Layered Dynamic Control for Interactive Character Swimming

Abstract

This paper proposes a layered strategy for controlling character motion in a dynamically varying environment. We illustrate this approach in the context of a physically simulated human swimmer. The swimmer attempts to follow a dynamic target by augmenting cyclic stroke control with a set of pre-specified variations, based on the current state of the character and its environment. Control of a given swim stroke is decomposed into three layers: a basic stroke sequence, a set of per-stroke control variations, and a set of continuously applied control variations. Interactive control of the swimmer is possible as a result of an efficient physical simulation using a simplified fluid model. Our results show layered dynamic control to be an effective adaptive control technique in well conditioned physical simulations such as swimming, where simulation states resulting from control errors are recoverable.