Abstract: A system and method are provided for accelerating graphics processing utilizing multiple-pass rendering. Initially, geometry operations are performed on graphics data, and the graphics data is stored in memory. During a first rendering pass, various operations take place. For example, the graphics data is read from the memory, and the graphics data is rasterized. Moreover, first z-culling operations are performed utilizing the graphics data. Such first z-culling operations maintain a first occlusion image. During a second rendering pass, the graphics data is read from memory. Still yet, the graphics data is rasterized and second z-culling operations are performed utilizing the graphics data and the first occlusion image. Moreover, visibility operations are performed utilizing the graphics data and a second occlusion image. Raster-processor operations are also performed utilizing the graphics data, during the second rendering pass.

Abstract: A system, method and computer program product are provided for avoiding reading z-values in a graphics pipeline. Initially, near z-values are stored which are each representative of a near z-value on an object in a region. Such region is defined by a tile and a coverage mask therein. Thereafter, the stored near z-values are compared with far z-values computed for other objects in the region. Such comparison indicates whether an object is visible in the region. Based on the comparison, z-values previously stored for image samples in the region are conditionally read from memory.

Abstract: A system, method and computer program product are provided for avoiding reading z-values in a graphics pipeline. Initially, near z-values are stored which are each representative of a near z-value on an object in a region. Such region is defined by a tile and a coverage mask therein. Thereafter, the stored near z-values are compared with far z-values computed for other objects in the region. Such comparison indicates whether an object is visible in the region. Based on the comparison, z-values previously stored for image samples in the region are conditionally read from memory.

Abstract: Roughly described, the invention is employed within a z-buffer-system having a host processor and graphics hardware that performs hierarchical z-buffering. The z-buffer system renders three-dimensional scenes having geometric primitives that are organized in bounding boxes or rooms-with-portals. As an image is being generated, some but not all z-pyramid values are written from the graphics system into memory that can be quickly accessed by the host processor. This enables the host processor to perform visibility tests that cull occluded bounding boxes or portals, thereby accelerating rendering by reducing the number of primitives that need to be sent to graphics hardware and processed.

Abstract: An antialiased rendering algorithm that guarantees that each pixel of the output image is within a user-specified error tolerance of the filtered underlying continuous image wherein an object-space octree is used to cull hidden geometry rapidly, and a quadtree data structure is used to test visibility through image-space regions. When regions are too complex, quadtree subdivision is employed to simplify the geometry. Subdivision stops when the algorithm can either analytically filter the required region or bound the convolution integral appropriately with interval methods.

Abstract: A hierarchical Z-buffer scan-conversion algorithm that does well on both (a) quickly rejecting most of the hidden geometry in a model, and (b) exploiting the spatial and temporal coherence of the images being generated. The method uses two hierarchical data structures, an object-space octree and an image-space Z-pyramid, in order to accelerate scan conversion. The two hierarchical data structures make it possible to reject hidden geometry very rapidly while rendering visible geometry with the speed of scan conversion. For animation purposes, the algorithm is also able to exploit temporal coherence. The resulting method is well suited to models with high depth complexity, achieving significant speedup in some cases compared to ordinary scan conversion.

Abstract: A method of treating gas includes the steps of (1) mixing pressurized air and treatment liquid and thereby generating treatment foam and (2) venting the gas through the treatment foam. Preferably, the liquid is liquid deodorant for deodorizing gas from a waste water treatment system. The treatment system is efficient, economical, uncomplicated and easy to install and operate.