Unexpected seams between symmetrical assets

Hi,

I’ve got some problems with an asset. When I duplicate and mirror it, an unexpected seams appears. Moreover the impact of lighting is changing.
Any idea on what’s going wrong ?

972d4b816b06b1cd1abfaa5502533beb6bf172e9.jpeg

Thanks.

Neither side looks correct to me–might be lightmapping issues.

Did you build lighting with only one side in the world, then duplicate it? Kinda looks like the left side has a lightmap and the right side is movable/preview lighting.

I think is because when you mirror a mesh, the normal map is flipped, you have to make a new material and flip the normal map (don’t remember what channels you have to invert). Fast test, apply a new material with only diffuse colour to check if this is the problem.

Seems like problem with normal map. How exactly you mirrored this model? When I mirror object in UE4 with negative scaling my normal map still works correctly

My guess is bad normal mapping on at least one side of the door.