Towards Optimal Shift Mapping Heuristics for ReSTIR-SSS
摘要
When attempting to decompose a scene’s complex light interplay into separate subproblems, subsurface scattering becomes one of many effects that needs to be accounted for. In the realm of real-time 3D graphics rendering, this visual cue has long been relied on approximations for plausible results to be achieved owing to computational constraints. Most recently, the proposed ReSTIR algorithm [1] greatly advanced Monte Carlo ray-traced simulations of light-transport for computer graphics. To achieve plausible and computationally efficient subsurface light transport rendering via ReSTIR, two advanced shift-mapping techniques were proposed as part of the ReSTIR-SSS framework [2]. In this work, limitations of both techniques are discussed and the heuristics comprising the hybrid strategy’s criteria for primitive shift selection are re-evaluated. Additionally, noting error trends between material properties and shift mapping transformations, a simple and practical reparameterization of the hybrid scheme is proposed which demonstrates great promise in the pursuit of optimal light-path correlation.