Apple Motion 3 User Manual
Page 707
 
Chapter 8
Working with Particles
707
For example, you can create a particle system that simulates an explosion by offsetting 
the appearance of three different types of particles. First, dense white particles emerge 
from the center. Half a second later, more diffuse orange particles appear around a 
larger area. One second after that, small sparks emerge 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 “
About Rasterization and Groups
Some operations, as well the application of certain filters or a mask, cause a group to 
be rasterized. When a group is rasterized, it is converted into a bitmap image. Because 
all particles live in groups, this affects how particles interact with other objects within 
your project. For more information on rasterization,
in the Motion
Supplemental Documentation PDF.