Hsuen Chung Ho

US Patent:

54287189, Jun 27, 1995

Filed:

Jan 22, 1993

Appl. No.:

8/007952

Inventors:

John Peterson - Palo Alto CA
Hsuen C. Ho - Cupertino CA

Assignee:

Taligent, Inc. - Cupertino CA

International Classification:

G06F 1510

US Classification:

395123

Abstract:

A method and apparatus for tessellating a three-dimensional spline surface into shards operates on a surface which can be separated into columns having a series of subpatches. Each column is processed by performing a series of evaluations upon each of the subpatches of the column. Such evaluations include continuity between subpatches, visibility of subpatches and granularity for discretization of the subpatches and the results are stored within caches. Once the evaluations are completed, a grid which holds the discretized points of each subpatch, is computed by dynamic selection of an algorithm. Thereafter, any cracks between subpatches of the column and between columns are removed. Ultimately, the column is rendered for display. Each of the columns is handled in the same manner so as to ultimately render a set of adjacent columns that form the two-dimensional representation.