Applying Smart Material Turns One Area of Normal Map Dark Grey

ImsumDave

I've been trying out the texturing tools in Toolbag 4. I am woefully behind on the smart material and painter type texturing process, and I am trying to get familiar. Unfortunately I've run into a problem that I am clueless as to it's cause. When I apply any smart material included with toolbag 4, my normal map goes grey in one area. My input maps look normal and have no issues. The area in particular is completely flat and floating unattached to other geo. Any idea what is causing this?

ImsumDave

Ok, I fixed it 5 minutes after posting. For anyone else having this problem here is what fixed it: I made the geometry nonplanar. This piece of geo is a circle with a vert in the middle which I shifted down so the circle is not completely flat. 

EarthQuake

@ImsumDave thanks for the report, could you email support@marmoset.co with a copy of this scene so we can debug this problem? The easiest way to do this is to go to File > Export > Scene Bundle

ImsumDave

@EarthQuake
I tried to reproduce the issue, as I don't have the files as they were when the problem occurred. At first I was not able to, which lead to me discovering what may be the actual issue. Before posting the thread, I tried mirroring the UVs in that area, this didn't seem to have an effect. However going back over things, the appearance of dark grey normals seems to be dependent on the mirroring of the UV island in that area. I think I mirrored the UV island, tried to re-export, re-bake, and re-apply the smart material, but for whatever reason the exported mesh with the UV change didn't make it into marmoset properly before hand. Out of ideas, I posted the thread. I then nudged the mesh out of planar and re-exported, at which point the fixed UVs came along too, and the issue went away. Is this behavior unexpected and would it be defined as a bug? I can still send the scene over if so.

Edit: To clarify, when I say I am mirroring UVs what I am doing is using "mirror X" command in the blender UV editor, which I think is equivalent to flipping in the horizontal. After more playing around with it, it seems both flatness and UV mirroring have an effect. Planar and unmirrored = dark grey, nonplanar and unmirrored = all good, planar and mirrored = all good. I'll send the file over.