I'm trying to apply a normal map on a plane with two textures painted on it, but in a way that it's only applied to the second one. It's a really simple scene of a crossroad going through a field (for testing the normal map).
The thing is that I can't figure out how to apply the normal map so that it uses only the road texture and not the whole plane. I have done my researches about this problem with no luck, so I'd really appreciate any help.
Not sure if I'm using correct terms to describe this but here's a figure and link to the .blend file to give you a better idea what I mean.