# Getting overlapping UV Error as soon as I mirror mesh to the opposite side

**URL:** <https://forums.unrealengine.com/t/getting-overlapping-uv-error-as-soon-as-i-mirror-mesh-to-the-opposite-side/334556>\
**Category:** Asset Creation\
**Tags:** overlapping-uvs, unreal-engine, question\
**Created:** [October 7, 2015, 5:01pm UTC](https://forums.unrealengine.com/t/getting-overlapping-uv-error-as-soon-as-i-mirror-mesh-to-the-opposite-side/334556 "2015-10-07T17:01:44Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![geistXIII](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@geistXIII](https://forums.unrealengine.com/u/geistXIII)\
**Post date:** [October 7, 2015, 5:01pm UTC](https://forums.unrealengine.com/t/getting-overlapping-uv-error-as-soon-as-i-mirror-mesh-to-the-opposite-side/334556/1 "2015-10-07T17:01:44Z")

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I’m pretty new to Unreal 4, so not sure if I’m missing the obvious. I’m trying to create a coordior with windows to the left and right. As long as I only build them on one side of the corridor, it works fine. As soon as I duplicate the same set up for the other side of the corridor, I get following error:

Object has overlapping UVs  
Lightmap UV are overlapping by 5.5%. Please adjust content - Enable Coloroing to visualize.

The set up contains windows with colored shadows (I made the material according to this tutorial: [A new, community-hosted Unreal Engine Wiki - Announcements - Unreal Engine Forums](https://wiki.unrealengine.com/Colored_Shadows)). Has anybody an idea what I’m doing wrong?

 ![](https://d3kjluh73b9h9o.cloudfront.net/original/3X/c/8/c8ced04a40a5c47cc810dabb81d4ccea7c3031a8.jpeg)

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**Author:** ![geistXIII](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@geistXIII](https://forums.unrealengine.com/u/geistXIII)\
**Post date:** [October 7, 2015, 8:50pm UTC](https://forums.unrealengine.com/t/getting-overlapping-uv-error-as-soon-as-i-mirror-mesh-to-the-opposite-side/334556/2 "2015-10-07T20:50:58Z")

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Not sure what caused the error, but I removed the glass plane from the mesh and added it as separate mesh. Seems like the plane effed the UVMap up somehow. No idea why the error only showed up, when I had the windows on both sides though.