Dynamics and unification of animation control

Abstract

We present an analysis of unified animation control processes. The design of an animation system is strongly coupled with the considered application. Most of the existing systems are specialized. For example, in audiovisual production or in C.A.D., only a few systems specialized in mechanical computation have capabilities in the image synthesis field. We are working on the design of a general animation system, including generation of motion defined by use of mechanical laws, in an audiovisual environment. Our system is built around a structured graph in which we store a hierarchical description of the objects and mechanical joints. The joints may be used to link the objects together to allow the building of multibody mechanical systems. For objects which are not submited to mechanical laws, motion control can be specified by key-framing techniques or explicit trajectories. We use a dynamical formalism based upon the principle of virtual work associated with LAGRANGE's multipliers and that takes into account holonomic and nonholonomic constraints. The generation of the differential motion equations system is automatically built by performing symbolic derivations. These equations are then solved for each time step and give object locations and orientations.