I’ve rendered a scene in Yafray with some characters flying around. I’ve taken the same scene and rendered a billowing cloud of smoke using Blender’s particles. I want to superimpose this smoke onto the Yafray render in such a way that the characters flying around fly in front of the billowing smoke.
I thought the way to do this was to render the characters with a black shadeless material and render as a series of RGBA files, but that isn’t working.
What kind of material do I have to give the foreground characters so that they mask out the background smoke when the scene is composited?