EP0212774A2
Expired / Lapsed
EP
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Display system
Assignee: Yamaguchi Fujio
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Filing: 1986-04-23
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Granted: —
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Expires: 2006-04-23
Abstract
Abstract The hidden lines and surfaces of two interfering objects to be displayed in two-dimensions, are calculated by considering the polygonal plane surfaces defining each object, dividing them into triangles, projecting one triangle of one object onto the plane of a triangle of the other object, calculating a 4 × 4 determinant of the vertex coordinates of one triangle and one vertex coordinate of the projected triangle, determining intersection points to define hidden lines and surfaces and repeating as necessary.
Inventors
- 👤 Fujio Yamaguchi
- 👤 Ryoji Ebisawa
- 👤 Takaomi Tatemichi
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 23:13
CPC Classifications
G; G06; G06T; G06T15/00; G06T15/10; G06T15/40; G06T15/405
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
120 words
A system for determining hidden lines and surfaces of three dimensional objects to be displayed in two dimensions, comprising means (1) for dividing polygonal plane surfaces which form first and second geometric models, into triangles by diagonal lines drawn from vertices thereof, and which produces vertex coordinates of triangles which form the geometric models, transformation means (3) which produces vertex coordinates of an image that is formed when one triangle produced by the triangular division means (1) is projected onto another triangle, determinant operating means (7a, 7b) which calculates values of 4 × 4 determinants, and which calculates logical values among determinants, and means (8) for calculating interference points which operates relying upon the results from the determinant operating means.
Claim 2
Independent Claim
120 words
A system for determining hidden lines and surfaces of three dimensional objects to be displayed in two dimensions, comprising means (1) for dividing polygonal plane surfaces which form first and second geometric models, into triangles by diagonal lines drawn from vertices thereof, and which produces vertex coordinates of triangles which form the geometric models, transformation means (3) which produces vertex coordinates of an image that is formed when one triangle produced by the triangular division means (1) is projected onto another triangle, determinant operating means (7a, 7b) which calculates values of 4 × 4 determinants, and which calculates logical values among determinants, and means (8) for calculating interference points which operates relying upon the results from the determinant operating means.
Claim 3
Dependent Claim
124 words
A system according to claim 1, including shape determining means (10), wherein each 4 × 4 determinant is constituted relying upon the vertex coordinate of said another triangle and the coordinate of another one point with respect to the figure of the projected image from said transformation means (3) and with respect to said another triangle, the operation being performed by said operation means (7), said intersecting point coordinate calculation means (8) being operated relying upon the calculated result to form a new figure, and when the shape of a newly formed figure is determined by said shape determining means (8) to be composed of four or more vertices, the data of said figure are returned to the means (1) for dividing into triangles.
Claim 4
Independent Claim
98 words
A method of determining hidden lines and surfaces of three dimensional objects to be displayed in two dimensions, comprising dividing polygonal plane surfaces of first and second geometric objects into triangles, and producing coordinates of the vertices of the triangles, transforming the vertex coordinates of a triangle of one object into coordinates of a projected triangle in the plane of a triangle of the other object, and thereafter determining interference by calculating the value of 4 × 4 determinants using the vertex coordinates of one triangle and the coordinates of each vertex of the projected triangle in turn.
Claim 5
Independent Claim
98 words
A method of determining hidden lines and surfaces of three dimensional objects to be displayed in two dimensions, comprising dividing polygonal plane surfaces of first and second geometric objects into triangles, and producing coordinates of the vertices of the triangles, transforming the vertex coordinates of a triangle of one object into coordinates of a projected triangle in the plane of a triangle of the other object, and thereafter determining interference by calculating the value of 4 × 4 determinants using the vertex coordinates of one triangle and the coordinates of each vertex of the projected triangle in turn.
References Cited (Backward Citations)
No citation records indexed.
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