Jeff William Burrell

US Patent:

6573893, Jun 3, 2003

Filed:

Nov 1, 2000

Appl. No.:

09/704185

Inventors:

Hasan Shahzad Naqvi - Ft Collins CO
Jeff William Burrell - Fort Collins CO
Barthold Lichtenbelt - Fort Collins CO

Assignee:

Hewlett-Packard Development Company, L.P. - Houston TX

International Classification:

G06T 1700

US Classification:

345424

Abstract:

A voxel transfer circuit that implements high-speed voxel transfer operations. When implemented in a 2D or 3D texture mapping circuit of a graphics system, or in a graphics card adapter of a workstation, the voxel transfer circuit provides a comprehensive, accelerated volume rendering capability to the existing imaging pipeline. For each voxel in a volume data set, the voxel transfer circuit generates a texel having an opacity value and a color value based on one or more properties of the voxel including the local gradient magnitude and a lighting model. The relationship between these values is referred to herein as a classification or transfer function. In the present invention, the voxel transfer circuit implements a transfer function that employs a gradient-influenced classification. Such a transfer function generates opacity and color values of structures with excellent edge and surface discrimination. Preferably the voxel transfer circuit also includes the influence of a lighting model on the voxel, providing improved three-dimensional clarity and depth cues.