Measuring and Modeling Complex 3-D Light Sources

This paper presents a method that, based on a field-theoretic approach to photometry, accurately and efficiently measures and models arbitrarily complex three-dimensional light sources. It allows the prediction of direct illuminance at any point on any surface anywhere within the surrounding 3-D space without requiring any knowledge of the geometry of the source or its distance from the surface being illuminated. The method is easily integrated with ray tracing techniques and radiosity methods, including multiprocessor implementations. NOTE: this is a revised version of a paper called “Modeling Complex 3-D Light Sources” that was presented in ACM SIGGRAPH ‘93 Course 22 Notes, “Making Radiosity Practical.”