Can a decal material be used with Vertex paint the same way a regular material can? I made some graffiti decals, and wanted to add a way to paint parts of them out so that I could get more mileage from one material, but since the decal basically rests "on top" of the geo it doesn't appear to be letting me paint it. Is it…
So how do you paint it? I only know how to use the "Mesh Paint" brush, and I can't even paint on a decal on that since there is no Mesh I guess to paint on?
You wont be able to paint the textures behind the decal onto the decal to make it fade away but you should be able to blend off the decal from showing to not showing. Example. White is 100% showing decal, black is 0% showing decal (ie 100% alphaed out) and then paint away parts you dont want.
What you could try, is making a plane with enough verts to allow for vertex painting, apply your graffiti texture and mask to this and float it as close as possible to the wall without producing z fighting, and set it to not cast shadows. Then you should be able to do what you're wanting to do.