Hi, I'm new to After Effects and am wondering if anyone knows how to create the appropriate masks for this odd-shaped object? I'd like to highlight each section (1, 2, 3) in succession using a shape that is, say 10 percent filled. To get the curve at the base of the shape, I figured I should use a circle mask. But what about the sides?
That shape is not odd. You just have to use Pen Tool and draw Bezier shape wit it.
You can find more on that here:
Effects --> Generate --> Circle
Effects --> Transition --> Radial Wipe
All you are ever going to need.