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Reverse effect of expression
Hi,
I have the following expression:
t = time - inPoint;
startVal = 0;
endVal = 100;
dur = thisComp.layer("Controls").effect("Stretch Duration")("Slider")/10;
if (t < dur){
s = linear(t,0,dur,startVal,endVal);
}else{
amp = (endVal - startVal)/dur;
freq = 3;
decay = 5;
w = freq*Math.PI*2;
s = endVal + amp*Math.sin((t-dur)*w)/Math.exp(decay*(t-dur))/w;
}
[s,s]As it is, it scales the layer from 0=100 with a slight elastic effect, the duration of the elasticity determined by the slider. I would like to then reverse this effect so that the layer, after a period determined by a slider, returns to 0, again with some elasticity.
Your help will be greatly appreciated.
Thanks -
1 Reply
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I’m not sure this is what you’re after, but it might get you headed in the right direction:
period = thisComp.layer("Controls").effect("Period")("Slider");
dur = thisComp.layer("Controls").effect("Stretch Duration")("Slider")/10;t = time - inPoint;
if (t < period){
startVal = 0;
endVal = 100;
}else{
startVal = 100;
endVal = 0;
t -= period;
}
if (t < dur){
s = linear(t,0,dur,startVal,endVal);
}else{
amp = (endVal - startVal)/dur;
freq = 3;
decay = 5;
w = freq*Math.PI*2;
s = endVal + amp*Math.sin((t-dur)*w)/Math.exp(decay*(t-dur))/w;
}
[s,s]
After the time set by the Period slider it will do a reverse ramp with bounce at the end.
Dan
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