This is also an important mathematical operation that can be folded
if it is known that one argument is a certain constant. For colors
the operation is provided as a Gamma node.
The SVM Gamma node needs a small fix to make it follow the 0 ^ 0 == 1
rule, same as the Power node, or the Gamma node itself in OSL mode.
Reviewers: #cycles
Differential Revision: https://developer.blender.org/D2263
These values often either turn the node into a no-op, or even make it
evaluate to 0 no matter what the other input value is, thus allowing
deletion of a branch of the node graph that otherwise is not constant.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D2085
These are complex nodes, and it's conceivable they may end up constant
in some circumstances within node groups, so folding support is useful.
Reviewed By: brecht
Differential Revision: https://developer.blender.org/D2084
