Producing circle shaped particles

[David Bogie]

Foam.

bogiesan

[Stuart Elith]

Or you could create a little comp that has the animation and look that you want, and use it as a custom particle with particular. This would probably give you the most customisation both from the particle aspect (since Particular has great controls and options) and also as it would let you do anything you like to get the circles looking good. You may want to render out your particle comp so that it’s not calculating them all as it goes, if things start getting heavy.