X3D and HTML5 Summary
From Web3D.org
- 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
- Forthcoming InstantReality demo: html5+x3d with event passing connections
- (Can we structure our non-scripted examples to correspond to MathML and SVG examples?)
- (We likely need multiple examples corresponding to DOM/SAI approaches)
- Joe Example #1, served as application/xhtml+xml
<?xml version="1.0" encoding="utf-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<body>
<x3d:x3d xmlns:x3d="http://www.web3d.org/specifications/x3d-3.2.xsd">
<x3d:Scene>
<x3d:Shape>
<x3d:Box x3d:size="4 4 4" />
</x3d:Shape>
</x3d:Scene>
</x3d:x3d>
</body>
</html>
- Joe Example #2, served as text/html
<!DOCTYPE html>
<body>
<X3D>
<Scene>
<Shape>
<Box x3d:size="4 4 4" />
</Shape>
</Scene>
</X3D>
</body>
</html>
- Recommendation actions for HTML5 Recommendation
- Ensure proper X3D references in HTML5 specifications
- Document correct integration and best practices
- What about XHTML?
- Other recommendations?
