Real-Time Stochastic Rasterization on Conventional GPU Architectures

This paper presents a hybrid algorithm for rendering approximate motion and defocus blur with precise stochastic visibility evaluation. It demonstrates---for the first time, with a full stochastic technique---real-time performance on conventional GPU architectures for complex scenes at 1920x1080 HD resolution. The algorithm operates on dynamic triangle meshes for which per-vertex velocity or corresponding vertices from the previous frame are available. It leverages multisample antialiasing (MSAA) and a tight space-time-aperture convex hull to efficiently evaluate visibility independently of shading. For triangles that cross z=0, it fall backs to a 2D bounding box that we hypothesize but do not prove is conservative. The algorithm further reduces sample variance within primitives by integrating textures according to ray differentials in time and aperture.