Animating mask points in After Effects involves manipulating the shape of a mask over time, creating dynamic visual effects. You can achieve this by setting keyframes for mask paths. Here's how:
Animating Mask Shapes
To animate the mask's shape, you'll work directly with the mask points and the Timeline. The process is like this:
- Create a Mask: First, draw a mask on your layer using the pen tool or shape tools.
- Set the Initial Keyframe: Go to the beginning of your animation in the Timeline.
- In the layer properties, find the Mask dropdown.
- Click the stopwatch icon next to "Mask Path" to set your initial keyframe.
- Move in Time and Adjust the Mask: Now, move the playhead forward in the Timeline to a point where you want to change the mask's shape.
- Adjust the mask directly in the Composition panel. As you move the mask points, After Effects will automatically generate a keyframe at the current time.
- Refine Animation: Keep repeating step 3 to create multiple keyframes that transition between different mask shapes, resulting in the animation.
- Adjust Timing (Optional): you can use techniques like ease-in and ease-out to make your transitions more fluid.
Example: Concealing Animation
As illustrated in the reference, let's say you want a shape to gradually conceal itself using a mask. Here's a practical walkthrough:
- Initial Mask Position: At the start of your animation, have your mask fully cover the shape.
- Animation Start Point: set a keyframe at the mask path.
- Conceal Animation: Move the Playhead to a later time. Then, modify your mask shape by dragging the mask to the side until the shape is fully concealed. This action will set another keyframe.
- Playback When you play this you will see that the shape gets concealed as the mask moves.
- Timing Effect: By default After Effects automatically applies a "Natural (Ease In Out)" effect to make the animation smoother.
Key Points:
- Keyframes are Crucial: Animation happens through keyframes. Every change to your mask path after the initial keyframe will create a new one.
- Modify Masks Directly: Adjusting mask points in the Composition panel at different times sets the animation in motion.
- Ease In/Out: Adjust the timing using "Ease In," "Ease Out," or "Ease In/Out" to smooth the transitions between keyframes.
- Timeline Control: Use the Timeline to navigate between keyframes and to make further modifications to the mask path.
By using these steps, you can effectively animate your mask points in After Effects for various effects, from simple reveals to complex transformations.
