Material Node trees:
SSS wasn't displaying in Nodes.
Implementation notes:
- Currently copying local data for preview render, only copies
the base material. Node materials are re-used.
- This causes data to be in 2 "main" databases... complex.
- To make it work for preview, I had to add another loop in the
SSS code that checks the original Main dbase. That's marked
as warning in code to be fixed up.
Another bug:
- Material properties "SSS presets" copied settings to the
active material, not to the displayed one. Added RNA call
to retrieve this from Objects.
(Next commit will fix preset scripts)
6b1258f5b8