A Comprehensive Light-Source Description for Computer Graphics

For realistic simulation, light source descriptions require definitions of the geometry, the spectral distribution, and the spatial distribution of the luminous intensity. A procedure is described in which these light source characteristics are defined, and the resultant intensity computations are integrated into a testbed ray-tracing system. Point, linear, and area light sources are considered. Results are shown which account for the spectral distribution and illustrate the directional dependence of the intensity calculations. The procedures are applicable to environments of unlimited complexity. Light sources can be arbitrarily placed within the environment and contained within the simulated image.