# SSAO not working with my light function

**URL:** <https://forums.unrealengine.com/t/ssao-not-working-with-my-light-function/601317>\
**Category:** Rendering\
**Tags:** UE4-23, light-function, unreal-engine, Lighting, question\
**Created:** [July 10, 2022, 1:08am UTC](https://forums.unrealengine.com/t/ssao-not-working-with-my-light-function/601317 "2022-07-10T01:08:08Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Nerf\_My\_Thumbs](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Nerf\_My\_Thumbs](https://forums.unrealengine.com/u/Nerf_My_Thumbs)\
**Post date:** [July 10, 2022, 1:08am UTC](https://forums.unrealengine.com/t/ssao-not-working-with-my-light-function/601317/1 "2022-07-10T01:08:08Z")

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Hey everyone, I have a light in my scene that’s using a light function material and has “cast shadows” disabled. I noticed that as soon as I turn on my light function, SSAO is completely erased from my scene. Does anyone know of a fix for this? I’m working on 4.23 at the moment.

I’ve attached an image of my light function material in case it helps track down the issue. I’m using it to create a “flickering” effect in my scene.

 ![lightfunction](https://d3kjluh73b9h9o.cloudfront.net/original/4X/3/f/5/3f5f1d9eef03a653ff93999bb00b31c373d759a1.png)

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**Author:** ![TobiasRusjan](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/tobiasrusjan/32/1004445_2.png) [@TobiasRusjan](https://forums.unrealengine.com/u/TobiasRusjan)\
**Post date:** [January 10, 2023, 9:59pm UTC](https://forums.unrealengine.com/t/ssao-not-working-with-my-light-function/601317/2 "2023-01-10T21:59:21Z")

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I’m having the same problem: as soon as I add the Light Function material to my light, the screen space ambient occlusion of the Post Process disappears. Have you been able to fix it? Thank you!

And this happens even with the most basic parametters (1 in Emissive Color):

 ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/e/7/d/e7d33f06696d10f59a647a0b1dae6a26861de6bd.png)