Radiance

Radiance is a quantity in Physics (like voltage or length), specifying the amount of energy radiated in a given direction from a surface. Mostly used with non-ionizing, electromagnetic radiation in the visible spectrum ( light), ultra-violett (UV) or infrared (IR). More precisely, it's defined as radiated power over solid angle and "projected" area... , the SI unit being [Watt/(m2 sr)]. Other websites (not related to us) with info on Physics and Optics: hyperphysics.phy-astr.gsu.edu has a nice overview, and en.wikipedia.org/wiki/Radiance has the math. What is the Radiance lighting simulation tool ? Radiance is also the name of a physically based rendering package written largely by Greg Ward, initially at LBNL, EPFL, then SGI, now running Anyhere Software . It is a physically-based, image-generating, backward raytracer with very a powerful rendering engine. It is used worldwide for lighting analysis and can generate accurate values for radiance/luminance (W/sr.m?,cd/m?) and irradiance/illuminance (W/m,Lux).Read More