# Why do niagara particles collide properly, but not all of the collisions provide a collision event.

**URL:** <https://forums.unrealengine.com/t/why-do-niagara-particles-collide-properly-but-not-all-of-the-collisions-provide-a-collision-event/2536913>\
**Category:** FX\
**Tags:** unreal-engine, question\
**Created:** [June 1, 2025, 8:51pm UTC](https://forums.unrealengine.com/t/why-do-niagara-particles-collide-properly-but-not-all-of-the-collisions-provide-a-collision-event/2536913 "2025-06-01T20:51:14Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Konstipus](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Konstipus](https://forums.unrealengine.com/u/Konstipus)\
**Post date:** [June 1, 2025, 8:51pm UTC](https://forums.unrealengine.com/t/why-do-niagara-particles-collide-properly-but-not-all-of-the-collisions-provide-a-collision-event/2536913/1 "2025-06-01T20:51:14Z")

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Greetings!

White particles sometimes trigger events properly (on collision - red particles are being spawned and white ones killed), but sometimes they do not.

What could be the problem? I tried slowing them down, speeding them up, making them larger. The only way to make them collide properly is to spawn them all at once (burst instantaenous) as opposed to running emitter several times with loop delay for 1 spawn burst (as shown in video). Spawn rate does not work either.

I am attaching video that displays the problem.

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**Author:** ![nande](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/nande/32/1057698_2.png) [@nande](https://forums.unrealengine.com/u/nande)\
**Post date:** [June 1, 2025, 11:47pm UTC](https://forums.unrealengine.com/t/why-do-niagara-particles-collide-properly-but-not-all-of-the-collisions-provide-a-collision-event/2536913/2 "2025-06-01T23:47:45Z")

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how do you know they are being killed?  
they might be inside the box

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**Author:** ![Konstipus](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Konstipus](https://forums.unrealengine.com/u/Konstipus)\
**Post date:** [June 2, 2025, 3:59am UTC](https://forums.unrealengine.com/t/why-do-niagara-particles-collide-properly-but-not-all-of-the-collisions-provide-a-collision-event/2536913/3 "2025-06-02T03:59:23Z")

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THey have restitution set up, so if they didnt die they would bounce back

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**Author:** ![nande](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/nande/32/1057698_2.png) [@nande](https://forums.unrealengine.com/u/nande)\
**Post date:** [June 2, 2025, 4:34am UTC](https://forums.unrealengine.com/t/why-do-niagara-particles-collide-properly-but-not-all-of-the-collisions-provide-a-collision-event/2536913/4 "2025-06-02T04:34:20Z")

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sorry i don’t know what could be the issue. i thought for a moment it could be a sweep issue.  
or maybe the resolution of the distance field.  
does the fact that they collide with a wall that you can barely see an issue?  
( the wall is facing orthogonal to the view direction).

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**Author:** ![Narg](https://d1ap1mz92jnks1.cloudfront.net/user_avatar/forums.unrealengine.com/narg/32/870597_2.png) [@Narg](https://forums.unrealengine.com/u/Narg)\
**Post date:** [August 12, 2026, 6:43pm UTC](https://forums.unrealengine.com/t/why-do-niagara-particles-collide-properly-but-not-all-of-the-collisions-provide-a-collision-event/2536913/5 "2026-08-12T18:43:28Z")

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I have this exact same issue with my Rain/Snow Particles, looking for a proper answer.

Were you able to fix this @Konstipus ?