Multiple cameras in VR


Our product needs to render two different cameras of our world in the same viewport, sharing Z-buffers as if world A had teleported into world B. We solved this with 2D render targets (RGBD) without VR but now are running into issues both in VR and with AA and transparency.

Does anybody have any ideas how can we use two cameras to ultimately render into to one framebuffer as described above such that the two camera worlds intersect, occlude, and perform transparency correctly… in VR?