Real-time image rendering of diffuse and glossy objects in low-frequency
lighting environments captures soft shadows, interreflections, and
caustics. As a preprocess, a global transport simulator creates functions
over the object's surface representing transfer of arbitrary,
low-frequency source lighting into exiting radiance, but including global
effects like shadowing and interreflection from the object onto itself.
At run-time, these transfer functions are applied to the actual source
lighting. Dynamic, local lighting is handled by sampling close to the
object at 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. Functions for
radiance transfer from a dynamic lighting environment through a
preprocessed object to neighboring points in space further allow cast
soft shadows and caustics from rigidly moving casters onto arbitrary,
dynamic receivers.