Hierarchical Higher Order Face Cluster Radiosity for Global Illumination Walkthroughs of Complex Non-Diffuse Environments

We present an algorithm for simulating global illumination in scenes composed of highly tessellated objects with diffuse or moderately glossy reflectance. The solution method is a higher order extension of the face cluster radiosity technique. It combines face clustering, multiresolution visibility, vector radiosity, and higher order bases with a modified progressive shooting iteration to rapidly produce visually continuous solutions with limited memory requirements. The output of the method is a vector irradiance map that partitions input models into areas where global illumination is well approximated using the selected basis. The programming capabilities of modern commodity graphics architectures are exploited to render illuminated models directly from the vector irradiance map, exploiting hardware acceleration for approximating view dependent illumination during interactive walk-throughs. Using this algorithm, visually compelling global illumination solutions for scenes of over one million input polygons can be computed in minutes and examined interactively on common graphics personal computers.