A popular effect is to place video inside of text or a shape, and place that on top of a background video. Understanding how to stack clips in Final Cut Pro X, how to group them, and how to apply Blend Modes can help you achieve this effects in really interesting ways. I'll even show you to put one video inside text, that inside a shape, another video as the shape's background, and all of that on top of another video full frame background. Relax, it is a lot easier than it sounds.
Basics first, and that means simply filling the Face of a title with an actual video clip. I'll place a video clip in my Primary Storyline of passing clouds. Just for fun I'll tweak it with some color correction. Then I drop a title connected above it. I'm using the Basic Title with an Arial Black font at 250 points. And just to exaggerate the texture of my background, I'll click the Transform button, lower left of Canvas, and squeeze it down to be only behind the text.
Finally, all I have to do is highlight the Basic Title clip in my timeline, go to the Inspector, and to the Video section. At the bottom of that section is a block called Compositing. I'll change Blend Mode to Stencil Alpha.This uses the alpha channel in my title clip to mask out what we see below it. I could also use Stencil Luma, which uses luma values to do the same thing. White shows through 100%, black masks out, and shades of gray show various opacity percentages between 100% white and 0% black.
In this way, I can use any shape or image that is black and white or gray scale to create very complex and interesting masks. You can even animate a gray scale shape to move and distort in Motion, bring that in to FCPX, and use it as an ever moving, animated mask.
I'm going to connect a copy of the Blobs generator below the Primary storyline now. But I can't see it! That's because the Blend Mode set to the Basic Title clip applies to everything below it, period. Thus I'll click the cloud clip to select it, command-click the Basic Title clip to select it also. Then right-click either and choose 'New Compound Clip', and name it 'Title Compound 1'. Now I can see my Blobs generator. That is because the Blend Mode on the title clip will not effect anything outside of the Compound. The Compound makes it a self-contained effect. This is the key to everything in this article; Blend Modes can't effect anything outside of a Compound Clip.
I'll use the Shape generator, and add it to my timeline. It may sit above the Title Compound 1 clip right off the bat. So I'll pull down, so it sits in between the Title Compound 1 clip and the Blobs generator clip. I'll make it a diamond with a blue outline and drop shadow. Finally I'll go to the Scale parameters in the Inspector, Video section, Transform block, and increase it so my diamond fills the frame.
Since I want to put a video image inside of that shape, but not effect anything else in my timeline, guess what my next move is? Yep, I'm going to right-click it and choose 'New Compound Clip'. This puts the Shape generator clip into its own Compound. I'll call it 'Shape Compound 2'.
To access this new Compound Clip's own timeline, I simply double-click it. I'll drop a video clip below the Shapes generator. Then I'll change the Shapes clip's Blend Mode to Stencil Luma, not Alpha. I want to pull a trick here. Luma is based on how white (100% opacity) or black (0% opacity) or what shade of gray in-between something is. So now I'll change the Shape's outline color by clicking on the color square, not the arrow head for the Outline Color parameter. That brings up the Apple Color Picker, and I'll set it to Steel in the Apple Picker's Crayon section. This makes the outline semi-transparent.
To polish this effect off, I'll move my video clip that is now inside of the shape, over so that my model is centered inside of it.
Clicking the Timeline's Back button (top right of Timeline pane), to get back to my original Timeline. Now you can see the effect that gray outline gives in the overall scheme of things. Not your typical outline, but something that tends to pull the background and the shape mask together more. But I'm not done yet. The text is not all that clear now. It doesn't pop out at me like I want it to.
But that's OK, because I have one last trick up my sleeve. I'm going to the Effects browser (Command-5), select All under the Video heading in the left column, and type Drop in the search field at the bottom of the Effects Browser. I'll apply the Drop Shadow effect to my Title Compound 1 clip. With some adjustments, I can get my text to stand out much more clearly. Drop shadows are almost always applied to titles that sit on top of video that can obscure them.
The point to remember here is that I'm applying the Drop Shadow to the Compound. If I applied it directly to the title clip inside the Compound, it would interfere with the Blend Mode. It wouldn't be a drop shadow, it would add to the area being masked.
This is a pretty simple trick to pull off. Just remember that these Blend Mode tricks, if used with other clips or effects, which they need to be kept separate from, must be placed inside of a Compound Clip. That keeps them isolated so Blend Modes don't effect anything outside of the Compound. And these Blend Mode effect Compounds can be placed on top of each other, in appropriate order, to give layered looks.
You can also animate the titles, shapes, and video clips inside each by keyframing position, rotation, and other parameters. Or by applying other effects to them. Using Blend modes, black & white or grayscale shapes as mask sources, and generators, you can really spice up presentations and videos quite well.