Time for action — refining the use of the Bézier curve handles
Ironically, you can sometimes get more control by restricting the motion. You'll try limiting the motion of the control handles to a particular axis and you will set the control point so that only one control handle moves at a time:
In the Graph Editor, zoom into the keyframe where you stretched the cube, select one of the handles with theRMB, press the G key to grab it, and move it around with the mouse. Press the Y key. Move the cursor around and observe how this affects the movement.
Press the X key. Move the cursor around and observe how this affects the movement. Press theRMB to release the curve handle without making a change.
Now, select the control point in the center.
Press the V key. Select Free from the drop-down menu as shown in the following screenshot. Pick one of the control handles and move the cursor around and observe how this affects the curve.
What just happened?
You discovered that pressing the X or Y key locks...