High-fidelity rendering of animations on the grid: a case study

Abstract

Generation of physically-based rendered animations is a computationally expensive process, often taking many hours to complete. Parallel rendering, on shared memory machines and small to medium clusters, is often em- ployed to improve overall rendering times. Massive parallelism is possible using Grid computing. However, since the Grid is a multi-user environment with a large number of nodes potentially separated by substantial network distances; communication should be kept minimum. While for some rendering algorithms running animations on the Grid may be a simple task of assigning an individual frame for each processor, certain acceleration data structures, such as irradiance caching require different approaches. The irradiance cache, which caches the in- direct diffuse samples for interpolation of indirect lighting calculations, may be used to significantly reduce the computational requirements when generating high-fidelity animations. Parallel solutions for irradiance caching using shared memory or message passing are not ideal for Grid computing due to the communication overhead and must be adapted for this highly parallel environment. This paper presents a case study on rendering of high- fidelity animations using a two-pass approach by adapting the irradiance cache algorithm for parallel rendering using Grid computing. This approach exploits the temporal coherence between animation frames to significantly gain speed-up and enhance visual quality. The key feature of our approach is that it does not use any additional data structure and can thus be used with any irradiance cache or similar acceleration mechanism for rendering on the Grid.