Fast shadow casting algorithm in analytical polygon-based computer-generated holography

Abstract

Shadow casting is essential in computer graphics, which can significantly enhance the reality of rendered images. However, shadow casting is rarely studied in polygon-based computer-generated holography (CGH) because state-of-art triangle-based occlusion handling methods are too complicated for shadow casting and unfeasible for complex mutual occlusion handling. We proposed a novel drawing method based on the analytical polygon-based CGH framework and achieved Z-buffer-based occlusion handling instead of the traditional Painter’s algorithm. We also achieved shadow casting for parallel and point light sources. Our framework can be generalized to N-edge polygon (N-gon) rendering and accelerated using CUDA hardware, by which the rendering speed can be significantly enhanced.