Abstract:
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.
Keywords:
Final gathering, diffuse interreflections, glossy interreflections, GPU programming, HLSL,
globa illumination. .