Fine tuning an animation

Now you can improvise adjustments to the animation on your own. For example, you might choose to speed the ball’s horizontal movement up to the first bounce but not thereafter. You might also decide to raise the peak height of the ball’s motion so that it doesn’t seem to hover over the fence unrealistically.

Whatever you choose to do, you’ll likely need to edit both the Translate X and Translate Y curves, not just one of them. Play the animation after each adjustment.

The following two figures show examples of curves after modification. The two graphs are identical, except the curve points are selected in the second figure. The second graph shows the position of the tangent handles.

If you want your curves to match the shape of the curves in the above figure, here’s what you would need to do:

To adjust the animation curves to match the above images

  1. On the Translate X curve, delete the three key points between the two key points at the end. To delete keys, select the key points and press Delete. (The preceding figures show the curve after the points were deleted.) To delete the points, drag a selection box around them and press Delete.

    With fewer key points on the curve, it’s easier to maintain the curve’s smoothness for larger distances as you edit its shape. Small kinks in an animation curve can ruin an otherwise perfect animation, so it’s useful to remove key points that you aren’t using.

  2. On the Translate X curve, select the left-most key point and move its right tangent handle down slightly. (Remember to use the middle mouse button when moving a handle or point.) Select the right-most key point and move its left tangent handle up slightly.

    Notice that the slope of the Translate X curve increases slightly in the early part of the animation, then tapers off toward the end. This causes the ball to accelerate slightly at the beginning of the animation, then decelerate after its first bounce.

  3. On the Translate Y curve, remove the key point at frame 22. (The preceding figures show the curve after the point was removed.) This point wasn’t essential to the curve shape.
  4. On the Translate Y curve, select the left-most key point and move its right tangent handle up slightly.
  5. At the key point where the bounce occurs on the Translate Y curve, move the left tangent handle up a bit. This raises the high part of the curve left of that key point, which makes the ball rise higher over the fence.
  6. If you want to change the shape of Translate Y curve but lack adequate control with the existing key points, you can add a key point at the position of your choice. (No key points were added in the prior figures.) To add a key, click the Add Keys Tool icon , select the curve, and middle-click the desired position on or off the curve.