programmable tesselation unit

What is a programmable tesselation unit?

Is it the old tesselator? I think it was called pn-triangles
Or this is the one and the same, geometry shader unit?

Currently I don’t think it does more than the good old Radeon 7000 pn-trinagles tesselator… The API it’s exposed neither in Direct3D neither in OpenGL… “Fixed tessellation unit” would be more appropriate so far.

However, I saw a great lecture during Siggraph 2007 demonstrating the possibilities of the tessellation unit with a terrain rendering demo based on a CLOD algorithm running on the GPU (a Radeon HD 2900). Very impressive!

Yeah, the programmable tessellator does indeed have intresting potential (more so when combined with the other programmable components of the GPU), it’s just a same no API is out there.

However, I do recall reading something about DX11 possibly requiring a programmable tessellator so in theory we’ll get it at some point.