A quick demo of the glsl shader I implemented for the Blender Game Engine to do real-time decal projection.
My implementation is based heavily on the method presented in a paper titled "Implicit Decals." Unfortunately, I don't know who authored the paper or where I found it but I'm sure it's somewhere out there on the Internet so you can find it if you want.
Sorry for the nasty quality, I still haven't ironed out all the bugs in my screen capture pipe yet.