Pre-Comping a layer with Element 3d resets its layout

[drmontrays]

I have 3d layer of a spinning skull, about after 5 seconds I have a camera and null zoom in on the eye of the skull, I want to rotobrush the eye of the skull but everytime I rotobrush it forces me onto one layer, I know if I pre-comp the layer I'll probably be fine to rotobrush, but when I pre-comp the 3d skull as a duplicate of my bottom 3d skull layer, the 3d skull resets and goes to the middle of the screen and doesn't spin and doesn't get affected by the camera.

The first image shows what it looks like after I dupe and pre-comp, the second image is before that.

One note is that if I simply press the "Make a 3D Layer" option on the pre-comp, it becomes blurry, low quality, and a little enlarged.

[Mylenium]

Not sure what you're asking. That's just how E3D works. Why would you even rotobrush anything? If you have the skull as a 3D object, you can generate all sorts of mattes and custom channels just by using duplicates and customizing the materials like inserting a white sphere or disk into the eye with a white luminous material while the skull is black and non-reflective. And since you can just dupe the comp and/ or copy&paste the camera around, everything will still line up. You're really using the completely wrong approach and only make things unnecessarily complicated.

Mylenium

[drmontrays]

Jesus it's mr Passive Aggressive himself'!

listen Dr. Look like he has down syndrome, the camera zooms in on the eye of a 3d skull model. I want to cut out the eye so I can transition it into a tunnel. Everytime i try to basically mask the eye, the rotobrush messes up like I explained. Looks like youre assuming I want to cut out an already cut out 3d object by rotobrushing the whole thing. This shouldn't even matter to my question, I won't repeat it but read it again but tell me how using a rotobrush in any way I want has anything to do with why my method isn't working. I hope you know that your answer literally didn't help me at all. You basically said "don't know what you're doing but if you were doing this, then you would be able to do whatever you want." I think the screenshots show how obvious it is that the skull is reflecting an image, world environment is set on a layer. Don't give me random answers acting like I'm doing something wrong if you aren't sure what I'm asking. 

[Warren Heaton]

The Rotobrosh is not the right tool for this.

[Mylenium]

You use a mask or generate a matte as I said.

Mylenium