Apple Motion 4 - Manual (Page 1150)

The Paint Stroke Tool HUD is replaced with the Shape HUD. In the Layers tab, a Write On
Shape behavior is automatically applied to the stroke. To modify the Write On parameters,
select the behavior and use the HUD or the Behaviors tab in the Inspector.
The speed at which the stroke is “painted” (including the duration it took to draw the
stroke) is mapped over the time extent (in frames) of the stroke. The faster a stroke is
drawn, the shorter the duration of the Write On behavior.
Note: If your Motion Project Preferences Create Layers At option is set to Current Frame,
the paint stroke is created at the current playhead position. If set to Start of Project, the
stroke is created at frame 1.
5 Play back your project. The stroke is “painted on” as the project plays.
6 To modify the speed at which the stroke is painted, adjust the duration of the behavior
in the Timeline or mini-Timeline.
You can also modify additional parameters, such as customizing the speed at which the
stroke is drawn, drawing on only a percentage of the stroke, offsetting the stroke, or
drawing the stroke in reverse. These parameters are available in the Write On behavior,
described above.
Creating a Write On Paint Stroke Using an Existing Shape
You can apply the Write On behavior to an existing shape to draw its outline over time.
Because the Write On behavior only affects outlines, Outline must be enabled in the
Shape parameters.
Note: When a Write On behavior is added to an existing shape, the behavior spans the
duration of the shape to which it is applied.
To create a write on stroke using an existing shape
1 Select the shape you want to use and select its Outline checkbox in the HUD or Shape
tab of the Inspector.
Note: You can leave the Fill checkbox selected, but only the outline is affected by the
Write On behavior.
2 In the Toolbar, click Add Behavior and choose Shape > Write On.
The Write On behavior appears in the Layers tab. If the playhead is located at the start of
the shape, the visual shape disappears and only the path is visible.
1150 Chapter 17 Using Shapes, Masks, and Paint Strokes