2010

Table Of Contents
Note that you can change the beginning red color to random colors by
changing the creation expression to this:
BubblesShape.rgbPP = sphrand(1);
This is the same expression as the runtime expression.
3 Save the scene if you plan to examine it later. This concludes the lesson.
Beyond the lesson
In this lesson you learned how to:
Control particles using creation and runtime expressions.
Apply a random function to your expression.
For a particle object, you typically create two expressionsa creation expression
that initializes an attribute value in the first frame, and a runtime expression
that controls the attribute value in subsequent frames. (Creation and runtime
expressions exist only for particle objects, not for other types of objects.)
This lesson described how to color stationary particles as a simple way to
describe creation and runtime expressions. However, its more typical to use
particle expressions to:
Create sophisticated particle motion and life span; for example, the
movement and fading of exploding fireworks.
Create complex colors for emitted particles, for example, rocket exhaust
flames.
Create complex colors and movement of particles following collision with
geometry, for example, sparks resulting from fired bullets.
Creating such effects requires experience and experimentation. Expression
writing can be as complex as computer programming. A detailed
Beyond the lesson | 649