Digital Lighting & Rendering, Second Edition

CHAPTER FOUR: Lighting Environments and Architecture 113

[Figure 4.29]

Conventional radiosity

stores irradiance informa-

tion in polygon vertices.

Photon Mapping

The same kind of results that conventional radiosity calculates can also be

rendered via photon mapping. With this approach to global illumination, a

separate data type—the photon map—is created to store the global illumina-

tion solution. The resolution of a photon mapped solution is independent

from the resolution of the geometry.

The speed and accuracy of photon mapped global illumination depends

on the number of photons used. Extra photons take longer to compute, so

for quick test-renders ...