• Adobe After Effects Expressions

  reducing the effect of keyframes over time

  Posted by Dave Macomber on August 21, 2015 at 7:08 pm

  Hi,

  I have a series of shots with two men running — some were shot handheld, while others were shot stabilized using a Ronin. What I’d like to do is to take one of the Ronin shots (which was shot wide in 4K), add shake to it to match the handheld shots, and have it stabilize over time.

  I’ve motion tracked one of the handheld shots, and have applied that data to a null object, to which my stabilized shot has been parented (although I suspect that isn’t actually what I want…). Is there a way to diminish the effect of the position and rotation keyframes from the tracking data to the stabilized shot over time?

  Thanks,

  Dave

  Dan Ebberts replied 10 years, 8 months ago 2 Members · 1 Reply
• 1 Reply

• 

  Dan Ebberts

  August 21, 2015 at 7:38 pm

  I think you can do it if you define a reference value that you want it to settle into. For rotation (assuming it settles to 0) it would look like this:

  ref = 0;
  beginFade = inPoint;
  endFade = inPoint +5;
  fade = linear(time,beginFade,endFade,1,0);
  ref + (ref – value)*fade;

  and like this for position(assuming it settles to the center of the comp):

  ref = [thisComp.width,thisComp.height]/2;
  beginFade = inPoint;
  endFade = inPoint +5;
  fade = linear(time,beginFade,endFade,1,0);
  ref + (ref – value)*fade;

  Dan

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