# Why is one side of my mesh not illuminated?

**URL:** <https://forum.babylonjs.com/t/why-is-one-side-of-my-mesh-not-illuminated/57769>\
**Category:** Questions\
**Tags:** lighting, material\
**Created:** [April 11, 2025, 12:22pm UTC](https://forum.babylonjs.com/t/why-is-one-side-of-my-mesh-not-illuminated/57769 "2025-04-11T12:22:38Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![TimonC](https://avatars.discourse-cdn.com/v4/letter/t/22d042/32.png) [@TimonC](https://forum.babylonjs.com/u/TimonC)\
**Post date:** [April 11, 2025, 12:22pm UTC](https://forum.babylonjs.com/t/why-is-one-side-of-my-mesh-not-illuminated/57769/1 "2025-04-11T12:22:38Z")

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I am building a scene where a “house” building mesh can be viewed from different angles. I want each wall to be illuminated with their own DirectionalLight. For whatever reason, however, the right wall is not illuminated. I know it has something to do with conflicts between the left and right light sources, as when I disable the left light source the problem disappears.

I replicated my project here, the positions of the camera, building and light source are the same.

> **[Babylon.js Playground](https://playground.babylonjs.com/#WCJAZH%2310)**
>
> Babylon.js playground is a live editor for Babylon.js WebGL and WebGPU 3D scenes

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**Author:** ![CodingCrusader](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/codingcrusader/32/29857_2.png) [@CodingCrusader](https://forum.babylonjs.com/u/CodingCrusader)\
**Post date:** [April 11, 2025, 12:32pm UTC](https://forum.babylonjs.com/t/why-is-one-side-of-my-mesh-not-illuminated/57769/2 "2025-04-11T12:32:13Z")

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I added some helplines and disabled HemisphericLight. Does it look now better?

[BuildingLights | Babylon.js Playground](https://playground.babylonjs.com/#WCJAZH#12)

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**Author:** ![Joe\_Kerr](https://sea2.discourse-cdn.com/flex024/user_avatar/forum.babylonjs.com/joe_kerr/32/39017_2.png) [@Joe\_Kerr](https://forum.babylonjs.com/u/Joe_Kerr)\
**Post date:** [April 11, 2025, 12:34pm UTC](https://forum.babylonjs.com/t/why-is-one-side-of-my-mesh-not-illuminated/57769/3 "2025-04-11T12:34:23Z")

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There is a limit per material (for performance I guess): [https://playground.babylonjs.com/#WCJAZH#13](https://playground.babylonjs.com/#WCJAZH#13)

See also: [Babylon.js docs](https://doc.babylonjs.com/features/featuresDeepDive/lights/lights_introduction/#limitations)

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<div class="post-metadata">

**Author:** ![TimonC](https://avatars.discourse-cdn.com/v4/letter/t/22d042/32.png) [@TimonC](https://forum.babylonjs.com/u/TimonC)\
**Post date:** [April 11, 2025, 12:38pm UTC](https://forum.babylonjs.com/t/why-is-one-side-of-my-mesh-not-illuminated/57769/5 "2025-04-11T12:38:34Z")

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This was the issue, thank you. Removing any light or increasing the limit solves it.