5.5

857Motion User Guide
Tip: You can apply different filters and effects to the foreground and background of
an image by first masking the foreground subject, duplicating the layer and its mask,
then inverting the duplicate layer’s mask. Effects applied to the background can then
be completely isolated from the foreground, or vice versa. You can adjust the opacity of
a mask in the Properties Inspector.
• Feather: A slider that softens the edges of a mask. Positive feathering values soften the
edge of the mask from its edge outward. Negative feathering values soften the edge
of a mask inward from the edge. Feathering the edge of a mask can soften a harsh
rotoscoping job, making the masked object blend more easily with the background.
• Falloff: A slider that controls how “steep” the feathering is. Higher values result in
feathering that’s pushed farther inward, so the edge of the feathering effect is more
transparent. Lower values result in the “core” of the feathering effect being pushed
farther outward, so the edge of the feathering effect is less transparent.
• Mask Color: A pop-up menu that controls the color of the mask as displayed in the
canvas when it’s selected. This setting has no effect on the final output. Setting masks
to different colors may aid you in identifying which mask is which.
• Convert to Points: A button (available when a simple mask is selected) that, when
clicked, converts a simple mask to a complex mask with editable control points. See
Convert a shape or mask to control points in Motion.
Control Points controls
When a complex mask with control points is selected, this list becomes available,
displaying the X and Y position parameters for the mask’s control points. The Control
Points list also contains a single Animation menu (the down arrow that appears when you
move the pointer over the right side of the Control Points heading row) that affects all
the control points, letting you add keyframes, reset the shape’s animation, display the
animation curve in the Keyframe Editor, and so on. For more information on using the
Animation menu, see Animation menu controls in Motion.
To show or hide the Control Point lists, double-click the Control Points name in the Inspector.
Use Image masks
Intro to image masks in Motion
Another way to create transparency in a layer is by using image masks. An image mask
creates transparency in a layer by deriving an alpha channel from another layer, such as a
shape, text, movie, or still image.
Note: You can use masks and image masks together.
The power of image masks is that they do not have to be drawn or animated.
Using image masks is easy. First you apply an image mask, and then you make adjustments
in the Behaviors Inspector.