I have tried to use Substance Painter with Blender.
Imagine to have a cylinder with some bumps and to cut it along one vertical line. You obtain an unwrapped horizontal rectangle in the UV map editor (I haven’t anymore this UV map to show you, but it’s extremely simple to imagine).
In Substance, I have done the Bake and the model looked correct there, so I added bumps, carvings ecc, but when exported and imported to Blender with tangent space (OpenGL) it showed the vertical seam VERY hardly, due to opposite orientation of the normal colors, since the unwrapping goes all around the cylinder but the flat normal maps can’t know it.
So, I solved it slicing the cylinder in 2 parts, by adding a new seam on the opposite side so that I obtained the “front” and “rear” separated UV maps, being able to flip one of them along the X axis to obtain a coherence with the normal red shading. And so, seams are disappeared.
Is this the right workflow? If yes, why do I continuously see tutorials where this stuff is not taken in consideration during the UV map creation?
Or is there a way to “force” the engine to process differently the normal map, in order to avoid seams? In Substance Painter viewer, in fact, seams are not visible in any case. So maybe there is a similar setting in Blender?