We implement Monte Carlo-based parallel ray tracing to achieve quick irradiance evaluation for freeform lenses with nonuniform rational B-splines(NURBS)surfaces.We employ the inverse transform sampling method to sampl...We implement Monte Carlo-based parallel ray tracing to achieve quick irradiance evaluation for freeform lenses with nonuniform rational B-splines(NURBS)surfaces.We employ the inverse transform sampling method to sample rays uniformly from the Lambertian light source and adopt the analytical form of the B-spline basis function to achieve fast surface interpolation.When performing parallel calculations for the intersections between the rays and the NURBS surfaces,we propose a parameter transformation method to avoid the parameters escaping from the defined range in the iteration process.Simulation results of two complex picture-generating freeform lenses show that our method is fast and effective.展开更多
基金supported by the National Key Research and Development Program of China(No.2017YFA0701200)the National Natural Science Foundation of China(No.11704030)the CAAI-Huawei MindSpore Open Fund(No.CAAIXSJLJJ-2021-014A)。
文摘We implement Monte Carlo-based parallel ray tracing to achieve quick irradiance evaluation for freeform lenses with nonuniform rational B-splines(NURBS)surfaces.We employ the inverse transform sampling method to sample rays uniformly from the Lambertian light source and adopt the analytical form of the B-spline basis function to achieve fast surface interpolation.When performing parallel calculations for the intersections between the rays and the NURBS surfaces,we propose a parameter transformation method to avoid the parameters escaping from the defined range in the iteration process.Simulation results of two complex picture-generating freeform lenses show that our method is fast and effective.
