Projector materials on particle systems?

I have an idea for a ghostbuster avatar with a slime-blower pack (from Ghostbuster’s 2), I can figure out most of the particle system but I’m trying to figure out a way to use a projector-like function for the ‘splatter’ that can cover objects and avatars. I’ve seen this function on a less-than-appropriate avatar (the nutter butter avatar) and am completely stumped about how to reproduce it so that I can cover things in glorious mood slime :slight_smile: