Keyframe Thinning

Due to the way keyframing works, if the playhead is at a new frame, and you set a new value for a parameter, a keyframe is added. For animating while the project is playing, this might mean setting a new keyframe on every single frame. This doesn’t create a problem until you want to make a change to the curve.

In many cases, the curve created by your animation can be represented using fewer keyframes. Often, this will provide a smoother rate of change and will enable you to take advantage of the various interpolation methods such as Ease In and Ease Out.

You can simplify your keyframes in two ways: either while you are recording them, or afterwards, by simplifying an existing animation curve using the Reduce Keyframes command in the Animation menu for that parameter.

Figure. Keyframe Editor showing a parameter with reduced keyframes.

Recording Options

The Recording Options dialog allows you to set the Keyframe Thinning setting, to record only on parameters that are already animated or to disable recording during playback.

The Keyframe Thinning setting only applies to recording animation while playing back. This setting has no effect on ordinary keyframing.

To access Recording Options
Do one of the following:
  • Choose Mark > Recording Options (or press Option-A).

  • Double-click the Animate button.

    The Recording Options dialog appears.

Figure. Recording Options dialog.
  • Keyframe Thinning: There are three options of how thinning can be applied.
    • Off: No thinning is applied. Keyframes are applied at every frame where the parameter is changed.
      Figure. Keyframe Editor showing a curve with no thinning applied.
    • Reduced: Motion eliminates keyframes that can easily be replaced with a simple curve.
      Figure. Keyframe Editor showing a curve with reduced keyframes.
    • Peaks Only: Only keyframes with dramatic value changes are recorded.
      Figure. Keyframe Editor showing a curve with peaks-only thinning applied.
  • Don’t record keyframes during playback: When this checkbox is selected, keyframes are not recorded while the project is playing back.
  • Record keyframes on animated parameters only: When this checkbox is selected, keyframes are recorded only on parameters that are already animated.

Disabling Animation While Playing

If you leave the Record button on, keyframes are added whenever you make adjustments. If you want to restrict keyframing to when the project is not playing, you can disable that feature individually.

To disable animation recording while playing
  1. Choose Mark > Recording Options.

    The Recording Options dialog appears.

  2. Select “Don’t Record keyframes during playback.”

  3. Click OK.

Recording Keyframes on Animated Parameters Only

When “Record keyframes on animated parameters only” is selected, keyframes are added only to parameters that are already animated. For example, if the position of a shape is animated (keyframed) and “Record keyframes on animated parameters only” is enabled, only changes made to the position of that object are keyframed. If you change the color of the object over time, the color changes are not keyframed—even when the Record button is enabled.

Important: The Record button must be on when using the “Record keyframes on animated parameters only” option. You can still manually add keyframes, regardless of whether or not Record is enabled, by using the Animation menu in the Inspector or Keyframe Editor list, or by pressing Option-K.

Tip: If you are a Final Cut Pro user, it is recommended that you use this option to emulate the workflow with which you are familiar.

To record keyframes on animated parameters only
  1. Enable Record (or press A).

  2. Choose Mark > Recording Options (or press Option-A).

  3. Select “Record keyframes on animated parameters only.”

  4. Click OK.

    Keyframes are now added only when you make changes to parameters that are already animated. To observe how the “Record keyframes on animated parameters only” works, walk through the following brief exercise.

To see the “Record keyframes on animated parameters only” in action
  1. Enable Record (press A).

  2. Choose Mark > Recording Options, and make sure “Record keyframes on animated parameters only” in the Recording Options dialog is turned off, then click OK.

  3. At frame 1 (press Home), draw a shape in the Canvas and move the object into a start position.

    A position keyframe is created.

  4. Advance to a different frame and move the object into another position.

    A second position keyframe is created.

  5. Choose Mark > Recording Options, and select “Record keyframes on animated parameters only” in the Recording Options dialog, then click OK.

  6. Go to a frame in between the two position keyframes, and move the shape in the Canvas.

    A third position keyframe is added.

  7. At frame 1 (press the Home key), click the Fill color well in the shape’s HUD, then change the color of the object.

    Figure. HUD showing rectangle Fill color set to white.
  8. Advance to a different frame, then change the color object again.

  9. Go to frame 1 and click the Play button (or press the Space bar).

    Notice that the position of the object is animated, but the color is not. This is because the shape had position keyframes when “Record keyframes on animated parameters only” was selected.