Fachbereich Informatik

Kautz

Kolloquium am 10.06.2002



Precomputed Radiance Transfer for Real-Time Rendering in Dynamic, Low-Frequency Lighting Environments


Dr. Jan Kautz
(MPI fuer Informatik/Saarbrücken)

We present a new real-time method for rendering diffuse and glossy objects in low-frequency lighting environments that captures soft shadows, interreflections, and caustics. As a preprocess, a novel global transport simulator creates functions over the objects surface representing transfer of arbitrary, low-frequency incident lighting into transferred radiance which includes global effects like shadows and interreflections from the object onto itself. At run-time, these transfer functions are applied to actual incident lighting. Dynamic local lighting is handled by sampling it close to the object every frame; the object can also be rigidly rotated with respect to the lighting and vice versa. Lighting and transfer functions are represented using low-order spherical harmonics. This avoids aliasing and evaluates efficiently on graphics hardware by reducing the shading integral to a dot product of 9 to 25 element vectors for diffuse receivers. Glossy objects are handled using matrices rather than vectors. We further introduce functions for radiance transfer from a dynamic lighting environment through a preprocessed object to neighboring points in space. These allow soft shadows and caustics from rigidly moving objects to be cast onto arbitrary, dynamic receivers. We demonstrate real-time global lighting effects with this approach. frequency lighting environments, using a low-order spherical harmonic (SH) basis to represent such environments efficiently without aliasing. The main idea is to represent how an object scatters this light onto itself or ist neighboring space.

Termin : Montag, 10.06.2002, 17.15 Uhr
Raum : Gebäude 46, Raum 280