I have an animation in After Effects where I am animating a slider to move up and down at certain points. The slider should be mainly stationary, but moves occasionally in line with other actions on the project.

enter image description here

What I am finding though, is the slider is moving a small amount even when the keyframes are set such that it should be static. E.g. the following two keyframes are the same (Y position = 524.6) but if I move the marker in between, you'll see the value deviates from this. (As a result the slider moves.)

1st Keyframe (Y Position = 524.6): 1st Keyframe

2nd Keyframe (Y Position = 524.6): 2nd Keyframe

In between (Y position varies, up to 525.4): In between

This is driving me nuts! As far as I can see the anchor point does not move, so I don't understand why this should happen.

  • 1
    Do you have a splined move between the keyframes?
    – Jim Mack
    May 6 '15 at 16:07
  • What is a splined move? ;-) (Possibly - how do I tell?)
    – Ben
    May 6 '15 at 16:30
  • 1
    I can't give you the AE settings but when you have two position keyframes you can choose to move between them linearly or with a curve / easing / spline to smooth the motion. Sometimes even when the positions are the same, the tension of the spline results in a bump.
    – Jim Mack
    May 6 '15 at 17:11

It's because of spatial interpolation. Here's a previous answer:

Object moving to a position I didn't specify

Not the answer you're looking for? Browse other questions tagged or ask your own question.