Research And Implement Of Photon Mapping Rendering Algorithm Based On GPU-Accelerated

The ray tracing based on physical rendering can produce higher quality images than other methods. However, the computational costs of tracking whole photon paths are huge. Also, it takes a few hours to render high-quality images in complex scenes. So, it is a good choice using Graphics Processing Unit (GPU) accelerate the rendering process. The rendering based on parallel GPU-accelerated becomes a hot research area with the advent of Compute Unified Device Architecture (CUDA) and OptiX rendering engine.In the paper, the research of photon mapping rendering based on GPU-accelerated is divided into two associated sections.First section, we research the realization of GPU-based photon mapping. Firstly, we introduce three implementations of global illumination, including the description of the photon mapping algorithm. Then, we discusses two realization algorithms of photon mapping adapted to GPU architecture, including sorted grid and stochastic hash. Finally, we analyze the photon mapping performance of the two algorithms on the GPU.Second section, we research the parallel implementation of progressive photon mapping based on CUDA. Firstly, we describe the progressive photon mapping algorithm, and modify the algorithm to run on the CUDA and multi-GPU architecture. Secondly, we propose distributed GPU rendering architecture and progressive photon mapping in order to implement the parallel rendering of progressive photon mapping based on CUDA. Finally, we analyze the performance of distributed rendering when executing the algorithm on the GPU.The results show that the rendering performance of photon mapping is similar when using sorted grid and stochastic hash. However, it costs about72%of construction time for sorting the photon in sorted grid, sorted grid will be more suitable for GPU-based photon mapping with the increasing of GPU sorting capabilities. And after1000iterations rendering in six GPUs of distributed system, the speedup increased to5.7, so it gets close to linear acceleration.