Surfels: Surface elements as rendering primitives

Surface elements (surfels) are a powerful paradigm to efficiently render complex geometric objects at interactive frame rates. Un-like classical surface discretizations, i.e., triangles or quadrilateral meshes, surfels are point primitives without explicit connectivity. Surfel attributes comprise depth, texture color, normal, and oth-ers. As a pre-process, an octree-based surfel representation of a geometric object is computed. During sampling, surfel positions and normals are optionally perturbed, and different levels of texture colors are prefiltered and stored per surfel. During rendering, a hi-erarchical forward warping algorithm projects surfels to a z-buffer. A novel method called visibility splatting determines visible sur-fels and holes in the z-buffer. Visible surfels are shaded using tex-ture filtering, Phong illumination, and environment mapping using per-surfel normals. Several methods of image reconstruction, in-cluding supersampling, offer flexible speed-quality tradeoffs. Due to the simplicity of the operations, the surfel rendering pipeline is amenable for hardware implementation. Surfel objects offer com-plex shape, low rendering cost and high image quality, which makes them specifically suited for low-cost, real-time graphics, such as games