Ray tracing on a connection machine

  • Authors:
  • H. C. Delany

  • Affiliations:
  • MIT Media Laboratory, Cambridge, MA

  • Venue:
  • ICS '88 Proceedings of the 2nd international conference on Supercomputing
  • Year:
  • 1988

Quantified Score

Hi-index 0.00

Visualization

Abstract

A new ray-tracing algorithm designed specifically for massively parallel hypercube connected processors is introduced. World space is subdivided according to a fixed size 3-D orthogonal grid. Rays are traced using ray-points which move along the rays, referencing the voxels intersected. One processor is assigned per ray, as well as one processor per object fragment.A pointerless data structure called an induced octree is used. This structure exists only as an ordering of the data in processor-address space, yet with it, all processors can determine the jump-distance to the nearest non-empty voxel in parallel to within a power of two. Ray-points move by large jumps whenever possible, and ray-object intersection proceeds in log time in the average ray length. Sorting via the network is the parallel analogue to octree-traversal.A code-scheduling mechanism is introduced which improves processor usage for SIMD architectures.Preliminary results are presented for an implementation using a CM-1 CPU equipped with 16k processors.