Apple Motion 3 - Manual (Page 517)

Chapter 6 Keyframes and Curves 517
5 Click the Inspector tab where the parameter you want to modify is located (filters in
this example).
6 Set the parameter to the beginning value.
7 Move the playhead to a new position.
8 In the Inspector, change the parameter to a new value.
9 Click the Record button (or press A) again to disable record.
The parameter now changes over time.
Animation Menu
Animating in the Inspector provides additional options, such as the ability to delete or
reset keyframe information. You can also navigate between keyframes in the Inspector.
Every keyframeable parameter contains an Animation menu. If a parameter lacks a
menu, it cannot be animated.