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 version="1.0" encoding="UTF-8"?> • XML notation <X3D profile='Interactive'> <Scene> • Interfaces to scripting languages <Transform DEF=“myObject1" translation=“0 -7 0.5“ scale="2 2 2"> <Shape> •Consortiumregisters new components <Appearance> <Material DEF="MAT1" ambientIntensity="1.0“ shininess="0.2“ (OpenGL strategy) diffuseColor="0 0.5 0" specularColor="0 0.2 0.0"/> </Appearance> • Open source reference browser <IndexedFaceSet implementation … </IndexedFaceSet> </Shape> </Transform> </Scene> </X3D> 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 3.