Compositing is the process by which you combine multiple video layers, usually with special effects such as animations, painted images and digital transformations, using filters.

Setting the composition style for a clip: The composition style controls how the colors in a clip are combined with the colors in clips in the underlying layers of the video.

All composition happens from top to bottom. The top track in the Timeline takes priority. The image of the highest track hides the tracks below it.

To sort the composition style for a clip:

  • Select the clip in the Timeline
  • Open the Modify menu and select Composite Mode, then select the item you want from the sub-menu.

Composition styles create a variety of effects. Experiment to find the best style for your clip. For details on composite style options, see “Setting the Clip Composite Mode” in chapter 12 of the FCP User's Guide.

Using Travel matte

One compositing style, the travel matte, is useful for playing one clip through another, just as video images play under a title or graphic design. You can also use a travel matte to hide part of the image that you don't want to show.

To create a travel matte:

  • Place the clip you want to use as a "mask" on a video track (V1 or a different track, if desired) in the Timeline.
  • Place the clip you want to mask through (the main clip) on the track immediately above the mask clip (track V2, for example).
  • Select the clip on the top track (the main clip).
  • Open the Modify menu and select Composite Mode, then select one of the two Travel Matte options from the sub-menu. The Alpha option uses the clip's alpha channel, if any, as a 'mask'. The Luma option uses the luminance, or black and white image, of the clip as a 'mask'. The RBG information of the matte clip will not be visible.
  • Select one of the clips and render the area (choosing Render Selection from the Sequence menu) to render the edited area of the sequence.