[property name] line, and drag it to the Slider property name in the Audio Amplitude
layer. When you release the mouse, the pick whip snaps, and the expression in the
shape layer time ruler now means that the property values for the layer will depend on
the Slider values of the Audio Amplitude layer.
Review questions
1 What is a shape layer, and how do you create one?
2 How can you create multiple copies of a layer, including all of its properties?
3 How can you snap one layer to another?
4 What does the Pucker & Bloat path operation do?
Review answers
1 A shape layer is simply a layer that contains a vector graphic called a shape. To create a shape
layer, draw a shape directly in the Composition panel, using any of the drawing tools or the
Pen tool.
2 To duplicate a layer, select it, and choose Edit > Duplicate, or press Ctrl+D (Windows) or
Command+D (macOS). All of the original layer’s properties, keyframes, and other attributes
are included in the new layer.
3 To snap one layer to another in the Composition panel, select Snapping in the options section
of the Tools panel. Then click next to the handle or point you want to use as a snapping
feature, and drag the layer close to the point to which you want to align it. After Effects
highlights the points to which it will align when you release the mouse button.
4 Pucker & Bloat pulls the vertices of a path outward while curving the segments inward
(puckering), or pulls the vertices inward while curving the segments outward (bloating). You
can animate the degree of pucker or bloat over time.