RGBA Blend for material nodes

(Sorry guys this was copied from the comp, vis and ren sub-forum, I foolish miss posted in the wrong forum :o)

Hi guys, I have been using material nodes for a little while now experimenting and loving it, so kl, the same sensation when I started to use the compositor more, adds a whole new depth to blender.

Anyway I know in the compositor that you can blend two sets of RGBA data in all of the standard blend types (mix, screen etc), but in the material nodes editor there is no option to do that, you can only blend RGB data together but it wont include their alpha channels. I know of course that there are the separate alpha sockets, but that is also true for the compositor.

I don’t even really need the other blend types, just a simple mix, but I was guessing that perhaps due to the fact that the alpha channel can effectively be dependent on the geometry that that may be a reason why there isn’t one (but then I also realised that the compositor too has access to some geometry data, perhaps not quite as much as the Mat Nodes but still ?)

I was thinking it may be possible to write a dynamic node to fufil this task, which I may have to end up doing but I did want to see if anyone new a way to blend RGBA channel in the Mat Nodes Editor anyway, thanks so much guys :smiley:

This question just cropped up again - is there any way to do it?

You can use a separate mixRGB node to mix between 2 alphas if you want.