Changing the shape of a mask

In the Layer or Composition window, you can freely change the shape of a mask. You can move, delete, or add vertices to reshape a mask; create a flexible outline to accommodate any shape; and even change a mask shape over time.

Some changes require the use of tools grouped with the pen tool in the Tools palette. To reveal these tools, click and hold the pen tool in the Tools palette. When modifying a mask, make sure that you click only existing vertices or segments; otherwise, you may create a new mask instead.

To change a mask shape numerically:

1. Select the mask.
2. In the Timeline window, expand the Mask options.
3. Next to the Mask Shape property, click the underlined word "Shape," and specify the changes.
4. Click OK.

To replace one mask shape with another:

1. In the Layer window, select the mask you want to replace from the Target pop-up menu.
2. Draw a new mask shape.

Note: After you create the new mask shape in the Layer window, select None from the Target pop-up menu; otherwise, all subsequent masks you create will replace the targeted mask. (See Specifying one mask as the target for animation.)

To reset a mask to its default boundaries:

Select the mask in the Timeline window and choose Layer > Mask > Reset Mask.

To delete one mask:

Select the mask in the Timeline window and press Delete.

To delete all masks:

Select the layer containing the masks you want to remove and choose Layer > Masks > Remove All Masks.

To move a vertex:

Using the selection tool , drag the vertex.

You can temporarily switch from the pen tool to the selection tool by pressing Ctrl (Windows) or Command (Mac OS).

To add a vertex to a mask:

Using the add vertex tool , click the line between two existing vertices.

To delete a vertex from a mask:

Using the delete vertex tool , click a vertex.

To adjust the shape of a curve segment:

Do one of the following with the selection tool:

• Drag a vertex.
• Drag the direction lines extending from an adjoining smooth vertex.
• Drag a curved segment.

Note: Dragging a curved segment on a RotoBezier mask also moves the vertices.

To change a vertex from a corner to a smooth vertex or vice versa:

Do one of the following:

• Using the convert vertex tool , click the vertex.
• Using the selection tool, hold down Ctrl (Windows) or Control (Mac OS) as you click the vertex.
• Using the pen tool, click the vertex.