• Adobe After Effects Expressions

  Trigger Expression for X value

  Posted by Victor Nash on January 3, 2008 at 8:20 pm

  I looking to fly in an object on it’s x axis and bounce to still when it hits the center mark.. I’ve added a “marker” to trigger the expression. My question is how to modify this expression to trigger the expression again further down in the timeline. It seems like the “bounce” is relative to the beginning of the ‘time’line. Thanks Guys

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

  if (n == 0){
  value;
  }else{
  veloc = 35;
  amplitude = 150;
  decay = 4;
  t = time – marker.key(n).time;
  x = amplitude*Math.cos(veloc*time)/Math.exp(decay*time);
  value+[x,0];
  }

  Victor Nash replied 18 years, 4 months ago 2 Members · 3 Replies
• 3 Replies

• 

  Victor Nash

  January 3, 2008 at 8:52 pm

  Opps I see what I did.. Thanks anyway.

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

  if (n == 0){
  value;
  }else{
  max_dev=35; // max deviation in pixels
  spd=150; //speed of oscillation
  decay=4; //how fast it slows down
  t = time – marker.key(n).time;
  x = max_dev*Math.sin(spd*(t))/Math.exp(decay*t);
  value + [x,0];
  }
• 

  Dan Ebberts

  January 3, 2008 at 8:53 pm

  Just change “time” to “t” in the line that calculates the bounce, like this:

  x = amplitude*Math.cos(veloc*t)/Math.exp(decay*t);

  That should make it trigger at each marker.

  dan
• 

  Victor Nash

  January 3, 2008 at 8:55 pm

  haha. I beat you Dan 🙂

  When Is your Master Series of Expressions Coming Out? 🙂

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