Finding the Global Scale Value of an object?

[Darryl Torke]

I have a layer (result_layer) that uses the scale property of another layer for it’s value. However, that secondary layer is a child of a parent that is scaled up by a few factors. When I use my expression all I get is the child’s scale, not the true/global scale.

What I am trying to find out is the global scale property of the child layer. Is this possible in After Effects?

result_layer's scale expression (to which I only get the child's 'local' scale:
thisComp.layer("CHILD").transform.scale*.5;

[Dan Ebberts]

Something like this:


L = thisComp.layer("CHILD");
s = L.transform.scale;
while (L.hasParent){
sp = L.parent.transform.scale;
s = [s[0]*sp[0],s[1]*sp[1]]/100;
L = L.parent;
}
s*.5;


Dan

[Darryl Torke]

it worked! thank you

[Wouter Dijkstra]

I’m having the same sort of issue. I have a PreComp that is 2160×3680 and I put this in a smaller comp. Now parented this Precomp to a null, but now I’m not able to see how far I scale my PreComp. Since I don’t want to go beyond the maximum resolution (scale > 100) I would like to have some kind of controller that will tell me when I reach 100.

Of course I could check this by unparenting my PreComp from the null, but is there a way where I can check the absolute/global scale value at all times even when it is parented to another layer and therefore relative data?

[Oleg Pirogov]

This gives an absolute scale (in %) of parented layer:
L=thisComp.layer("CHILD_LAYER");
length(L.toWorld([1,0,0])-L.toWorld([0,0,0]))*100;

[Wouter Dijkstra]

Hi Oleg,

For some reason it doesn’t work the expression you gave me. You apply it to the “Scale” Property and Child layer?

This eventually turned out quite nicely. I don’t understand the code, but it works:

s = scale[0];
L = thisLayer;
while (L.hasParent){
s = s*L.parent.scale[0]/100;
L = L.parent;
}
s

[Wouter Dijkstra]

I might have cheered too soon.

It gives me an error:

expression result must be of dimension 2, not 1

Is this an easy fix?

[Tomas Bumbulevičius]

Wouter, as easy as it could be, one of the easiest in fact, hehe!

Scales requires an array of 2 or 3 items. Just add retrieved value into array and you will be good to go.

[s,s]

Find out more:
After Effects Tutorials: motion design, expressions, scripting.
Boxer – Dynamic Text Boxes Template with a Live Preview

[Wouter Dijkstra]

???? I should have known. Thanks for clearing it up –> It works now.