View-Warped Multi-View Soft Shadows for Local Area Lights

Abstract

Rendering soft shadows cast by dynamic objects in real-time with few visual artifacts is challenging to achieve. We introduce a new algorithm for local light sources that exhibits fewer artifacts than fast single-view approximations, and is faster than high quality multi-view solutions. Inspired by layered depth images, image warping, and point-based rendering, our algorithm traverses complex occluder geometry once and creates an optimized multi-view point cloud as a proxy. We then render many depth maps simultaneously on graphics hardware using GPU Compute. By significantly reducing the time spent producing depth maps, our solution presents a new alternative for applications that cannot yet afford the most accurate methods, but strive for higher quality shadows than possible with common approximations.