Realtime Ray Tracing on a Hibrid Parallel Architecture

Octrees are attractive data structures for rendering of volumes, as they provide simultaneously uniform and hierarchical data encapsulation. We present a simple and efficient algorithm for interactive ray tracing on a hybrid architectures, which takes advantage of the parallelism present by heavily exploiting the hardware for the CPU and GPU, which has been observed to give superior performance in ray tracing compared to other acceleration structures. Instead of alternating between phases of rendering and (potentially infrequent) building, our approach exploits the parallelism inherent in a multi-core system by continuously and asynchronously rebuilding new octree (potentially over the course of multiple frames) while the threads in the GPU concurrently update and traverse the most recently built octree.