Apple Motion 4 - Manual (Page 642)

Life: A slider that defines the duration of every particle, in seconds. This parameter specifies
how long each particle lasts before vanishing from existence. This effect is similar to how
sparks disappear after flying away from a sparkler. Unless the Color Over Life parameter
or Opacity Over Life parameter is used to fade each particle out over its life, particles
immediately vanish at the end of their lifetimes.
Life set to 5 (frame 60) Life set to 2 (frame 60)
Life Randomness: A slider that defines an amount of variance in the life of generated
particles. A value of 0 results in no variance—all particles from the selected cell emerge
with the same lifetime. A value greater than 0 introduces a variance defined by the Life
parameter, plus or minus a random value falling within the Life Randomness.
Speed: A slider that defines initial speed. This parameter determines how quickly each
particle flies away from the emitter. This, in conjunction with the Life and Birth Rate
parameters, determines how many particles appear in the Canvas at any given frame. It
is equivalent to one of the functions of the graphical emission control in the HUD.
Speed Randomness: A slider that defines an amount of variance in the speed of generated
particles. A value of 0 results in no variance—all particles from the selected cell emerge
with the same speed. A value greater than 0 introduces a variance defined by the Speed
parameter, plus or minus a predetermined random value falling within the Speed
Randomness.
Align Angle: When selected, the particles automatically rotate to match the shape on
which they are positioned. This parameter is available in all cases but the following:
Rectangle, Circle, Image, Box, and Sphere shapes with Tile Fill or Random Fill and Point.
Angle: A dial that defines the angle of rotation, in degrees, at which new particles are
created.
Angle Randomness: A dial that defines an amount of variance in the angle of generated
particles.
Spin: A dial that animates particles in a system by initially spinning each individual particle
around its center. Adjustments to this control are in degrees per second.
642 Chapter 11 Working with Particles