The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 30, 1989
Filed:
Aug. 15, 1986
Robert A Drebin, Corte Madera, CA (US);
Loren C Carpenter, Novato, CA (US);
Pixar, San Rafael, CA (US);
Abstract
Method and apparatus for shading an image volume so that surfaces and boundaries may be rendered to subvoxel accuracy. A gradient vector is generated for each voxel of an image volume by calculating the change in opacity across that voxel in relation to its immediate neighbors. The gradient in the X, Y and Z direction of a three-dimensional voxel array is used to define a gradient length. By multiplying the RGBA values of individual voxels by their gradient length, a image volume may be shaded so that surfaces remain, but the interiors of solids are rendered more transparent revealing additional detail. Surfaces are shaded by multiplying the RGBA values of each voxel by a shading function. A reference point for a light source illuminating the displayed image volume is defined. A light vector is chosen for each voxel, a shading function is then generated based on the angle between the gradient vector and the light vector. The shading function allows for inputs for backlighting and side lighting.