Method and apparatus for determining visibility of groups of pixels
AssigneeNVIDIA Corporation
InventorBenjamin M. Zhu
Life of this patent
Estimating the term…
Abstract
A display is partitioned into a plurality of cells. Each of the plurality of cells includes a depth interval and a coverage for each of a plurality of surfaces having coverage within the cell. A depth interval and a coverage for a group of pixels having coverage within one or more of the cells is received. Visibility of the group of pixels, for each of the one or more cells, is determined based on comparisons of the depth interval of the group of pixels with the depth intervals of the plurality of surfaces.
Claims31
A method for determining visibility of groups of pixels performed by a computer graphics system, the method comprising:
- partitioning a display into a plurality of cells, wherein each of the plurality of cells includes a depth interval and a coverage for each of a plurality of surfaces having coverage within the each of the plurality of cells;
- receiving a depth interval and a coverage for a group of pixels having coverage within one or more of the cells;
- and
- for each of the one or more of the cells, determining a visibility of the group of pixels based on comparisons of the depth interval of the group of pixels with the depth intervals of the plurality of surfaces.
A visibility subsystem in a computer graphics system for determining visibility of groups of pixels, the visibility subsystem comprising:
- a group depth buffer having a plurality of group depth buffer cells, each group depth buffer cell corresponding to a display region of a display;
- wherein each group depth buffer cell is configured to receive a depth interval of a group of pixels within the corresponding display region and a coverage of the group of pixels within the corresponding display region, and to generate a visibility coverage of the group of pixels within the corresponding display region.
A computer system for processing graphics data, comprising:
- a visibility subsystem coupled to a memory, the visibility subsystem including a scan converter coupled to a group depth buffer, the group depth buffer having a plurality of group depth buffer cells corresponding to a plurality of regions of a display, the visibility subsystem configured to generate visibility coverages of groups of pixels;
- and
- a rendering engine coupled to the visibility subsystem and the memory, the rendering engine configured to receive visibility coverages of the groups of pixels and to render visible portions of the group of pixels.
A method performed by a computer graphics system of determining a depth interval of a group of pixels within a region, the method comprising:
- determining a depth of the group of pixels at a center of the region;
- determining a bound on a positive change in depth of the group of pixels from the center of the region to any pixel of the group of pixels within the region;
- determining a first endpoint of the depth interval based on the sum of the depth of the group of pixels at the center of the region with the bound on the positive change in depth;
- determining a bound on a negative change in depth of the group of pixels from the center of the region to any pixel of the group of pixels within the region;
- and
- determining a second endpoint of the depth interval based on the subtraction of the bound on the negative change in depth from the depth of the group of pixels at the center of the region.
Dependencies are inferred from the claim text.