- replace ptex indexing with the FarPtexCoord structure as a way to pass per-patch
ptex data to the shaders.
We are replacing a vector<int> arranged as :
int[0] : ptex face index
int[1] : (u,v) as 16 bits encoding the log2 coordinate of the top left corner
Instead we are now using a struct arranged as :
int[0] : ptex face index
int[1] : is a bit-field containing u,v, rotation, depth and non-quad
The u,v coordinates have been reduced to 10 bits instead of 16, which still
gives us a lot of margin.
- Replace OsdVertexBufferDescriptor with something more adequate for general
primvar representation (this name will probably eventually change...)
- Improve OsdPatchDescriptor
- add a "loop" boolean (true if the patch is of loop type)
- add a GetPatchSize() accessor
- OsdPatchArray :
- remove some redundant elements (still more to do there)
- Fix all shader / examples / regressions & stuff to make this all work.
fixes#143
2 client APIs are changed.
- VertexBuffer::UpdateData() takes start vertex offset
- ComputeController::Refine() takes FarKernelBatchVector
Also, ComputeContext no longer holds farmesh.
Client can free farmesh after OsdComputeContext is created.
(but still need FarKernelBatchVector to apply subdivision kernels)
This avoids adaptive tessellation artifacts near silhouette edges
by using the projected diameter of an edge's bounding sphere
rather than the length of the projected edge itself.
There is a nice writeup of this by Bryan Dudash of NVIDIA at:
https://developer.nvidia.com/content/dynamic-hardware-tessellation-basics
- [Feature Adaptive GPU Rendering of Catmull-Clark Surfaces](http://research.microsoft.com/en-us/um/people/cloop/tog2012.pdf).
- New API architecture : we are planning to lock on to this new framework as the basis for backward compatibility, which we will enforce from Release 1.0 onward. Subsequent releases of OpenSubdiv should not break client code.
- DirectX 11 support
- and much more...
