• Adobe After Effects Expressions

  Scale position keyframes with expression

  Posted by Bohdan Stehlik on May 19, 2008 at 1:02 pm

  Hello everybody, this is my first post in the expressions forum.

  My problem is the following : I have a Comp (NTSC – DV – Widescreen Preset), containing multiple layers parented to a null. The null is used to scale and move all the layers together. So far so good.
  Now I need to rebuild all my Comps in HD (HDTV 720 – Squarepix Preset). I can easily position the HD-footage and adjustment layers on the first frame, so they match the SD Comp, but when I paste the null from the SD Comp, the position keyframes are obviously off, since they are in pixel-values and my new Comp is bigger.

  Is it possible to scale the position keyframes with an expression, so the movement would be in the same proportions as in my SD Comp?

  I hope all this makes sense.

  Many thanks in advance for your responses!

  Bohdan

  P.S. There is a wiggle expression on the position keyframes, if that makes any difference.

  Bohdan Stehlik replied 17 years, 12 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Dan Ebberts

  May 19, 2008 at 1:42 pm

  You should be able to do it by encasing your wiggle expression in somethng like this:

  xRatio = 1280/720;
  yRatio = 720/486;
  w = wiggle(1,50); // use your wiggle expression here
  [w[0]*xRatio, w[1]*yRatio]

  Dan
• 

  Bohdan Stehlik

  May 19, 2008 at 4:51 pm

  Thank you very very much, Dan!

  Your expression is the solution, and saves me over a week of work…..I have to redo more than fifty comps.

  I am extremely grateful for your help!

  Bohdan

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