 30 to 50 overlap between adjacent images For a 35 mm lens equivalent for example an 18 stop detect disk with a horizontal angle increment of about 18 9 degrees 1s specified This setting results in a total of 11 images for a 180 degree partial panorama and 18 images for a 360 degree complete panorama In general more pictures will be required for multiple span and longer bridges For these cases arrangements should be made to have sufficient time disk space and battery power to complete the digital photography Regardless of the camera model certain settings are recommended which can help in creating high quality panoramic images The first recommendation is to adjust the camera to 1ts highest f stop in aperture priority auto exposure mode This camera setting controls the aperture size and hence the amount of light that passes through the lens Higher f stop settings will increase the depth of field which
36. er panoramas and or individual pictures When the cursor is positioned in the delineated area of a hot spot a narrative appears towards the bottom of the screen in the footer area to describe the link In Figure 4 for example the hot spot on the right side of the screen 1s linked to a panorama designated to Advance in Westward direction towards 15 Abutment 1 A simple click of the computer mouse with the cursor positioned within the hot spot area will show the linked panorama in the image area this new panorama is now active and may have associated links of 1ts own As mentioned earlier hot spots may also link a panorama to individual pictures of noted problem areas For instance clicking on the hot spot on the left side of the image area shown in Figure 4 brings up the picture of a spalled area with exposed rebar beneath the curb of the reinforced concrete deck shown in Figure 5 Menu buttons in the footer area of the screen allow the inspector to zoom in and out of the scene to toggle the display of the hot spots on and off and to return to the previous panorama and or individual picture Further training of virtual reality development for general applications is available online at the Apple 9 website as well as others l 10 Steel Bridge mov i X File Edit Movie QTY Window Help Go back Toggle hot spot Zoom out Zoom in FIGURE 5 Virtual Reality Record of Reinforced Concrete Deck Showing Display
37. er speed to a constant for the next pictures Rotate the camera and take the next picture Press the same button to undo the shutter speed constraint A constant shutter speed will keep colors uniform from one picture to the next Alternatively the manual camera setting can be applied discussed in next section 35 Avoid windy days if possible wind creates problems with stitching pictures due to camera movement In addition the surrounding brush may move which does not allow a well defined overlap of pictures Single shot photographs should isolate the defect area This requires positioning the camera and framing the defect inside the Viewfinder or Screen Monitor from edge to edge to maximize the defect size in the photograph zoom as needed FIGURE A8 shows the differences in zoom when capturing a specific defect 1 e picture b shows more detail of the defect than picture a Let panoramic views show the area surrounding the defect In single shots some scalable object may be a helpful reference to size the defect in the image a b FIGURE AS Spall with Exposed Rebar at Abutment a Poor and b High Quality Picture ADVANCED PHOTOGRAPHY The difference between mode A and mode M i e fully manual is shutter speed In mode M the shutter speed is manually set The Mode Dial is used to change this setting see FIGURE A2 a Shutter speed is the time in which film is exposed to light thus allowing
38. era This camera has aperture settings ranging from 1 to 8 On a lower aperture setting the camera will focus on the foreground with the background remaining out of focus With a larger aperture setting the camera will focus more on both the foreground and background Thus for virtual reality applications set the aperture to the largest setting of 8 22 Viewfinder Erase button Power switch Control dial QUICK VIEW button Monitor button AF Macro MF button AFAM MF Control panel Shutter button Mode dial Self timer Remote control button a b Self timer Remote control lamp Remote control receiver Viewfinder window Strap eyelet c FIGURE A1 View of Olympus C 5060 from a Top b Back and c Front 14 25 To set the aperture first go to the mode dial of the camera and set it on A as shown in FIGURE A2 a Then rotate the control dial FIGURE A2 b to the right until the monitor indicates F8 0 in green Turn the control dial to the right to increase the aperture setting Turn the control dial to the left to decrease the aperture setting b FIGURE A2 a Mode Dial and b Control Dial of the OLYMPUS C 5060 14 Manual Focus Manual focus maintains the same focus for all the pictures that are taken On auto focus the camera will refocus before every picture Refocusing causes physical objects such as bridge components to be captured at different sizes in
39. g in drivers are automatically loaded for the Netscape and Internet Explorer browsers so that virtual reality content may be viewed over the web This means that several smaller sized panoramas may be linked together with a web browser rather than having all the panoramas on a single large file Web based applications also make 1t possible to manage conventional bridge inspection forms Internet files can also be accessed by supervisors or bridge experts when needed without visiting the site In fact the integration of virtual bridge inspections and the Internet provides a vast array of possibilities for further development An important final note about virtual reality is that the field work may be challenging for some bridges For example bridges located in areas of heavy traffic or crossing a river may need to be closed or require traffic control to perform the photography Furthermore a river crossing may require special equipment to position the inspector underneath the bridge to take pictures Bridge sites having other forms of moving obstructions such as those located in construction zones are also demanding candidates for virtual reality since the photography must be carried out during periods of either low or no construction To summarize situations where traffic control bridge closure and or special equipment rental is needed will demand more of a time investment and also result in higher inspection costs compared to that of a typical in
40. hutter speeds for each 20 interval depending on the level of illumination 3 Set the camera on mode M and adjust the shutter speed with the Control Dial see FIGURE A2 b to that determined in step 2 above Take all pictures at the camera station using the same shutter speed 4 Repeat steps 1 through 3 for each camera station Also mode M is only needed for panoramas use mode A for individual pictures of problem areas NOTE this completes the appendix related to photography procedures 37 APPENDIX C PANORAMIC CREATION Once the pictures are taken they should be transferred to the computer They will later be used in the virtual reality software for stitching into panoramic images TRANSFERRING PICTURES FROM THE CAMERA l 2 6 Connect the laptop computer to the camera using the USB cable Turn the camera on and click the Camedia Master Icon located on the desktop Go to transfer images and then select from camera Images will automatically appear on the left side If you want all images to be on one file click on new album and give the file a name next select the large arrow tab located above all images Alternatively if you want to select only some images or put the pictures under separate files you must highlight those pictures and then click selected images and then create a new album as just described e Tip 1 to select more than one picture at a time hold down the Ctrl button and click on the pictures
41. in size from 90 to 360 The photography procedures for creating the panoramas will be similar regardless of the angle of coverage the major difference will be the number of pictures required for the panorama PREPARING FOR THE FIELD To make full use of the time spent at the bridge site it is helpful to prepare a checklist and have items ready before leaving The following list 1s a good place to start Camera make sure camera settings are already set before departure Tripod assembly Camera picture card packing an extra card 1s also recommended Camera battery check that the battery is fully charged and inserted into the camera packing an extra battery 1s also recommended Laptop computer and accessories Computer camera connection cord Notebook and pencil to take notes of inspection and photography Preparation of the following items is also suggested before leaving to the site Plan view before leaving sketch a plan view of the bridge with cardinal directions marked If this 1s not possible prepare a sketch as soon as arriving at the bridge site Panorama plan designate where the camera will be situated for taking the pictures required for the panoramas as well as individual pictures of deteriorated areas referred to 33 as camera stations Record the stations in chronological order as pictures are taken More information on the selection of camera locations 1s provided in the next section e Su
42. is the range of distance measured along the lens axis over which the subject is in sharp focus in the photograph Without a flash the camera will adjust the exposure time in order to get adequate images advanced digital cameras use through the lens TTL light metering to determine the appropriate exposure An important detail is that the white balance sensor in front of the camera should not be directly exposed to the sunlight The use of an umbrella to cast a shadow on the sensor while remaining out of the view of the lens will result in better exposure of darkened areas such as the abutments and between girders Due to the likelihood of long exposure times self timer or remote control shooting is suggested instead of manual shutter release This allows hands free operation of the camera during exposure thus preventing camera movement and blurry images The third recommendation is to set auto focus to manual mode and use the same shooting range for all images of the panoramic picture set If the focal length changes considerably between images the virtual reality software may have problems stitching the individual pictures into a single panorama Changes in lighting and moving objects are also factors which can influence the quality of the final panorama An effort should be made to take each panoramic picture set with the level of sunlight constant throughout the duration of image acquisition Lastly there should be no moving object on the oute
43. ktime qtvr gt Accessed August 2004 Kaidan Photographic VR Solutions lt http www kaidan com gt Accessed August 2004 VR Toolbox The VR Worx user manual Version 2 5 Pittsburgh VR Toolbox 2003 Realviz The Stitcher user manual Version 4 0 Valbonne Realviz 2004 Squamish Media Group VR Enhancement Suite http www smgvr com Accessed August 2004 CAMEDIA Reference Manual C 5060 Wide Zoom CD ROM Olympus Corporation Tokyo Japan 2003 pp 2 255 QuickTilt Leveler Kaidan Products Feasterville PA lt http www kaidan com Detail bok no 53 gt Accessed June 19 2006 20 16 Kiwi User s Guide Kaidan Products Feasterville PA lt www kaidan com pdf K1W1 L_Kiwi _Manual pdf gt Accessed June 19 2006 7 APPENDIX A EQUIPMENT REQUIREMENTS BASIC EQUIPMENT The instructions given in this and subsequent appendices are valid for the following equipment e Digital Camera Olympus CAMEDIA C 5060 Wide Zoom e Tripod Slik Master Classic e Panoramic Tripod Head QuickTilt Leveler Kaidan Kiwi Head e Laptop Computer e Virtual Reality Software VR Worx e Photo Transfer Software Camedia Master CAMERA SETUP Settings The names of the camera parts of the Olympus C 5060 are given in Figure Al There are three settings that need to be correctly applied to the camera before use the aperture setting manual focus and pixel resolution Aperture Aperture refers to the opening of the shutter in the cam
44. mage of a prestressed concrete I girder bridge Panoramic image e Inspector a b FIGURE 2 Creation of Cylindrical Panorama a General Process and b Prestressed Concrete Bridge Example A powerful feature of VR Worx is its ability to adjust the orientation and exposure of the photos to achieve uniformity across the panoramic area Like the VR Worx program the 12 Stitcher 12 software operates on an IBM PC This program has a highly developed stitching algorithm that can successfully stitch images together in difficult situations where other software programs may fail however one constraint 1s that cylindrical panoramas must be 360 degrees and nothing smaller As mentioned earlier the main feature of Realviz Stitcher is its capability to create cubic panoramas Figure 3 a shows the camera setup for taking the set of pictures needed for a cubic panorama 45 0 st A 45 b FIGURE 3 Creation of Cubic Panorama a Camera Setup and b Steel Truss Bridge Example As shown in the figure three rows of images are taken at vertical angles of 45 zero and 45 degrees using the Kaidan QuickPan III System Hence a full cubic panorama requires three times the number of images needed for a full cylindrical panorama e g 54 versus 18 images for a 35 mm lens equivalent A final note about Realviz Stitcher is that cubic 13 panorama creation is more complicated since images have to be manu
45. mote Control to Olympus C 5060 14 TRIPOD SETUP The Panoramic Tripod Head is comprised of two main components the QuickTilt Leveler and the KiWi Head see FIGURE A5 a and b These two parts fit on top of the tripod 28 Vertical Bracket Fore aft Indicator Camera Adj Shoe Knob Captive Camera Knob Twin Axis Bubble Level Locking Knob Friction C riction Lap Side to Side Indicator Horizontal Bracket b FIGURE A5 Panoramic Tripod Head Components a QuickTilt Leveler and b Kiwi Head 15 16 Detect Disc Installation in KiWi Head Several different detent discs are provided with the KiWi Head The detent discs ensure that the tripod head rotates at predetermined intervals For the Olympus C 5060 camera with a 27 mm lens the maximum range and overlap will be achieved using an 18 hole detent disc which results in pictures taken at intervals of 20 The instruction manual for the KiWi Head is camera specific to determine the proper detent disc The following steps describe the procedure for installing or replacing the detect discs in the Kiwi Head 29 Remove the friction cap by first loosening the side knob on the friction cap then unscrewing the friction cap see FIGURE A6 a The assembly can then be taken apart as shown in FIGURE A6 b The detent disc may be replaced in the recessed area on the bottom of the horizontal bracket a b FIGURE A6 Disassembly of KiWi He
46. n position consider the time of day the pictures will be taken in relation to the sun In the early morning or the late afternoon the sun is closer to the horizon and may create glare in the pictures Consequently mid day photography is recommended e Recheck camera settings and KiWi Head before taking pictures WHERE TO TAKE PICTURES The camera stations should be selected before the on site visit If this 1s not possible stations should be chosen immediately after arriving on site Selection of the camera stations is a function of several parameters mainly accessibility and obstructions some stations may need to be modified from a picture sequence to single shots or not taken at all Initially pictures should be taken to create global panoramic views of the bridge as described below e Overall bridge horizontal sweep of bridge elevation between abutments from both sides of bridge width e End spans horizontal sweep of span elevation from the abutment to the adjacent interior pier from each side of bridge width and horizontal sweep of cross section in the direction of the abutment from the interior pier and vice versa e Interior spans horizontal sweep of span elevation between interior piers from both sides of bridge width and horizontal sweep of cross section from one interior pier to the other Apart from the panoramas just described individual pictures should also be taken which focus on defect areas containing
47. n the Preview tab which will show a preview of the final panoramic image 2 Click and drag your mouse over the movie until your preview is in approximately the same view as FIGURE A16 2 Untitled 1 Panorama setup acquire dy Stitch 4 Blend A Hot Spots 9 Compose 8 Preview Actions E Export Resize Properties ele Annotate Interaction BIO Imaging Data Rate Constraints Initial i 5 fae bale Res Seti Go Min Zoom 1 0 Hes Set Go Max Zoom 53 0 Est File Size 660 3K Pan 106 1 Tilt 1 9 Zoom 44 3 Dimensions 320 x 240 FIGURE A16 Preview Panel Screen of VR Worx 3 Select the Set button under Initial Constraints to ensure each time this QTVR movie is opened it will display this initial view 45 Under File gt save your work as Mesa_North Saving a panorama retains all of the setup acquisition and assembly information in a single prx file Note that saving is not the same as exporting a movie Select the Export button Enter Mesa_North mov in the Export movie dialog box Leave the format as QuickTime VR 2 0 so it can be viewed on QuickTime Save your movie to a folder of your own making Under File gt choose Exit Verify the movie was successfully saved this can be done by finding and opening Mesa_North mov from your folder Repeat the steps given above to create panoramas from the pictures stored under the Mesa Mesa South Mesa West
48. oooooooo I Coke Element Guide s 5 0045 botas NE a EAS G4 Ree a HA aie NE ED 2 FHWA Bridge Inspection Studies 0 0 ccc cee ee eee 3 QUICKTIME VIRTUAL REALITY QTVR 0 0 0000 aes 5 QTVR DOCUMENTATION PROCEDURES ees 7 Planning and Taking of Photographs 0 0 cece eee eee 7 Creation of Panoramas seiko dane airada 11 Rendering of Virtual Reality Records with Hot Spots 14 CONCLUSIONS AND RECOMMENDATIONS 0005 17 REFERENCES vce icees vinculados EE PLE dba ed ios Ed bu ate ts 20 Table 1 Fig 1 Fig 3 Fig 4 Fig 5 Fig Al Fig A2 Fig A3 Fig A4 Fig A5 Fig A6 Fig AT Fig AS Fig A9 Fig A10 Fig All Fig A12 Fig A13 Fig A14 Fig A15 Fig A16 Fig A17 Fig AI Fig A19 Fig A20 Fig A21 Fig A22 Fig A23 Fig A24 LIST OF TABLES Page Standard Condition Rating System 5 o oooooooooooo 2 LIST OF FIGURES Page Camera Stations for Global Panoramas of Three Span Bridge 8 Creation of Cylindrical Panorama a General Process and b Prestressed Concrete Bridge Example 12 Creation of Cubic Panorama a Camera Setup and b Steel Truss Bridge Example ooooooooooo 13 Virtual Reality Record of Steel Girder Bridge Showing Screen ATIS ia A a a OA DA 15 Virtual Reality Record of Reinforced Concrete Deck Showing Display Buttons 29 93 52d
49. pose all the pictures Here you can view the panorama before it is blended together which allows the pictures to be aligned manually 1f necessary 3 Under the left down corner of the stitching cylinder there is a percentage showing the zoom ratio Beside this number there are two buttons for zoom in and zoom out Click on the zoom out button until the zoom ratio reaches 25 Check all the images to see 1f they are stitched roughly to a panoramic image Make sure all the images are vertical and in the right sequence If not go back to the Acquire tab and adjust them 4 Check the alignment of the images some may need to be finely adjusted Zoom in the images to 100 Select the images you wish to finely align and use the arrow keyboard keys for realignment purposes the mouse is not recommended for fine alignments 43 3 Click on the Option button and set the Display with Transparency This will allow you to see how the images overlap so you can make precise adjustments Once the zoom ratio reaches 10 do not click on the zoom out button anymore The computer may run out of memory and crash if this 1s done It appears that this may be a software bug or computer memory issue which the user should be aware of Blend Panel 1 Click on the Blend tab after all the pictures are aligned 2 Click on the Build button The panorama should now look like one whole picture check the panorama for any imperfections 3 f necessary go back
50. r edge of any picture since the next picture in the series will not have the same object In summary out of focus 10 pictures non uniform exposure and moving objects can all hinder a project since the software may not be able to properly match pixels between images and thus stitching may not be possible Although the conditions at a bridge site are somewhat beyond control the photographer should follow good photographic procedures taking as much care as possible After the photography is complete the images should be properly transferred to a laptop The laptop should be equipped with a reasonably large hard drive and also with a writeable CD DVD drive so that pictures can be backed up prior to leaving the bridge site Two ways for transferring images to the laptop are flash memory cards which plug into the digital camera and direct wire connection between the camera and computer Flash memory cards or microdrives range in capacity from 16 megabytes to 2 gigabytes Direct wire connection 1s normally done through an IEE1394 also known as Firewire standard connection For further details related to image storage and transfer the reader should consult the manual for the digital camera CREATION OF PANORAMAS The two kinds of virtual reality panoramas are cylindrical and cubic The cylindrical type are produced using single row images and provide the experience of standing in the center of a panoramic cylinder and looking straight ahead in
51. re critical bridge members bridge bearings and substructures As part of the course participants are asked to review as built drawings previous inspection reports and photographs for various case studies Alternatively this bridge condition data could be put together for examination in a virtual reality setting thus making the inspection exercise much more valuable and realistic Certainly time must be allotted in any practical oriented training course to include hands on field inspections at the actual bridge site however in an interest of time only so many can be made Virtual bridge inspections cannot replace but can definitely help the inspector gain valuable additional field experience without having to leave the classroom Also on the job training by supervisors and more experienced inspectors could be accomplished by this method A major concern in adopting a virtual reality approach for documenting bridge inspection projects is that the size of the final output files can be quite large Several factors influence the file size a few of which are 1 the resolution of the digital camera 2 the size of the 18 panoramic image display 3 the compression algorithm chosen for the rendering process and 4 the number of panoramas and or individual pictures integrated into the final output file A possible way to address this issue is to post the virtual reality files on the Internet When the Apple QuickTime Player is installed plu
52. s the most common technique used to evaluate the condition state of highway bridges and 2 a professional engineer is rarely on site during the inspections All the survey participants also indicated that inspectors are allowed to review old inspection reports In another study Phares et al 7 investigated the reliability of routine bridge inspections participants in the study included 49 state highway inspectors from 25 different states in the U S Each participant inspected six different bridges without the aid of previous inspection reports and then assigned NBIS condition ratings for the deck superstructure and substructure of each bridge Findings from the study showed that on average between four and five different ratings were assigned to each primary bridge element with a minimum of three and a maximum of six Based on a statistical analysis of the results approximately 58 of the individual ratings were assigned incorrectly compared to reference ratings established by the FHWA bridge elements in poorer condition were assigned fewer correct ratings The statistical results also showed that the ratings varied 2 points at a 95 confidence interval and 1 point at a 68 confidence interval from the average inspector rating QUICKTIME VIRTUAL REALITY QTVR The two FHWA studies just summarized were performed by the Non Destructive Evaluation Validation Center NDEVC and raise several important issues in need of further action to
53. se a Preview Source Format Multiple Images Acquire From PLUG IN Image File Mechanism None Mode Sweep 180 Y Max Frames 118 Y LensParams Lenath 27 l mm 35mm equivalent C FON 659 v vertical Image Size fuo y Frame Count 9 FIGURE A11 Setup Panel Screen in VR Worx Acquire Panel The Acquire Panel is where you will load your source images before stitching them together as shown in FIGURE A12 s Untitled 1 Panorama setup Acquire IZ stitch lt Biend J Hotspots y compose E Preview eje Clear Edit eje Rotate Rotate All Project Attributes Frame Count 18 Master Dims 1200 x 1601 40 Origin Reverse b Sweep 180 Q Selection Attributes Dims Not Acquired Single Multiple 240 220 e 140 au View Mode Circular y FIGURE A12 Acquire Panel Screen of VR Worx 1 Click on the Acquire tab 2 Click on the Multiple button which will automatically take you to Import Images as shown in FIGURE A13 4 Import Images Look in CQ Mesa N v id Mesa N Tiff 1 9 mov 3 P1010005 TIF Q Mesa N Tiff 1 9 prx P1010006 TIF 5 P1010001 TIF 5 P1010007 TIF 5 P1010002 TIF 5 P1010008 TIF B P1010003 TIF P1010004 TIF Show Preview Files of type All Supported Images m Source Rotation Remove E gt bis Remove All Done 90 degrees Cancel FIGURE A13 Import Images Screen of
54. spection 19 10 11 12 13 14 15 REFERENCES National Bridge Inspection Standards NBIS Code of federal regulations No 23CFR650 Washington U S Government Printing Office 1996 American Association of State Highway and Transportation Officials AASHTO Manual for condition evaluation of bridges 2 Edition Washington AASHTO 2000 White K R Minor J and Derucher K N Bridge maintenance inspection and evaluation 2 Edition New York Marcel Dekker Inc 1992 Federal Highway Administration FHWA Bridge inspector s training manual 90 Washington United States Department of Transportation 1995 a Federal Highway Administration FHWA Recording and coding guide for the structure inventory and appraisal of the nation s bridges Washington United States Department of Transportation 1995 b American Association of State Highway and Transportation Officials AASHTO AASHTO guide for commonly recognized CoRe structural elements Washington AASHTO 1998 Phares B M Graybeal B A Rolander D D Moore M E and Washer G A Reliability and accuracy of routine inspection of highway bridges Transportation Research Record 1749 2000 pp 82 92 Rolander D D Phares B M Graybeal B A Moore M E and Washer G A Highway bridge inspection state of the practice survey Transportation Research Record 1749 2000 pp 73 81 Apple QuickTime VR Authoring lt http www apple com quic
55. the pictures This will cause problems when stitching them together One side will match up but the opposite side will not even though it will look like both pictures are the same length The preferred manual focus setting is oo infinity which provides the best depth of field With reference to Figure A3 the step by step procedure for setting the camera to the manual infinity focus is as follows 1 Check that the camera mode is on A 2 Turn the control dial while holding down the AF MZ MF button 24 3 Do not let go of the button use the control dial and select MF when it is highlighted then let go of the AFAM MF button 4 On the left side of the screen find the vertical bar representing the focus setting the setting ranges from 0 8 m 2 6 ft to infinity oo 5 Use the from the Arrow Pad to take the green bar up to infinity o return to the main screen by pressing the ONM AF MF AF Macro MF aun button Control dial ate d Arrow pad OK button FIGURE A3 Setting of MF for Olympus C 5060 14 Pixel Resolution The number of pixels used when saving an image is known as the resolution There are several considerations to make when deciding what resolution to use when taking pictures A higher resolution will take up more space on the camera and computer and a lower resolution will result in pictures that are not as clear To make picture taking efficient the 23 pictures should
56. the return button on the QuickTime Player will be needed to get back to the previous node The scissors icon is used to delete any of the arrows To get out of Tools mode click on the mouse button located at the upper left corner in the Tools option Double click on the Mesa_North mov This will open the Node Brower Window This window 1s made up of three panels the Properties Hot Spots and Preview panels Click on the Properties tab see FIGURE A21 Select the check box for Initial node Leave all of the other settings at their defaults 50 Node Browser Properties Hot Spots Preview Node Kind QTVR Panorama Reference ID 1001 Name Mesa N orth mov Comment Initial Node Iv Media File c Documents and Settingsqtwr My Documents ZHIYONG Mesaiscene Mesa_North mov Change FIGURE A21 Scene Nodes Property Panel Screen of VR Worx Keep in mind that the node in red shown in FIGURE A20 is the first node that is opened and represents the main area of the scene This node can be changed to any other by highlighting the desired node To do this click on the Browse icon or just double click on the desired node and click on the Initial Node blank square in the Node Browser menu A check will appear on the selected node e Tip l the file name imported to the Nodes Panel will be the name shown in the Node Browser as in FIGURE A21 In this case Name Mesa_North mov is the default name to the hot spot The text
57. uild button The default settings are usually adequate however when the file size exceeds 50 MB the computer runs out of memory and closes This is another potential problem in the software 53 To remedy this select the Sef button in the Compression panel adjust the quality to a lower setting in the pop up menu to decrease the file size Preview Panel 1 Click on the Preview tab 2 The scenes are put together and are a preview of the movie Check each link position and check if it functions as intended 3 Under File gt save your work 4 Click on the Export icon and name the movie as Mesa_Scene mov 5 The scene is now done exit VR Worx THE QUICKTIME PLAYER At this point you are now ready to display your completed movie in the QuickTime Player as given below 1 Click on the QuickTime Player icon located on the Start Menu under programs 2 Click on File and select Open 3 Select the file that you wish to view as a movie it will automatically pop up 4 The menu bar will be used to navigate through the movie see FIGURE A24 Item Identification Display Main Mem FIGURE A24 Menu Bar of QuickTime Player 5 To move horizontally through the movie hold down the left button on the mouse An arrow will appear Then move the mouse left or right to scroll through the panoramic 54 scene To pan through a single photo hold down the control and shift keys then move the mouse left or right this 1s the same
58. when zoomed in a picture 6 Press the reveal hot spots button and the hot spots will appear Selecting the hot spots will either highlight the selected area or move to another panoramic image NOTE this completes the appendix related to scene creation 55 New AEX CO DEPARTMENT OF TRANSPORTATION New Mexico Department of Transportation RESEARCH BUREAU 7500B Pan American Freeway NE PO Box 94690 Albuquerque NM 87199 4690 Tel 505 841 9145
59. y David J uregui Associate Professor New Mexico State University Kenneth White Professor and Head New Mexico State University Wesley Cook Graduate Research Assistant New Mexico State University Hyunsik Moon Graduate Research Assistant New Mexico State University Report NMO4STR 05 A report on research sponsored by New Mexico Department of Transportation Research Bureau in cooperation with The U S Department of Transportation Federal Highway Administration July 2006 NMDOT Research Bureau 7500B Pan American Freeway PO Box 94690 Albuquerque NM 87199 4690 2006 New Mexico Department of Transportation PREFACE The research reported herein describes the equipment and procedures for using QuickTime Virtual Reality software and high resolution digital photography as a supplement to visual inspection of bridges The purpose of this work was to provide the information needed to implement this process and provide training information to NMDOT bridge inspectors so that they may use the technology to supplement their inspection reports as needed or desired A training manual is provided as the appendix of this report NOTICE The United State Government and the State of New Mexico do not endorse products or manufacturers Trade or manufacturers names appear herein solely because they are considered essential to the object of this report This information is available in alternative accessible formats To obtain an

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