View-dependent precomputed light transport using nonlinear Gaussian function approximations

We propose a real-time method for rendering rigid objects with complex view-dependent effects under distant all-frequency lighting. Existing precomputed light transport approaches can render rich global illumination effects, but high-frequency view-dependent effects such as sharp highlights remain a challenge. We introduce a new representation of the light transport operator based on sums of Gaussians. The nonlinear parameters of our representation enable 1) arbitrary bandwidth because scale is encoded as a direct parameter, and 2) high-quality interpolation across view and mesh triangles because we interpolate the mean direction of the Gaussians, thereby preventing linear cross-fading artifacts. However, fitting the precomputed light transport data to this new representation requires solving a nonlinear regression problem that is more involved than traditional linear and nonlinear (truncation) approximation techniques. We present a new data fitting method based on optimization that...

• Type: Conference
• Year: 2006
• Where: SI3D
• Authors: Paul Green, Jan Kautz, Wojciech Matusik, Frédo Durand
• Keywords: Complex View-dependent Effects, Computer Graphics, Precomputed Light Transport, SI3D 2006, View-dependent Effects