# How to spawn particles on a surface with CPU Sim?

**URL:** <https://forums.unrealengine.com/t/how-to-spawn-particles-on-a-surface-with-cpu-sim/1314337>\
**Category:** Issues and Bug Reporting\
**Tags:** particle-systems, disappear, gpu-particles, unreal-engine, CPU, particle, bug-report, editor, Rendering, question\
**Created:** [September 27, 2023, 3:23pm UTC](https://forums.unrealengine.com/t/how-to-spawn-particles-on-a-surface-with-cpu-sim/1314337 "2023-09-27T15:23:16Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![DanceDown](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@DanceDown](https://forums.unrealengine.com/u/DanceDown)\
**Post date:** [September 27, 2023, 3:23pm UTC](https://forums.unrealengine.com/t/how-to-spawn-particles-on-a-surface-with-cpu-sim/1314337/1 "2023-09-27T15:23:16Z")

</div>

Hey,  
I created a particle system with an emitter **on GPU Compute** and then used the **static mesh location** to let my particles spawn on the surface of a sphere (radius: 100.000.000). But there is a feature (synonym for bug) that I can’t see these particles **EXCEPT** my camera is moving **OR** I’ve selected the emitter in the viewport.

 ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/b/5/e/b5edc43127ec07925d35172edf55f60f1298f433.jpeg)  
Here I select the emitter.

 ![image](https://d3kjluh73b9h9o.cloudfront.net/original/4X/b/3/b/b3b811d3bf999f22d43c492ca41a63daabc2c664.jpeg)  
Here I don’t select the emitter and therefore I can’t see the particles??? Maybe because they are not visible when the camera is too far away or something, idk?

But another reason, why I want to use CPU Sim is, because particles are also not rendered when the camera is not looking a the Niagara System directly. But when I try switching to CPU Sim, the system doesn’t emit on the surface anymore, it just uses the Simulation Position.

How?