• Adobe After Effects Expressions

  Using a marker with specific name to trigger animation multiple times

  Posted by Andrew Millen on March 14, 2019 at 2:03 am

  I’ve got two markers on a shape layer each called “Click.” I use this expression to animate the scale:

  
rampStart = marker.key("Click").time;
rampEnd = marker.key("Click").time + .15;
startVal = [100,100];
maxVal = [85,85];

  rampMid = rampStart + (rampEnd - rampStart)/2;
if (time < rampStart || time > rampEnd){
value
}else if (time < rampMid){
ease(time,rampStart,rampMid,startVal, maxVal)
}else{
ease(time,rampMid,rampEnd,maxVal,startVal)
}


  Using the code found here, I want to replace the “wobble” effect with my own scale expression above AND have it specify the marker by name, not just any marker on the layer.

  
n = 0;
t = 0;
if (marker.numKeys > 0){
n = marker.nearestKey(time).index;
if (marker.key(n).time > time) n--;
}
if (n > 0) t = time - marker.key(n).time;

  amp = 15;
  freq = 5;
  decay = 3.0;

  angle = freq * 2 * Math.PI * t;
scaleFact = (100 + amp * Math.sin(angle) / Math.exp(decay * t)) / 100;
[value[0] * scaleFact, value[1] / scaleFact];


  But I’m not conversant enough in expressions to make it happen. Can anyone help? I’m sure it’s super obvious to someone who knows what they’re doing.

  Andrew Millen replied 7 years, 4 months ago 2 Members · 2 Replies
• 2 Replies

• 

  Oleg Pirogov

  March 14, 2019 at 4:38 am

  I suppose you only need to add a line that checks, if the comment of nearest (from the left) marker equals “Click”:

  theMarker = marker.key("Click");

  n = marker.nearestKey(time).index;
  if (marker.key(n).time > time) n--;
  if (n!== 0 && marker.key(n).comment == "Click") theMarker=marker.key(n);

  rampStart = theMarker.time;
  rampEnd = theMarker.time + .15;
  startVal = [100,100];
  maxVal = [85,85];

  rampMid = rampStart + (rampEnd - rampStart)/2;
if (time < rampStart || time > rampEnd){
value
}else if (time < rampMid){
ease(time,rampStart,rampMid,startVal, maxVal)
}else{
ease(time,rampMid,rampEnd,maxVal,startVal)
}

  P.S. I’ve omitted marker.numKeys > 0 condition since your code assumes there’s at least one marker anyway.
  And if there are several markers with the same comment (a.k.a key(name)) “Click”, this: marker.key(“Click”) – returns the first of them
• 

  Andrew Millen

  March 15, 2019 at 2:21 am

  That did it, thanks!

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