US 2015/0317825 A1 · GRAPHICS PROCESSING SYSTEMS

Abstract

To simulate the effect of shadows in an image being rendered a light source bounding frustum is produced for a tile for a light source, and used to determine a set of geometry for the tile that could cast a shadow in the tile. The determined set of geometry is then used to determine a light source visibility parameter for each sampling position in the tile by determining for each tile screen space sampling position, whether rays cast between the tile sampling position and a set of sampling positions representing the light source would intersect occluding geometry or not. The determined number of visible light source sampling positions for each tile sampling position is used to determine a light source visibility parameter value for each tile sampling position, and the determined light source visibility parameters are then used to modulate the light source when shading the geometry.

Claims28

Dependent claims

A method of operating a graphics processing system when rendering a frame for output that includes a light source that could cast shadows, the method comprising:

for at least one region of the frame being rendered:
determining a set of the geometry to be processed for the frame that could cast a shadow from a light source to be considered for the frame for the region of the frame being rendered;
and
for each sampling position of a set of sampling positions for the region of the frame being rendered, determining a light source visibility parameter using the determined set of geometry.

1 more element

A graphics processing system comprising:

a plurality of processing stages, including at least a rasteriser that rasterises input primitives to generate graphics fragments to be processed, each graphics fragment having one or more sampling points associated with it, and a renderer that processes fragments generated by the rasteriser to generate output fragment data;
and wherein the graphics processing system is capable of, when rendering a frame for output that includes a light source that could cast shadows:
for at least one region of the frame being rendered:
determining a set of the geometry to be processed for the frame that could cast a shadow from a light source to be considered for the frame for the region of the frame being rendered;
and
for each sampling position of a set of sampling positions for the region of the frame being rendered, determining a light source visibility parameter using the determined set of geometry.

3 more elements

Dependencies are inferred from the claim text.

Graphics processing systems

Life of this patent

Graphics processing systems

Life of this patent

Abstract

Claims28