Non-linear (smooth) keyframes

Handles connected to keyframes control the graph curve that controls how one value changes into another.

• OPTION- or COMMAND-drag on a line to add a non-linear keyframe, dragging out two symmetric handles to create a Bezier curve.
• OPTION- or COMMAND-drag on a keyframe to add handles to a linear keyframe, or reset and redraw the handles on an existing non-linear keyframe.
• Optionally, hold SHIFT while doing this to lock the curve to horizontal (0°).
• OPTION- or COMMAND-click on a keyframe to remove handles and reset the keyframe to linear.
• OPTION- or COMMAND-drag on a handle to split a handle pair and make it asymmetric.
• SHIFT-drag a handle to maintain its current angle and only change distance.