NVIDIA Corporation
Ray-guided water caustics

Abstract:

Raytracing can be used to generate high quality, physics-based water caustics patterns in real time. A caustics map is generate to represent locations and normals of points across a water surface. Rays from a light source that are reflected and refracted from these points, as determined by the locations and normals, and can generate hit points on a surface. Neighboring points can be used to help determine the resulting caustics pattern. In one embodiment, information for neighboring points in the caustics map can be used to generate scale factors for geometric regions to be projected onto the surface for each hit point. In another embodiment, these points serve as vertices of a caustic mesh that can be projected onto the surface, where the brightness at a primitive is determined by the size of the primitive area defined by the vertices of the caustics mesh.