A fast ray tracing scheme for dynamic scenes

• Published in: 2017 4th International Conference on Control, Decision and Information Technologies (CoDIT) pp. 0872 - 0875
• Main Authors: Yun-Nan Chang, Chin-Lun Yang
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.04.2017
• Subjects: Acceleration; Buildings; Information technology; Life estimation; Ray tracing; Rendering (computer graphics); Software
• DOI: 10.1109/CoDIT.2017.8102705

This paper proposes an efficient ray-tracing scheme to render dynamic scenes by exploring the coherence between consecutive frames. By assuming that only few objects in a scene may move from frame to frame, the rays emitted from the same pixels of two consecutive frames may hit the same object with high possibility. By using extra buffers to store the index of triangle each ray intersects for the current scene, the trace of each ray for the following scene can start by testing if this ray intersects the same triangle. Once the ray hits the same triangle, the intersection depth can then be used to exclude the test operation of the other nodes during the tree traversal. In addition, instead of rebuilding the bounding volume hierarchies (BVH) tree structure of the next scene, it can also be obtained by updating the current one. The unmodified nodes can be annotated such that their intersection test can be simply skipped during the tree traversal for those rays which hit the same primitives in the current scene. For our own test scenes whose total number of modified triangles is less than 5% of the overall triangle count, our experimental results show that more than one half of ray-node and ray-triangle intersection operations can be saved, which can result in more than 50% reduction in the software ray-tracing time. For the common test scene TOASTER where more than 90% of triangles have been moved in consecutive scenes, the proposed scheme can still achieve the saving of trace time up to 24%.