Depth-presorted triangle lists

Abstract

We present a novel approach for real-time rendering of static 3D models front-to-back or back-to-front relative to any viewpoint outside its bounding volume. The approach renders depth-sorted triangles using a single draw-call. At run-time, we replace the traditional sorting strategy of existing algorithms with a faster triangle selection strategy. The selection process operates on an extended sequence of triangles annotated by test planes, created by our off-line preprocessing stage. Based on these test planes, a simple run-time procedure uses the given viewpoint to select a subsequence of triangles for rasterization. Selected subsequences are statically presorted by depth and contain each input triangle exactly once. Our method runs on legacy hardware and renders depth-sorted static models significantly faster than previous approaches. We conclude demonstrating the real-time rendering of order-independent transparency effects.