Apple Motion 2 - Manual (Page 598)

598 Chapter 8 Working With Particles
Birth Rate: A slider that defines the birth rate of the cell. In other words, this parameter
defines how many particles of this cell emerge from the emitter every second. Higher
values create denser particle effects.
Birth Rate Range: A slider that defines an amount of variance in the Birth Rate of
generated particles. A value of 0 results in no variance—particles emerge from the
emitter at the same rate. A value greater than 0 introduces a variance defined by the
the Birth Rate parameter, plus or minus a random value falling within the Birth Rate
Range. This parameter is not available if the emitter contains more than one particle
cell.
Initial Number: A slider that defines the initial number of particles. This parameter
determines how many particles of this cell appear at the first frame of a particle effect.
The result is an initial burst of particles that eventually evens out according to the Birth
Rate parameter.
Low birth rate particle system High birth rate particle system
Initial Number set to 5 (frame 3) Initial Number set to 20 (frame 3)
01112.book Page 598 Sunday, March 13, 2005 10:36 PM