US Patent 11315327 Beam-racing fallbacks in a display engine

In one embodiment, a method includes determining a first time interval for rendering pixel values for a first portion of a display, where the first portion of the display is one of a plurality of portions of the display, accessing a representation of virtual objects in a virtual scene, and determining that the first time interval is insufficient for rendering pixel values for the first portion of the display based on the representation of virtual objects. The method further includes, for each of the portions of the display, determining a current viewpoint of a user, rendering, based on the current viewpoint of the user, pixel values for that portion of the display, and sending the rendered pixel values to be output by the display, where the rendered pixel values for the first portion of the display are rendered based on a simplified representation of virtual objects in the virtual scene.