Mainly the changes are related on establishing API to feed UV islands
to OpenSubdiv, so it will know all the connectivity information and
will be able to do proper interpolation.
Island calculation is currently rather slow, not sure how to make it
fast and not use lots of allocations.
Shouldn't be THAT bad, since this code is only runs once when creating
OSD mesh, and it's probably still faster than our orientation code.
A bit work in progress, currently the following limitations:
- Texture shading only, Material shading will come later
- No UVs subdivision yet
- Always uses active UV and currently changing active UV will
not properly update the viewport.
Well, need to start somewhere :)
Now the conversion code uses mesh element mapping to speed up lookups.
Gives really nice speed improvement here, but the cost is higher memory
usage during refiner construction.
On the dragon scene here topology refiner construction time goes down
from 5 seconds to around 0.01.
It's possible to reduce the memory footprint by allocating mapping in
stages (don't allocate all of them at once, but do it on demand only
and free them after they're not needed anymore).
Those files are still not in use (SCons will tyr to compile new CCGSubSurf files
but no code will be in use at all because those new files are fully wrapped by
ifdef WITH_OPENSUBDIV check).
