Radiance is a set of tools which provide an advanced lighting simulation software package. It allows very detailed definition of materials' and light sources' properties through the use of advanced techniques like brdf and ies files, as well as a powerful mathematical scripting language, resulting in accurate renderings of scenes which are usually imported from CAD and 3D modelers. It uses the hybrid approach of Monte Carlo and deterministic ray tracing to achieve a reasonably accurate result in a reasonable time.
