• Adobe After Effects Expressions

  Change Specific Position to Random Motion

  Posted by Neil Floyd on September 14, 2012 at 11:57 am

  Hi there, I have an expression that works fine but I want it to do the opposite. I have an image that I want to randomly move across the screen and then end at 232,100. I have it at one speed for 3 seconds and then I want it to speed up for the rest of the comp. So I duplicated the layer and changed the speed but I want the startPos to be the same as the finalPos on the other layer. Anyone be able to help me with this. I know it’s something simple I’m just missing.

  Or if someone knows how I could make it start at 232, 100 then be random and end at 232, 100 after 30seconds. Thanks in advance

  finalPos = [232,100];
  maxTime = 3;
  transitionTime = 0;

  segDur = 2;// duration of each “segment” of random motion
  minVal = [0.1*thisComp.width, 0.1*thisComp.height];
  maxVal = [0.9*thisComp.width, 0.9*thisComp.height];

  t = Math.min(time, maxTime);
  seed = Math.floor(t/segDur);
  segStart = seed*segDur;
  seedRandom(seed,true);
  startVal = random(minVal,maxVal);
  seedRandom(seed+1,true);
  endVal = random(minVal,maxVal);
  randPos = ease(t,segStart,segStart + segDur, startVal, endVal);

  ease(time,maxTime,maxTime + transitionTime,randPos,finalPos)

  Neil Floyd replied 14 years ago 1 Member · 0 Replies
• 0 Replies

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