Pickwhip 2 x 3D plains together.

If I am stacking 3D layers, I always set them 1 pixel apart by adding this expression to the position property of the bottom layer. Then I link the Rotation and Orientation with these four other expressions. I then only have to keyframe the top layer.

//POSITION
thisComp.layer(index - 1).position + [0, 0, 1];

//ORIENTATION
thisComp.layer(index - 1).orientation;

//X ROTATION
thisComp.layer(index -1).transform.xRotation;

// Y ROTATION
thisComp.layer(index -1).transform.yRotation;

// Z ROTATION
thisComp.layer(index -1).transform.zRotation;

Add those five expressions to a 3D layer, press the 'u' key twice to reveal all modified properties of the bottom layer, drag a selection around the Position, orientation, and rotation properties, then choose Animation/Save Animation Preset from the Animation Menu and give it a name. You can then use it any time to stack layers in 3D space, and it works with all three of the 3D rendering engines.

Hey there,

Welcome to the forum. Thanks for the question. While we await a solution from a community or team member, let us know any further details about your comp. I did find this expression that may help you. See if it works: 

thisComp.layer("Plane 1").transform.position + [0,0,1]

I hope we can help you soon.

Thanks,
Kevin