# Lightmap. Black lines appear where geometry is

**URL:** <https://forums.unrealengine.com/t/lightmap-black-lines-appear-where-geometry-is/328356>\
**Category:** Rendering\
**Tags:** unreal-engine, Lightmap, question\
**Created:** [August 11, 2015, 9:04pm UTC](https://forums.unrealengine.com/t/lightmap-black-lines-appear-where-geometry-is/328356 "2015-08-11T21:04:52Z")\
**Posts on this page:** 1\
**Showing post:** 7

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**Author:** ![anonymous\_user\_cc69b907](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_cc69b907](https://forums.unrealengine.com/u/anonymous_user_cc69b907)\
**Post date:** [August 17, 2015, 7:55pm UTC](https://forums.unrealengine.com/t/lightmap-black-lines-appear-where-geometry-is/328356/7 "2015-08-17T19:55:02Z")

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Hi PsychicFreak,

I was able to reproduce this issue in UE4.

I am going to link you our lighting troubleshooting guide as well as a guide that gives a great, in-depth, explanation on how to set up lightmaps for UE4 and how they are intended to work.

Link to Troubleshoot :

> **[A new, community-hosted Unreal Engine Wiki](https://forums.unrealengine.com/t/a-new-community-hosted-unreal-engine-wiki/141494)**
>
> After over a year in maintenance mode, the official Unreal Engine Wiki is now permanently offline. These resources now live on a new community-run Unreal Engine Community Wiki — https://unrealcommunity.wiki/! You will be able to find content from...

Link to Light Maps,

> **[Understanding Lightmapping in Unreal Engine](https://docs.unrealengine.com/5.1/en-US/understanding-lightmapping-in-unreal-engine/)**
>
> Techniques and guidelines for setting up lightmap UVs for Static Meshes.

There are a few things you can do to increase the calculation of your lightmaps.

1.) Min Lightmap Resolution,  
2.) Engine Scalability Settings,  
3.) Amount of Illumination on the object.  
4.) Project Settings \> Rendering \> Generate Mesh Distance Fields

Have a look at the documentation and try and see if any of these are a viable solution to your project.

Thanks,

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