Why do my uv seams on my model create visible seams in substance painter even if layer has no textures. only channel values, or even if my model has no layers at all
To add to the above : The fact that shading seams may show in Substance Painter is 100% irrelevant, since Substance Painter is (obviously) not your target game engine, and likely not the context in which you'll capture your final renders either. Based on your screenshots alone it looks like your model was not triangulated…