Creating the composition
Next, you’ll import the background movie and create the composition.
Click New Composition From Footage in the Composition panel.
Navigate to the Lessons/Lesson04/Assets folder on your hard disk, select the Background.mov file, and then click Import or Open.
After Effects adds the Background.mov file to the Project panel, creates a composition based on the Background.mov file, and opens the new composition in both the Timeline and Composition panels.
Press the spacebar to preview the background movie. In the scene, night turns to day, as the sky lightens and the colors brighten.


