Lighting Design Glossary

The Radiance Software

The Radiance software is a distributed raytracing package developed by Greg Ward Larson, then at the Lawrence Berkeley National Laboratory (LBNL) in Berkeley, California.

The software implements a distributed, or "stochastic", raytracing method, which is optimized to simulate the diffuse distribution and propagation of light in the built environment.

Radiance is currently the most powerful and robust system for computing the effects of architectural lighting and daylighting, and can output images in photorealistic (or rather "photo accurate", as its author claims) quality. Consequently, the special image format used does not store subjective "brightness" values, but the actual luminance on all visible surfaces. Apart from that, Radiance can compute illuminance values at arbitrary points in space, which is useful to determine daylight factors and illuminance levels on the workplane.

Radiance is the simulation engine used in the Rayfront lighting design toolkit.