Contents Computer Graphics Group Computer Graphics Group
1. Web3D Consortium 2. X3D specification 3. GeoVRML 4. NurbsVRML JiříŽára
1 X3D 2
X3D = Next VRML version Web3D Consortium Computer Graphics Group Computer Graphics Group
About 15 Working Groups (www.web3d.org): • The next generation • source: reference browser (Xj3D) Open Web3D standard • h-anim: humanoid animation (done: ISO standard) • Concerted action by key VRML browser companies • web3d-mpeg: integration with MPEG (blaxxun, ParallelGraphics, • dis: distributed interactive simulation Nexternet, OpenWorlds) • GeoVRML, NurbsVRML (done) • Full compatibility with VRML97 • vrml-streams: streaming scene graph & data • Influence to other standards (MPEG-4, XML) • media: universal media (like fonts in op. systems)
X3D 3 X3D 4
Architecture Profiles and Components Computer Graphics Group Computer Graphics Group
Preserves VRML content Components: Rendering, Geometry, GeoVRML, Small download, Language, Texture, Navigation, Nurbs, Capable browsers for Scripting, Sensor, etc. many applications Profiles (subset of components + limitations): Cooperative framework to Core – light renderers (Java applets) implement and distribute Base – full functionality future components and Interactive, Immersive, … profiles
X3D 5 X3D 6
1 Features Sample code Computer Graphics Group Computer Graphics Group • XML notation
X3D 7 X3D 8
Specification GeoVRML Computer Graphics Group Computer Graphics Group
1) Abstract specification • Coordinate systems object oriented • Multi-resolution 2) Three notations • Navigation - UTF-8 (like VRML97) • Metadata -XML - Binary (like MPEG-4) 3) Scene authoring interface Java, ECMAScript, DOM 10 “Geo” nodes
X3D 9 X3D 10
GeoVRML: Coordinates GeoVRML: Multi-resolution Computer Graphics Group Computer Graphics Group 12 coordinate systems: GeoLOD { } - quadtree • Geodetic 1 3 •Geocentric root • UTM, LCC, etc. 2 4 Level n Level n+1 Precision: Float => String
GeoInline { } – load/unload children SFBool load TRUE
X3D 11 X3D 12
2 GeoVRML: Navigation GeoVRML: Data Computer Graphics Group Computer Graphics Group
GeoViewpoint { } GeoElevationGrid { } – elevation exaggeration • navigation speed dependent on height • no terrain tracking /
Other “Geo” nodes: GeoPositionInterpolator { } GeoTouchSensor { } GeoMetaData { } – 14 predefined keywords
X3D 13 X3D 14
NurbsVRML NurbsVRML: Modeling Computer Graphics Group Computer Graphics Group • Non Uniform Rational B-Spline NurbsSurface { }, NurbsCurve { } • Trimmed surfaces • Grid of control vertices (CV) •Animations • Weights for CV •FFD Trimmed Surface { } • Surface with holes • Curve contoured surfaces
X3D 15 X3D 16
NurbsVRML: Tessellation NurbsVRML: Animations Computer Graphics Group Computer Graphics Group Tessellation – Object x Screen space NurbsPositionInterpolator { } Criteria: fixed, chord length, angle • Interpolated position on the NURBS surface fine near silhouette Live example CoordinateDeformer { } Automatic LOD • Free form deformation Criteria: fps, triangles/object, • Parameterized 3D volume (u,v,w) triangles/frame, CPU power, • Applicable to any child geometry distance to viewer, screen area, etc.
X3D 17 X3D 18
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