AfterEffects

Work with the speed graph

After you have set the shape of a motion path or created keyframes for a property, you can adjust the speed. Using the speed graph, you can adjust the rate of change of a value.

For example, you can change the motion of a layer so that it slows just before a keyframe and then speeds up just after the keyframe, or so that it moves quickly over a certain distance and then slows down smoothly. By adjusting the rise and fall of the speed graph, you can control how fast or slow a value changes from keyframe to keyframe.
Note: Like the value graph, the speed graph displays x, y, and z (3D only) values in different colors: x values are red, y values are green, and z values are blue.
You can control the values approaching and leaving a keyframe together, or you can control each value separately. The incoming handle increases the speed or velocity when you drag it up, and decreases the speed or velocity when you drag it down. The outgoing handle influences the next keyframe in the same way. You can also control the influence on speed by dragging the handles left or right.
Direction handles in speed graphs

A.
Incoming direction handle

B.
Speed control

C.
Outgoing direction handle

Note: If you want a handle to have influence over more than one keyframe, use roving keyframes.

Adjust the rate of change with the speed graph

  1. In the Timeline panel, expand the outline for the keyframe you want to adjust.
  2. Click the Graph Editor button and select Edit Speed Graph from the Graph Options menu .
  3. Using the Selection tool, click the keyframe you want to adjust.
  4. (Optional) Do one of the following:

    • To split the incoming and outgoing direction handles, Alt-drag (Windows) or Option-drag (Mac OS) a direction handle.

    • To join the direction handles, Alt-drag (Windows) or Option-drag (Mac OS) a split direction handle up or down until it meets the other handle.

  5. Do any of the following:

    • Drag a keyframe with joined direction handles up to accelerate or down to decelerate entering and leaving the keyframe.

    • Drag a split direction handle up to accelerate or down to decelerate the speed entering or leaving a keyframe.

    • To increase the influence of the keyframe, drag the direction handle away from the center of the keyframe. To decrease the influence, drag the direction handle toward the center of the keyframe.

    Note: When you drag a direction handle beyond the top or bottom of the Graph Editor with Auto Zoom Graph Height on, After Effects calculates a new minimum or maximum value based on how far you dragged outside the graph, and it redraws the graph so that all the values you specify for that layer property are visible in the graph by default.

Create a bounce or peak

Use direction handles to simulate the type of acceleration seen in a bouncing ball. When you create this type of effect, the speed graph appears to rise quickly and peak.

  1. In the Timeline panel, expand the outline for the keyframe you want to adjust.
  2. Click the Graph Editor button and display the speed graph for the property.
  3. Make sure the interpolation method for the keyframe you want to peak is set to Continuous Bezier or Bezier.
  4. Drag the desired keyframe (with joined direction handles) up until it is near the top of the graph.
  5. Drag the direction handles on either side of the keyframe toward the center of the keyframe.
    Dragging direction handle to create a peak

Start or stop change gradually

Direction handles can create gradual starts and stops, such as a boat slowing to a stop and then starting again. When you use this technique, the speed graph resembles a smooth U shape.

  1. In the Timeline panel, expand the outline for the keyframe you want to adjust.
  2. Click the Graph Editor button and display the speed graph for the property.
  3. Make sure the interpolation method for the keyframe you want to adjust is set to Continuous Bezier or Bezier.
  4. At the desired keyframe, drag the direction handle down until it is near the bottom of the graph.
  5. Drag the direction handles on either side of the keyframe away from the center of the keyframe.
    Dragging the direction handle to make a gradual change

Adjust influence of a direction handle on an adjacent keyframe

Along with controlling the level of acceleration and deceleration, you can also extend the influence of a keyframe outward or inward in relation to an adjacent keyframe. Influence determines how quickly the speed graph reaches the value you set at the keyframe, giving you an additional degree of control over the shape of the graph. The direction handle increases the influence of a keyframe value in relation to the neighboring keyframe when you drag it toward the neighboring keyframe, and it decreases the influence on the neighboring keyframe when you drag it toward the center of its own keyframe.

  1. In the Timeline panel, expand the outline for the keyframe you want to adjust.
  2. Click the Graph Editor button and display the speed graph for the property.
  3. Using the Selection tool, click a keyframe and drag the direction handle left or right.