GPU-Based Data Structure for a Parallel Ray Tracing Illumination Algorithm

Ray tracing is a largely employed technique for generating computer images with high fidelity and realism. However, this technique is very costly, mainly because of the intersection calculations made by the algorithm. Still, ray tracing is a highly parallelizable algorithm, since the calculations for a single light ray are independent from the others. This way, the implementation of the ray tracing on the GPU is a natural process. Data structures can be employed for reducing the processing load of the ray tracing algorithm, minimizing the number of intersection calculations. In recent works, these structures are being ported to the GPU, so they can be used to accelerate various parallel algorithms. In this work, we proposed a GPU ray tracing implementation using an octree as acceleration structure. Every single step of the algorithm runs in parallel on the GPU, so the communication bottleneck between the GPU and the CPU is eliminated. This work also proposes the study of which is the best way to represent the octree on the GPU, by comparing two different approaches.