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  • Weird “ghost” keyframes…

    Posted by Maxime Marquis on January 12, 2010 at 3:52 pm

    I’m animating a camera using a Null object with separate XYZ. Between two identical keyframes on X value (i.e. the value is the same on position A and B) , for no reasons, the value changes anyway. An example: X value at 10:00 is 0, x value at 10:16 is 0 but the value between the two key frame will change going from 0 to 5 and going back to 0.

    And no, there are no other keyframes or expressions on the camera or any other layer that could explain the change.

    It happens to me once in a while. The only way to arrange this is to erase all the keyframes of the problematic section, and the one following, and keyframing again.

    Any ideas what’s wrong?

    AE CS4, DVCPRO HD 24p footage

    Christopher R. green replied 16 years, 3 months ago 3 Members · 6 Replies
  • 6 Replies
  • Wieger De leur

    January 12, 2010 at 4:07 pm

    Hi Maxime,

    This is probably an interpolation issue; change the first of the identical keys to a hold-keyframe and it will be solved.

    Cheers,
    Wieger

  • Maxime Marquis

    January 12, 2010 at 4:32 pm

    Thanks, I’ll try that.

  • Maxime Marquis

    January 12, 2010 at 4:34 pm

    It works, thanks. I still don’t know what causes it. Did I press the wrong button somewhere?

  • Maxime Marquis

    January 12, 2010 at 8:43 pm

    Thanks Dave, I’ll have a look.

  • Christopher R. green

    January 13, 2010 at 8:19 pm

    [Maxime Marquis] “The only way to arrange this is to erase all the keyframes of the problematic section, and the one following, and keyframing again.”

    There is another issue with keyframes that I feel should be mentioned (and may or may not have anything to do with what you’re describing).
    Linear keyframes used to behave differently (sorry, I won’t be able to give you exact version-specificity here). In the old days, when you made a linear (default) keyframe, you could rely on the motion to be perfectly, well, linear. Nowadays, you may find that sometimes there is some floating going on close to the keyframes, and that the motion has curves to it. This graphic shows you what linear keyframes look like when applied to a solid position:

    This can be seen only when you have “Motion Paths” selected in the View Options. The solution below requires this also. When dealing with camera animation, you need to switch from “Active Camera” view to another view, like “Front” (or another camera).
    My favorite way of dealing with this, when I want to be sure I have true linear movement (no curving, easing, etc.) is to do the following (Windows users, please excuse the mac-specific key command here; I’m sure you can work out the equivalent): Float your cursor over the keyframe in the Composition window, hold down Command-Option and notice the cursor changes to the bezier control/break tool. If you click on the keyframe, the bezier curves will ‘break’ and become perfectly linear.

  • Christopher R. green

    January 13, 2010 at 8:25 pm

    [sorry; this was in error, and i cannot delete the post]

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