sourceRectAtTime(); | After Effects Expressions

sourceRectAtTime() is a crazy useful expression, but there isn&a great explanation of what it exactly does, or how to wrangle it to do what you want. In this tutorial I&demystify this expression and teach everything you need to use it to your full advantage. Feel free to ask questions or leave feedback in the comments! And if you have any ideas for other tutorials, I&all ears!