Abstract: A stereo viewpoint graphics processing subsystem and a method of sharing geometry data between stereo images in screen-space processing. One embodiment of the stereo viewpoint graphics processing subsystem configured to render a scene includes: (1) stereo frame buffers configured to contain respective pixel-wise rendered scene data for stereo images, and (2) a sharing decision circuit operable to determine when to share geometric data between the stereo frame buffers for carrying out screen-space effect processes to render the scene in the stereo images.

Abstract: A cache-efficient processor and method for rendering indirect illumination using interleaving and sub-image blur. One embodiment of the processor is configured to render an indirect illumination image and includes: (1) a buffer restructurer configured to organize a reflective shadow map (RSM), rendered with respect to a reference point, into a plurality of unique sub-RSMs, each having sub-RSM pixels, (2) an indirect illumination computer configured to employ interleaved sampling on the plurality of unique sub-RSMs to generate a plurality of indirect illumination sub-images, and (3) a filter operable to smooth accumulated light values of the indirect illumination sub-images for subsequent interleaving into the indirect illumination image.

Abstract: A graphics processing subsystem for recovering projection parameters for rendering effects and a method of use thereof. One embodiment of the graphics processing subsystem includes: (1) a memory configured to store a buffer having a plurality of constants determinable upon execution of an application for which a scene is rendered, and (2) a central processing unit (CPU) operable to determine projection parameters from the buffer according to shader-reflection metadata attached to a programmable shader submitted for execution, and employ the projection parameters to cause an effect to be rendered on the scene by a graphics processing unit (GPU).

Abstract: A cache-efficient processor and method for rendering indirect illumination using interleaving and sub-image blur. One embodiment of the processor is configured to render an indirect illumination image and includes: (1) a buffer restructurer configured to organize a reflective shadow map (RSM), rendered with respect to a reference point, into a plurality of unique sub-RSMs, each having sub-RSM pixels, (2) an indirect illumination computer configured to employ interleaved sampling on the plurality of unique sub-RSMs to generate a plurality of indirect illumination sub-images, and (3) a filter operable to smooth accumulated light values of the indirect illumination sub-images for subsequent interleaving into the indirect illumination image.

Abstract: The method includes receiving a plurality of graphics primitives for rendering at a GPU of a computer system and rendering graphics primitives into pixel parameters of the pixels of a display, wherein the parameters include pixel depth values and pixel normal values. For each pixel of the display, an ambient occlusion process is performed. The algorithm takes as input a ND-buffer containing pixel depth values and pixel normals. Based on the pixel 3-D position and the pixel normal vector, horizon heights are computed by sampling the ND-buffer and an occlusion term is computed for each pixel based on the horizon heights. Based on the pixel 3-D position, the pixel normal vector, a normal occlusion term is computed by sampling the ND-buffer above the horizon in multiple directions. An ambient occlusion illumination value is computed by combining the horizon occlusion term and the normal occlusion term.

Abstract: A stereo viewpoint graphics processing subsystem and a method of sharing geometry data between stereo images in screen-space processing. One embodiment of the stereo viewpoint graphics processing subsystem configured to render a scene includes: (1) stereo frame buffers configured to contain respective pixel-wise rendered scene data for stereo images, and (2) a sharing decision circuit operable to determine when to share geometric data between the stereo frame buffers for carrying out screen-space effect processes to render the scene in the stereo images.

Abstract: A visible polygon data structure and method of use thereof. One embodiment of the visible polygon data structure includes: (1) a memory configured to store a data structure containing vertices of at least partially visible polygons of the scene but lacking vertices of at least some wholly invisible polygons of the scene, and (2) a graphics processing unit (GPU) configured to employ the vertices of the at least partially visible polygons to approximate an ambient occlusive effect on a point in the scene, the effect being independent of the wholly invisible polygons.

Abstract: A method for rendering a volumetric shadow includes defining a light source ray emanating from a light source, wherein the light source ray intersects a plurality of occluding primitives included within the scene. The method further includes computing an aggregate absorption function for the light source ray, whereby a per-primitive absorption function is computed for each of the plurality of occluding primitives intersecting the light source ray, and the resulting plurality of per-primitive absorption functions are summed to form an aggregate absorption function for the light source ray. A transmittance value is computed as a function of the aggregate absorption function, the transmittance value used to render the volumetric shadow within the scene.

Abstract: A graphics processing subsystem operable to efficiently render an ambient occlusion texture. In one embodiment, the graphics processing subsystem includes: (1) a memory configured to store a depth data structure according to which a full-resolution depth texture is represented by a plurality of unique reduced-resolution depth sub-textures, and (2) a graphics processing unit configured to communicate with the memory via a data bus, and, for a given pixel, execute a program to employ the plurality of unique reduced-resolution depth sub-textures to compute a plurality of coarse ambient occlusion textures, and to render the plurality of coarse ambient occlusion textures as a single full-resolution ambient occlusion texture for the given pixel.

Abstract: One embodiment of the present invention sets forth a technique for performing dual depth peeling, which is useful for order-independent transparency blending. Multiple rendering passes are performed on a graphics scene. After each rendering pass, the front-most and back-most layer of pixels are peeled away by computing a reference window. In subsequent rendering passes, only pixels within the reference window survive depth sorting. In each subsequent rendering pass, the reference window is narrowed by the front most and back most surviving pixels. By performing depth peeling in two directions simultaneously, the number of rendering passes needed to generate a completed graphics image is reduced from L to 1+L/2, which results in improved rendering performance.

Abstract: One embodiment of the present invention sets forth a technique for performing dual depth peeling, which is useful for order-independent transparency blending. Multiple rendering passes are performed on a graphics scene. After each rendering pass, the front-most and back-most layer of pixels are peeled away by computing a reference window. In subsequent rendering passes, only pixels within the reference window survive depth sorting. In each subsequent rendering pass, the reference window is narrowed by the front most and back most surviving pixels. By performing depth peeling in two directions simultaneously, the number of rendering passes needed to generate a completed graphics image is reduced from L to 1+L/2, which results in improved rendering performance.

Abstract: The method includes receiving a plurality of graphics primitives for rendering at a GPU of a computer system and rendering graphics primitives into pixel parameters of the pixels of a display, wherein the parameters include pixel depth values and pixel normal values. For each pixel of the display, an ambient occlusion process is performed. The algorithm takes as input a ND-buffer containing pixel depth values and pixel normals. Based on the pixel 3-D position and the pixel normal vector, horizon heights are computed by sampling the ND-buffer and an occlusion term is computed for each pixel based on the horizon heights. Based on the pixel 3-D position, the pixel normal vector, a normal occlusion term is computed by sampling the ND-buffer above the horizon in multiple directions. An ambient occlusion illumination value is computed by combining the horizon occlusion term and the normal occlusion term.

Abstract: A method of and a system for presenting a plurality of workflows that describe an evolutionary workflow process associated with creating a result are provided. A first workflow is received at a first device. The first workflow comprises a first module which applies a first instruction to form a first result. A modification of the first workflow is received at the first device. The received modification includes a second workflow which includes a second module that applies a second instruction to form a second result. The evolutionary workflow process is presented to a user at a second device. The evolutionary workflow process includes the first workflow and the second workflow and indicates a parent-child relationship between the first workflow and the second workflow.

Abstract: Soft shadows in computer graphics images are created by rendering the scene from the camera viewpoint and at least one light viewpoint. The positions of scene fragments and light fragments in the scene are stored. For each scene fragment, a frustum is defined between the position of the scene fragment and the light source. Light fragments are evaluated with respect to the frustum to select light fragments blocking light between the light source and the scene fragment. A color or monochromatic shading value is determined for each scene fragment that indicates the amount of light blocked or transmitted by the light fragments. The shading values are then used to alter scene fragments accordingly. Computer graphics images with soft shadows can be created entirely by a graphics processing subsystem or by a graphics processing subsystem in conjunction with a central processing unit using a pipelined, deferred shading approach.