Controlling the Particle Movement

Okay; so you created a school of exactly 20 fish. Now you need to limit their movement so that they stay together in a cluster rather than drift apart. How far and fast particles move away from each other is determined by the Speed parameter. The higher the speed value, the faster and farther apart the particles move. The lower the speed value, the slower and less scattered the particles move. Your goal in this exercise is to stop the particlesthe fishfrom moving apart completely. That means that you need to set the speed value to 0.

1.	On the Emitter tab, drag the Speed slider all the way to the left until the value is 0. You restricted the movement, but now you've created a 20-fish pileup in the middle of the Canvas. I may not be an expert in aquatic life, but I'm pretty sure fish don't travel around in neat stacks. We're going to need to give them some distance.
2.	Press Cmd-S to save your progress.