VT Project

Animation Study


The following two VRML applications show a running football player and illustrate the relation between the internal skeleton and the geometry envelop. The first application uses a rigid envelop, the second a flexible envelop or "skin".



Instructions

  • Use "Next Viewpoint" to follow the animated character from different positions

  • Use the slider (on top) to make the geometry envelop transparent and reveal the skeleton

  • The button on the left of the slider allows to stop/restart the animation

  • The button on the right only appears when the animation has been stopped. The button allows to toggle between fast (normal speed) and slow (slow motion).

VRML Applications
Load VRML Animation
with Rigid Geometry
(size 4,105 KB)


Load VRML Animation with
Flexible Geometry (skin)
(size 8,426 KB)


Shortcomings

The two VRML applications still contain several errors that have not yet been corrected:
  • When running the animation for a longer period of time, the CosmoPlayer will display red error bars indicating an "out of memory" condition.

  • The internal skeleton and the two geometry envelops are not correctly aligned. Some joints (yellow balls) are sometimes outside the envelops' geometry.

  • The character's shoes (and foot joints) sometimes penetrate the ground plate. However, the movement over the ground plate seems to be correct (no sliding).

  • There seems to a small jerkiness in the animation probably caused by improper looping of the key frame sequence.

  • After switching between fast and slow, the animation restarts at a different position.

  • Parts of the geometry still need improvements (especially in the upper body).

  • The flexible geometry envelop (skin) has only been implemented for the lower body part (below the waist).

  • The creaseAngle field in all IndexedFaceSet nodes is (intentionally) not being used since this reduces the frame rate significantly (to an unacceptable level).

Credits

Both VRML applications were developed using 3D Studio Max and Poser by Alexis Kinter as part of an independent study project. Several refinements and controls were added by K.-P. Beier.

Last Update: May 31, 2003, kpb
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