[Dan Ebberts]

Really hard to say without seeing it, but I suspect it will end up looking something like this:

L = thisComp.layer(“Light_POS”);

p1 = L.toWorld(L.anchorPoint);

p2 = toWorld(anchorPoint);

v = p1 – p2;

v2 = fromWorldVec(v);

-radiansToDegrees(Math.atan2(v2[1],v2[0]))

[Dan Ebberts]

What 2D effect are you using? It might help to post a diagram of exactly what you’re trying to do.

[Dan Ebberts]

If I understand what you’re asking, this should work:

xPos = thisComp.layer("controls").effect("Left X")("Slider");
gap = thisComp.layer("controls").effect("Gap")("Slider");
firstLayer = 1;
curEdge = 0;
for(i = firstLayer; i <= index; i++){
  L = thisComp.layer(i);
  r = L.sourceRectAtTime(time,false);
  w = r.width;
  if (i == index) myOffset = r.left;
  if (i < index) curEdge += w + gap;
}
x = xPos + curEdge - myOffset;
[x,value[1]]

[Dan Ebberts]

Have you tried submitting a trouble ticket on the aescripts site? Sounds like a question for the developer.

[Dan Ebberts]

The plain vanilla version (no position keyframes, no scaling) would look something like this (replaces your copyToComp line):

comp.layer(selectedLayer.name).copyToComp(newComp);
var newLayer = newComp.layer(1);
var rect = newLayer.sourceRectAtTime(0,false);
newLayer.property("Position").setValue([-rect.left, -rect.top]);

[Dan Ebberts]

See if this helps:

https://ae-expressions.docsforadobe.dev/random-numbers.html

ae-expressions.docsforadobe.dev

Random Numbers — After Effects Expression Reference 0.0.3 documentation

Random Numbers — After Effects Expression Reference 0.0.3 documentation

[Dan Ebberts]

>I can’t seem to figure out how to store the variable for reference in the next frame

You can’t. Expressions have no memory. There’s no way for a variable to survive from frame to frame. What an expression can do, is examine previous pre-expression values, using .valueAtTime() to re-create previous calculations. This is a an expression I have in the archive that implements a vu meter with a 300 ms decay, which you may find useful:

decay = .3; // 300 ms
a = thisComp.layer("Audio Amplitude").effect("Both Channels")("Slider");
maxVal = a.value;
t = thisComp.frameDuration;
while (t < decay){
  temp = a.valueAtTime(time - t);
  maxVal = Math.max(maxVal, easeOut(t,0,decay,temp,0));
  t += thisComp.frameDuration;
}
maxVal

[Dan Ebberts]

That’s not the kind of thing you can do with an expression. An expression can only modify the value of the property it’s applied to, so if it’s not something you can keyframe you won’t be able to do it with an expression.

You could do it with a script, but it wouldn’t be automatic–you’d have to run the script each time you wanted to update the drop-down.

[Dan Ebberts]

This is not an area I’m very familiar with, but I think you can do what you want with Master Properties. You’d add the text from your nested precomp to the Essential Graphics panel, then, in each comp that has the nested precomp you will have an Essential Properties section where you can modify the text with an expression (I think).

[Dan Ebberts]

This is a keyframe overshoot expression from my site, which I’ve modified to skip the overshoot unless the checkbox is on at that keyframe. It may not exactly fit whatever you’re using for overshoot, but hopefully it will give you an idea on how to incorporate the checkbox.

cb = effect("Checkbox Control")("Checkbox");
freq = 3;
decay = 5;
n = 0;
if (numKeys > 0){
  n = nearestKey(time).index;
  if (key(n).time > time) n--;
}
if (n > 0 && cb.valueAtTime(key(n).time)){
  t = time - key(n).time;
  amp = velocityAtTime(key(n).time - .001);
  w = freq*Math.PI*2;
  value + amp*(Math.sin(t*w)/Math.exp(decay*t)/w);
}else
  value