Using temporal and spatial coherence for accelerating the calculation of animation sequences

Abstract

Ray tracing is a well known technique for generating realistic images. One of the major drawbacks of this approach are the extensive computational requirements for image calculation. When generating animation sequences frame by frame the computational cost might easily become intolerable. In the last years several methods have been devised for accelerating the computational speed by using spatial and temporal coherence. While these techniques work only under certain restrictions, a new approach is presented in this paper which leads to a considerable speed-up of the calculation process without putting any limitations on camera or object movement. In principle, the method is an extension of /ArKi87/, where rays are considered points in 5D space, by the time dimension. CSG is used for object description and has been modified correspondingly to allow easy use of coherence properties. The paper describes the theoretical background and the main concepts of a practical implementation.