B582-Spring 2000 - Programming Assignment #3

"VRML Rube Goldberg Competition"

updated 3/22/2000

Goal:

To create a simple "Rube Goldberg" contraption for the desktop and the CAVE using VRML

VRML Concepts:

simple VRML modeling
animation through timers and interpolators
simple scripting for triggers and synchronization
sensors for interaction

Misc Info:

Due: Monday, March 27 by noon.
Value: 50 points
Sample Code:

simple scene with single timer and no script (less flexible, but okay)
simple scene with multiple timers and trigger script (more flexible, slightly more complex to code)
complex scene with single timer and no script
complex scene with multiple timers and trigger script

Working with VRML on SGIs

when modeling with CosmoWorlds or Showcase, it is difficult to determine the final scale and orientation of the object. Use the models below to help you. Import these reference models while working on your objects (.iv for showcase, .wrl for cosmoworlds), then size and orient your shape relative to these reference models. Be sure to delete the reference model before saving your scene.

unitaxes.iv , grids10x10.iv , axesAndGrid.iv (requires other two files)
unitaxes.wrl , grids10x10.wrl , axesAndGrid.wrl (requires other two files)

to convert from Inventor to VRML2:

/usr/sbin/ivToVRML foo.iv > foo.vrml1
/usr/sbin/vrml1tovrml2 foo.vrml1 > foo.wrl

to convert RGB images to PNG

/usr/sbin/imgcopy foo.rgb foo.png

to convert RGB images to GIF or JPEG

/usr/sbin/imgcopy foo.rgb foo.jpg
or use xv

Tasks:

1. Design a Rube Goldberg style contraption or animation sequence. Your system should contain a minimum of four objects which move in sequence, plus a method to trigger the sequence and a button to reset the objects so that the sequence can be repeated. It is recommended that you plan your contraption or sequence on paper before coding. See the official Rube Goldberg web site and gallery for some inspiration.

2. Implement your design using VRML97. You may wish to start with the sample as a basis for your code, modifying for your particular sequence using the VRML97 specifications and the VRML97 SIGGRAPH course notes. (The VRMLScript spec is also available.) You may wish to create your static models in showcase or CosmoWorlds and incorporate them via Inline nodes. Please code the animations (interpolators) by hand; do not use a keyframe animator such as that provided by CosmoWorlds.

3. Test your application on the desktop using CosmoPlayer, and in the CAVE using cave6u. For the CAVE, remember that units are assumed to be meters (although you can override that via the .caverc) and that the "walk" viewer is preferable to the "examiner" viewer. (e.g. add the following
node to your code):

    NavigationInfo {
        type ["WALK", "ANY"] #can still switch to examiner on desktop
        speed 10              #travel speed in units per second
    }

Also remember that there is no support for the Text node, so any text should be handled through texture mapping.

4. Bring you judge's hat on Wednesday, March 29; the class will select a winning design. The winner will receive a special award and bonus.