Silicon Graphics, Incorporated

Paolo Farinelli

Angus Dorbie

Alex Chalfin

A method is disclosed for culling an object database in a graphics processing system. In one embodiment, the method comprises encoding per-object parameters and culling parameters. The per-object parameters are encoded in texture format thereby creating at least one per-object texture containing the encoded per-object parameters. Next, a fragment program used in a fragment processor of the GPU is optionally updated. The updated fragment program embodies a culling operation. A polygon is then rendered, wherein the rendering step includes per-fragment operations. During the per-fragment operations, the updated fragment program is executed. The culling operation embodied therein (i) accesses the culling parameter, (ii) samples the per-object textures, and (iii) produces cull results for a set of database objects. In this fashion, the fragment processor in the GPU is leveraged to perform computationally intensive culling operations.

System and method for graphics culling

Methods, systems, and computer program products for blending textures used to render computer generated images are provided. In an embodiment of the invention, a MIP-mapped mask texture is constructed. Each MIP-level of the MIP-mapped mask texture includes texels representative of different mask information. The MIP-mapped mask texture is sampled during rendering to obtain mask information. The obtained mask information is used to blend between textures. The invention is used to blend, for example, between multiple textures wherein, zero, one, or more of the textures are MIP-mapped and/or between different levels of one or more three-dimensional textures. In an embodiment, the most appropriate texture amongst multiple textures, each providing coverage at different resolutions, is selected for a fragment being rendered, thereby avoiding texture scintillation.

Method, system, and computer program product for blending textures in a texture paging scheme

The present invention provides texture roaming via dimension elevation. A degree elevated texture is used to contain level of detail (LOD) levels (or tiles) of a clip-map across a degree elevated coordinate space. For example, a three-dimensional (3D) texture is used for two-dimensional (2D) clip-mapping, a four-dimensional (4D) texture is used for 3D clip-mapping, and a 2D texture is used for one-dimensional (1D) clip-mapping. Once the levels of a clip-map are placed in an extra dimension coordinate space, the extra dimension texture coordinate value can be computed based on clip-mapping rules.

Texture roaming via dimension elevation

A variable number of textures are blended together using a single texture as a mask. At least four textures are received. Masks are extracted from one of the received textures and used to blend together the remaining textures. In an embodiment, N masks are extracted from a single texture and used to blend N&plus;1 additional textures. In this embodiment, two of the N&plus;1 textures are initially blended together in accordance with one of the N masks to form an image. Another texture of the N&plus;1 textures is then blended with the image in accordance with another one of the N masks. This iterative blending process continues until all of the N&plus;1 textures have been blended together. In another embodiment, N textures are blended together by multiplying each of the N textures by one of the N masks and adding together the results of the N multiplications.

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Mountain View, CA, United States of America

Paolo Farinelli