- Catmull-Clark subdivision is standard for smooth surfaces in offline rendering, used in film since 1997.
- It refines meshes recursively, allowing artists to sculpt low-poly meshes and subdivide during rendering.
- Key innovation in new approaches splits the problem into tessellation and subdivision calculations.
- Feature-adaptive subdivision focuses tessellation only around irregular vertices, reducing workload.
- Bicubic B-Splines allow analytical evaluation on regular quads; semisharp edges can also be handled analytically.
- OpenSubdiv precomputes stencil tables for efficient deformation, avoiding per-frame subdivision.
- New algorithm uses irregular subdivision rings stored at first level, computed on-the-fly for finer levels.
- Primitives are categorized into Regular, Subdiv 1, or Subdiv 2 regions; triangles require double subdivision.
- Adaptive tessellation concentrates triangles in high-curvature areas, improving efficiency and visual quality.
- Performance tests show adaptive compute tessellation can match or exceed Edge-Friend efficiency on comparable hardware.