1 / 11


VRML. Dr. Alun Moon alun.moon@unn.ac.uk. What is VRML.

Télécharger la présentation


An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.


Presentation Transcript

  1. VRML Dr. Alun Moon alun.moon@unn.ac.uk

  2. What is VRML • The Virtual Reality Modeling Language (VRML) is a file format for describing interactive 3D objects and worlds. VRML is designed to be used on the Internet, intranets, and local client systems. VRML is also intended to be a universal interchange format for integrated 3D graphics and multimedia. VRML may be used in a variety of application areas such as engineering and scientific visualization, multimedia presentations, entertainment and educational titles, web pages, and shared virtual worlds. • From the VRML specification • Web3D consortium – source of the VRML specshttp://www.web3d.org/ • (http://www.web3d.org/fs_specifications.html)

  3. Features • Extensible • New nodes can be created using a PROTOTYPE mechanism • Dynamic • Interaction and animation is achieved via an event model, behaviour can be programmed in Java and JavaScript (ECMAScript) • Compact • Descriptions of geometry can be compact, using a reuse mechanism. High compression ratios are achieved with gzip. • Text file • Tools for revision control and versioning, compilation and automatic generation, can all be used.

  4. Basic shapes Cube Cylinder Sphere Cone Advanced shapes Elevation grid Terrain modelling IndexedFaceSet Generic shape Extrusion Very powerful tool if used well. Lathe shapes Surfaces of revolution Concepts: Geometry No constructive solid geometry, but shapes can occupy the same volume.

  5. Translation (x,y,z) Rotation Axis and angle (x,y,z,) Based on quaternons Scaling orientation non-uniform Transformations can be nested, giving a complex transformation hierarchy. Assemblies When combined with interpolators, can simulate joints. Concepts: Transformations

  6. TimeSensor DragSensors PlaneSensor CylinderSensor SphereSensor Interpolators Coordinate – mesh Position Rotation Scalar Bounded linear interpolation Animation and interaction • Event model. • Event outputs (sensor outputs) can be routed to nodes to set parameters (e.g. rotation). A complex interaction model can be constructed.

  7. Model creation • Text editor • Good for learning VRML. • Often used for tidying VRML and adding behaviour. • Automatic generation • Large model generation from data file, script can generate VRML from data. • Custom perl scripts • Macro tools m4, cpp ?

  8. Commercial tools • CAD export • Some only produce VRML1.0, and quality can be poor • Pro/Engineer • AutoCAD • 3D modelling tools • Good geometry and texture editing, less capable in some respects than CAD • 3D Studio Max • Analysis tools • Visualisation of scientific data • Matlab • Fluent (next version)

  9. Some models • Basic models • Basic light • Bezier patch extension • Engineering uses • Models I developed while at the RCID, Newcastle University. • Spray bottle • Mechanical animation. • CFD post processing. (470kb / 73kb) • Inverse kinematics. • Beam mechanics (Wendy Parker)

  10. Other peoples models • by Ivan Klíma http://vrml.environs.com/ivan/ • A good site of well built VRML models (by “hand” in text editor). • Lathe demonstration • Lunar site • Boeing E3-A Sentry • University of Arizona http://ag.arizona.edu/agnet/vrml/ • Virtual terrain (71kb / 12kb , texture 289kb) • Manchester Visualization Centre • Medical simulations http://synaptic.mvc.mcc.ac.uk/simulators.html

  11. Other users and sites • Paul Fishwick, University of Florida,VRML as an environment for engineering systems modelling http://www.cise.ufl.edu/~fishwick/vrml/ • NISTA number of projects using VRML for visualisationhttp://www.nist.gov/ (search for VRML) • A good site for reference and background material, links and tools http://hiwaay.net/~crispen/vrmlworks/ • VRML RepositoryA good place to find links to tools, and object librarieshttp://www.web3d.org/vrml/vrml.htm

More Related