Blender Git Loki

Fix T55062: Depsgraph: Crash with COW with EEVEE viewport

We now remove the shader for every update.

So at the moment the whole point of UBO (Uniform Buffer Objects) is that they
are more efficient than individual uniforms.

Next steps is a harmless refactor to stopping UBO from referring to original
data in the UBO, and simply copying it.

It would also be interesting to make the final shader more granular as far as
the library and required functions are concerned. Even if this doesn't impact
performance, it should give us smaller easy to debug shaders
(a simple shader now has > 5k lines!).

If performance for animated values is measureable slower after this commit we
can port the shader creation CPU side to the depsgraph - localizing the tree,
hashing, lookup, ...

Additionally we can stick to update the UBO when the material changes but not
its topology. This is very trick because of localized trees. So we will only
re-visit this if profiling hints at any benefit from it.