How to split SteamVR Camera into Left/Right ?

Hi all --

I have a special use case where I need to render an object that doesn't actually exist in the space -- I do this by aligning one version with the right eye, and one version with the left eye -- each is rendering a different texture which accounts properly for any stereo properties. However, a little bit of the right object is visible from the left eye and vice versa.

I need to have a couple of separate layers -- one for only the right eye, one for only the left eye. The standard Unity VR setup doesn't allow for this.

It doesn't look like I can make the SteamVR Camera behave properly with this case -- how do I render an object only in a single eye?

I tried setting the vrCamera eye to right only, and put a child left camera, but they don't rotate the same way and the image is very different. I also tried having left and right as children, having the steamvr camera not render anything -- this also did not work.

Any ideas?