@ambershee Agreed - though the rendertarget solution does work with VR, and reasonable FPS on a very simple test level, it is rendering lots of useless pixels, and does not lend its-self well to the concept of recursive portals.
Finally been making some progress on a better rendering method this morning:
still not much to look at, but should be running faster than rendertarget method already, and avoids a bunch of issues.
Ending up making more engine modifications than I wanted to, and still quite a bit of work to do…