How Do I Scale a Mask Path in After Effects?

Scaling a mask path in After Effects is straightforward. There are several ways to achieve this, offering varying degrees of control.

Accessing the Transform Controls

The primary method involves accessing the mask's transform properties. This allows you to scale the mask independently of the underlying layer.

• Keyboard Shortcut: The quickest way is to use the keyboard shortcut Ctrl+T (Windows) or Cmd+T (Mac). This instantly displays the mask's bounding box, enabling you to scale it using the handles. Holding Shift while scaling maintains the aspect ratio.

• Direct Selection: Alternatively, double-clicking the mask path directly in the Composition panel activates the transform controls. You can then scale using the handles.

• Transform Panel: The Transform panel, found under the Window menu, displays the mask's scale properties numerically. This offers precise control and the ability to animate scale changes over time.

Scaling from the Center

To scale a mask from its center point, hold down the Shift key while using either the keyboard shortcut or the handles in the Composition panel. This prevents distortion and maintains the mask's proportions.

Refining Control

For more nuanced adjustments, you can manipulate the mask path's individual points directly. This allows for selective scaling and shaping of specific areas within the mask.

• Select Points: Select the mask path and use the Pen tool or other selection tools to adjust individual points. You can then directly manipulate the positions of these points to achieve the desired scale.

• Animating Masks: To animate mask scaling, you add keyframes to the mask's scale properties within the Transform panel. This is ideal for creating dynamic effects.

Examples

• Simple Scaling: Quickly resizing a mask to fit a new area. Use the Ctrl+T (or Cmd+T) shortcut and drag the corner handles.
• Precise Scaling: Adjusting a mask to a specific dimension. Use the Transform panel to enter exact values for the scale.
• Animated Scaling: Creating a growing or shrinking mask over the course of an animation. Use keyframes in the Transform panel to control the scaling at specific frames.

Remember, scaling the mask affects only the mask's shape, not the underlying layer.