# Fullscreen postprocessing using light layers

**URL:** https://discussions.unity.com/t/fullscreen-postprocessing-using-light-layers/1734657
**Category:** Post-Processing
**Tags:** Universal-Render-Pipeline, Shaders, Question, 6.4
**Created:** [August 24, 2026, 10:50am UTC](https://discussions.unity.com/t/fullscreen-postprocessing-using-light-layers/1734657 "2026-08-24T10:50:37Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![alexandrethery1202](https://avatars.discourse-cdn.com/v4/letter/a/a698b9/32.png) [@alexandrethery1202](https://discussions.unity.com/u/alexandrethery1202)
#### Post date: [August 24, 2026, 10:50am UTC](https://discussions.unity.com/t/fullscreen-postprocessing-using-light-layers/1734657/1 "2026-08-24T10:50:37Z")

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Hello, I am currently working on a game that takes place in a dark cartoonish environment. I need to make visuals to differenciate between two mode of vision simultaneously (let’s call them “normal” and “sonar”). I got this working in a material shader, by differentiating between two light layers (in the screenshot, red light is “normal” layer, white is “sonar” :

 ![image](https://europe1.discourse-cdn.com/unity/original/4X/8/c/8/8c8b27e3ee626444b451a36399f359ea88eab77a.jpeg)

but now I need to add a postprocessing layer to add outlines, which I also got working:

 ![image](https://europe1.discourse-cdn.com/unity/original/4X/9/4/a/94a33c2449a223a72a3b7be46a9168631550eb7d.jpeg)

But now the problem is, I need to make the outline different depending on the light layer affecting the material (and none at all outside light sources). I was intending on using camera textures for that, but camera culling masks won’t work because they apply to entire objects, and I can’t find a way to have a camera texture render only one light layer… Is it even possible?

And if anyone has a better take on how to implement this, I will take it 😉

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<div class="post-metadata">

### Author: ![alexandrethery1202](https://avatars.discourse-cdn.com/v4/letter/a/a698b9/32.png) [@alexandrethery1202](https://discussions.unity.com/u/alexandrethery1202)
#### Post date: [August 26, 2026, 12:47pm UTC](https://discussions.unity.com/t/fullscreen-postprocessing-using-light-layers/1734657/2 "2026-08-26T12:47:17Z")

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To make things more clear, here is the test setup with lights being the same color, bu on different rendering layers :

 ![image](https://europe1.discourse-cdn.com/unity/original/4X/a/d/a/adac7ee62a81788a7dc0ab0440c32517fea5e0c6.jpeg)

In the material shader, I have the information of the light’s rendering layer, that I can directly render :

 ![image](https://europe1.discourse-cdn.com/unity/original/4X/1/c/f/1cff18ee23f56445b3f6e97d2eea928c594a1f42.jpeg)  
Here, layers 1, 2 and 3 are rendered as Blue, Green and Red.

What I try to acheive is to somehow store the light layer information, to later use it as a mask on a post precessing effect (fullscreen shader) and I can’t find a way to do it.