The site Road to VR has an article about Nvidia and the changes they are making to improve VR performance and that tech moving into game engines. See: Unreal Engine and Unity to get NVIDIA’s New VR Rendering Tech.
Until recently video cards were given geometry (the mesh world), lights, and a camera position and they rendered an image. As the camera moved the geometry was reloaded shaded and rendered again with mesh and lights in relation to the camera. (Which is technically saying it backward. Consider the camera fixed and to change the view we move the world. Think of your computer screen as the camera. It sits on your desk never moving. Everything displayed on it moves. Thus the reason for reloading geometry.)
