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Smoothing motion and velocity


    Smooth motion paths, value curves, and velocity curves to eliminate bumpiness or excess keyframes using The Smoother, which adds keyframes or removes unnecessary keyframes. (You can also use the smooth expression to accomplish this. See Property attributes and methods.)

    Although you can smooth a curve for any property, The Smoother is most useful when applied to curves that have been automatically generated by either Motion Math or Motion Sketch, where you may have excess keyframes. Applying The Smoother to keyframes that have been set manually may result in unexpected changes to the curve. (For information on using Motion Sketch, see Using Motion Sketch to draw a motion path.)

    When you apply The Smoother to properties that change spatially (such as position), you can smooth only the spatial curve (the curve defined by the motion). When you apply The Smoother to properties that change only in time (such as opacity), you can smooth only the value and velocity curves (the curve defined by the value or the velocity).

    In addition to adding keyframes or eliminating unnecessary keyframes, The Smoother also applies Bezier interpolation at each keyframe when smoothing the temporal curve.

To smooth a spatial or temporal curve:

  1. In the Timeline window, either select all the keyframes for a property to smooth the entire curve, or select at least three keyframes to smooth only a portion of a curve.
  2. Choose Window > The Smoother.
  3. In the Apply To menu, The Smoother automatically selects Spatial Path or Temporal Graph, depending on the type of property for which you selected keyframes in step 1.

  4. Set a value for Tolerance. The units of Tolerance match those of the property you are smoothing. New keyframe values will vary no more than the specified value from the original curve. Higher values produce smoother curves, but too high a value may not preserve the original shape of the curve.
  5. Click Apply and preview the results.
  6. If necessary, choose Edit > Undo The Smoother to reset the keyframes, adjust the value for Tolerance, and then reapply The Smoother.