Real-time soft shadow rendering

Abstract

Rendering shadows is an important issue in computer graphics. Shadows not only give realism to the rendered images, but also help viewers to understand the spatial relationship in the virtual scene. The computer generated shadows can be classified as hard shadows and soft shadows. Since light sources in real life occupies area or volume, soft shadows give more realism when comparing with hards shadows. Although many researches on real time soft shadow rendering have been conducted, a fast, general, scalable and robust method still does not exist. In this project, several commonly adapted real time shadow rendering method will be analyzed; and a new method, Dual Resolution Percentage Closer Filtering is purposed. Dual-Res PCF not only effectively render soft shadows in real time, but also able to model the relationship between the penumbra size and the distance to occluder. The Dual-Res PCF method can benefit various kinds of computer graphics applications by greatly improving their realism.