Ray-casting CRT algorithm for holographic 3D display with full parallax occlusion effect

Abstract

In this paper, a full parallax occlusion algorithm for holographic 3D display is developed and the motion parallax and dynamic occlusion effect of the reconstructed 3D object is successfully demonstrated. The ray-casting, directional clustering and vertical angle marking technologies are integrated with coherent ray tracing (CRT) hologram computation algorithm. By applying the vertical angle marking technology, only a single pass of the entire horizontal viewing angle is needed to compute full parallax occlusion. The complexity of the algorithm is reduced by about one order compared to standard occlusion algorithm which considers the entire range of combination of horizontal and vertical viewing angles for occlusion. Compared to conventional CRT computation which does not consider occlusion effect, the algorithm has also increased the computation speed to about 350%. The algorithm is able to work with any forms of 3D data. The optimal horizontal angular resolution has also been identified as 0.007 degree for our system experimentally which enables the optimization of the algorithm. Various 3D objects with full parallax occlusion effect have been reconstructed optically.