OFF.TWG 3D/VR File Format Requirements
PUBLIC WORKING DRAFT

REQUIREMENTS

The following set embodies baseline requirements for 3D/VR file formats specified by the Open File Formats Technology Working Group (OFF.TWG):

1. Open and Royalty-Free Standards. File formats must be open (i.e., non-proprietary and publicly available) and not conditioned on payment of royalties, fees or other financial consideration.

2. Modular design. File formats must be modular in design. That is, where aspects of the data can be separated or compartmentalized they should be in such a way that updates or changes within one modularized area cannot affect other areas.

3. Identification of Core and Optional Modules. File formats may, where applicable, identify core modules (where support or handling is required) and optional modules (where support or handling are optional).

4. Extensions. File formats must support extensions to core and optional modules if such extensions do not introduce side effects.

5. Extensible. File formats must have an extensible architecture.

6. Validatable. File formats must support conformance of instances to corresponding definitions that may be testable in such a way as to guarantee the validity of those instances for processing by target applications (e.g., virtual world applications and content development tools).

7. Wide support. File formats must be widely supported by content development tools. At a minimum the content development tools cited in Appendix A of this document should support the ability to export [and import?] 3D/VR content in the target file format(s). APPENDIX A IS NEW AS OF THIS REVISION OF THIS DOCUMENT: PLEASE REVIEW AND COMMENT USING THE LINK BELOW OR VIA THE OFF.TWG EMAIL LIST.

8. Mesh-based Geometry. File formats must be capable of representing mesh-based (polygonal) geometry.

9. Text-based (with support for binary compression and encryption). File formats must be text-based (i.e., file descriptors must be representable using plain-text character sets compatible with UTF encoding). Support for binary compression and encryption may also be considered.

10. Arbitrarily complex content. File formats must scale to handle arbitrary degrees of complexity in models and scenes (i.e.., complexity arising from polygon count, primitive objects and groups, etc.).

11. State-of-the-art rendering. File formats must support state-of-the-art rendering features and capabilities (e.g., shaders, lighting, texturing, effects, etc.).

12. Animation. File formats must support animation.

13. Physics. File formats must support physics.

14. Continuous Level of Detail (LoD). File formats must support continuous rendering of content varying levels of detail.

15. Metadata. File formats must support system-supplied and user-supplied metadata.