Physical animation of quadrupeds

Computer animation of animal locomotion has important applications in computer games and interactive virtual environments.  Below are some samples of our recent and ongoing work on physical animation of quadrupeds.

Extracting locomotion from video data

Paul Kry, Lionel Reveret

This example shows a 3D animated dog trot which was extracted video. The 2D Markers trajectories are extracted from a rectified video of a nodal pan camera. The 3D motion is reconstructed by guiding a physically based simulation with 2D trajectories. While the motion is largely planar, the degrees of freedom of the dog model combine with dynamic effects (e.g., inertia of different body parts) to produce subtle out of plane motions, such as spinal flexion. This work has been done with Paul Kry (now at McGill University). The original video footage has been collected by the National Museum of Natural History in Paris, France.

Modal Locomotion

Paul Kry, Lionel Reveret, Francois Faure, Marie-Paule Cani

Locomotion is an energetically expensive activity, and it is possible that animals use their bodies in efficient ways to produce gaits that dependent on speed and task (for instance, a slow gate to search for shelter or a fast gate to escape a predator). The idea behind this work is that locomotion strongly depends on the morphology of the animal, and we can deduce a lot of information about plausible modes of locomotion just by observing the natural vibrations of an animal's musculoskeletal structure.

Predefined quadruped controller

Gregory Clauzel, Lionel Reveret

This video shows a user defined controller which produces locomotion in a dynamic environment.  This work has been done with Gregory Clauzel, who is now at EdenGames.  The virtual animal is able to walk over and interact with dynamic obstacles, while maintaining balance using additional forcing inspired from a ZMP approach.