Apple Motion 3 - Manual (Page 1092)

1092 Chapter 12 Using Shapes and Masks
3 To return to your previous view (the view before you isolated the layer), click the Isolate
button again.
Note: Clicking a camera’s Isolate button activates that camera’s view.
Mask Parameters
A selected mask’s parameters appear in the Mask tab of the Inspector. These
parameters allow you to adjust how the mask is drawn, how each mask operates upon
an object, and how masks are combined with one another.
Shape Type: This pop-up menu lets you change the type of control points that are
used to define the mask. For example, if you originally created a Bezier mask, you can
choose B-Spline from this menu to change how the mask is drawn. You can change a
mask’s shape type at any time, but changing a mask from a Bezier shape to a B-Spline
shape might dramatically change its form.
 Linear: All of a mask’s control points are joined by hard angles, and the resulting
mask is a polygon. The control points of a Linear mask lie directly on its edge.
 Bezier: Control points can be a mix of Bezier curves and hard angles, creating any
sort of mask. The control points of a Bezier mask lie directly on its edge.
 B-Spline: Control points are all B-Spline points, with different degrees of curvature.
B-Spline control points lie outside the surface of the mask, but are connected by the
B-Spline frame.
Note: You can hide the B-Spline frame by turning off Lines in the View pop-up menu
above the Canvas.
Mask Blend Mode: Determines how a mask interacts with the alpha channel of the
layer to which it’s applied. When a layer has multiple masks, each mask can have a
different Mask Blend Mode. When this happens, each mask adds to, or subtracts from,
the layer’s alpha channel according to the selected mode. The final alpha channel is the
combined result of all the masks that are applied. The four choices are:
Active Isolate button