MPI-I-2004-4-006

This paper presents a generic technique for acceleration of ray tracing of polygonal scenes. We propose scheduling rays in a way that forms pyramidal shafts. We show that under certain conditions fulfilled by the corner rays of a shaft, it is possible to immediately and conservatively answer visibility queries for the inner rays without expensive ray traversal through acceleration data structures (kd-tree in our case). We show that the presented technique is suitable for primary, secondary, and shadow rays.