Re: Render all surfaces
Yes, existing 2d (and 3d stereoscopic) systems already account for most of that. With VR a few new problems appear, and a few new solutions to deal with them.
Such as transparency only being accounted for for one camera, and now having two. With some textures "cheating" a fake depth, then the effect being obviously fake in 3d (The old trick of rendering a 3d like shadow/lighting effect onto a 2d billboard no longer works, as it's obviously 2d, and now needs to be fully rendered in 3d).