Sun Microsystems, Inc.

Randall G Keller

Henry A Sowizral

Karel Zikan

A system for performing visible object determination. Visualization software executing on one or more processors searches a cone tree with respect to a hull tree. Both trees respect the same group of transformations. Thus, the cone tree as stored in memory need not store all branches down to ultimate resolution. For example, the cone tree may store a selected cone and all its subcones down to the ultimate resolution, while subcones of other cones at the same level as the selected cone may not be represented in the stored cone tree. When the visualization software encounters a nonstored cone and a given hull H in its search procedure, the visualization software may apply an appropriate one of the group transformations to the given hull, and search the tranformed hull with respect to the selected cone (or a subcone of the selected cone).

Geometric folding for cone-tree data compression

A system and method that manages scene graphs by data staging is contemplated. Data staging entails selectively loading only the portions of the scene graph that are currently needed or likely to be needed in the near future. Other objects in the scene graph that are not currently needed or likely to be needed may be replaced by pointers. The pointers may point to the location from which the objects may be accessed if necessary for a future frame. The replaced portions of the scene graph may be compressed and/or cached to a local memory device (e.g., a local array of read-write optical drives) capable of storing large amounts of data, with the pointers indicating where the objects are stored.

Managing scene graph memory using data staging

A system for performing visible object determination. Visualization software running on a host processor represents space with a hierarchy of cones, and generates a hierarchy of bounding hulls from a collection of objects by recursively grouping clusters of objects. Each hull node in the hull hierarchy stores parameters which characterize a bounding hull for the corresponding cluster or object. The visualization software searches the cone and hull hierarchies starting with the root cone and the root hull. Before exploring a given cone-hull pair, a normalized cone size for the cone and a normalized hull size for the hull may be computed, and the sizes compared. If the cone size is larger than the hull size, subcones of the cone are explored with respect to the hull. Conversely, if the hull size is larger than the cone size, subhulls of the hull are explored with respect to the cone.

Size conditioned visibility search system and method

A system and method for determining graphical object visibility by utilizing ancillary geometry. When comparing visibility cones with bounding hulls of scene graph hierarchy leaf nodes, ancillary geometry may be used in place of the bounding hulls and the leaf node's actual geometry. The ancillary geometry may be created through a manual process, or by an automated decimation process. The ancillary geometry may be a simplistic analytic surface (e.g., a sphere or a cylinder), a NURB surface, a collection of polygons, or a combination of surfaces and polygons.

Using ancillary geometry for visibility determination

A system and method for performing visible object determination based upon a dual search of a cone hierarchy and a bound hierarchy performed by multiple processors. Each processor is configured to read a (global and/or local) problem queue to access a bound-cone pair. The bound-cone pair points to a bound in the bound hierarchy and a cone in the cone hierarchy. The processor computes a bound-cone distance between the bound and the cone, and compares the bound-cone distance to a visibility distance associated with the cone. If the bound-cone distance is smaller than the visibility distance, the processor may write two or more refined bound-cone pairs corresponding to a refinement of the original pair to the global or local problem queue. When the processor detects a leaf bound and a leaf cone, it updates a nearest object pointer and the visibility distance associated with the leaf cone.

Multiple processor visibility search system and method

A system for determining nearest leaf bounds per leaf cone of a cone hierarchy based on a dual-tree search of the cone hierarchy and a bound hierarchy. A processor, performing the dual-tree search, maintains for each leaf cone a collection of nearest leaf bounds. The collection evolves as the dual-tree search progresses. The processor may maintain the N closest leaf bounds for each leaf cone. The processor may classify leaf bounds as occluders or non-occluders, and store any non-occluder closer than the N occluder. Alternatively, the processor may assign an occlusion metric value to each leaf bound, and may maintain closest leaf bounds so that the sum of their occlusion metric values is less than or equal to an occlusion threshold. The dual-tree search may be followed by a search of the bound hierarchy with probe cones of the leaf cones.

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San Carlos, CA, United States of America

Randall G Keller