Scale Down Bounce Expression

[chrisc59063722]

I have a bounce expression that works when scaling up, but it doesn't work when I scale down. I need an expression that adds a bounce when scaling down. 

[Dan Ebberts]

What's the scale up expression? It should help to define the kind of motion you're looking for on scale down.

[chrisc59063722]

This is the expression I use. 

amp = .03;

freq = 3.0;

decay = 5.0;

n = 0;

time_max = 4;

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 < time_max){

v = velocityAtTime(key(n).time - thisComp.frameDuration/10);

value + v*amp*Math.sin(freq*t*2*Math.PI)/Math.exp(decay*t);

}else{value}

Numbers with Commas

var num = effect("Slider Control")("Slider")

num = Comma(num);

[num]

function Comma(number)

{

number = '' + Math.round(number);

if (number.length > 3)

{

var mod = number.length % 3;

var output = (mod > 0 ? (number.substring(0,mod)) : '');

for (i=0 ; i < Math.floor(number.length / 3); i++)

{

if ((mod == 0) && (i == 0))

output += number.substring(mod+ 3 * i, mod + 3 * i + 3);

else

output+= ',' + number.substring(mod + 3 * i, mod + 3 * i + 3);

}

return (output);

}

else return number;

}

[Dan Ebberts]

It works for me, going in either direction (it even goes below zero if your last keyframe is close enough to zero). What's the particular issue you're seeing?

[chrisc59063722]

How's it's working for you? I am trying to get the bounce to scale up before scaling down.

[Dan Ebberts]

The expession you posted is for inertial overshoot--it keeps going in the direction it's moving, goes past the stopping point, and then settles out. It sounds like you may be talking about bounce rather than overshoot. I go over the difference here:

http://www.motionscript.com/articles/bounce-and-overshoot.html