I have very low poly models, nothing to really bake, and I want to add some details like scratches to a surface with a normal map. Or bump map?
I want to paint it in Photoshop and as it seems there are 2 methods I could use.
1- use a seamless map and just attach it as normal map in UE4. But what kind of map would this be? I only find those black/white maps with scratches. Aren’t these specular maps? I don’t want a wooden table or a wall to be shiny.
2- load the UV template of my model in Photoshop, add some scratches and use the Nvidia plugin to convert it to a normal map.
I think I’ll rather try 2, since I don’t want the scratches to be all over, only in certain places.
Now my question - I have in 3dsmax channel 1 for my texture. It’s a tileable texture I am using and the faces overlap on the whole map, so they just fit on the model. Also the back of the wall is on the front of the wall.
Channel 2 is my lightmap, here nothing overlaps.
Now I wonder if I can make a third channel for the normal map, because I want certain damage on the back of the wall, but not on the front, so I don’t want to use my first channel since here the faces overlap.
I would just load the UV template of the lightmap in Photoshop, paint it, convert it and use this as Normal Map since all faces are nicely separated. BUT - Can I tell UE4 which channel to use for the normal map? Can a model have different unwraps for different maps?
I hope my question is understandable.