VRML Virtual Reality Modeling Language

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VRMLVirtual Reality Modeling Language
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VRML

• Brings 3 Dimensional Capabilities to the WWW
• Provides standard format for displaying,
  manipulating and navigating 3D worlds using a WEB
  Browser (with Plug-ins)

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VRML Objectives

• Interactive 3D simulations
• Multi-participant
• Hyperlinked with pointers to other Worlds or
  other WEB sites
• Latest standard includes 3D sound

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History

• 1994
• Discussion of VR interface to the World-Wide Web
• 1000 members joined discussion group within 3
  weeks.
• Open Inventor adopted as file format
• Originally developed by Silicon Graphics as
  method of developing interactive 3D multimedia

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Requirements for VRML 1.0

• Platform Independence
• Extensibility
• Ability to work over low-bandwidth connections

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VRML 2.0

• Extend VRML to include object behaviors
• Objects can have preprogrammed responses
• Provide a scripting language for objects
• Will allow multi-participant worlds

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VRML Concepts

• Nodes
• cubes, spheres, transformations, texture maps
• In general, shapes, properties or groups
• Parameters to describe nodes
• Name to identify node
• Child nodes - implements object hierarchy (group
  nodes can have children)

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Some nodes ...

• Shapes
• text,Cone,Cube, Cylinder, IndexedFaceSet,
  IndexedLIneSet, Pointset,Sphere
• Properties
• Coordinate3, FontStyle,Info,LOD. Material,
  MaterialBinding, Normal,...

• Properties
• MatrixTransform, Rotation,Scale,
  Transform.Translation
• DirectionalLight, PointLight,SpotLight
• Group Nodes
• Group, Separator,Switch, TransforSeparator,
  WWWAnchor

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Important Concepts

• Need to build 3D objects and place them in 3
  space
• Use Spheres, cones, polygons, cubes etc. to
  build an object.
• Cover the object using materials, and specify
  qualities of object surface (reflectance,
  transparency etc.)
• Need to specify light sources
• From viewer
• From infinity
• from a fixed spot
• Objects can have hyperlinks (WWWanchors)
• Viewer can move around the objects using the mouse

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More Concepts

• Worlds can have links to other worlds, so they
  can be developed independently and then linked
  together with hyperlinks

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Applications

• Architecture
• Equipment Design
• Sales and Marketing
• Multiparticipant games

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To View VRML

• Download Cosmo viewer from Netscape (or another
  VRML viewer)
• Upgrade Netscape Navigator
• Point Netscape at a VRML site

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To Create VRML

• Can just edit VRML code, but quickly gets
  difficult if you want to create complex objects
• Use a system like Fountain from Caligari, or
  Virtual Homespace Builder to create the objects,
  and then export them as a VRML (.WRL) file. There
  are a rapidly growing number of ways to create
  VRML

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Some VRML Terms

• Rendering -
• Performing all of the computations necessary to
  display an object given the lighting,
  reflectance, materials colors, transparency etc.
• Ray Tracing
• Common rendering technique. All possible light
  paths are traced and the ligting effects computed
  for every point on the object. Interactions
  between light sources have to be taken into
  account
• LOD - Level of Detail
• As a user zooms in, increasingly complex models
  of the world are rendered. Saves Rendering time
  when objects are far away

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VRML Terms continued

• Inverse Kinematics
• Given a connected set of objects (like an arm)
  allow user to manipulate part of it and have
  program compute paths of related objects.
• Collision Detection
• Browser provides real-time collision detection so
  that user can not move through walls etc.

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Future of VRML

• VRML will continue to evolve rapidly as
  computation speeds increase and 3D extensions are
  built into the hardware
• The incorporation of Java as a scripting language
  means that 3D worlds can have sophisticated built
  in behaviors
• Browsers now coming with VRML plug-ins as
  standard