• Adobe After Effects Expressions

  random pick a comp, play through it, random pick another

  Posted by Victor Jantea on February 11, 2018 at 11:16 pm

  hi everyone
  what i would like to ideally have happen is this:
  one of 7 comps is randomly chosen, it fades in, plays through, another one of the comps is chosen, the first fades out as the second fades in and so on.

  i am selecting one of the comps with a (random) slider, and ideally, when the slider animates (and holds for a while) to an integer between 1 and 7, that comp starts to fade in (as the old one fades out), holds 100% opacity for a while, fades out and so on… the big advantage being that i can smoothly scale the durations of the fade in/out/hold of the comps

  so far i’ve managed to: get some checkboxes to randomly turn on one at a time and get a comp to fade out every time a checkbox turns to OFF. but i can not figure out how to get it to also fade in as the checkbox turns to ON in the same expression, it’s either one or the other and i need both… i probably need a WHILE or a FOR expression going back from current playhead time but it’s really exhausted me just from figuring the rest out… help? ☺ thank you!

  t=time
fadeTime=effect("fade")("Slider")
threshold = 0.5
above = false
frame = Math.round(time / thisComp.frameDuration)

  while (true){
  t = frame * thisComp.frameDuration;
  if (above){
  if (thisComp.layer("test slider to checkbox").effect("check 1")("Checkbox").valueAtTime(t) < threshold){
  frame++;
  break;
  }
  }else if (thisComp.layer("test slider to checkbox").effect("check 1")("Checkbox").valueAtTime(t) >= threshold){
  above = true;
  }
  if (frame == 0){
  break;
  }
  frame--
  }
  if (! above){
  t = 0;
  }else{
  t = time - frame * thisComp.frameDuration;
  }

  ease(t,0,fadeTime,value,0)

  //https://forums.adobe.com/thread/2267339

  Victor Jantea replied 8 years, 3 months ago 1 Member · 0 Replies
• 0 Replies

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