# \[Request\] Render GPU particles when emitter is not visible **URL:** \ **Category:** FX\ **Tags:** particle-systems, gpu-particles, unreal-engine, UE4, question\ **Created:** [March 11, 2014, 4:43am UTC](https://forums.unrealengine.com/t/request-render-gpu-particles-when-emitter-is-not-visible/276855 "2014-03-11T04:43:57Z")\ **Posts on this page:** 10\ **Page:** 1
**Author:** ![ue4-archive](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@ue4-archive](https://forums.unrealengine.com/u/ue4-archive)\ **Post date:** [March 11, 2014, 4:43am UTC](https://forums.unrealengine.com/t/request-render-gpu-particles-when-emitter-is-not-visible/276855/1 "2014-03-11T04:43:57Z")
Currently when emitter of GPU particles is not in screen space, it stops emitting particles. While I understrand it is probably due to optimization, it would be nice to be able to specify this behavior on per emitter basis. I have run into this probablem today while trying to make flowing sand, on pretty narrow space, and it just look odd, when particles suddenly stop being visible. ---
**Author:** ![ue4-archive](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@ue4-archive](https://forums.unrealengine.com/u/ue4-archive)\ **Post date:** [March 11, 2014, 4:43am UTC](https://forums.unrealengine.com/t/request-render-gpu-particles-when-emitter-is-not-visible/276855/2 "2014-03-11T04:43:58Z")
Hi Lukasz, Ignore my previous response if you already saw it. I have an answer for you now. When you set the **TypeData** to **GPU Sprites** , you may have noticed this message appear in the Preview window: _“WARNING: This particle system has no fixed bounding box and contains a GPU emitter”_ The missing bounding box is what causes the particles to disappear when the emitter is off-screen, since GPU particles require a fixed bounding box. To enable this, in Cascade, click in the black background (not on the emitter), and in the Properties tab search for “bounding”, click the checkbox for **Use Fixed Relative Bounding Box** , then up on the toolbar, click the **Bounds** button to see the bounds on screen. The size of the box can be modified by expanding the dropdown in Properties and modifying the Min/Max. In the level, you will now notice that the particles will only disappear when the edges of the bounding box are off-screen. I hope that helps! ---
**Author:** ![ue4-archive](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@ue4-archive](https://forums.unrealengine.com/u/ue4-archive)\ **Post date:** [March 11, 2014, 4:43am UTC](https://forums.unrealengine.com/t/request-render-gpu-particles-when-emitter-is-not-visible/276855/3 "2014-03-11T04:43:59Z")
Hi Lukasz, I am not currently aware if there is any reason that GPU particles _must_ function this way, but I have reported the issue to our rendering team. Thanks ---
**Author:** ![MickD777](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@MickD777](https://forums.unrealengine.com/u/MickD777)\ **Post date:** [November 18, 2014, 4:21pm UTC](https://forums.unrealengine.com/t/request-render-gpu-particles-when-emitter-is-not-visible/276855/4 "2014-11-18T16:21:25Z")
Thanks for that, exactly my issue! ---
**Author:** ![HavocBlast](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@HavocBlast](https://forums.unrealengine.com/u/HavocBlast)\ **Post date:** [July 6, 2015, 12:17pm UTC](https://forums.unrealengine.com/t/request-render-gpu-particles-when-emitter-is-not-visible/276855/5 "2015-07-06T12:17:37Z")
I have this same thing happening to me. I have a fireplace in my scene and it is my only source of lighting and when I look away from the fireplace the fire goes out and everything is dark. ---
**Author:** ![HuntaKiller](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@HuntaKiller](https://forums.unrealengine.com/u/HuntaKiller)\ **Post date:** [December 2, 2015, 11:09am UTC](https://forums.unrealengine.com/t/request-render-gpu-particles-when-emitter-is-not-visible/276855/6 "2015-12-02T11:09:21Z")
^^ Thanks! ---
**Author:** ![mrmseto](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@mrmseto](https://forums.unrealengine.com/u/mrmseto)\ **Post date:** [September 16, 2016, 1:35am UTC](https://forums.unrealengine.com/t/request-render-gpu-particles-when-emitter-is-not-visible/276855/7 "2016-09-16T01:35:11Z")
Thank you! Fixed my issue too. ---
**Author:** ![jinzay](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@jinzay](https://forums.unrealengine.com/u/jinzay)\ **Post date:** [February 14, 2017, 8:11pm UTC](https://forums.unrealengine.com/t/request-render-gpu-particles-when-emitter-is-not-visible/276855/8 "2017-02-14T20:11:39Z")
awesome! Someone should think about something to prevent people searching for the same missunderstanding over 3 years 😃 ---
**Author:** ![steve1222](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@steve1222](https://forums.unrealengine.com/u/steve1222)\ **Post date:** [September 13, 2019, 11:59am UTC](https://forums.unrealengine.com/t/request-render-gpu-particles-when-emitter-is-not-visible/276855/9 "2019-09-13T11:59:18Z")
i need this to be on screen at all times, to create a cascading lava effect. this is a scene i put together [![](https://d3kjluh73b9h9o.cloudfront.net/original/4X/6/0/1/6015a11c47a36472419cd81c32377ad57f6a647a.jpeg "dank particle lava") ](https://www.youtube.com/watch?v=PndtPCyVrgo) Though not demonstrated in the video, When i play in the level the lava stops creating new particles when i look away from it, even with the fixed bounding box set incredibly high it seems to be dependent moreso on the camera being able to view the actual collision of a particle to occur in able to keep rendering that specific particle without deleting it ---
**Author:** ![steve1222](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@steve1222](https://forums.unrealengine.com/u/steve1222)\ **Post date:** [September 13, 2019, 6:04pm UTC](https://forums.unrealengine.com/t/request-render-gpu-particles-when-emitter-is-not-visible/276855/10 "2019-09-13T18:04:10Z")
i found a bit of an answer as to what’s going on at 8:14 of this video [![](https://d3kjluh73b9h9o.cloudfront.net/original/4X/a/2/9/a299a94cf258ac5982c7714636c59cfda88d61fb.jpeg "Particle Effect Collision | Live Training | Unreal Engine") ](https://www.youtube.com/watch?v=7kaVFLThYRI)