# occlusion Culling Problem (white flashes) on Mobile devices

**URL:** <https://forums.unrealengine.com/t/occlusion-culling-problem-white-flashes-on-mobile-devices/1817639>\
**Category:** Mobile\
**Tags:** Mobile, occlusion-culling, unreal-engine, question\
**Created:** [April 23, 2024, 6:32pm UTC](https://forums.unrealengine.com/t/occlusion-culling-problem-white-flashes-on-mobile-devices/1817639 "2024-04-23T18:32:47Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Hariomjangra](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/hariomjangra/32/967493_2.png) [@Hariomjangra](https://forums.unrealengine.com/u/Hariomjangra)\
**Post date:** [April 23, 2024, 6:32pm UTC](https://forums.unrealengine.com/t/occlusion-culling-problem-white-flashes-on-mobile-devices/1817639/1 "2024-04-23T18:32:47Z")

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Hello Everyone, For a long time I am facing a problem related to occlusion culling on mobile devices. Whenever the player looks at meshes there is a white flash before it get culled. I am sharing some footages below

  

Any Help will be appreciable!

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**Author:** ![Feas](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/feas/32/921368_2.png) [@Feas](https://forums.unrealengine.com/u/Feas)\
**Post date:** [January 1, 2025, 6:23pm UTC](https://forums.unrealengine.com/t/occlusion-culling-problem-white-flashes-on-mobile-devices/1817639/2 "2025-01-01T18:23:48Z")

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![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/3/d/7/3d7f2980d389d0994001415571c378079a2ebeb2.png)  
Hi, you can try changing this command and the flickering should be less (default 1)

![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/9/b/3/9b3337856ff449634451fc21939a2f576795097e.png)  
Or change Actor bound scale

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**Author:** ![AndrewFord](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/andrewford/32/755855_2.png) [@AndrewFord](https://forums.unrealengine.com/u/AndrewFord)\
**Post date:** [January 1, 2025, 6:29pm UTC](https://forums.unrealengine.com/t/occlusion-culling-problem-white-flashes-on-mobile-devices/1817639/3 "2025-01-01T18:29:52Z")

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Add to your device profiles config or execute in console command:

`+CVars=r.Mobile.EnableOcclusionExtraFrame=0`

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<div class="post-metadata">

**Author:** ![AndrewFord](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/andrewford/32/755855_2.png) [@AndrewFord](https://forums.unrealengine.com/u/AndrewFord)\
**Post date:** [January 1, 2025, 7:44pm UTC](https://forums.unrealengine.com/t/occlusion-culling-problem-white-flashes-on-mobile-devices/1817639/4 "2025-01-01T19:44:18Z")

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You can also use this command to expand occlusion test bboxes. Meshes will be shown before crossing the scope boundary and there will be no white flash at all, but you may lose a few fps in theory as fewer meshes will be clipped by the Occlusion Culling system.

This will expand the bboxes up to 100 centimeters.

`r.ExpandAllOcclusionTestedBBoxesAmount 100`

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**Author:** ![system](https://d3kjluh73b9h9o.cloudfront.net/original/4X/7/1/3/713c9d3f58553f0de89543d76a8a3a2779dc9fa4.png) [@system](https://forums.unrealengine.com/u/system)\
**Post date:** [January 31, 2025, 7:45pm UTC](https://forums.unrealengine.com/t/occlusion-culling-problem-white-flashes-on-mobile-devices/1817639/5 "2025-01-31T19:45:18Z")

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