Top/Bottom Stereo mode for custom output?

I have developed a live stereo panoramic material which takes into account a projector’s lens and position relative to a panoramic screen. It is assigned to a mesh which is attached to a player pawn and sits in front of ortho camera. (hacky, I know!) Its output is a Top/Bottom stereo image.

I would like to do this using the HUD–but Camera Vector, which I use to transform my rays, does not appear to be updated in this context.

SO-- I have a tall aspect ratio image with top/bottom stereo, prewarped for projection, but cannot figure out how to get this to function with Nvidia hardware as stereo. It appears my video output needs to tell the GPU that this is a TOP/BOTTOM stereo pair. Any thoughts on how to achieve this?

Super new to Unreal–and these issues. Any help would be appreciated!

Cheers

-m