[Bf-funboard] Lurking for way to use drivers between layers rendering

[Ilja Razinkov]

Hello!

There is two great functionalities in Blender - drivers, to change
parameters in a smart way and RenderLayers to break up scenes in smart
way. But for now they are not playing together nicely: drivers are
evaluated at the beginning of frame, and not at the beginning of Layer
rendering.

Is there a way to change it? Or is it possible to tweak at source
level? To be specific, i need to change integrator parameters
according to rendered layer - in my case there is special layer for
glossy things, which needs one set of limitations, where others not.

Another useful case would be Seed change via renderlayer-aware driver,
to combine nice smoothed image in composer (and automatically, without
manual rerenders, etc). It would be also cool to change samples count
via driver, avoiding duplication of parameters. Current way of "this
option in renderlayer overrides main option on render tab" will
definitely explode UI after several iteration :)

So... can be drivers extended for that?

---
sincerely, Ilya Razinkov