Parent expression using Layer control effect

[Dan Ebberts]

Probably something like this then:


target = effect("Layer Control")("Layer").position; //select which layes it will follow
seedRandom(index, true);
delay = random(effect("Slider Control")("Slider"));
delta = target.valueAtTime(time - delay) - target.valueAtTime(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){
v = velocityAtTime(key(n).time - thisComp.frameDuration/10);
amp = .05;
freq = 4.0;
decay = 2.0;
value + delta + v*amp*Math.sin(freq*t*2*Math.PI)/Math.exp(decay*t);
}else{
value + delta
}


Dan

[Neil Stubbings]

Hi Dan

Thanks so much for looking into this!
Buuuut, unfortunately it does not seem to work (i’ve gotten this far by myself before 🙂

the layer with the expression follows the leader layer, but has no springy motion to it.
Is it because the expression needs keyframes on its layer in order to calculate the springy motion?

—
Neil Stubbings
Graphic Design | Motion Graphics
https://www.stubbings.ch
—

[Dan Ebberts]

Yup. That’s what I meant when I asked about what was supposed to trigger the springy motion. The way you have it set up now, it would be keyframes on the property with the expression.

Dan

[Dan Ebberts]

This might be closer to what you’re looking for. It’s triggered by the keyframes of the leader:


target = effect("Layer Control")("Layer").position; //select which layes it will follow
seedRandom(index, true);
delay = random(effect("Slider Control")("Slider"));
delta = target.valueAtTime(time - delay) - target.valueAtTime(0);

n = 0;
if (target.numKeys > 0){
n = target.nearestKey(time-delay).index;
if (target.key(n).time > time-delay){
n--;
}
}
if (n == 0){
t = 0;
}else{
t = time - delay - target.key(n).time;
}

if (n > 0){
v = target.velocityAtTime(target.key(n).time - thisComp.frameDuration/10);
amp = .05;
freq = 4.0;
decay = 2.0;
value + delta + v*amp*Math.sin(freq*t*2*Math.PI)/Math.exp(decay*t);
}else{
value + delta
}


Dan

[Neil Stubbings]

oh wow!

it works great! this is exactly what I was looking for!

thanks a lot, Dan!

—
Neil Stubbings
Graphic Design | Motion Graphics
https://www.stubbings.ch
—