# UE FACETED SMOOTHING GROUPS AFTER BAKING (Luoshuang's GPULightmass)

**URL:** <https://forums.unrealengine.com/t/ue-faceted-smoothing-groups-after-baking-luoshuangs-gpulightmass/464347>\
**Category:** Rendering\
**Tags:** smoothing-groups, shadows-problem, baking, unreal-engine, Lightmap, lighting-problem, question\
**Created:** [April 27, 2020, 6:26pm UTC](https://forums.unrealengine.com/t/ue-faceted-smoothing-groups-after-baking-luoshuangs-gpulightmass/464347 "2020-04-27T18:26:39Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![christianstamati](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@christianstamati](https://forums.unrealengine.com/u/christianstamati)\
**Post date:** [April 27, 2020, 6:26pm UTC](https://forums.unrealengine.com/t/ue-faceted-smoothing-groups-after-baking-luoshuangs-gpulightmass/464347/1 "2020-04-27T18:26:39Z")

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Hi,  
I’m trying to bake a scene with rounded objects and I’m currently having problem with smoothing groups. I created this simple scene made of a plane a cylinder and a point light. To bake the scene I’m using Loushuang’s GPULightmass plugin on RTX project and I’m using Unreal Engine 4.26 dev-rendering. (I also tried on 4.24.3 the problem is the same)

- To make shadow softer I increased Soft Radius to 100 (even if it’s 0 the problem will be the same)
- The Cylinder has lightmap resolution to 1024px
- If I set Cylinder’s lightmap resolution to something like 64px the artifact seems to disappear but I will have more EDGE BLEEDING
- The artifact will appear only when I BAKE light, in real time it’s working perfectly the surface is SMOOTH

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**SCENE SETUP:**

 ![300736-test-02-baking.jpg](https://d3kjluh73b9h9o.cloudfront.net/original/4X/e/9/8/e987f11d373543197f5b2462148d0e9019df11fd.jpeg)

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**UV 0:**

 ![300737-test-02-uv-01.jpg](https://d3kjluh73b9h9o.cloudfront.net/original/4X/8/a/a/8aa8d712f16980bcfcd3e7a991c3b7916983f53c.jpeg)

**UV 1:**

 ![300738-test-02-uv-02.jpg](https://d3kjluh73b9h9o.cloudfront.net/original/4X/5/0/6/506fb2460fd1c4ac63e3a6af5c180111167f1312.jpeg)

UE 4.24.3 + Default Baking + Source Radius of pointlight

 ![300739-unrealengineshadowoverlap.png](https://d3kjluh73b9h9o.cloudfront.net/original/4X/8/f/3/8f366c151d55220b4165ffed82d4820770be4717.png)

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UE 4 24.3 + GPU Lightmass

 ![300740-bathroomtest.jpg](https://d3kjluh73b9h9o.cloudfront.net/original/4X/4/8/0/480c9213e7866d5dce620b4ef305fcf72402967d.jpeg)

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**Author:** ![anonymous\_user\_68e1492a](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_68e1492a](https://forums.unrealengine.com/u/anonymous_user_68e1492a)\
**Post date:** [December 14, 2020, 7:05am UTC](https://forums.unrealengine.com/t/ue-faceted-smoothing-groups-after-baking-luoshuangs-gpulightmass/464347/2 "2020-12-14T07:05:42Z")

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The Shadow Terminator Problem. Google it. Epic, what do you suggest we do?

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**Author:** ![anonymous\_user\_68e1492a](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_68e1492a](https://forums.unrealengine.com/u/anonymous_user_68e1492a)\
**Post date:** [December 14, 2020, 7:08am UTC](https://forums.unrealengine.com/t/ue-faceted-smoothing-groups-after-baking-luoshuangs-gpulightmass/464347/3 "2020-12-14T07:08:50Z")

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The problem happens will all ray-tracers, including Path tracers.  
The ray-tracers always looks at the geometry non-interpolated and faceted. Phong tesselation before raytracing could be a good idea? Thoughts Epic?