Selecting masks and vertices

Before you can modify or animate masks, you must know how to select them, especially when you've created more than one mask on a layer. Also, unlike layers, masks can have more than one level of selection. You can select a mask as a whole path, which is appropriate when you want to move or resize a mask. However, if you want to change the shape of a mask, select one or more points on a mask. Selected points appear solid, and unselected points appear hollow.

To select all or part of one or more masks in the Layer or Composition window:

1. Click the selection tool .
2. Do one of the following:
• To select a vertex on a mask, click it.
• To select a mask segment, click the edge of the mask.
• To select an entire mask by clicking, press Alt (Windows) or Option (Mac OS) as you click a mask. To select more masks, hold down Alt + Shift (Windows) or Option + Shift (Mac OS) as you click other masks.
• To select masks by dragging, hold down Shift, click inside the mask, and draw a marquee completely around the vertices or masks you want to select.

To use the selection tool when the pen tool is selected, hold down Ctrl (Windows) or Command (Mac OS).

To select masks in the Timeline window:

1. Click the right-facing arrow next to a layer name to expand it.
2. Click the right-facing arrow next to the Masks heading to expand it, revealing all masks on that layer.
3. Do any of the following:
• To select one mask, click its name.
• To select a contiguous range of masks, hold down Shift as you click the names of the first and last masks in the range.
• To select several discontiguous masks together, hold down Ctrl (Windows) or Command (Mac OS) as you click the names of any masks you want to include.

Note: You can select only whole masks in the Timeline window. To select individual vertices on a mask, use the Composition or Layer window.

To add or remove masks or vertices to or from the selection:

Do one of the following:

• In the Composition window, use the selection tool  to drag a marquee to enclose all vertices on all desired masks.
• In the Layer window, hold down Shift as you drag a marquee over other unselected vertices.
• In either the Layer or Composition window, select a mask and hold down Shift as you click other unselected masks with the selection tool.

To select or deselect all vertices in a mask:

Press Command + A. To deselect all vertices, press Command + Shift + A.

To select all masks on a layer:

Choose Edit > Select All.

To select an adjacent mask on a layer:

Press the tilde (~) key to select the next mask, or Shift + ~ to select the previous mask.

To deselect the mask:

Click anywhere other than on or inside a mask.