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A VRML Overview

by Sanjeev S. Vadhavkar

Table of Contents

Introduction: What is VRML?

VRML stands for Virtual Reality Modeling Language. VRML, like HTML, is a set of standards for writing code. The Virtual Reality Modeling Language (VRML) can be considered as a developing standard for describing interactive three-dimensional scenes delivered across the internet. One of the hottest topics in Virtual Reality research is the idea of "distributed" VR. A lot of ideas have been tossed around in various newsgroups and mailing lists. There are however no concrete ideas on how VRML can be enhanced by extending existing HTTP servers to provide fast and scalable multi-user support.

To run it on athena

If you are on a SGI/SUN machine, congratulations, you're in luck. Athena has the VRWeb browser for SGI's and SUN's in the outland locker. You need to put a add outland command in your .environment file. You wil also have to make sure that netscape knows you will be using VRWeb to view VRML files. You can do this by writing in the .mailcap file the following line : x-world/x-vrml; vrweb -URL '%u' -remote %s . Hopefully you are set. The SGI's are obviously faster and offer better graphics than the SUN's.

There are a zillion VRML browsers for Windows.

Demos

Sample VRML code

Since VRML includes an enormous number of tags, headers and calls, a brief overwiew of VRML cannot do justice to do all its capabilities. A VRML file is basically an ascii file with a .wrl header. It looks something like this: 
#VRML V1.0 ascii

Separator {
    MatrixTransform {
        matrix  1 0 0 0
                0 -3.69549e-06 -1 0
                0 1 -3.69549e-06 0
                0 0 0 1
    }
    Separator {
        Info {
            string      "group0"
        }
        Separator {
            Info {
                string  "group*U94"
            }
            Material {
                ambientColor    0.25 0.25 0.25
                diffuseColor    1 1 1
            }
            Separator {
                Coordinate3 {
point       [ 3.68729 5.58333 -3,
                                      3.75142 5.67308 -3,
                                      3.68729 3.07051 -3,
                                      3.75142 2.95513 -3,
                                      3.40513 3.07051 -3,
                                      3.16145 5.58333 -3,
                                      3.07167 5.67308 -3,
                                      3.32818 2.95513 -3,
                                      3.68729 5.58333 12,
                                      3.68729 3.07051 12,
                                      3.75142 5.67308 12,
                                      3.75142 2.95513 12,
                                      3.32818 2.95513 12,
                                      3.16145 5.58333 12,
                                      3.07167 5.67308 12,
                                      3.40513 3.07051 12 ]
                }
                ShapeHints {
                    vertexOrdering      COUNTERCLOCKWISE
                    shapeType   SOLID
                }
/* Much More Code After This */
Just like HTML, you need a VRML browser to view the .wrl file. No compilation required.

Links

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