[Dan Ebberts]

Like this maybe:

p = thisComp.layer("Shape Layer 1")("Contents");
nGroups = 0;
for (i = 1; i <= p.numProperties; i++){
  if (p(i).name.indexOf("Group") == 0) nGroups++;
}
nGroups

[Dan Ebberts]

When importing PSD files, you can set Import Kind to “Composition”, or “Composition – Retain Layer Sizes”. Does that help?

[Dan Ebberts]

Like this maybe:

s = Math.round(effect("Slider Control")("Slider"));
txt = value;
n = 0;
for (i = 0; i<txt.length; i++){
  if (txt[i] == " "){
    n++;
    if (n == s) break;
  }
}
txt.substr(0,i)

[Dan Ebberts]

You generally access a marker by its key index, like this:

property("Marker").key(1)

or by time, like this:

property("Marker").nearestKeyIndex(myComp.time)

[Dan Ebberts]

I think I would try not to use any menu commands, if possible. So I’d try a workflow like this: you drop a marker layer at one end of the area you want to cut out and move the CTI (current time indicator) to the other end, and run a function like this (which you could attach to your button):

function splitAdjust(){
	var myComp = app.project.activeItem;
	if (!(myComp && (myComp instanceof CompItem))){
		alert ("No comp selected.");
		return;
	}
	if (! (myComp.selectedLayers.length > 0)){
		alert("No layer selected.");
		return;
	}
	var myLayer = myComp.selectedLayers[0];
	if (! (myLayer.property("Marker").numKeys > 0)){
		alert("Selected layer has no marker.");
		return;
	}
	var compTime = myComp.time;
	var markerTime = myLayer.property("Marker").keyTime(1);
	myDup = myLayer.duplicate();
	myDup.moveAfter(myLayer);
	if (markerTime < compTime){
		var t1 = markerTime;
		var t2 = compTime;
	}else{
		var t1 = compTime;
		var t2 = markerTime;
	}
	myLayer.outPoint = t1;
	myDup.inPoint = t2;
	myDup.startTime -= t2-t1;
	myLayer.property("Marker").removeKey(1);
	myDup.property("Marker").removeKey(1);
}
splitAdjust();

[Dan Ebberts]

If that’s the situation, layer moving on z, camera not moving, a position expression like this might work:

p0 = valueAtTime(0);
d = length(value,p0);
v = normalize(thisComp.layer("Camera 1").position - p0);
p0 + v*d

[Dan Ebberts]

Are you animating the photos by moving them on their z axis?

[Dan Ebberts]

It’s a little ambiguous, so a picture would help.

[Dan Ebberts]

I think the important takeaway is that it’s not reliable. It might appear to work in some situations, but you shouldn’t count on it.

[Dan Ebberts]

I would expect that not to work reliably just because of the way AE is designed to render frames asynchronously, where you can drop the CTI anywhere in the timeline and any expressions will solve without depending on results from previous frames. I suspect there is no good way to do global variables.