# CPU particle collision doesn't work properly in game

**URL:** <https://forums.unrealengine.com/t/cpu-particle-collision-doesnt-work-properly-in-game/310616>\
**Category:** FX\
**Tags:** particle-collision, unreal-engine, question\
**Created:** [March 12, 2015, 8:07am UTC](https://forums.unrealengine.com/t/cpu-particle-collision-doesnt-work-properly-in-game/310616 "2015-03-12T08:07:51Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![anonymous\_user\_b8a497af](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_b8a497af](https://forums.unrealengine.com/u/anonymous_user_b8a497af)\
**Post date:** [March 12, 2015, 8:07am UTC](https://forums.unrealengine.com/t/cpu-particle-collision-doesnt-work-properly-in-game/310616/1 "2015-03-12T08:07:51Z")

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Hi. I have read several similar questions on AnwserHub but I still can’t find a solution. And since the problem persists in the latest release 4.7.1, I decide to post this question. Recently, I am following the particle system video tutorial on UE4 website and having problem with CPU particle collision.

So the problem is like this:

1. I dragged a CPU particle system into the level directly (i.e. it’s not a component of a BP or spawned in-game);
2. Collision works fine in the editor window;
3. No collision occurs if I play the game in a new editor window;
4. When played in the current viewport or as a separate process, collision occurs when the camera is far from the particles but collision disappears when the camera gets close to the particles.

Additional Information:  
I am using UE 4.7.1 (binary) on OS X 10.10.2

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**Author:** ![Lovecraft\_K](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Lovecraft\_K](https://forums.unrealengine.com/u/Lovecraft_K)\
**Post date:** [March 13, 2015, 11:45pm UTC](https://forums.unrealengine.com/t/cpu-particle-collision-doesnt-work-properly-in-game/310616/2 "2015-03-13T23:45:13Z")

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Hey ChucklingDinosaur -

Thank you for your report. I was able to reproduce this behavior and opened a ticket to investigate the cause, for reference UE-11854. As our investigation continues I will keep you informed.

Thank You Again -

Eric Ketchum