How to get relative position of layer in larger precomp.

[Navarro Parker]

The Setup:

Comp 1 is 2000x3000 pixels. Comp 1 contains Layer X that is positioned at 1750,1250. (or whatever)

I pull Comp 1 into Comp 2 which is 800x600. I scale and move Comp 1 inside Comp 2 by an arbitrary amount.

How can I determine Layer X's position using Comp 2's coordinate space?

[Dan Ebberts · Accepted solution]

Something like this:

L1 = comp("Comp 1").layer("Layer X");
P1 = L1.toWorld(L1.anchorPoint);
L2 = thisComp.layer("Comp 1");
L2.toWorld(P1)

Dan

[Navarro Parker]

Perfect! Dan, you are indeed the man! 

[Navarro Parker]

Hey Dan.

I'm having trouble using this with a null.

So Null A is in Comp XX.  Comp XX is pulled into Comp ZZ and moved/scaled. When I put your expression into an effect's Point Control, it doesn't line up where the Null is supposed to be in Comp XX.

What am I missing?

[Dan Ebberts]

Try changing the last line to this:

L2.toComp(P1)

Dan

[Navarro Parker]

Hmmmm... That's not working either.

Inserting this expression into an Effect's point control doesn't put it in the right position.  I tried inserting this expression into another (2D) null's position, but it's in the same incorrect place.

Original Null A Position (from C4D project import).  This comp is put into Comp ZZ.

Applying that Expression to Null's position in Comp ZZ puts the new Null B way off in the corner.

[Dan Ebberts]

Hard to say without looking at it. What's the exact expression you're using? Also, are all layers and comps square pixels?

Dan

[Navarro Parker]

Ooookay. I think I got it. The generic comp names was mixing me up. I didn't understand that the L2 should refer to the same pre-comp as where the original null is.  I was putting the name of the layer I was applying this expression to.

So yeah, this works when applied to Point Control of an effect and an objects position

L1 = comp("MyLogo").layer("FlareNull");

P1 = L1.toComp(L1.anchorPoint);

L2 = thisComp.layer("MyLogo");

L2.toWorld(P1)

What's the diff between toWorld and toComp?  World = 3D and Comp= 2D?

[Dan Ebberts]

Pretty much. toComp() is what you use to get the 2D position in the comp view.

Dan

[Navarro Parker]

See if this helps...

http://db.tt/7IBNIhu