ABSTRACT
The animation of articulated figures may be thought of as applying to two different types of structures. The first type are those animals and mechanisms that have rigid skeletons connected together with joints. The skeletons may have complex topologies, such as arms and legs, and require consideration of the dynamics of hierarchical rigid structures (Isaacs and Cohen, 1987). The second type of structure is topologically simple, consisting of a tube that can bend and stretch and may be modeled using simple formulations of elastically deformable materials. Worms have no skeleton and so naturally lend themselves to this description. Snakes do have skeletons, with many links, but may be approximated using a continuum model.
