• Adobe After Effects Expressions

  Animate text on per letter using a custom flicker expression

  Posted by Tom Holmes on July 10, 2017 at 6:34 am

  I have the following expression which animates a layers opacity on in a flickering fashion:

  if (time < inPoint || time > outPoint){
  f = 0;
  }else if (time < (inPoint+outPoint)/2){
  f = timeToFrames(time – inPoint);
  }else{
  f = timeToFrames(outPoint – time);
  }
  switch(f){
  case 0:
  case 2:
  case 4:
  case 6:
  0;
  break;
  case 1:
  25;
  break;
  case 3:
  50;
  break;
  case 5:
  75;
  break;
  case 7:
  100;
  break;
  default:
  100;
  break;
  }

  Is there a way I can adapt and use this with a text layer’s animate and expression selector so the letters animate on separately (either randomly or in sequence) with this same animation.

  Thank you! ☺

  Tom

  Tom Holmes replied 8 years, 10 months ago 2 Members · 4 Replies
• 4 Replies

• 

  Dan Ebberts

  July 10, 2017 at 3:51 pm

  Add an Opacity Animator, set its value to 0, and an Expression Selector and use this for Amount:

  
totalDur = 1.0;
myStart = inPoint + (textIndex-1)*totalDur/textTotal
myEnd = outPoint - (textIndex-1)*totalDur/textTotal;
if (time < myStart || time > myEnd){
f = 0;
}else if (time < (myStart+myEnd)/2){
f = timeToFrames(time - myStart);
}else{
f = timeToFrames(myEnd - time);
}
switch(f){
case 0:
case 2:
case 4:
case 6:
100;
break;
case 1:
75;
break;
case 3:
50;
break;
case 5:
25;
break;
case 7:
0;
break;
default:
0;
break;
}


  Dan
• 

  Tom Holmes

  July 10, 2017 at 5:14 pm

  Thank you so much Dan! You’re such a huge help.

  How could make the letters appear in a random order instead of in sequence?

  Thanks

  Tom
• 

  Dan Ebberts

  July 10, 2017 at 8:09 pm

  Like this maybe:

  totalDur = 1.0;
seedRandom(textIndex,true);
myStart = inPoint + random(totalDur - framesToTime(8));
myEnd = outPoint - random(framesToTime(8),totalDur);
if (time < myStart || time > myEnd){
f = 0;
}else if (time < (myStart+myEnd)/2){
f = timeToFrames(time - myStart);
}else{
f = timeToFrames(myEnd - time);
}
switch(f){
case 0:
case 2:
case 4:
case 6:
100;
break;
case 1:
75;
break;
case 3:
50;
break;
case 5:
25;
break;
case 7:
0;
break;
default:
0;
break;
}


  Dan
• 

  Tom Holmes

  July 10, 2017 at 8:24 pm

  Perfect, you’ve done it again.

  Thank you so much!

  Tom

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