5

Modifying Curves
The Keyframe Editor lets you make changes to the curves between keyframes. This might
be the Keyframe Editor’s most valuable feature. Although you can manually create nearly
any curve shape to create the animation you want, Motion also provides tools to control
the automatic interpolation and extrapolation of parameter values.
To set the interpolation for a curve, you select the keyframe you want to modify. The
method you choose determines the distribution of values through, into, or out of the
selected keyframe. By using different preset mathematical algorithms, you can dramatically
alter the impact of your effects.
To set an interpolation method for a keyframe
µ
Control-click a keyframe, choose Interpolation from the shortcut menu, then choose a
method from the submenu.
µ
Select multiple keyframes, Control-click one of them, choose Interpolation from the
shortcut menu, then choose a method from the submenu.
The interpolation method chosen is applied to the entire selection.
To set an interpolation method on a curve segment
µ
Control-click a segment between two keyframes, choose Interpolation from the shortcut
menu, then choose a method from the submenu.
Only the segment between the surrounding two keyframes is affected by the interpolation
method you choose. You can set different interpolation methods for other segments of
the same curve.
619Chapter 12 Keyframes and Curves