Additive Alpha

I’d like to set a node so that it uses additive blending; that is, I want to add its color to the background rather than mixing it. Is there a simple way to do this? I tried fiddling around with the setTransparency function, but I couldn’t seem to get anywhere.

Use the ColorBlendAttrib instead of the simpler TransparencyAttrib. Since there’s not a convenience method on NodePath to control ColorBlendAttrib, you do it by hand like this: