This is just caused by a mismatch in the way your 3d software triangulates vs how Marmoset triangulates the mesh. You can export your mesh triangulated to fix this issue.
Hello, I am having an issue on my mesh where some of the faces on my mesh have problems (black surface). I used 3ds max for modeling and substance for baking. The bake in Substance, however, didn't have this issue. I also tried to use smoothing groups in Max but it didn't change the outcome. Any suggestions would be…