A Parallel Computer for Ray Tracing

长期以来，光线跟踪因其在可视化三维数据方面的质量和灵活性而被公认。到目前为止，限制该算法使用的唯一因素是它的计算复杂性。为了解决这一问题，提出了一种专用并行计算机。与以前的空间划分方法不同，该体系结构基于射线划分方法。它使用了许多处理单元，每个处理单元都可以访问全局共享内存。为了减少各个处理器和该共享存储器之间的带宽需求，出现了对高效专用高速缓存的需求。我们认为，设计一个专门用于访问射线示踪器数据库的高速缓存是射线分区方法实际实现的一个最重要的因素。这项研究的目的是确定光线分配方案、内部数据库结构和适当的高速缓存参数，以提供足够高的命中率来支持实时光线跟踪性能所需的处理器数量。还将特别关注负载均衡和实际的VLSI实现。

Ray tracing has long been recognized for its quality and flexibility in visualizing three dimensional data. To date, the single factor which has been limited the algorithm's use is its computational complexity. In an effort to overcome this problem an application specific parallel computer is proposed. This architecture is based upon a ray partitioning approach, in contrast to previous spatial partitioning approahces. It employs a multitude of processing elements, each with access to a global shared memory. To reduce the bandwidth requirements between individual processors and this shared memory the need for an efficient private cache arises. We suggest that the design of a cache specialized for accessing ray tracer databases is the single most important factor in the practical realization of the ray partitioning approach. The objective of this research is to determine the ray allocation scheme, the internal database structure, and the appropriate cache parameters which provide hit rates high enough to support the number of processors required for real-time ray tracing performance. Special attention will also be paid to load balancing and practical VLSI implementation.