Animate Rotoscoping Mask Shapes in Kdenlive

Animating a mask’s shape over time in Kdenlive allows you to isolate, obscure, or highlight moving elements within your video. By using the Rotoscoping effect, you can create a custom shape with control points and use keyframes to adjust those points as your subject moves. This guide provides a straightforward, step-by-step process to apply the Rotoscoping effect, draw your initial mask, and animate its control points across the timeline for precise video editing.

Step 1: Apply the Rotoscoping Effect

  1. Select the video clip on your timeline that you want to mask.
  2. Open the Effects tab (usually located in the bottom-left or side panel).
  3. Search for Rotoscoping in the search bar.
  4. Drag and drop the Rotoscoping effect onto your selected video clip.

Step 2: Draw the Initial Mask Shape

  1. Ensure your playhead is at the exact frame where you want the mask animation to begin.
  2. Select the clip to open the Properties/Effect Stack panel.
  3. Click inside the Project Monitor (the video preview window) to start drawing:
    • Left-click to add control points (nodes) around the object you want to mask.
    • Right-click to connect the last point to the first point, closing the mask shape.

Step 3: Set Up the Animation (Keyframing)

  1. Go to the Properties/Effect Stack panel where the Rotoscoping effect controls are listed.
  2. Locate the timeline ruler inside the effect controls. A keyframe is automatically created at the first frame where you drew your shape.
  3. Move the playhead forward in the timeline to the next point where the object in your video moves or changes shape.

Step 4: Adjust and Animate the Control Points

  1. In the Project Monitor, click and drag individual control points (nodes) to reposition them to match the object’s new position or shape.
  2. To move the entire mask at once, click and drag the center pivot point.
  3. As soon as you adjust any control point at a new frame, Kdenlive will automatically create a new keyframe at that position on the timeline.
  4. Continue this process: move the playhead forward, adjust the nodes, and let Kdenlive auto-generate the keyframes. Kdenlive will smoothly interpolate (transition) the shape of the mask between these keyframes.

Step 5: Fine-Tune the Mask