Making a flat "decal" texture? (stains, bullet holes, etc)

[legacy-The Toe]

Here's the skinny:

I'm making a "rats" style map (I know, I know...another one), and in certain spots on the carpet I'd like to make some stains.

The only way I know how is to make a copy of my original carpet texture and use Photoshop to add stains on the texture and then subtract a brush out of the carpet, and add the brush back in using that new carpetstain texture.

But surely there's got to be an easier way. I'd like to avoid any unnecessary extra polygons if I can. Not to mention, sometimes I'd like to increase the size of the stain texture without blowing up the detail on the carpet texture along with it, since it won't match up with the rest of the carpet after that.

Is there a way in UnrealEd to make a "decal"-like texture that you can slap on top of any existing textured brush?

[legacy-NiTrOcALyPsE]

Projectors.

All you need is a nasty stain texture with a transparent background projected onto the carpet. Projectors also have an option to destroy themselves as soon as the map starts, leaving the texture projected onto the surface, but not on players who inevitably will get in between the target surface and the projector itself.

The full documentation on projectors can be found here: http://udn.epicgames.com/Two/ProjectorsTableOfContents

[legacy-The Toe]

Awesome! Thanks, I'll start studying it.

[legacy-LoPing]

I've used projectors and the classic square-mesh-with-a-stain-on-a-transparent-background and have found the latter to be easier to impliment.

Anyone know the performance difference?

Of course projectors can do many more things, but if you just want to add some details here and there, a flat mesh usually suffices.

[legacy-The Toe]

Originally posted by LoPing
I've used projectors and the classic square-mesh-with-a-stain-on-a-transparent-background and have found the latter to be easier to impliment.

Anyone know the performance difference?

Of course projectors can do many more things, but if you just want to add some details here and there, a flat mesh usually suffices.

I agree with you, using a flat brush or mesh is easier to go with. But there's going to be quite a few, and this area of my map is already filled to the gills with meshes, and it's a big area. So I'd like to see if someone can answer your question about performance differences with using projectors. I'm trying to shave off unnecessary computations anywhere possible. Any takers?