A Virtual Light Field for Propagation and Walkthrough of Globally Illuminated Scenes
Pankaj Khanna, Mel Slater, Jesper Mortensen, Insu Yu
Abstract:
This paper describes an algorithm that provides real-time walkthrough for
globally illuminated scenes comprising of ideal diffuse and specular polygonal
surfaces. A type of light field data structure is used for propagating radiance
outward from light emitters through the scene and accounts for all L(S|D)* light
paths. The light field employed is constructed by choosing a regular point
subdivision over a hemisphere, to give a set of directions, and then
corresponding to each direction creating a rectangular grid of parallel rays.
Each rectangular grid of rays, called a ‘parallel subfield’ is further
subdivided into rectangular tiles, such that each tile references a sequence of
2D “images” containing colour values corresponding to the outgoing radiances of
surfaces intersected by the rays belonging to that tile. Following propagation,
this structure is used for final image rendering. Propagation times are
currently very long and the memory requirements high. This algorithm, however,
offers a global illumination solution for real-time walkthrough even on a single
processor.
Media:
The paper (1.9MB)