When you create a particle system, its duration can be as long or short as necessary,
regardless of the duration of the original source objects used to create the particle system.
The duration of a particle system is defined by the duration of the emitter object. Changing
the In or Out point of an emitter in the Properties Inspector, Timeline, or mini-Timeline
changes the duration of the entire particle system.
By default, particles are generated by every cell in a system for the duration of the emitter.
The duration of each generated particle is defined by the Life parameter of the cell that
generated it, and not by the duration of the cell itself.
The duration of the cell controls the duration over which new particles are generated.
You can change a cell’s duration by dragging its position or its In and Out points in the
Timeline. In this way, you can adjust the timing that defines when each cell’s particles
Working with Particles
For example, you can create a particle system that simulates an explosion by offsetting
the appearance of three types of particles. First, dense white sparks emerge from the
center. Half a second later, more diffuse orange blast particles appear around a larger
area. One second after that, hot smoke emerges from underneath both of these layers
as they fade away.
You can offset a cell in the Timeline or mini-Timeline to start before the emitter. This
creates a “preroll” in which the particle simulation starts before the particles are drawn.
For more information on adjusting the timing of layers in the Timeline, see