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.

Date of Patent:
Nov. 10, 1998

Filed:

May. 08, 1995
Applicant:
Inventors:

Karin P Smith, Madison, AL (US);

George R Smith, Jr, Madison, AL (US);

Assignee:

Intergraph Corporation, Huntsville, AL (US);

Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G06T / ;
U.S. Cl.
CPC ...
345421 ;
Abstract

Objects are represented in a coordinate space which is twice scanned by scan lines, once in one direction and then once in another direction. At each scan line, a list of line segments is generated, where each line segment represents the intersection of the projection of a polygon and the scan line. The segments are then examined to determine which are visible segments, using the z values of the end points of the segments. The visible segments of a scan line are compared to the visible segments of a previous scan line or an accumulation of visible lines, and if the end points of a visible segment taken from a polygon differ by less than a threshold amount, the lines formed between end points in one scan line and the adjacent scan line are considered to be visible lines. Where the two scans are a horizontal scan and a vertical scan, the threshold amount for vertical scans is the distance between horizontal scans and the threshold amount for horizontal scans is the distance between vertical scans.


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