Create Seamless Mask Transitions in Final Cut Pro (No Plugins)

A mask transition uses something in the foreground of your shot (an arm, a door, a passing object) to naturally wipe between two clips. When done well, it looks cinematic and intentional. Here's how to build one from scratch in Final Cut Pro without any third-party plugins.

Choose the right shots

The key requirement is a shot where something enters the frame and covers most or all of it. This is your wipe element. The second clip needs to match direction: if the wipe moves left to right, the second clip should feel like it continues the same movement. The more similar the two shots are in camera angle and motion, the more seamless the result.

Stack the clips

Place Clip A (your wipe clip) on the primary storyline. Place Clip B (the destination clip) as a connected clip below it in the timeline. To prevent the magnetic timeline from pulling things out of position, add a gap clip underneath if needed.

Apply the Draw Mask to Clip A

With Clip A selected, go to the Effects Browser and find Draw Mask. Apply it to the clip. In the Viewer, click to create mask points tracing the edge of your wipe element. Hold Cmd while dragging a point to create a curve. The masked area shows the clip below (Clip B) through the "hole" you're cutting.

Keyframe the mask frame by frame

This is the work. Move to the start of the wipe, click the keyframe buttons for Transform and Control Points in the Inspector, then step forward 2 to 3 frames at a time and adjust the mask to track the edge of the wipe element. FCP interpolates between keyframes, but check the in-between frames and correct any tracking drift. The more carefully you track, the cleaner the final result.

Set composite mode and feather

Set Clip A to Composite mode. Add feathering to the mask edge to soften any hard lines. A feather of 5 to 15 pixels usually looks natural. The goal is that the transition reads as organic movement rather than a clearly edited composite.