Shifted UVs after FBX import

Hi everyone, I have a problem with UV’s.
Exporting my model from 3ds Max to Sketchfab, via FBX, results into a weird shifted UVs. The lighting map is thus displaced from the geometry and looks bad. I tried everything: tested the FBX by importing back in Max or in UE4 works fine. Exporting the same model from Max, via OBJ, also preserves the correct UVs. The problem appears only when I use FBX transfer, even with the Sketchfab plugin. Is this a known problem?
I put here the test model (where I used AO map instead of Diffuse just to show the issue better.)

Thanks in advance.


Thats because the back plane that is receiving the shadows has mirrored uvs. I personally dont use 3dsmax so I wouldn’t know how to fix that. But I think it should fix it if you unwrap that back plane as an entire island, instead of mirroring one side onto the other. In sketchfab if you inspect the model with the uv checker you can visibly see your tubes arent lining up.

Yes, you are right, I used mirrored UVs to save space in my textures. I will try your advice, thanks a lot!

Either that, or check and make sure your tubes are mirroring at the same point as the back plane.

Didn’t work.
Very strange things happens here. Seems to me that not the uvs were the problem, but the geometry itself. The mirror plane has to be at the midpoint between columns, and so it is, at least in Max. But here in Sketchfab, in wireframe mode I see that the right side of the plane is shorter that the left side. Thanks anyway, I have to do more tests.

Two more things I can think of is:
-Try applying the location/scale of your objects. Sketchfab may or may not be scaling an object back to its default 1 by 1 by 1 while you may have an object scaled up a bit.
-If you have a light source in the scene, it might be that the shadows/ao is being projected like a sphere. Switch to like an area light or something like that.

Call me crazy, but the left side looks a bit longer than the right.

Yes, the geometry was the problem. Instead of a long background plane with only two quads, I connect the columns one by one. Now everything is one object with no exaggerate long quads and the result is fine.

Thank you so much, you put me on the right way to solve this problem.

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