user8064: I want all particles that I emitted to settle down on a circle shape after animating them in space. What would be perfect is to be able to draw a circle shape which works as a particle attractor after a certain time.

user9161: I would recommend you use a different plugin, use the shatter plugin.
Follow the steps in this tutorial
http://www.macprovideo.com/hub/after-effects/after-effects-text-that-blows-away-like-sand
This will let you break apart your circle into particles. Then when done the composition, simply pre-comp the layer and use the time/time-reverse layer to let the particles come into a circle.
While it seems a little backwards(literally) to do it this way, I think this is the best way to accomplish what you are trying to do. 
You won't be able to get a particle attractor or other advanced functions like that unless you are working in cinema 4d or other 3 rendering software.

8064: <p>I want all particles that I emitted to settle down on a circle shape after animating them in space. What would be perfect is to be able to draw a circle shape which works as a particle attractor after a certain time.</p>
 9161: <p>I would recommend you use a different plugin, use the shatter plugin.</p>

<p>Follow the steps in this tutorial</p>

<p><a href="http://www.macprovideo.com/hub/after-effects/after-effects-text-that-blows-away-like-sand" rel="nofollow">http://www.macprovideo.com/hub/after-effects/after-effects-text-that-blows-away-like-sand</a></p>

<p>This will let you break apart your circle into particles. Then when done the composition, simply pre-comp the layer and use the time/time-reverse layer to let the particles come into a circle.</p>

<p>While it seems a little backwards(literally) to do it this way, I think this is the best way to accomplish what you are trying to do. </p>

<p>You won't be able to get a particle attractor or other advanced functions like that unless you are working in cinema 4d or other 3 rendering software.</p>
