Projecting Decals

[RobertMtx]

So this is probably an unusual question. Are there any utilities in PhysX to assist with projecting decals onto triangle meshes? In my engine, I've always used my collision meshes to generate decals when their rendered counterparts are struck by things like bullets or blood spatter. When a decal is generated, I use the "projection quad" to cut the polygons out of the struck mesh, fix the resulting UVs, then use that as the decal itself. Now I'm switching to PhysX collision meshes, and will have to redesign this system a little.

Are there any utilities that assist with things like uv/quad/triangle projection, clipping, etc.?

How in the world do other games do this stuff? Does anyone know how Unreal does it? Do they keep system memory versions of all of their render meshes around for this kind of thing? Or do they use their collision mesh counterparts?