3D Compositing with Action > Action: Masks >
Changing Basic Mask Properties

You can customize a mask's properties by changing settings in the node's Mask tab.

Transparency field
  Displays the percentage of transparency of the mask.

Intensity field
  Displays the blend between the outgoing and incoming image inside the mask.

Smoothing field
  Displays the percentage of gradient blur softness.

Closed button
  Connect a spline from the last point in the mask to the first control point. This button is enabled automatically if you close the mask gesturally.

Invert button
  Enable to apply settings to the area outside of the mask.

Lock button
  Lock the relative position of vertices.

Shape animation
  Enable to animate a mask using the Shape channel.

Blending box
  Displays the blending mode of the mask when it overlaps with another mask.

Correlation box
  Select how overlapping gradients are blending. This box is displayed when a Autodesk Maya Composite blending mode is selected in the Blending box.

Motion Blur button
  Enable to apply a blur effect to the selected mask. (Motion blur must be enabled in the Setup menu.)

Visibility box
  Select to apply the mask to the Right, Left, or Mono camera in a stereo scene.