Abstract: A µ-mesh (“micromesh”), which is a structured representation of geometry that exploits coherence for compactness and exploits its structure for efficient rendering with intrinsic level of detail is provided. The micromesh is a regular mesh having a power-of-two number of segments along its perimeters, and which can be overlaid on a surface of a geometric primitive. The micromesh is used for providing a visibility map and/or a displacement map that is accessible using barycentric coordinates of a point of interest on the micromesh.

Abstract: Techniques applicable to a ray tracing hardware accelerator for traversing a hierarchical acceleration structure with reduced round-trip communications with a processor are disclosed. The reduction of round-trip communications with a processor during traversal is achieved by having a visibility mask that defines visibility states for regions within a geometric primitive available to be accessed in the ray tracing hardware accelerator when a ray intersection is detected for the geometric primitive.

Abstract: One embodiment of the present invention includes a parallel processing unit (PPU) that performs pixel shading at variable granularities. For effects that vary at a low frequency across a pixel block, a coarse shading unit performs the associated shading operations on a subset of the pixels in the pixel block. By contrast, for effects that vary at a high frequency across the pixel block, fine shading units perform the associated shading operations on each pixel in the pixel block. Because the PPU implements coarse shading units and fine shading units, the PPU may tune the shading rate per-effect based on the frequency of variation across each pixel group. By contrast, conventional PPUs typically compute all effects per-pixel, performing redundant shading operations for low frequency effects. Consequently, to produce similar image quality, the PPU consumes less power and increases the rendering frame rate compared to a conventional PPU.

Abstract: A graphics processing pipeline includes three architectural features that allow a fragment shader to efficiently calculate per-sample attribute values using barycentric coordinates and per-vertex attributes. The first feature is barycentric coordinate injection to provide barycentric coordinates to the fragment shader. The second feature is an attribute qualifier that allows an attribute of a graphics primitive to be processed without conventional fixed-function interpolation. The third feature is a direct access path from the fragment shader to triangle data storage hardware resources where vertex attribute data and/or plane equation coefficients are stored. Allowing the fragment shader to calculate per-sample attribute values in this way advantageously increases system flexibility while reducing workload associated with triangle plane equation setup.

Abstract: One embodiment of the present invention includes a parallel processing unit (PPU) that performs pixel shading at variable granularities. For effects that vary at a low frequency across a pixel block, a coarse shading unit performs the associated shading operations on a subset of the pixels in the pixel block. By contrast, for effects that vary at a high frequency across the pixel block, fine shading units perform the associated shading operations on each pixel in the pixel block. Because the PPU implements coarse shading units and fine shading units, the PPU may tune the shading rate per-effect based on the frequency of variation across each pixel group. By contrast, conventional PPUs typically compute all effects per-pixel, performing redundant shading operations for low frequency effects. Consequently, to produce similar image quality, the PPU consumes less power and increases the rendering frame rate compared to a conventional PPU.

Abstract: Methods and apparatuses are disclosed for reporting texture footprint information. A texture footprint identifies the portion of a texture that will be utilized in rendering a pixel in a scene. The disclosed methods and apparatuses advantageously improve system efficiency in decoupled shading systems by first identifying which texels in a given texture map are needed for subsequently rendering a scene. Therefore, the number of texels that are generated and stored may be reduced to include the identified texels. Texels that are not identified need not be rendered and/or stored.

Abstract: A graphics processing pipeline includes three architectural features that allow a fragment shader to efficiently calculate per-sample attribute values using barycentric coordinates and per-vertex attributes. The first feature is barycentric coordinate injection to provide barycentric coordinates to the fragment shader. The second feature is an attribute qualifier that allows an attribute of a graphics primitive to be processed without conventional fixed-function interpolation. The third feature is a direct access path from the fragment shader to triangle data storage hardware resources where vertex attribute data and/or plane equation coefficients are stored. Allowing the fragment shader to calculate per-sample attribute values in this way advantageously increases system flexibility while reducing workload associated with triangle plane equation setup.

Abstract: Methods and apparatuses are disclosed for reporting texture footprint information. A texture footprint identifies the portion of a texture that will be utilized in rendering a pixel in a scene. The disclosed methods and apparatuses advantageously improve system efficiency in decoupled shading systems by first identifying which texels in a given texture map are needed for subsequently rendering a scene. Therefore, the number of texels that are generated and stored may be reduced to include the identified texels. Texels that are not identified need not be rendered and/or stored.

Abstract: Methods and apparatuses are disclosed for reporting texture footprint information. A texture footprint identifies the portion of a texture that will be utilized in rendering a pixel in a scene. The disclosed methods and apparatuses advantageously improve system efficiency in decoupled shading systems by first identifying which texels in a given texture map are needed for subsequently rendering a scene. Therefore, the number of texels that are generated and stored may be reduced to include the identified texels. Texels that are not identified need not be rendered and/or stored.

Abstract: One embodiment of the present invention includes techniques for processing a multi-resolution hierarchy, where an application configures a ROP unit to render all the levels included in the multi-resolution hierarchy to a single composite render target. The ROP unit renders memory pages to the composite render target in pitch order. In contrast, the texture unit accesses the composite render target with memory pages in pitch order for each level of the hierarchy. The application configures the MMU to ensure that the composite render target is correctly interpreted by the texture unit. Notably, the MMU translates ROP unit virtual addresses and texture unit virtual addresses using different mapping strategies to the same physical address space. One advantage of the disclosed embodiments is that rendering to the multi-resolution hierarchy does not require the CPU to execute the state parameter changes that are associated with rendering the different hierarchical levels using prior-art techniques.

Abstract: A method for providing state inheritance across command lists in a multi-threaded processing environment. The method includes receiving an application program that includes a plurality of parallel threads; generating a command list for each thread of the plurality of parallel threads; causing a first command list associated with a first thread of the plurality of parallel threads to be executed by a processing unit; and causing a second command list associated with a second thread of the plurality of parallel threads to be executed by the processing unit, where the second command list inherits from the first command list state associated with the processing unit.

Abstract: A system, method, and computer program product are provided for rendering at variable sampling rates. Vertex coordinates for 3D primitive are received from a shader execution unit, and an arithmetic operation is performed on the vertex coordinates by fixed operation circuitry to produce modified vertex coordinates in homogeneous coordinate space. The modified vertex coordinates are transformed from homogeneous coordinate space into screen-space to produce screen-space vertex coordinates of a transformed 3D primitive and the transformed 3D primitive is rasterized in screen-space using the screen-space vertex coordinates to produce an image for display.

Abstract: A system, method, and computer program product are provided for executing processes involving at least one primitive in a graphics processor, utilizing a data structure. In operation, a data structure is associated with at least one primitive. Additionally, a plurality of processes involving the at least one primitive are executed in a graphics processor, utilizing the data structure. Moreover, the plurality of processes include at least one of selecting at least one surface or portion thereof to which to render, or selecting at least one of a plurality of viewports.

Abstract: A method, computer readable medium, and system are disclosed for generating multi-view image data. The method includes the steps of processing primitive data of a model to generate processed primitive data that includes multiple position vectors for each vertex in the primitive data, the number of position vectors associated with each vertex being equal to the number of views in at least two views being generated. The method further includes storing the processed primitive data in a buffer. Finally, the processed primitive data may be read from the buffer for each view in the at least two views and transmitted to a raster pipeline to generate image data corresponding to a particular view.

Abstract: Techniques are disclosed for storing post-z coverage data in a render target. A color raster operations (CROP) unit receives a coverage mask associated with a portion of a graphics primitive, where the graphics primitive intersects a pixel that includes a multiple samples, and the portion covers at least one sample. The CROP unit stores the coverage mask in a data field in the render target at a location associated with the pixel. One advantage of the disclosed techniques is that the GPU computes color and other pixel information only for visible fragments as determined by post-z coverage data. The GPU does not compute color and other pixel information for obscured fragments, thereby reducing overall power consumption and improving overall render performance.

Abstract: A technique for multiresolution consistent rasterization in which a setup unit calculates universal edge equations for a universal resolution. A rasterizer evaluates coverage data for two different resolutions based on the edge equations. The rasterizer evaluates coverage data for different effective pixel sizes—a large pixel size and a small pixel size. Optionally, the rasterizer may determine a first set of coverage data by performing conservative rasterization to determine coverage data for large pixels. Optionally, the rasterizer may then determine a second set of coverage data by performing standard rasterization for small pixels. Optionally, for the second set of coverage data, the rasterizer may evaluate only the small pixels that are within large pixels in the first set of coverage data that evaluate as covered.

Abstract: A method, computer readable medium, and system are disclosed for generating multi-view image data. The method includes the steps of processing primitive data of a model to generate processed primitive data that includes multiple position vectors for each vertex in the primitive data, the number of position vectors associated with each vertex being equal to the number of views in at least two views being generated. The method further includes storing the processed primitive data in a buffer. Finally, the processed primitive data may be read from the buffer for each view in the at least two views and transmitted to a raster pipeline to generate image data corresponding to a particular view.

Abstract: A system, method, and computer program product are provided for rendering at variable sampling rates. Vertex coordinates for 3D primitive are received from a shader execution unit, and an arithmetic operation is performed on the vertex coordinates by fixed operation circuitry to produce modified vertex coordinates in homogeneous coordinate space. The modified vertex coordinates are transformed from homogeneous coordinate space into screen-space to produce screen-space vertex coordinates of a transformed 3D primitive and the transformed 3D primitive is rasterized in screen-space using the screen-space vertex coordinates to produce an image for display.

Abstract: A graphics processing pipeline within a parallel processing unit (PPU) is configured to perform path rendering by generating a collection of graphics primitives that represent each path to be rendered. The graphics processing pipeline determines the coverage of each primitive at a number of stencil sample locations within each different pixel. Then, the graphics processing pipeline reduces the number of stencil samples down to a smaller number of color samples, for each pixel. The graphics processing pipeline is configured to modulate a given color sample associated with a given pixel based on the color values of any graphics primitives that cover the stencil samples from which the color sample was reduced. The final color of the pixel is determined by downsampling the color samples associated with the pixel.

Abstract: A system, method, and computer program product are provided for shading using a dynamic object-space grid. An object defined by triangle primitives in a three-dimensional (3D) space that is specific to the object is received and an object-space shading grid is defined for a first triangle primitive of the triangle primitives based on coordinates of the first triangle primitive in the 3D space. A shader program is executed by a processing pipeline to compute a shaded value at a point on the object-space shading grid for the first triangle primitive.