Optimized shadows in a foveated rendering system

A computer system comprising:

• a processor;
• memory coupled to the processor and having stored therein instructions that, if executed by the computer system, cause the computer system to execute a method for implementing a graphics pipeline, comprising:
• building a first shadow map of high resolution;
• building a second shadow map based on the first shadow map, wherein the second shadow map has a lower resolution than the first shadow map;
• determining a light source affecting a virtual scene;
• projecting geometries of objects of an image of the virtual scene onto a plurality of pixels of a display from a first point-of-view;
• determining a first set of geometries is drawn to a first pixel, wherein the first set of geometries includes at least one fragment;
• determining the first set of geometries is in shadow based on the light source;
• determining a foveal region when rendering the image of the virtual scene, wherein the foveal region corresponds to where an attention of a user is directed using a fragment shader of the graphics pipeline;
• determining the first set of geometries is outside of the foveal region using the fragment shader;
• rendering the first set of geometries for the first pixel using the second shadow map;
• and
• disabling other shadowing effects during rendering of the first set of geometries for the first pixel.

A non-transitory computer-readable medium storing a computer program for implementing a graphics pipeline, the computer-readable medium comprising:

• program instructions for building a first shadow map of high resolution;
• program instructions for building a second shadow map based on the first shadow map, wherein the second shadow map has a lower resolution than the first shadow map;
• program instructions for determining a light source affecting a virtual scene;
• program instructions for projecting geometries of objects of an image of the virtual scene onto a plurality of pixels of a display from a first point-of-view;
• program instructions for determining a first set of geometries is drawn to a first pixel wherein the first set of geometries includes at least one fragment;
• program instructions for determining the first set of geometries is in shadow based on the light source;
• program instructions for determining a foveal region when rendering the image of the virtual scene, wherein the foveal region corresponds to where an attention of a user is directed using a fragment shader of the graphics pipeline;
• program instructions for determining the first set of geometries is outside of the foveal region using the fragment shader;
• program instructions for rendering the first set of geometries for the first pixel using the second shadow map;
• and
• program instructions for disabling other shadowing effects during rendering of the first set of geometries for the first pixel.