This paper presents a fast approximation method to obtain the indirect
diffuse or glossy reflection on a dynamic object, caused by a diffuse or a
moderately glossy environment. Instead of tracing rays to find the incoming
illumination, we look up the indirect illumination from a cube map rendered from
the reference point that is in the vicinity of the object. However, to cope with
the difference between the incoming illumination of the reference
point and of the shaded points, we apply a correction that uses geometric information also stored in cube map texels. This geometric information is the distance between the reference point and the surface visible from a cube map texel. The method computes indirect illumination although approximately, but providing very pleasing visual quality. The method suits very well to the GPU architecture, and can render these effects interactively. The primary application area of the proposed method is the introduction of diffuse and specular interreflections in games.
Final gathering, diffuse interreflections, glossy interreflections, GPU programming, HLSL,
globa illumination. .