The normal maps are guided by the objects UV’s. Rotating one of the parts and combining the objects should not cause any problems.
There’s world space normal maps that will have issues when rotated and object space normal maps that look the same as world space, but offsets get added for rotation when they are used. These are very rare because the textures requirements are larger, they don’t support deformation, aren’t as flexible with stacking UVs, and don’t work well for tiling textures or trim sheets. You may see them rarely used in some tech art situations. These generally have a pink, green, purple rainbow of colors instead of the tangent space normal map purple.
Tangent space normal maps, generally just referred to as normal maps since it’s what you’ll see 99% of the time. Tangent space normal maps use a tangent based on the vertex normal and vertex UV (U direction). This makes importing tangents into UE and triangulating you mesh before baking important, which aren’t needed with world/object space. Otherwise you might get some incorrect shading or UV seams. These textures compress much better in memory and work where there’s deformation with characters, spline meshes, etc. And as said previously, tiling textures and trim sheets.
Thanks for the help guys. I understood.
So I can cut, rotate and join vertices and it wouldn’t be a problem, right?
If it’s in tangent space then all should be good.
Probably want to lock the normals or smoothing if you can, unless you’re going to rebake the normal map.
This is a texture-based modeling process.
The modeling was done by hand based on a scanned texture, but the embossing material was problematic. That’s why it was modeled three-dimensionally by hand. That’s why I can’t generate Bake. Unfortunately.
You could use software like substance B2M that can convert normal textures to bump / normal maps though built in extraction algorithms. I’m sure there are also open source alternatives.
