Yea I think offsetting each channel might be to expensive in the shader instructions. So probably going to use an extra texture map. Just wish epic could add support for bump maps instead. I could just use one of the channel from another texture instead and save a texture call. Unless it's already supported and I am just…
http://www.youtube.com/user/OffsetSoftware#p/u/7/5KH7Wbi0clo Neat video from Project Offset, showing some vertex blending used on a building. Looks like they can paint vertex colors in-engine too. Also looks like they are using one of their RGB channels to provide some type of "darkening", probably just to make fake…