# Lightmap artifacts and normal maps

**URL:** <https://forums.unrealengine.com/t/lightmap-artifacts-and-normal-maps/1397477>\
**Category:** Rendering\
**Tags:** normal-map, limitation, artifacts, unreal-engine, Lightmap, question\
**Created:** [November 17, 2023, 2:07pm UTC](https://forums.unrealengine.com/t/lightmap-artifacts-and-normal-maps/1397477 "2023-11-17T14:07:58Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![GIS3000](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@GIS3000](https://forums.unrealengine.com/u/GIS3000)\
**Post date:** [November 17, 2023, 2:07pm UTC](https://forums.unrealengine.com/t/lightmap-artifacts-and-normal-maps/1397477/1 "2023-11-17T14:07:59Z")

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Hi, Unreal newbie here. I’m having issues with lightmap artifacts even thou the normal maps look perfect on my models.

- I have **Use Normal Maps for Static Lighting** checked.

- Lightmap compression is turned **off**

- Changing the **Overridden Light Map Res** does very little. I tend to set it to 256 or 512.

-Here are my World Settings/ Lightmass settings.

 ![Screenshot 2023-11-17 151337](https://d3kjluh73b9h9o.cloudfront.net/original/4X/a/d/6/ad65b6f259339f2f7b47fec04853400350591c5a.png)

- Below are some examples.  
LightMap with Nmap (Bad black seam):  
 ![Lightmap01](https://d3kjluh73b9h9o.cloudfront.net/original/4X/6/6/7/667319c6f38f5bb7e40f4a22d990ff3cb5e83149.jpeg)

Nmap Only (Looks Good):

 ![Nmap01](https://d3kjluh73b9h9o.cloudfront.net/original/4X/3/0/d/30d875a4acd6bc33d0821d25d39090a073222dc4.jpeg)

Base Mesh only:

 ![BaseMesh01](https://d3kjluh73b9h9o.cloudfront.net/original/4X/3/8/6/38662ad63b4fc6b4e15186860dd3208322b70036.jpeg)

Below are some examples for a simple cube. Some edges are made hard while others are soft to avoid Normal map artifacting.

Nmap Only (Looks good):

 ![Nmap02](https://d3kjluh73b9h9o.cloudfront.net/original/4X/4/0/5/4059b335be578ea7b9fd2b5bdb0cdc9b86d4999d.jpeg)

BaseMesh:

 ![BaseMesh02](https://d3kjluh73b9h9o.cloudfront.net/original/4X/e/d/e/ede6557f57cb1d61bf9ed626052f49092769d03f.jpeg)

Lightmap with normal map (Unexplained Blotches on different sides):

 ![Lightmap02](https://d3kjluh73b9h9o.cloudfront.net/original/4X/e/5/9/e59f251d8829a0e801d17c119ad59d3e3e910410.jpeg)  
 ![LightmapB02](https://d3kjluh73b9h9o.cloudfront.net/original/4X/5/6/8/568d0399072604d8abe8e8d02f0548b38a1b3909.jpeg)

Any help would be nice as I’ve been spending hours trying to wrap my head around Lightmass and it limitations.

I could also upload the meshes and their normal maps too since they are personal works of mine.

Thanks for you time.

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<div class="post-metadata">

**Author:** ![GIS3000](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@GIS3000](https://forums.unrealengine.com/u/GIS3000)\
**Post date:** [November 19, 2023, 5:26am UTC](https://forums.unrealengine.com/t/lightmap-artifacts-and-normal-maps/1397477/2 "2023-11-19T05:26:19Z")

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Hi. Can anyone help?  
Thanks for your time!