I’ve always had a problem when using particle systems with unity, this is probably something noob but still I don’t get how to fix it.
I’ve uploaded an image, and you can see there is a little circle in the center of the image that destroys the whole idea of the particle.
That’s supposed to be a bullet travelling at high speed, but there’s a circle in there, and this happens all the time.
Does anyone know how to remove that circle from there or what’s causing it?
Thanks for your time!
Do you have any “particle bursts” under your emission rate?
No, it’s just a simple particle system with a Box Shape emitter with 0 on all components(so the particles all spawn on the same place) and World simulation space with zero speed.
Try changing the emission rate to distance so they do not spawn in the same place.
That works better, thanks!
But isn’t there any fix to the issue I was having?
Yeah the fix is using distance instead of time 
Its not a bug. The system emits particles at a fixed rate over time so you have multiple particles in one space. The particles all have an accumulation shader so the more there are the brighter they get.
If you use distance then a particle is only emitted when the system has moved a certain distance and so prevents them building up.
