Can someone please give me a short rundown of how the mix node handles alpha?
I have two render layers, one which is opaque in the lower half and transparent in the upper half and one with the opposite. I try to use the mix node to combine the images but it does not work as I expected. Doesn’t the mix node take alpha values into account?
I actually can achieve the correct result using an alpha over node, but I would like to understand why the mix node does not work.
Also, the reason for splitting the render layers (in case someone wonders) is to make the cloud (gray image) fade with z-values. I manage to do so by using the z-buffer, a normalize node, a color ramp and a set alpha node.