1. Patch-based Tessellation for Dual Subdivision on GPU
Fengtao Fan1 Fuhua (Frank) Cheng1
1University of Kentucky, USA
【OVERVIEW】
【RESULTS】
Models are fully reevaluated to depth 5 after deforming control meshes. Real time performance for moderate meshes;
Implemented by CUDA on a GeForce 8800 GT GPU(512M) card.
Subdivision surface tessellation on GPU
Patch-based method
Local, space and time efficiency;
Catmull-Clark, Loop, well developed;
Doo-Sabin Vs. Catmull-Clark, Loop etc.
One patch per vertex; per face;
1D array for storing patches; D array;
No numerical roundoff gaps; with gaps;
One subdivision needed for preprocessing;
(a) 298 patches at 14fps
【ALGORITHM】
Each vertex corresponds to a patch;  
(b) 354 patches at 19 fps
Two key operations:
Extract faces from the array:
Vertices and faces organized as layers;
Faces: corner, virtual corner or regular quad;
Vertices: corner vertex  a corner & regular quad; regular vertex  a regular quad;
(c) 505 patches at 14 fps
Store new faces back to the array:
i-th face layer  (2i)-th face layer in refined mesh;
(d) 66 patches at 56 fps
Given subdivision depth d ( 2), this procedure is performed d 1 times:
For each vertex , extracting faces:
One corner and regular quad for corner vertex ;
One irregular face and regular quad for virtual corner vertex;
One regular quad for regular vertex;
Subdivide extracted faces
Store back
Subdivide the most inner face and store back
(e) 314 patches at 14 fps