Compact Rectilinear Grids for the Ray Tracing of Irregular Scenes

Abstract

Regular grid spatial subdivision is frequently used for fast ray tracing of scanned models. Scanned models feature regular sized primitives, with a regular spatial distribution. Grids have worse performance, than other subdivision techniques, for irregular models without these characteristics. We propose a method to improve the performance of grids for rendering irregular scenes by allowing the individual placement of grid split planes: the rectilinear grid. We describe how to construct and traverse a rectilinear grid. To exploit cache memory in modern processors compression is used for the split plane and grid cell data. We demonstrate in a series of tests that the method has faster ray tracing rendering performance than a compressed regular grid of similar dimensions.