• Adobe After Effects Expressions

  Inertia Bounce Decay issue

  Posted by Brad Pickford on August 3, 2015 at 4:11 pm

  Hi all,
  I have been using this expression for years but I have only just stumbled on tis issue. I have an object swinging and as it hits the last keyframe I want it to sway for while (more than one second). When I change the decay value it clips at 1 second from last keyframe. I have included a screenshot of the graph editor where you can see how it stops. Is there a way of changing the expression so that it can decay over periods greater than 1 second?

  

  Cheers!

  amp = .1;
freq = 2.0;
decay = 2.0;
n = 0;
if (numKeys > 0){
n = nearestKey(time).index;
if (key(n).time > time){
n--;
}}
if (n == 0){ t = 0;
}else{
t = time - key(n).time;
}
if (n > 0 && t < 1){
v = velocityAtTime(key(n).time - thisComp.frameDuration/10);
value + v*amp*Math.sin(freq*t*2*Math.PI)/Math.exp(decay*t);
}else{value}

  Jp Pelc replied 9 years, 3 months ago 3 Members · 3 Replies
• 3 Replies

• 

  Dan Ebberts

  August 3, 2015 at 4:32 pm

  Try changing this line:

  if (n > 0 && t < 1){

  to this:

  if (n > 0 && t < 15){

  Dan
• 

  Brad Pickford

  August 4, 2015 at 12:03 am

  As always, PERFECT! Thanks so much Dan!
• 

  Jp Pelc

  January 24, 2017 at 9:24 pm

  Dan you are a true hero

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