As a thought experiment, imagine the perfect VR system. As the head moves, the viewpoint must accordingly change for visual rendering. A magic oracle perfectly indicates the head position and orientation at any time. The VWG continuously maintains the positions and orientations of all objects in the virtual world. The visual rendering system maintains all perspective and viewport transformations, and the entire rasterization process continuously sets the RGB values on the display according to the shading models. Progressing with this fantasy, the display itself continuously updates, taking no time to switch the pixels. The display has retina-level resolution, as described in Section 5.4, and a dynamic range of light output over seven orders of magnitude to match human perception. In this case, visual stimulation provided by the virtual world should match what would occur in a similar physical world in terms of the geometry. There would be no errors in time and space (although the physics might not match anyway due to assumptions about lighting, shading, material properties, color spaces, and so on).
Steven M LaValle 2020-11-11