Apple Motion 2 Tutorials - Manual (Page 198)

198 Tutorial 4 Working With Particles
3 One at a time, select one of the two end points of the emitter, and drag to reposition it.
Set a low speed while in line mode for a nice effect.
4 In the Emitter tab, set Speed to 20.
Changing the shape of the emitter can have a significant effect on the pattern of
generated particles. Now, change the emitter shape to a circle.
To change the particle emitter shape to a circle:
m Choose Circle from the Emitter Shape pop-up menu.
The particles are now emitted within the circle.
Since the Adjust Item tool is still selected, the circle is visible in the Canvas. Change the
Fill Pattern so the particles are emitted from the circumference of the circle.