How to create particles in a 3D environment that don't disappear?

Hi,

I’m trying to find a way to use a particle system where:

-Particles never disappear (in my final 2D render view, particles can disappear outside of the frame of course) and no more particles are generated once the emitter reaches the maximum of particles allowed.
-Particles are floating in a 3d environnement.

What is the best way to create a precise number of particles - in my case, around 25 - moving slowly and randomly, floating in the air without disappearing because they reach the limits of the 3D-region.

Any help, even small, would be greatly appreciated!

Thank you!

Edith

Hmm well, I would venture a suggestion? I’m not entirely sure what these particles are, but “25 slowly and randomly floating” objects might actually be easier to just do with a handful of art layers being shifted around the frame. 25 is actually not a lot of particles to be emitted at any point in time.

particles will continue to exist unless you explicitly “kill” them at a particular age or frame, or they move out of your user generated “sink”.