Apple Motion 3 - Manual (Page 33)

Chapter 1 Getting to Know Motion 33
Mask Tools
The Mask tools can only be accessed when a layer (a visible object in the Canvas, such
as an image or replicator) or 2D group is selected. Using a Mask tool creates a new
mask that hides portions of the selected layer. By default, the area inside the mask
remains visible. Masks have their own set of controls available in the Inspector.
Icon Tool name Keyboard shortcut Description
Rectangle
Mask tool Option-R Creates a new rectangular mask in the Canvas. Click at
the position where you want one corner to appear
and drag to the position of the opposite corner.
Pressing the Shift key while you drag constrains the
mask to a square.
Circle Mask
tool Option-C Creates a new circular mask in the Canvas. Click at the
position where one edge of the mask should begin
and drag toward the opposite edge. Pressing the Shift
key while dragging constrains the mask to a circle.
Freehand
Mask tool none Creates a freeform mask in the shape that you draw.
Drag to create the freeform shape. The shape
automatically closes the mask between the first and
last points.
Bezier Mask
tool Option-B
Toggles Bezier/
B-Spline Mask tools
Creates a new freeform mask with Bezier point
vertices. To create a mask, click repeatedly in the
Canvas to add points to your mask. To close the mask,
click the first point of the mask or press C. To create an
open-ended mask, double-click the last point.
B-Spline Mask
tool Option-B
Toggles Bezier/
B-Spline Mask tools
Creates a new freeform mask with B-Spline vertices. To
create a mask, click repeatedly in the Canvas to add
points to your mask. To close the mask, click the first
point of the shape or press C. To create an open-
ended shape, double-click the last point.