I am with Bobby Stahr here. I saw your hint but when you say masked, do you mean masked to eliminate something else? Or just hook it into the mask input option? Or do you mean, I already hooked up the PF and that is the mask? Sorry, I am not stupid, just lots of nodes.
Suffice it to say, we all spent yesterday trying to replicate or imitate your rocks, or untangle our own messes.

So that should be flattery enough