Dynamic Load Balancing for Raytraced Volume Rendering on Distributed Memory Machines

We present a technique for adaptive load balancing for ray traced volume rendering on distributed memory machines using hierarchical representation of volume data. Our approach partitions the image onto processors while preserving scanline coherence. Volume data is assumed replicated on each processor since our focus in this paper is to characterize computation and communication requirements for performing dynamic load balancing. We show that communication overheads are negligible to perform dynamic load balancing while rendering a sequence of frames on a distributed memory implementation. By exploiting image and frame coherence while distributing the image space, load balancing can be achieved at a relatively low cost.