Frame-to-frame coherence and the hidden surface computation

Abstract

Frame-to-frame coherence is the highly structured relationship that exists between successive frames of certain animation sequences. From the point of view of the hidden surface computation, this implies that parts of the scene will become visible or invisible in a predictable fashion. In this paper the frame-to-frame coherence constraints are identified and characterized for static scenes restricted to stationary, closed, convex, nonintersecting polyhedra. The animation derives from a continuous movement of the viewer. The mathematical analysis of the constraints is geometric, and leads to a characterization of the self-occlusion relationship over a single polyhedron; and to a characterization of the occlusion or change of occlusion relationship over two polyhedra. Based on these constraints, an algorithm is presented which generates successive frames in an animation sequence.