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Running into problems using the UV "Fold Method" UE4

Hello fellow creators!

Through tutorials, online guides, and other things, I’m trying to teach myself how to create assets for use in UE4, and have had pretty decent results without running into too much trouble. That is, until now.

I’m working on a scene that calls for a lamp post, so I made one in Maya. I’m using a normal map to add some details to it. Here’s the bottom of it: http://i.imgur.com/9SFp2gV.png

This is what the same asset (with a red material on it, to make the issue pop out a little more) in UE4: http://i.imgur.com/k5M3RvY.png

As you can see, even though the material is a flat color, the coloring on the faces is inconsistent. I first figured this was a light-map issue, but it wasn’t Is appears to be an issue with the method I used to map the asset’s UVs (the highlighted bit in the picture is the post’s base): http://i.imgur.com/xmIkGyZ.png

To test my theory that it was an issue with the UVs, I made a tessellated plane and mapped it using the folding method, and then brought it into UE4. The one on the left is using default mapping, and the one on the left is folded: http://i.imgur.com/l2hcWuC.png

I know it’s the issue, but I don’t understand why it’s the issue. From my understanding, the “fold method” is pretty widely used, and I can’t find anyone else online that seems to be having this problem. Any ideas on how to fix it?

Hello Megamansalzar!

Did you check the normals on your model before you imported to UE? I am guessing its an issue on how you moved or “folded” the UVs. Almost like some of the UV are flipped.

Few things to check, first, does the object have a second lightmap channel set of non-overlapping UV’s? If not, those are the exact kind of issues you will see when you build lighting.

Also check you imported your mesh smoothing groups from Maya (should do this automatically anyway. Also can we see the normal map and also the material?