Game Development Reference
Let's start at the top of the effect options in the Effect Controls
panel and work our way down, covering the highlights. Open the
Producer area to control the system that is creating the particles.
In particle systems like Foam, Shatter, and Particle Playground,
you don't (and usually can't) control the individual particles; you
only control the system making the particles. The Producer Point
is exactly where the bubbles are created. You can change its width
by adjusting the Producer X Size value or its height by adjusting
the Producer Y Size value. We'll use these later when we make
snow with the Foam effect.
Rotate the foam producer by adjusting the Producer Orientation
value. Increase the amount of bubbles (or, more precisely, the speed
at which they are created) by increasing the Production Rate value.
I'm going to increase the Production Rate value to 9 (Fig. 16.28).
Figure 16.28 Increasing the
Production Rate value creates
Open up the Bubbles area to adjust aspects of the bubble. I'm
going to decrease the size of my bubbles by lowering the Size
value to 0.2 (Fig. 16.29).
The Size Variance parameter adjusts the randomness of size.
This may be mildly important with bubbles, but may be hugely
important when working with your own custom textures. Lifespan
controls the duration the bubbles exist before they pop and dis-
appear. Many of the parameters in this effect—particularly those
in the Physics area—pertain to bubbly things. These are proper-
ties not seen in most other particle effects. This includes such
things as Wobble Amount, Pop Velocity, and Stickiness.
Also in the Physics area, I want to call your attention to one
of the reasons I am so devoted to the Foam effect. You'll notice
that there are Initial Speed and Direction values, as well as Wind
Speed and Direction values. This is so that you can have bubbles