X3D and HTML5 Summary

• Family of X3D Specifications;
  • X3D Abstract Specification describes basic functionality
  • Three file formats are available: XML (.x3d), ClassicVRML (x3dv), and Compressed Binary Encoding (.x3db)
  • High-performance Application Programming Interfaces (APIs) are defined for Ecmascript (Javascript) and Java

• X3D Strengths
  • Non-profit Web3D Consortium maintains and extends X3D via working groups
  • Set of International Standards certified over 12-year period by multiple national bodies in ISO
  • Multiple implementations are available (open and commercial source)
  • Numerous resources available online, including specifications themselves
  • Third-generation 3D graphics language that extends predecessor Virtual Reality Modeling Language (VRML97)
  • Long-time W3C member and contributor
  • Formal liaisons and working partnerships with International Organization for Standardization (ISO), Open Geospatial Consortium, Khronos, Digital Imaging and Communicatons in Medicine (DICOM)

• Relationships between scene graphs, APIs and render layers;
  • Scene graphs are high-level declarative models about how geometry is constructed, colored and animated; these can be expressed as an XML tree
  • APIs are mid-level libraries for programmers to create imperative source code about geometry and animation (various proprietary codebases, O3D, perhaps WebGL)
  • Render layers are low-level software libraries that expose the functionality of graphics hardware (e.g. OpenGL, DirectX)

• Similarities between MathML, SVG, and X3D;
  • MathML describes mathematical expressions and then renders a presentation of them
  • Scalable Vector Graphics (SVG) describes and presents renderings of 2D shapes, with optional animation and interaction
  • Extensible 3D (X3D) describes and presents renderings of 3D shapes, with optional animation and interaction
  • All three languages are formally specified and have well-developed XML encodings
  • Authors want to use these languages for multimedia content in HTML pages

• X3D scene graph APIs
  • X3D Scene Access Interface (SAI) provides a consistent standardized high-performance API
  • X3D SAI has Ecmascript and Java bindings, other programming languages can be added
  • X3D SAI is functionally equivalent and has same expressive power as file formats
  • Document Object Model (DOM) is also legal (X3D is XML after all) but infrequently used because of low performance

• Simple X3D + HTML5 examples; (how current integration looks like via object model then to html5)
  • X3D scene as external reference (Anchor link)
  • X3D embedded in object tag
  • HTML5 with embedded X3D as mixed-namespace document
  • Template for demo = html5+x3d event passing connections.

• Recommendations for html5 specification.