This adds support for ngons and attributes on subdivision meshes. Ngons are
needed for proper attribute interpolation as well as correct Catmull-Clark
subdivision. Several changes are made to achieve this:
- new primitive `SubdFace` added to `Mesh`
- 3 more textures are used to store info on patches from subd meshes
- Blender export uses loop interface instead of tessface for subd meshes
- `Attribute` class is updated with a simplified way to pass primitive counts
around and to support ngons.
- extra points for ngons are generated for O(1) attribute interpolation
- curves are temporally disabled on subd meshes to avoid various bugs with
implementation
- old unneeded code is removed from `subd/`
- various fixes and improvements
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D2108
This is to prevent situations such as when the camera gets very close to a mesh
and causes it to be tessellated into an excessive amount of micropolygons. In
REYES this is known as the eye-splits problem.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D1922
NOTE: this is only the first of many patches towards completing the subdivison
and displacement system in Cycles. These patches will be reviewed and committed
one by one over the coming weeks.
Reviewed By: brecht, sergey
Differential Revision: https://developer.blender.org/D1909
Not the most memory efficient way to store these things but it's simple and
implementing it better requires some work to natively support subd grids as
a primitive in some way.
It was never fully implemented and will be replaced by OpenSubdiv. Only linear
subdivision remains now. Also includes some refactoring in the split/dice code,
adding a SubdParams struct to pass around parameters more easily.