Adaptive mesh subdivision for precomputed radiance transfer

Abstract

In precomputed radiance transfer (PRT), the radiance transfer operator is precomputed on vertices of a mesh. During rendering the transfer operator is combined with illumination to produce global illumination effects at real-time frame rates. However, visible error can be introduced by interpolating the transferred radiance be-tween vertices. We propose to adaptively subdivide meshes with PRT in order to avoid the interpolation er-ror. The mesh density is increased where the transferred radiance can change rapidly and introduce high error. We exploit the fact that the illumination frequency in PRT is bounded to perform the subdivision in preprocess. This obviates the need for dynamic mesh subdivision at render-time. The adaptive subdivision is guided by an error measure based on the transfer operator