• Adobe After Effects Expressions

  Randomize numbers without having the same value occuring twice?

  Posted by Mikael Holmström on June 28, 2021 at 1:57 pm

  Hi,

  Let’s say I have ten layers of text. By an expression I’d like to assign text of sourceText a value between 1 and 10. I want them to be randomly ordered, but never to occur twice within my 10 text later. So, the result could look something like this (layer by layer):

  [5, 3, 1, 8, 2, 9, 4, 7, 6]

  But never, for instance:

  [5, 3, 1, 1, 2, 9, 4, 7, 6]

  Is there a way to accomplish this?

  Andrei Popa replied 5 years, 1 month ago 2 Members · 1 Reply
• 1 Reply

• 

  Andrei Popa

  June 28, 2021 at 3:12 pm

  You can make a master layer, and add this expression to text

  function shuffle(array) {
    var currentIndex = array.length,  randomIndex;
    // While there remain elements to shuffle...
    while (0 !== currentIndex) {
      // Pick a remaining element...
      randomIndex = Math.floor(Math.random() * currentIndex);
      currentIndex--;
      // And swap it with the current element.
      [array[currentIndex], array[randomIndex]] = [
        array[randomIndex], array[currentIndex]];
    }
    return array;
  }
  var arr = [1,2,3,4,5,6,7,8,9,10];
  "["+shuffle(arr).join(",")+"]"

  Then, to each layer add this expression. Assign firstIndex as the index of your first text layer.

  firstIndex = 2;
  val = eval(thisComp.layer("Master layer").text.sourceText)[index-firstIndex];
  val

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