Apple Motion 4 - Manual (Page 1124)

Jitter Over Stroke: This mini-curve editor allows you to customize the scatter of the dabs
over the length of the stroke. You can create a curve that gradually increases the dabs’
jitter over the length of the stroke, a curve that varies the dabs’ jitter over the length of
the stroke, and so on. Select or add a keyframe in the graph to make changes using the
Jitter Over Stroke and Stroke Length controls.
• Jitter Over Stroke: This parameter is divided into two channels. Click the disclosure
triangle to display the individual X and Y controls. Use the X parameter to adjust
keyframes that define the amount of dab movement parallel to the stroke’s curve at
certain points along the stroke (red curve). Use the Y parameter to adjust keyframes
that define the amount of dab movement perpendicular to the stroke’s curve at certain
points along the stroke (green curve). Use the Jitter Over Stroke parameter to adjust
the amount of dab movement in both directions at certain points along the curve
(adjusts red and green curve simultaneously).
• 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. For more on using the mini-curve
editor, see
Mini-Curve Editor .
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.
Using the Width Over Stroke Onscreen Controls
The Width Over Stroke control can be manipulated using the mini-curve editor, or you
can adjust its keyframe values directly in the Canvas. An editable control appears at each
keyframe in the stroke.
1124 Chapter 17 Using Shapes, Masks, and Paint Strokes