Data Parallel Path Tracing with Object Hierarchies

We propose a new approach to rendering production-style content with full path tracing in a data-distributed fashion---that is, with multiple collaborating nodes and/or GPUs that each store only part of the model. In particular, we propose a new approach to ray-forwarding based data-parallel ray tracing that improves over traditional spatial partitioning, that can support both object-hierarchy and spatial partitioning (or any combination thereof), and that employs multiple techniques for reducing the number of rays sent across the network. We show that this approach can simultaneously achieve higher flexibility in model partitioning, lower memory per node, lower bandwidth during rendering, and higher performance; and that it can ultimately achieve interactive rendering performance for non-trivial models with full path tracing even on quite moderate hardware resources with relatively low-end interconnect.