Then you render with multiple cameras rotated around their centre, using the same techniques as cubemap rendering. With high field of view, rendering a single s

Then you render with multiple cameras rotated around their centre, using the same techniques as cubemap rendering. With high field of view, rendering a single spherical view with homogeneous resolution would be inefficient for VR, not only due to the lack of hardware support (without noticeable artefacts or some subdivision scheme) and the created distortion, but also due to the foveated nature of human vision. You'd want a small view frustum rendered at a much higher pixel per angle blended with a lower resolution rendering of the entire field of view (optimally with a medium resolution view frustum surrounding the smaller one for a more progressive blending). See: https://www.youtube.com/watch?v=lNX0wCdD2LA https://www.youtube.com/watch?v=lNX0wCdD2LA With current GPUs and game engines, you need multiple cameras to achieve such effect, but it has the advantage of drastically lowering the computing demands for high-resolution VR graphics (compare 8k per eye, vs just two blended 1080p views). You could also ray trace a single view of non-homogeneous resolution that directly takes into account the distortion characteristics of the HMD lenses, but it would likely a lot less efficient than traditional rasterization with multiple blended cameras.