• Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint
Share this Page URL

Lesson 6. Station Identification > Setting the interpolation and velocity

Setting the interpolation and velocity

When creating certain types of motion, like the characters on the pogo sticks, you do not want the animation to progress at a constant rate of speed. The motion should reflect the bounce and peak of the pogo stick character. There should be acceleration on the descent, deceleration on the ascent, and a hold on the apex. To create these effects, you will change the interpolation and the velocity of the animation.

  1. In the Time Layout window, click the triangle next to the Position property. The Speed graph appears. Yours may look slightly different than the one shown below.

    Figure .

    When you create keyframes for any property, like the Position keyframes at 00:07 and 00:15, After Effects interpolates the positions of the layers in the frames between the two keyframes. The default temporal interpolation style is linear. With linear interpolation, the speed of the change between keyframes is uniform and constant and can result in sudden changes at the keyframe. Linear interpolation can give a mechanical and unnatural look to your animation. With Bezier interpolation, the velocity can be set to create a smooth rate of change through keyframes.

  2. Drag the right viewing-area marker to the left until the time ruler is displayed in five-frame increments. If the speed graph is not visible, press the Home key to move to the beginning of the composition.

    Figure . Viewing-area marker

    As you can see from the graph, the segments mapping the change between keyframes are straight.

  3. Press 0 on your numeric keypad to preview the motion with linear interpolation again.

    The speed is constant in between keyframes, but changes abruptly when a keyframe is reached. Now you'll change the interpolation method to Continuous Bezier.

  4. Click the word Position in the Time Lay-out window; all the Position keyframes are selected.

  5. Choose Layer > Keyframe Interpolation. Choose Continuous Bezier from the Temporal Interpolation menu, and click OK.

    Notice that the keyframe icon has changed from a diamond, which represents linear interpolation, to the Bezier interpolation icon. Bezier interpolation automatically creates a smooth rate of change through a keyframe. Notice that the graph curve has smoothed out.

    Figure . Continuous Bezier

  6. Preview the motion by pressing 0 on the numeric keypad.

    The motion should appear somewhat smoother than it did with the linear setting, especially at the top and bottom of the bounce.

    The handles that appear on the graph are known as ease handles and allow you to fine-tune the velocity. You will see a pair of ease handles only for keyframes that are cur-rently selected.

    Figure . Ease handles



Not a subscriber?

Start A Free Trial

  • Creative Edge
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint