GPU-Based Rendering of PN Triangle Meshes with Adaptive Tessellation

Numerous approaches to describe curved surfaces have been proposed in computer graphics. Basically all of them require the generation of an appropriately refined triangle mesh for rasterizationbased rendering characteristic of current-generation GPUs. In this paper we deal with PN triangles as surface primitives and render them with GPU-resident refinement patterns obtained by successive 1-to-4 splits of a generic triangle. The actual pattern and hence the subdivision level is chosen on a perprimitive basis by means of a novel screen-space error metric, yielding an adaptive tessellation according to the viewing situation with vertex position computations being performed solely on the GPU. To avoid visible cracks in the resulting mesh, stitching is performed by rendering appropriate connection patterns. These also help to close holes inherent to the PN triangulation of coarse base meshes with corner-like features.