If you use a track matte, no matter where you move your layer, the track matte stays in place. What that means for you is that if you put a mask onto a layer, then move the layer, the mask goes with it.
Now, you might be asking, why not use a mask? Here’s the main difference: Track mattes are not layer dependent, masks are. You want a picture of a flower placed in your text? Or a graphic to hide your video clip until you want it to be revealed? Track mattes are your friend. Simply put, you can shape a particular layer using the appearance of a track matte above it. Track mattes are a fun and powerful tool in After Effects that allows you to use a clip, still image, or text to dictate the transparency of the layer beneath.
This step-by-step tutorial will equip you with the essential skills to insert visuals into other objects and hide objects during animations, increasing the range of effects you can create. Discover how to effectively use "Track Mattes" and the "Preserve Transparency" tool in After Effects.