Mask Parameters

A selected mask’s parameters appear in the Mask Inspector.

Except for control points parameters, the parameters in the Mask HUD are identical to the parameters in the Inspector.

Mask Controls in the Inspector

These controls allow you to adjust how the mask is drawn, how each mask operates upon an object, and how masks are combined with one another. The Mask Inspector also allows you to fine-tune mask control point positions using value sliders.

  • Invert Mask: When this checkbox is selected, the mask is inverted—its solid and transparent areas are swapped. This is useful if you need to switch the solid and transparent areas of an existing mask.

    Tip: You can apply different filters and effects to the foreground and background of an image by first masking the foreground subject, duplicating the layer and its mask, then inverting the duplicate layer’s mask. Effects applied to the background can then be completely isolated from the foreground, or vice versa.

    Note: You can adjust the opacity of a mask in the Properties Inspector.

  • Roundness: Controls the roundness of the corners of a mask. This facilitates the creation of rounded rectangle masks, as well as generally smoothing the edges of any mask.
  • Preserve Scale: This checkbox controls whether the Roundness setting is absolute or relative to the overall mask size. When enabled, the roundness will remain at the same approximate percentage of curvature as the object is scaled. When disabled, the curvature will vary as the overall mask changes size.
  • Feather: A slider that feathers (softens) the edges of a mask. Positive feathering values soften the edge of the mask from its edge outward. Negative feathering values soften the edge of a mask inward from the edge. Feathering the edge of a mask can soften a harsh rotoscoping job, making the masked object blend more easily with the background.
  • Falloff: Controls how “steep” the feathering is. Higher values result in feathering that’s pushed in farther inward, so the edge of the feathering effect is more transparent. Lower values result in the “core” of the feathering effect being pushed farther outward, so the edge of the feathering effect is less transparent.
  • Control Points: Click the disclosure triangle to display the position parameters for the mask control points. Use the value sliders to adjust the position of a control point. The left value slider represents X and the right value slider represents Y.