Visible seams on tangent normal maps I'm having a small issue with visible seams on normal maps. The map was painted on Substance Painter and has no weirdness around seams. When I plug it into a Normal Map node set to Tangent Space this happens:


(it's a horse underside)

When I set the map to Blender Object Space the seams become nearly invisible, as they should be, but the shadows also looks awful.



What can be done to minimize the issue? I need to be able to use maps on tangent space. Moving the seams or hiding them under other stuff isn't always feasible.
Substance offers two options for normal maps, DirectX and OpenGl. DirectX is the default (normally set when you first setup a project). The difference between the two is that the green channel is inverted from one to the other. Blender expects normal maps in the OpenGl format. 

There should be options in Substance Painter to export with the OpenGl format instead.

You may need to look at export presets to do this:
https://support.allegorithmic.com/documentation/display/SPDOC/Creating+export+presets