Occlusion calculation algorithm for computer generated hologram based on ray tracing

Computer-generated holograms(CGHs) with occlusion information have a better sense of reality. There is also a reduction in the amount of calculation since the occluded part does not need to be calculated. We made adaptive changes to the traditional graphical ray tracing method and introduced it into CGH to get the correct occlusion effect of point cloud models and achieve fast intersection calculation. To realize the motion parallax effect, the hologram is divided into sub-holograms. A KD-Tree traversal algorithm for a GPU based on the virtual stack is proposed to implement efficient parallel computation in ray tracing. The effectiveness of the proposed algorithm was verified by several experiments in terms of the occlusion effect and motion parallax effect, and its temporal and spatial efficiency was proven.