Modeling of contact deformations between a synthetic human and its environment

In the absence of contact, several solutions have been proposed for skin deformations. In his hand animation system MOP, Catmull proposed a hand envelop made up of polygons in 1972 (5), spheres and B-splines were proposed by Badler and Morris in 1981 for hand deformations (6), Bézier surfaces were used by Komatsu for arm deformations (7), Magnenat-Thalmann et al. (8) used operators which are adjustable links between the skeleton and the skin, and more recently, Chadwick et al. (9) used a kind of "exoskeleton" which is a parallelepiped lattice to control skin deformations.