• Adobe After Effects Expressions

  Using loop expressions in conjunction with other expressions

  Posted by Seymour Frost on May 17, 2022 at 3:11 pm

  Hello! Is there any way to use a loop expression on a property that already has an expression on it? The problem I came across was in building a simple rig that used an expression on the scale property to maintain the volume of an object. But then, when I went to put an loopOut() expression on this property, it would not loop.

  on scale:

  var x = value[0];

  var xFactor = (100 – x);

  var y = 100 + xFactor;

  [x, y];

  and then to loop the set of keyframes I made, regardless of whether I needed to move the keyframes in the comp:

  loopIn() + loopOut() – value;

  I’ve tried redefining the value as the returned array from the first part of the code, but that didn’t work. I thought that the loop expressions simply read the value of the keyframes that were set, and thus wouldn’t be impacted by any expressions making calculations on every frame. Am I just fundamentally misunderstanding something?

  Thanks!

  Seymour Frost replied 4 years, 4 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Dan Ebberts

  May 17, 2022 at 4:18 pm

  I think you just need to stick the result of your loop calculation into a variable and use that instead of value in the other part of your expression, like this:

  val = loopIn() + loopOut() - value;
  x = val[0];
  xFactor = (100 - x);
  y = 100 + xFactor;
  [x, y];
• 

  Seymour Frost

  May 17, 2022 at 5:05 pm

  Thanks so much, Dan! That, of course, worked brilliantly.

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