5

Transform Parameters
As a particle system plays, the cells in the system are duplicated, according to the
parameters for that system, to create each particle in the Canvas. Because all particles
emerge relative to the position of the emitter, changing the emitter’s position in the
Canvas also changes the position of every particle in that system.
Origin of particle system
after emitter has been
repositioned
Origin of particle system
This rule of thumb has one exception: For an emitter whose position is animated using
a behavior or keyframes, particles move relative to their position at the time of their
release, regardless of changes to the emitter’s position in subsequent frames. In the
example shown below, an animated emitter moves across the screen leaving a trail of
particles that maintain their original trajectory, regardless of the changing emitter position.
The Attach to Emitter parameter in the Particle Cell Inspector modifies this behavior.
When set to 0%, the particles are completely independent of the emitter. When set to
100%, the particles try to keep up with the position of the animated emitter. Depending
on any applied behaviors, such as Drag, the particles might not be able to keep up with
the emitter.
685Chapter 14 Working with Particles