Fast ray tracing of sequences by ray history evaluation

Presents a method to reduce the time needed to render a sequence of ray traced images. We exploit the temporal and spatial coherence between consecutive frames. The algorithm does not only inspect the image plane in order to find regions with minor changes; the object space is analyzed by evaluating the so called ray history. With this method we obtain a speedup in the range of 1.2 to 2.8 almost without visible loss of quality. The method is more or less independent of the used ray trace algorithm and can be implemented in many ray trace programs without too much effort