Ray Tracing Massive Amounts of Animated Geometry 49

We present a method for efficiently ray tracing large amounts of uniquely animated complex mesh-based geometry. A tetrahedral cage is used to split the original non-animated triangle geometry into disjoint sets of triangles. For each tetrahedron, an acceleration structure is built over its enclosed triangles, and a separate one over all tetrahedra. Instead of applying animation transformations to the actual triangular geometry, we apply them only to the tetrahedral cage and transform rays intersecting the animated tetrahedra. Only the acceleration structure over all tetrahedra needs to be rebuilt once per frame. The cost of animating geometry per frame depends solely on the resolution of the tetrahedral cage and is decoupled from the density of the original geometry. Our method targets animations that preserve triangle connectivity and approximates vertex motion by a piecewise-linear deformation induced by the tetrahedral cage. We demonstrate that our method outperforms competing animation approaches in both update time and memory consumption, enabling ray tracing of large amounts of animated complex geometry in real time on current generation GPUs.