Material showing obvious seams from substance to UE4

gokitty199 · August 14, 2020, 5:04pm

MostHost_LA:

That harsh of a seam is usually an export with a sharp edge, or spliced geometry.

You can completely remove a sharp edge by using the exact same vertex normal of one seam on the other seam.
If for some reason the mesh can’t be whole, that is an important consideration.
Otherwise, merging one vertex onto the other.

the best way to check if the issue is the geometry or a material is to put a fully back or white (not specualr) materal on the mesh.
If the seam is still present you know that the smoothing group is off.

Should it be the material, first make double sure that your UV is properly split - with parts that are far enough apart.
second, make sure that your texture has a spill area that matches the same color overall.
usually you take the last pixel around the texture and stretchit out.
Repeat the same for the normal map, roughness, AO or any and all textures. Sometimes the seam is from something silly like the sub surface profile or the opacity (sub surf scattering).

Third, if you still aren’t happy with it, which is possible, you can bump up the values of the UV precision, as well with the values you can change on LODs or FBX import that deal with precision.

Aslo (not for OP but for the usual whiners), saying “blender doesn’t do it” doesn’t mean a thing. One is a DCC meant to work on high details, the other is a game engine. Even bumping up the detail you can’t really expect the same kind of rendering. In real time nonetheless.

Just tried with both a completely black and white material and the seam goes away entirely. I tried again by unwrapping the mesh again (without moving any of the islands around) and made sure there is no overlap or any verts going out of bounds (there was none on the old one either), then with using a different single smart skin material in substance i exported it out to UE and the same issue occurs where the seam is horrid.