• Adobe After Effects

  Trigger “position” with markers

  Posted by Henri Yates on October 25, 2021 at 10:31 am

  Hello, I want to animate “position” of an item. I want that the marker’s comment (which will be a number) to add or subtract from the previous keyframe value and place and new keyframe under the marker.

  For example; the first keyframe (marker, Y Position) is 50, which I initially set. I want the second keyframe value to be the second marker’s comment plus the previous keyframe’s second value (Y Position) which is 50 so the second keyframe will be 5 0+ 150 = 200. And the third keyframe will be 200 + 30 = 230 etc.

  

  Any help?

  Thanks

  Meng Zhiqun replied 4 years, 6 months ago 2 Members · 1 Reply
• 1 Reply

• 

  Meng Zhiqun

  October 30, 2021 at 7:34 am

  You can try this. Put this expression in the position. 🙂

  var aniTime = 10/30;// Change this to change the timing it takes to go up/down.
  n = 0;
  if (marker.numKeys > 0) {
      n = marker.nearestKey(time).index;
      if (marker.key(n).time > time) {
          n--;
      }
  }
  if (n == 0) {
  	var y = value[1];
  }else{
  	var y = value[1] + linear(time, marker.key(n).time, marker.key(n).time+ aniTime, newY().split(",")[0] , newY().split(",")[1]  );
  }
  function newY(){
  	var curYVal = 0;
  	var newYVal = 0;
  	var target = thisLayer;
  	var tNumKeys = target.marker.numKeys;
  	if (tNumKeys > 0) {
  		for (var i=1;i<=tNumKeys;i++){
  			var curKey = target.marker.key(i);
  			if (curKey.time <= time) {
  				newYVal+= Number(curKey.comment);
  				try{
  					curYVal+= Number(target.marker.key(i-1).comment);
  				}catch(e){
  					curYVal = 0;
  				}
  			}
  		}
  	}
  	return curYVal + "," + newYVal;
  }
  var x = value[0];
  [x,y];

  Hope this helps!

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