Can I pass results from ' toCompVec ' expression to a parent comp?

[spzspz]

Trying to work this out in my head how it would be possible.  I assume if it were possible it would be via Essential Graphics, but can't decipher what property needs to be "essential".

My end goal is to get a fully built Cube precomp (CYAN Label in GIF) into a comp with a camera (Brown Label), which will have many other cubes.  Need the sides for each cube to react/disappear via toCompVec expression.

Seems as right now, I can only get the toCompVec to work in the comp that has the cube-faces (CYAN Label).  Can I pass this data into another comp (Brown Label)?  Collapse transform doesn't work, obviously, but thought it would be possible when I initially conceptualized this in my head.

[Dan Ebberts]

I think you have to transform the vector twice--once in the nested comp and then transform that resulting vector in the outer comp. It will probably look something like this:

L = comp("Whole Cube").layer(thisComp.name);
v = toCompVec([0,0,1]);
L.toCompVec(v)[2] > 0 ? value : 0

[spzspz]

I am grateful for your response.  Could you possibly elaborate a little more?

I'm assuming you're implying I should apply this expression to the opacity in 'outer comp' -- however, I would need 6 parameters to alter opacity for each face of cube?  I tried to add a slider to see if this would register (so I could then carry it across each face), but it doesn't work.

Thank you.

[spzspz]

This is crazy, I just realized I was using your post from many many years ago as the foundation for this:  https://www.motionscript.com/design-guide/invisible-facing-away.html

🙂  Thank you for your contributions to the community.

I know it says I'm "new here" but I've been using AE for 10+ years, and my work acct won't let me use personal PC, so I have two accts. 

I couldnt do half of what I do without people sharing knowledge like you.  THANK YOU!

[spzspz]

So I kept trying to digest the logic you were sharing.

I tried referencing the outerComp 3D Cube Layer for each face's opacity in the nested comp.

And, I thought it was going to work, because my first test on Face_Front worked in the outer comp.

However, when I applied expression to the other faces, it had a weird response in outer comp (see GIF)

Worth noting, there is not two instances of toCompVec in this...  Still unsure what you mean about the 2nd instance.

[Dan Ebberts]

The expression was supposed to go inside the nested comp, just like your original attempt. You'd need to do that for each face of the cube.

Oops- I just noticed that's not how you did it originally, but with my test, I put the expression on the layer in the nested comp.

[spzspz]

Actually, I think I got it.  Using your reference from your website, I realized I was referencing Z coordinate [2] for each ... If I swapped the Left & Right faces to reference the X coordinate [0] it works now.