Parallel and Distributed Photo-Realistic Rendering

With the continuous improvement in ray tracing and radiosity algorithms, image synthe-sis quality has reached the level of photo realism. However, efforts to achieve real-timeperformances by implementing ray tracing and radiosity algorithms on parallelprocessors and dedicated hardware have not been very successful so far. Increasing thenumber of processors introduces a corresponding growth in inter-processorcommunication. Caching could be effective to reduce communication, if sufficientcoherence would be available in subsequent data requests. Unfortunately, standard raytracing and radiosity do not provide enough coherence. In this paper we review thedifferent parallel approaches and we try to ascertain those issues that are crucial forfurther improvement. In particular, we will focus on load and data managementstrategies that effect the amount of data coherence in ray tracing, and on methods toimprove ray and object coherence.