Apple Motion 3 - Manual (Page 1057)

Chapter 12 Using Shapes and Masks 1057
 Stroke Length: Stroke Length is mapped horizontally on the mini-curve editor graph
and provides a visual representation of the position of the changes in jitter value
(keyframes) over the length of the stroke. Use the sliders or enter a number in the
value field to change the value of the selected keyframe.
Random Seed: The variation of the Jitter, Brush Angle Randomness, and Brush Scale
Randomness parameters (in the Stroke pane) and the Life, Speed, and Spin
Randomness parameters (in the Advanced pane) are based on the number shown here.
If you don’t like the current random distribution of the dabs, you can change the seed
number by typing a new number or clicking Generate. The Jitter value must be 1 or
more for this parameter to have any effect.
Advanced Pane Controls
The Advanced pane of the Shape tab contains controls that allow the dabs of a paint
stroke to be animated like particles. Unlike particles, dabs are only “born” one time, but
age and die like particles. Dynamic dabs share several controls with particles, such as
Emission Angle, Life, Speed, and Spin. When Dynamics is turned off, dabs are immortal.
When you select a shape created with the Paint Stroke tool, Pen Pressure and Pen
Speed controls appear in the Advanced pane.
Note: All of the Dynamics controls can be animated using keyframes or by applying
Parameter behaviors to the individual parameters.
Dynamics: When this checkbox is selected, the dabs of a paint stroke become
particles.
Note: When a Simulation behavior is applied to a paint stroke, the Affect Subobjects
parameter only appears in the behavior if Dynamics is turned on for the paint stroke.
Emission Angle: A dial and value slider that set the direction in which the paint dabs
travel. This parameter works in conjunction with the Emission Range parameter.
A green line represents
the stroke length.