• Adobe After Effects Expressions

  expression for color control – frame hold – slider number?

  Posted by Bart Stevens on May 19, 2013 at 5:20 pm

  I’m using a great expression from created by Filip Vandueren
  to create a random fill effect via color control expressions.

  Currently the colors change every frame, what I would like to have a is a slider that determines how many frames the colors hold. 1 would be like it currently is (updating every frame), 2 it would hold for 2 frames, etc…

  Not exactly sure how to go about this,

  Here is the expression I’m using for the random fill:

  l=thisComp.layer(“Colors”);
  i=1;
  colors=[];
  try {
  while(l.effect(i)) {
  if (l.effect(i)(1).name==”Color”) {
  colors.push(l.effect(i)(1).value);
  }
  i++;
  }
  } catch (e) {}
  if (colors.length) {
  r=Math.floor(random(colors.length));
  colors[r];
  } else {
  value;
  }

  Thanks for the help

  Bart Stevens replied 12 years, 12 months ago 2 Members · 4 Replies
• 4 Replies

• 

  Dan Ebberts

  May 19, 2013 at 6:44 pm

  Adding this to the beginning or your expression should work:

  s=Math.max(Math.round(effect(“Slider Control”)(“Slider”)),1);
  f=timeToFrames(time);
  seed = Math.floor(f/s);
  seedRandom(seed,true);

  Dan
• 

  Bart Stevens

  May 20, 2013 at 4:17 pm

  Thanks Dan,
  This works great if my slider is on the same layer, but I have my slider on another layer called “Colors”.
  I tried modifying your expression, but the language is still off.
  Any ideas why it’s not seeing the slider on the master layer?

  s = thisComp.layer("Colors").effect("Slider Control")("Slider").value;
s=Math.max(Math.round(effect("Slider Control")("Slider")),1);
f=timeToFrames(time);
seed = Math.floor(f/s);
seedRandom(seed,true);
• 

  Dan Ebberts

  May 20, 2013 at 4:28 pm

  Try it this way:

  slider = thisComp.layer(“Colors”).effect(“Slider Control”)(“Slider”).value;
  s=Math.max(Math.round(slider),1);
  f=timeToFrames(time);
  seed = Math.floor(f/s);
  seedRandom(seed,true);

  Dan
• 

  Bart Stevens

  May 20, 2013 at 5:23 pm

  Great, thanks again Dan

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