Eva Schiffer

Constrained Animation by Matt Anderson, Eric McDaniel, and Stephen Chenney.

Summary:

This paper discusses a strategy to constrain the movement of simulated flocks by use of a multiple step process. The process includes a step to find paths which satisfy the constraints but not the agents' rules of motion as well as a step to try many possible agent motions in order to find a physically plausible solution.

Problem:

How does one enforce complex constraints on agents in a flocking simulation?
How can one define constraints for a flocking simulation in a simple and user friendly way?

Method:

The system described in this paper is able to enforce three different kinds of constraints: key frame like constraints for individual agents, center of mass constraints for the whole flock, and boundary constraints for the whole flock. Their system is able to offer these because it solves both forwards and backwards from constrained points and then bends together its two solutions. Their system also tries many different steps for the animation based on the rules that the agents follow and uses the steps that are most plausible but still follow the desired constraints.

Key Ideas:

It is possible to enforce complex constraints on flock motion.
It is possible to define complex constraints on flock motion in a simple and user friendly way.

Contributions:

This paper presented a very powerful strategy for constraining flock motion. The use of its blended paths and plausibility evaluation allowed it to satisfy constraints while still producing visually reasonable flocking behavior.

Questions:

I didn't have any major questions about this paper.