VRML Overview

    VRML stands for virtual reality modeling language that is used present 3D graphics on the web. It is similar to HTML in that it is simply a text file, but the contents of a VRML file are definitions of objects and their attributes that make up a world. To define something like a sphere at the center of the world with a radius of one would have the following text:

    Sphere {
      field SFFloat radius 1
    }

Unfortunately VRML only supports geometry files, so any fields that are to be used must first be converted into a geometry using something similar to the OutputVRML module in AVS Express. This module would then create an object that uses the IndexedFaceSet command which writes out all the points used in the file and then writes out all the triangles by their points that represent that model.

In addition to the 3D objects, VRML can be used to create animation sequences by using it’s scripting language. Using the scripting language, a programmer can write a procedure that will change the position of the camera over a certain interval of time. Unfortunately using this language is pretty tedious, so it sames a lot of headaches and is more powerful to use Java for more functionality.

To see VRML worlds you can get the CosmoPlayer plugin for Netscape at http://www.cosmoplayer.com or another VRML viewer.

Sydney MQP Virtual Bronchoscopy in VRML by John Stevens