Real-Time Soft Shadows Using a Single Light Sample

We present a real-time rendering algorithm that generates soft shadows of dynamic scenes using a single light sample. As a depth-map algorithm it can handle arbitrary shadowed surfaces. The shadow-casting surfaces, however, should satisfy a few geometric properties to prevent artifacts. Our algorithm is based on a bivariate attenuation function, whose result modulates the intensity of a light causing shadows. The first argument specifies the distance of the occluding point to the shadowed point; the second argument measures how deep the shadowed point is inside the shadow. The attenuation function can be implemented using dependent texture accesses; the complete implementation of the algorithm can be accelerated by today’s graphics hardware. We outline the implementation, and discuss details of artifact prevention and filtering. Keywords Soft Shadow Algorithms, Shadow Mapping, Graphics Hardware, Hardware-Accelerated Rendering

• Type: Conference
• Year: 2003
• Where: WSCG
• Authors: Florian Kirsch, Jürgen Döllner
• Keywords: Algorithm, Attenuation Function, Soft Shadow, WSCG 2003