Light beam tracing is an e cient rendering algorithm for simulating caustics,the envelopes of light that are scattered from shiny curved surfaces and focussedinto lines or spots of concentrated light. Light beam tracing is e cientfor rendering caustics because the algorithm is able to exploit the coherencyof the transport paths within an envelope of light. However, light beamtracing rendering algorithms found in the literature only support mirror-likespecular surface interactions. Therefore, there is motive for extending lightbeam tracing to include more realistic roughened specular and other glossysurfaces while maintaining the e ciency of the rendering algorithm.This thesis rst o ers a conjecture on how to extend light beam tracing toinclude glossy surface interactions. The glossy bidirectional reectance distributionfunction (BRDF) that is required to support the conjecture is thenderived and shown to be physically plausible. Following from the conjecturea new extension to light beam tracing that allows glossy surface interactionsfor more realistic rendering of caustics is formulated.Gauss' divergence theorem is used to replace the irradiance surface integralof the lighting equation with a more e cient boundary line integral. Thissolution is also shown to be reusable for all-frequency interactions althoughmore work is required to complete the derivations.Finally, multi-bounce glossy light beam tracing is demonstrated whichfurther extends the application domain of glossy light beam tracing. Thenew rendering algorithm is shown to be a good alternative for renderingsingle-bounce and multi-bounce caustics due to specular as well as glossysurfaces. The expectation is that the irradiance solution would also in futurebe useful for more general applications.
展开▼
