Is there a node which allows the user to perform a custom function based on 2 RGB input values from different render layers?
For example, "if both pixels are red change to blue otherwise just add" would require a node with a formula:
if R1 == 1 and R2 == 1 and (G1, G2, B1, B2) < .1 then:
(Rout = 0, Gout = 0, Bout = 1)
(Rout = R1 + R2, Gout = G1 + G2, etc...)
If there is no such node could it be programmed?