Apple Motion 2 Tutorials - Manual (Page 190)

190 Tutorial 4 Working With Particles
2 In the Dashboard, drag from the center of the circle to the right as far as you can.
Notice that in the Inspector the Throw Velocity has changed to a value of
approximately 100, if your zoom slider is in the same position as the screenshot above.
We want the butterflies to have a Throw Velocity of approximately 200, so use the
zoom slider in the Dashboard. If your zoom level is higher than indicated above, the
next two steps will not be necessary.
3 In the Dashboard, drag the zoom slider upward until it is a little more than halfway up.
4 Now drag the arrow to the right until the Throw Velocity in the Inspector is
approximately 200.
Notice that the butterflies should not pop into existence at the center of the Canvas.
For a more realistic effect, move the emitter offscreen to the left at the beginning of
the project.
To move the emitter off-screen:
1 Move the playhead to frame 1 (press Home).
2 In the Layers tab, select the Butterflies emitter.