Simulation of scattering from optical surfaces is usually based on Monte Carlo methods in which the bidirectional scattering distribution function (BSDF) of the optical surfaces are sampled randomly by many rays, resulting in long calculation times. In order to accelerate the simulation, a quasi-analytical phase space model is proposed. In this model, few rays are traced from the object and image space to the target surface to determine the illumination and acceptance areas in phase space, where these areas can be conveniently coupled simultaneously in the spatial and angular domain. Since no random sampling is involved in the phase space model, no statistical noise perturbs the result and the surface scattering simulation can be greatly accelerated. Additionally, due to the use of real raytracing, the phase space model removes the limitation of paraxial approximation, which usually limits the accuracy of deterministic stray light analysis models. Meanwhile, by the discretization of the optical surfaces into subareas, this new approach is able to model freeform surfaces with arbitrary geometries, and space-variant BRDFs can be applied for different subareas of the optical surface.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.