Parallel processing of incremental ray tracing on a shared-memory multiprocessor

This paper presents a novel parallel-processing method for image synthesis using incremental ray tracing on a shared-memory multiprocessor workstation. The most efficient technique for image synthesis is ray tracing, proposed by Whitted in 1980. Ray-tracing algorithms are simple and can generate realistic images. However, they are time-consuming, since calculations of the intersections between objects and ray increase exponentially as the complexity of scenes increases. Fast image synthesis for animation is one of the most important topics in computer graphics. As the area of computer applications has broadened, the complexity of images to be synthesized has increased. Parallel processing of computer graphics is one way of achieving fast image synthesis. This paper describes a parallel processing technique for incremental ray tracing, which recalculates only the rays changed by moving objects in successive scenes of continuous image synthesis. The performance of parallel ray tracing was evaluated on the multiprocessor workstation TOP-1. Strategies for allocating pixels to processes under a multiprocess operating system on this workstation are discussed.