Magnenat Thalmann and Thalmann [1991] propose a new classification of computer animation scenes involving synthetic actors both according to the method of controlling motion and according to the kinds of interactions the actors have. A motion control method specifies how an actor is animated and may be characterized according to the type of information to which it is privileged in animating the synthetic actor. For example, in a keyframe system for an articulated body, the privileged information to be manipulated is joint angles. In a forward dynamics-based system, the privileged.
