Acceleration Structures For Ray Tracing Animated Scenes

With the faster hardware improvement and longtime in-depth research on computer graphics, ray tracing become the focus of research on both real-time and offline rendering technology so that a lot of people pay attention to it. Ray tracing dynamic scenes and how to handling the dynamic scenes is the key technology. Accelerator need considering the cost of construction and ray traversal, and update strategies is also important to be considered.The purpose of this paper is that we do deep research on algorithms for construction and ray traversal of spacial accelerator on the topic of ray tracing dynamic scenes, and that we also try some new update strategies. The contribution and innovation of this paper is that: 1)we use SAH cost function to construct bvh-sah and bsp-sah in the pbrt rendering system; 2)we bring up two new accelerators bih-kdtree and grid-kdtree; 3)we compare our new accelerators bvh-sah, bsp-sah, bih-kdtree and grid-kdtree to kdtree, grid and occtree-sah on the purpose of finding out their advantages and disadvantages; 4)we make use of dynamic bvh-sah update strategies to design and fulfill the new rendering framework for dynamic scenes in the pbrt rendering system and find difference between the two update strategies that are all-update strategy and half lazy update strategy. The conclusion of this paper is that: 1)the cost of bvh-sah construction is very low for the scenes with small scale geometry primitives compared with other spatial accelerators especially for the deformable scenes, but the rendering performance using bvh-sah lag far the performance using space subdivision, and in the partly dynamic scenes the bvh-sah half lazy update strategy is very effective; 2)grid-kdtree is the most effective accelerator compared with kdtree and bih-kdtree; 3)bsp-sah is the most effective accelerator compared with grid and occtree-sah.