![Measuring 3D Model Similarity
• Surface Area
• If a faceted s rface simpl s m up area of all faces
surface simply sum p
• Statistics
• Mean, Standard deviation of vertices
• Spin Images [Johnson, 1999]
• Light Fields [Chen, 2003]
• Compares silhouettes from various viewing angles around the
objects
• …](https://image.slidesharecdn.com/keyaspectsin3dsaa09bajcsy-090818162205-phpapp02/85/Key-Aspects-in-3D-File-Format-Conversions-23-320.jpg)
Key Aspects in 3D File Format Conversions
- 1. Key Aspects in 3D File Format Conversions F tC i Kenton McHenry and Peter Bajcsy Image Spatial Data Analysis Group, NCSA Presented by: Peter Bajcsy -Research Scientist at NCSA Research -Associate Director of I-CHASS, I3 Institute -Adjunct Assistant Professor, CS & ECE UIUC National Center for Supercomputing Applications University of Illinois at Urbana-Champaign
- 2. Outline • Introduction • What do we know about 3D file formats? • Basic Archival Questions • Is there an optimal format to convert to? • Can we quantify 3D noise introduced during conversions? • NCSA Polyglot to Support Archival Processes • Automation of File Format Conversions • Quality of File Format Conversions • Scalability with Volume • Conclusions • Li d Live demonstration t ti
- 3. Introduction
- 4. Introduction to 3D File Format Reality *.ma, * b * * *.mb, *.mp *.k3d k3d *.pdf (*.prc, *.u3d) *.w3d *.lwo *.c4d *.dwg *.blend *.iam *.max, *.3ds
- 5. Introduction: Our Survey about 3D Content • Q: How Many 3D File Formats Exist? • A: We have found more than 140 3D file formats. Many are proprietary file formats. Many are extremely complex ( , y p (1,200 and more p g pages of specifications). • Q: How Many Software Packages Support 3D File Format Import, Export and Display? • A: We have documented about 16 software packages. There are many more. Most of them are proprietary/closed source code. Many contain incomplete support of file specifications specifications.
- 6. Examples of Formats and Stored Content Format Geometry Appearance Scene Animation Faceted Parametric CSG B-Rep Color Material Texture Bump Lights Views Trans. Groups 3ds √ √ √ √ √ √ √ √ √ igs √ √ √ √ √ √ √ lwo √ √ √ √ √ √ obj √ √ √ √ √ √ √ ply √ √ √ √ √ stp √ √ √ √ √ √ wrl √ √ √ √ √ √ √ √ √ √ √ u3d √ √ √ √ √ √ √ √ √ x3d √ √ √ √ √ √ √ √ √ √ √ • Some content may be more important than others • The relative importance is situation dependent
- 8. Motivation • Overall, the abundance of file formats makes it difficult to share 3D content • Depends on what applications the user has installed • In terms of preservation/archiving: p g • Closed/Proprietary formats are a problem • If specification is not public then full access to the content is restricted to software from the vendor • Format may change over time with versions of the software • If vendor goes out of business future viewing of the content may be very difficult difficult. • Difficult for users to view content
- 9. Basic Archival Questions • Are the 3D formats well formed? • Can we identify a minimal set of information to preserve? • Is there an optimal format to convert to? • Can we quantify 3D noise introduced during conversions? • Can we quantify differences in renderings?
- 10. Is There an Optimal File Format to Convert to? • Definition of ‘Optimal’? • Possible definition of ‘Optimal File Format to Convert to’: • The format that results in the least data loss when converted to by other formats. • Finding ‘optimal file format’ requires a converter between the many available f b t th il bl formats … t
- 11. Can We Quantify 3D Noise Introduced During Conversions? • Definition and Measurements of Data Loss or 3D C Conversion N i ? i Noise? • Definition and measurements of data loss during conversions should be application dependent • Quantifying ‘data loss’ needs a loader for both original format A and target format B so that we could load and compare the 3D content independent of how it is stored.
- 12. NCSA Polyglot to Support Archival Processes -Conversions -Data Loss Evaluation During Conversions
- 13. Towards a Universal Converter • Use what is available in 3rd party software to perform conversions f i • Document what formats can be opened/imported b each application d/i t d by h li ti • Document what formats can be saved/exported by each application • Automate the use of each application and combine their abilities to perform conversions over larger set of formats
- 14. Mapping Software Import and Export Functionality Adobe Ad b 3D R i Reviewer
- 15. Input/Output Graphs Adobe 3D Reviewer
- 16. Input/Output Graphs 3DS Max Adobe 3D Reviewer AutoCAD Blender Cinema 4D K-3D LightWave 3D y Maya Wings 3D
- 17. Input/Output Graphs Shortest conversion path
- 18. Building a Universal Converter • The I/O-Graph stores the information needed to convert between the formats represented in the graph graph. • In order to perform the conversion we must execute the conversion path found. p • Many high end graphics programs are found on the windows platform • Those on other platforms, such as Linux, tend to have windows ports • Some are command line driven (usually small converter applications). • Many have only GUI interfaces • AutoHotKey: a scripting language for the Windows GUI.
- 19. Architecture Cloud Computing Services to Archivists
- 20. NCSA Polyglot – Conversion Services • Web interface: user can drag and drop files into upload area for conversion • Java interface: PolyglotRequest pgr; pgr = new PolyglotRequest(“http://???”, “obj”); pgr.convertFile(“file.wrl”, “./”);
- 21. NCSA Polyglot – Data Loss Measurement Services We would like to assign a value to each conversion edge …
- 22. Measuring Information Loss good… (e.g. 1.0) not so good… (e.g. 0.1)
- 23. Measuring 3D Model Similarity • Surface Area • If a faceted s rface simpl s m up area of all faces surface simply sum p • Statistics • Mean, Standard deviation of vertices • Spin Images [Johnson, 1999] • Light Fields [Chen, 2003] • Compares silhouettes from various viewing angles around the objects • …
- 24. Geometry Based Content Retention
- 25. Conclusions • We have designed a framework for 3D file format conversions and information loss evaluation with the k components l i i h h key • Input to output conversion graph • Automated conversions using 3rd party software • Conversion scripting and execution monitoring i i • 3D model comparison before & after conversions • Search for “optimal” path or file format
- 26. Acknowledgements • This research was partially supported by a National Archive and Records Administration (NARA) supplement to t NSF PACI cooperative agreement CA #SCI ti t #SCI- 9619019. • The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressed or implied, implied of the National Science Foundation the National Foundation, Archive and Records Administration, or the U.S. government. • Contributions by: Peter Bajcsy, Kenton McHenry, Rob Kooper, Sang-Chul Lee, William McFadden, Rob Kooper, Kooper Jason Kastner and Michal Ondrejcek Imaginations unbound
- 27. Questions • Project URL: j http://isda.ncsa.uiuc.edu/NARA/index.html and http://isda.ncsa.uiuc.edu/CompTradeoffs/ • Publications – see our URL at http://isda.ncsa.uiuc.edu/publications http://isda ncsa uiuc edu/publications • Peter Bajcsy; email: pbajcsy@ncsa uiuc edu pbajcsy@ncsa.uiuc.edu
- 28. References to Presented Research • -Kenton McHenry and Peter Bajcsy, “3D Data Analysis,” WVU/NETL/ERA Workshop on Digital Preservation of Complex Engineering Data, April 21-22, 2009, Morgantown, WV. • - McHenry K. and P. Bajcsy "An Overview of 3D Data Content, File Formats and Viewers.", Technical Report NCSA ISDA08 002, NCSA-ISDA08-002 October 31 2008 31, • -McFadden W., K. McHenry, R. Kooper, M. Ondrejcek, A. Yahja and P. Bajcsy, “Advanced Information Systems for Archival Appraisals of Contemporary Documents,” the 4th IEEE International Conference on e-Science, December 8- 12, 2008, Indianapolis, IN. Imaginations unbound