Graphics processing using directional representations of lighting at probe positions within a scene

A graphics processing unit configured to render a sequence of frames, the graphics processing unit comprising:

• surface identification logic configured to determine, for each frame of the sequence of frames, visible surfaces of a scene for pixels in the frame, from a viewpoint for the frame;
• and
• processing logic configured to:
• maintain a directional representation of lighting for each probe position of a plurality of probe positions within the scene, by:
• tracing one or more rays from the probe position to determine, for each of the one or more rays, a lighting contribution for the probe position from the direction of the ray;
• and
• updating the directional representation of lighting for the probe position based on the determined lighting contribution for each of the one or more rays;
• use the directional representations of lighting for the probe positions to determine lighting indications for the determined visible surfaces of the scene for pixels in the frame;
• and
• shade the pixels in the frame in accordance with the determined lighting indications.

A non-transitory computer readable storage medium having stored thereon a computer readable description of an integrated circuit that, when processed in an integrated circuit manufacturing system, causes the integrated circuit manufacturing system to manufacture a graphics processing unit comprising:

• surface identification logic configured to determine, for each frame of a sequence of frames, visible surfaces of a scene for pixels in the frame, from a viewpoint for the frame;
• and
• processing logic configured to:
• maintain a directional representation of lighting for each probe position of a plurality of probe positions within the scene, by:
• tracing one or more rays from the probe position to determine, for each of the one or more rays, a lighting contribution for the probe position from the direction of the ray;
• and
• updating the directional representation of lighting for the probe position based on the determined lighting contribution for each of the one or more rays;
• use the directional representations of lighting for the probe positions to determine lighting indications for the determined visible surfaces of the scene for pixels in the frame;
• and
• shade the pixels in the frame in accordance with the determined lighting indications.

A non-transitory computer readable storage medium having stored thereon processor executable instructions that when executed cause at least one processor to:

• for each frame of a sequence of frames, determine visible surfaces of a scene for pixels in the frame, from a viewpoint for the frame;
• for each probe position of a plurality of probe positions within the scene, maintain a directional representation of lighting by:
• tracing one or more rays from the probe position to determine, for each of the one or more rays, a lighting contribution for the probe position from the direction of the ray;
• and
• updating the directional representation of lighting for the probe position based on the determined lighting contribution for each of the one or more rays;
• use the directional representations of lighting for the probe positions to determine lighting indications for the determined visible surfaces of the scene for pixels in the frame;
• and
• shade the pixels in the frame in accordance with the determined lighting indications.