Above, you can see a simple position animation of an object appearing on the screen using the Track Matte feature. This can be used for introducing logos, text, icons, or any other object into your video without the standard fade transition.
There are lots of cool ways to make objects or text appear or disappear in After Effects. One of my favorites is by using the Track Matte feature. The basic premise is that you create a shape that creates the ‘visible boundary’ by which your object can be seen or not. So wherever the shape is, your object will appear. Wherever your shape isn’t, your object doesn’t appear.
That may seem kind of confusing, so it is a lot easier to explain it through steps, pictures, gifs, and examples. Keep reading to find out how to implement this technique with your own videos.
Here’s an example of when you would practically use this – GoPro’s bumper:
Create your composition. Add object/text that you want to disappear.
Create a shape layer that will cover your object/text. It doesn’t matter what color. Make sure this layer is directly above your object.
Hit the ‘Toggle Switches / Modes’ button to bring up the TrkMat option for your layers.
Change the Track Matte of your object/text layer to ‘Alpha Matte.’
Now your object/text only appears wherever the shape layer (alpha layer) is. Try moving the shape layer and your object around to see how this is working. Also, check out the GIFs below to see this in action.
You can now add motion to the shape layer or object/text layer to make it appear or disappear. For example, set two position keyframes for your object: one with the object completely out of site (not where the shape layer is), and one with your object inside of the shape.
Above, you can see me moving around the ‘Shape Layer 1’ alpha layer. It shows how the object will only appear wherever the shape is.
Above, you can see me moving around the object/text layer. Again, it only appears where the alpha layer (Shape Layer 1) is. If you add motion to this object/text layer with keyframes, you can make it appear or disappear. See the GIF at the top of this post for an example of how this can be done.
Do you want to learn more about video creation?
Watch this YouTube tutorial on how to do it: