[Dan Ebberts]

This expression makes some assumptions (which may not be correct), but it should get you headed in the right direction.

L = thisComp.layer("Main Text");
cb = L.effect("Top Text Follow 2")("Checkbox");
if (cb.value){
  t = cb.numKeys > 0 ? cb.key(cb.numKeys).time : 0;
  p = L.position;
  y = p.value[1] - p.valueAtTime(t)[1];
  value + [0,y];
}else
  value

[Dan Ebberts]

It seems like your loop should be more like this:

totalOffset = 0;
for(i=1; i <= n; i++) {
    totalOffset += getContentHeight(i);
}

[Dan Ebberts]

>So there’s no way for an expression to change the value of the controller even if it’s on the same layer, right

That’s correct, unless the expression is on that controller’s value.

>Would you happen to have a good reading resource on how to set this up via a script?

There are some online training courses available (some free, I think), but first you need to decide if scripting will provide a workable solution. Expressions are live and immediate, where scripts are generally run only when you initiate them. So if setting the value of the expression controller is a one-shot thing, a script might be the way to go, but if you need the value to be updated automatically based on other values, then it’s probably not the right tool.

[Dan Ebberts]

Once you have the index of the most recent marker (n), you can use that to loop through all the comps associated with the previous markers and add up the heights + margins for the layers in those comps.

[Dan Ebberts]

Once your expression finds the current marker, I think it needs accumulate the heights for all the layers associated with previous markers. It looks like (I apologize if I’m incorrect about this) you’re assuming the the results of the expression’s previous calculations will be available as value[1], which is not the case (expressions have no access to values they previously calculated).

[Dan Ebberts]

An expression can only affect the value of the property hosting the expression. So you could only change the value of the controller with an expression applied to that controller (unless you use a script, which is a whole different story).

[Dan Ebberts]

I think the site redesign text formatting must have substituted a different character for the minus sign in line 6. Try it this way:

freq = 1;
amp = 110;
loopTime = 3;
t = time % loopTime;
w1 = wiggle(freq, amp, 1, 0.5, t)[0];
w2 = wiggle(freq, amp, 1, 0.5, t - loopTime)[0];
linear(t, 0, loopTime, [w1,w1], [w2,w2])

[Dan Ebberts]

For one thing, time remapping wants seconds, not frames. The other part isn’t completely clear to me but it sounds like your expression needs calculate the total time the checkbox has been in the on state up to the current time. To do that you need to loop through the checkbox keyframes and add up all the segments since time zero where the checkbox was on (plus the contribution of the current, incomplete segment if the checkbox is currently on). Not too tough, but not trivial.

[Dan Ebberts]

This should work:

w = wiggle(15,400);
[w[0],w[1],value[2]]

[Dan Ebberts]

Something like this should work:

txt = text.sourceText;
var z = effect("Size")("Slider");
var l = effect("Leading")("Slider");
var t = effect("Tracking")("Slider");
xRepeater = effect("xRepeat")("Slider");
yRepeater = effect("yRepeat")("Slider");
horzRepeat = txt.repeat(xRepeater);
vertRepeat = horzRepeat + "\n";
repeatTxt = vertRepeat.repeat(yRepeater);
createStyle().setFontSize(z).setAutoLeading(false).setLeading(l).setTracking(t).setText(repeatTxt);