How do I make particle effects not pop out entirely in some cases?

At the moment my particle effects randomly pop out of view in front of me even when light effects play.

How do I combat that? Is it some kind of draw limit or maybe bound problem?


This is getting very annoying and I cant seem to solve it, could anyone help please?


Hi Bruno_G -

Mr. Lincoln brought this to my attention can you post a screenshot of what you are experiencing (or even better a video)?

Thanks -

Eric Ketchum

Hi :slight_smile:

Thank you for assisting me.

Here is a footage of whats happening with basically all my effects VERY often:

link text

This is happening regardless of my fade out alpha effects I apply to my emitters (fading the sprite from alpha value of 1 to 0 gradually).

I hope that you understand my point. All effects seem to have this weird condition that makes them suddenly disappear completely at random times, sometimes even while through the first seconds of any effects I made so far for our game. It really ruins immersion and gameplay specially with smoke grenades which you would want to last long and cover designated areas with.

Hope you can help me.


Hi Bruno_G -

Ok a few questions to make sure I can get a clear idea of how you effect is running. How many Emitters are in your system, if there is more than try moving one higher in the rendering stack (to the left) by selecting the main emitter header module and pressing the left arrow key on the keyboard. Have you set a fixed bounds on this effect? The Material is Translucent Lit?

Let me know though I am fairly certain the popping that you are seeing is one particle suddenly rendering on top of another as it moves in space which should be able to be mitigated or eliminated by changing the Emitter Render order in Cascade.

Thank You -

Eric Ketchum


What would rendering order have to do with this? this effect I showed you on the video has 2 emitters, same happens wherever the emitters are located in the rendering stack. As i said it happends not only with this effect but with all my fx so far.

I,m wondering why would one particle be allowed to render on top of another one? So I would be able to see two smoke grenades being thrown at the same time, both playing the effect a short distance between each other?

Some facts:

  • I played around with the Bounds, making them very big or unchecking the Fixed Bouds wont solve this particular issue.

  • Yes the materials are translucent Lit.

  • Some of my effects have lots of emitters and some have very few but these are all still poping out at some points. It would happen randomly and without a pattern I could track.

Any other info you could need?

Here I recorded another video of the issue:

link text

Exactly at 4 seconds through the video, both effects (grenade blast and surface shockwave effect) just pop out entirely. Then the next blasts play out fine.

Here is another example of the issue:

link text

This also happens with our bullethit effects, you would be shooting at surfaces watching the impact effects go on normally from start to their respective fade out endings yet very often they would also just pop out out of the screen, all at the same time.

Seems like a Draw limit/Effect Bounds/LOD issue thats in place causing this at random times?

I,m just struggling to find a pattern to when this would happen and why.

Some support from you guys would be great.

Thank you once again.

Hi Bruno_G -

From your latest videos it looks less like a Particle Effect Problem and more about a Spawning issue with how your effect is substantiated in the level itself? Can you give me a breakdown of the blueprint (or code) that is spawning your grenade explosion effect?

Without seeing it I would look to how you are spawning the effect and make sure that you are spawning a new effect each time and not overwriting an effect in an existing emitter or variable.

Let me know -

Eric Ketchum

Hi, sorry about the delay. I was studying the case with my team and we think it would have to do with the engine collecting the effects at certain points as some sort of information garbage disposal.

Weird thing is that this pop out issue even happens with for example the footprint effects our materials have assigned, which is pretty much a feature of the engine and not our designed blueprint like our bullet hits or grenades.

Could this be a possibility? or something around this theory?

It also happens in this video of an artist showcasing his bullet VFX pack:

Check how his effects pop out at one moment then start displaying again

I would love finding a workaround this issue.


Hi -

I need some more information about how the effects are substaitiated into the level. Are they activated in Event Graph based on a placed Particle System in the Viewport Components? Are they their own individual Blueprints which are spawned in another blueprint? Again with footprints as well how are you getting them to produce in your level?

Let me know -

Eric Ketchum

I was having a similar problem where I couldn’t figure out why all my snow was just appearing instead of starting from the emitter then falling down.

Just figured out I had to bring the “Warmup Time” time down to “0” so it wouldn’t pre-compute everything. And that details setting is found when you click in the black space to the right of your emitters list.