• Adobe After Effects Expressions

  Give me the way to reverse Expresstion

  Posted by Trung Lê on December 25, 2020 at 10:53 pm

  freq = 1;

  decay = 8;

  duration = 0.25;

  retard = textIndex*thisComp.frameDuration*1;

  t = time – (inPoint + retard);

  startVal = [100,100,100];

  endVal = [0,0,0];

  if (t < duration){

  linear(t,0,duration,startVal,endVal);

  }else{

  amp = (endVal – startVal)/duration;

  w = freq*Math.PI*2;

  endVal + amp*(Math.sin((t-duration)*w)/Math.exp(decay*(t-duration))/w);

  }delay = .05;

  myDelay = delay*textIndex;

  t = (time – inPoint) + myDelay;

  if (t >= 0){

  freq =10;

  amplitude = 100;

  decay = 2;

  s = amplitude*Math.cos(freq*t*0.1*Math.PI)/Math.exp(decay*t);

  [s,s]

  }else{

  value

  }

  Dan Ebberts replied 5 years, 9 months ago 2 Members · 1 Reply
• 1 Reply

• 

  Dan Ebberts

  December 26, 2020 at 3:42 pm

  That’s a strange expression. It appears that the first chunk, down to the

  }delay = 0.05;

  line, doesn’t actually do anything. Getting the last part to run in reverse would be tricky, because it doesn’t really have an end time (it’s an exponentially decaying cosine wave), so it would be hard to pick a start time for the reverse action.

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