Inertial Bounce Expression

inertial-bounce-expression-after-effects.js

amp = .06; // amplitude
freq = 2; // frequency 
decay = 7; // decay (the more the value, the faster oscillations fade)
//----------------------------------
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){ 
  v = velocityAtTime(key(n).time - thisComp.frameDuration/10); 
  value + v*amp*Math.sin(freq*t*2*Math.PI)/Math.exp(decay*t); 
}else{ 
  value; 
}