Real-time Rendering of Dynamic Objects in Dynamic, Low-frequency Lighting Environments

This paper presents a pre-computation based method for real time global illumination of dynamic objects. Each frame of animation is rendered using spherical harmonics lighting basis functions. The pre-computed radiance transfer (PRT) associated with each object’s surface is unfolded to a rectangular light map. A sequence of light maps is compressed using a high dynamic range video compression technique, and uncompressed for real-time rendering. During rendering, we fetch the light map corresponding to each frame, and compose a light map corresponding to any arbitrary, low-frequency lighting condition. The computed surface light map can be applied to the object using the texture mapping facility of a graphics pipeline. The primary contribution of this paper lies in its precomputation based real time global illumination rendering of dynamic objects. Spherical harmonics light maps (SHLM) are used to represent the precomputation results, and the animation can be viewed from arbitrary viewpoints and in arbitrary lowfrequency environment lighting in real time. The consequence is an algorithm that is capable of high quality rendering of animated characters in real-time.