Fit path boundaries by scaling when comp layer is parented

[Dan Ebberts]

It’s hard to picture exactly how you have things set up, but if you have “Shape Layer 1” in a precomp named “shape”, a scale expression like this on the precomp layer “shape” in the main comp, it should fit the shape to the main comp’s size:

L = comp("shape").layer("Shape Layer 1");
r = L.sourceRectAtTime(time,false);
ul = L.toComp([r.left,r.top]);
lr = L.toComp([r.left+r.width,r.top+r.height]);
w = lr[0] - ul[0];
h = lr[1] - ul[1];
if (thisComp.width/thisComp.height > w/h)
  s = thisComp.height/h
else
  s = thisComp.width/w;
[s,s]*100

Sorry if that’s no help at all…

[Tomas Bumbulevičius]

Hey Dan, thanks a lot for sharing! The way you described it gave me a thought to clarify it properly. But just in case, I tested your described approach and it indeed works – thus – thumbs up for that already! It fits.

I need to scale not the “shape” comp itself, but adjust the controller/null in the comp, that it would set/accommodate scale in the main composition, based on shape’s size in pre-comp.

Through logic tree, it would look like the following:

Inside comp Y:

“controller” null – which scale animates in time from value K to L
“shape” aka comp X based on my definition – parented to controller.
“Shape Layer 1” – path layer inside “shape” comp aka compX.

Essentially, I want to modify scale end-value “L”, to fit the shape’s path size in the precomp when scaling down. What it will do is to allow changing shape in the pre-comp, while making sure scaling happens up to the proper zooming level, fitting whole size of the shape (or even adding some padding). Unfortunately, I can’t modify “shape” scaling directly, because it is linked by other logic. Do you think it can be possible, or at least how to compensate the parenting when comparing scaling levels? Thanks a ton for any hint!

[Dan Ebberts]

I’m still not sure I have it pictured exactly correctly yet, but this variation, applied to the controller null’s scale, should fit the shape to the “main” comp:

L = thisComp.layer("Shape Layer 1");
r = L.sourceRectAtTime(time,false);
ul = L.toComp([r.left,r.top]);
lr = L.toComp([r.left+r.width,r.top+r.height]);
w = lr[0] - ul[0];
h = lr[1] - ul[1];
if (comp("main").width/comp("main").height > w/h)
  s = comp("main").height/h
else
  s = comp("main").width/w;
[s,s]*100

[Tomas Bumbulevičius]

Hey Dan, thanks a lot for modified version of this! While I haven’t managed to make it work still, will try to break it down and see what could be the reason for it. Going to update here if figure it out, yet the setup I have is quite complex and unique for single-purpose I guess.

[Tomas Bumbulevičius]

Here is an example of what I am making, to have a visual sense and clarity:
https://www.instagram.com/tv/CcNHOmBFS67

The goal was to make sure “zoom out” goes far enough that a whole path map is visible, but because of multiple parenting inside the master comp, I yet to find the solution.