Chapter 12

Particle Systems

In a nutshell, this chapter will show you how to create animated effects and simulations using systems of mulstiple particles. Particle systems are very popular, and a lot of creative work has been done in the Flash community over the years using them. We can only really scratch the surface of what is possible in a single chapter. Therefore, we shall content ourselves with giving you a few ideas and examples to play with and build upon.

Topics covered in this chapter include these:

• Introduction to particle system modeling: This brief section will explain what we mean by a particle system and what is needed to set one up.
• Creating animated effects using particles: It is possible to produce some interesting animated effects such as smoke and fire using a bunch of particles and some simple physics. We'll walk you through some examples in this section.
• Particle animations with long-range forces: Particle animations don't have to look realistic; they can be just for fun! We look at a couple of wacky examples using long-range forces such as gravity.
• Interacting particle systems: More complex particle systems include interactions between the particles. But this can get pretty computationally expensive with large numbers of particles. We give a couple of examples, discussing tricks to overcome this problem.

The approach in this chapter is to create animations that use some physics, but without necessarily being accurate simulations. Above all, this is a subject where experimentation and creativity pay dividends. Therefore, don't be afraid to tinker and invent, even if that means breaking a few laws of physics!