Parallel Occlusion Culling for InteractiveWalkthroughs using Multiple GPUs

Abstract

We present a new parallel occlusion culling algorithm for interactive display of large environments. It uses a cluster of three graphics processing units (GPUs) to compute an occlusion representation, cull away occluded objects and render the visible primitives. Moreover, our parallel architecture reverses the role of two of the GPUs between successive frames to lower the communication overhead. We have combined the occlusion culling algorithm with pre-computed levels-of-detail and use it for interactive display of geometric datasets. The resulting system has been implemented and applied to large environments composed of tens of millions of primitives. In practice, it is able to render such models at interactive rates with little loss in image fidelity. The performance of the overall occlusion culling algorithm is based on the graphics hardware computational power growth curve which has recently outperformed the Moore’s Law for general CPU power growth.