Multi-Light Bidirectional Path Tracing Based on Triangle Grids

This paper presents a bidirectional path tracing algorithm for multiple light sources based on triangular grids. Ray tracing algorithms face challenges in lighting computation cost as the number of light sources increases. Existing methods face issues with storage resource waste. The proposed algorithm quickly builds a triangular mesh on the object surface, randomly samples each mesh for light source visibility tests, and filters out low-contributing light sources, thereby reducing storage space consumption. The algorithm pre-computes visibility between objects and light sources by sampling triangle grids, enhancing the efficiency of the bidirectional path tracing algorithm in multisource scenes and achieving real-time global illumination. A comparative analysis, conducted within the Falcor open-source rendering framework, revealed that the proposed algorithm exhibited comparable image quality to WRRBDPT, yet demonstrated significantly superior temporal performance.