Graphic display method for displaying a perspective view of an object on a CRT
First Claim
1. A graphic display method for transforming three-dimensional coordinate values (x, y, z) of an object to be displayed into coordinate values (X, Y) of a two-dimensional display coordinate system on a CRT display screen, and displaying and rotating a perspective view of the object on the CRT display screen by using two-dimensional coordinate values obtained by the transformation, where β
- represents an angle between x and y axes among three-dimensional coordinate axes of the perspective view displayed on the CRT screen with the x axis serving as a reference and the counter-clockwise direction defined to be positive, where α
represents the angle between the x axis and an X axis of a display coordinate system with the X axis serving as a reference and the counter-clockwise direction defined to be positive, and where (Xo, Yo) represent coordinate values of a three-dimensional coordinate origin of the perspective view in the display coordinate system, and a keyboard is provided with keys for incrementing and decrementing the angle α
, said method comprising the steps of;
(a) increasing α
by pressing the increment key or decreasing α
by pressing the decrement key;
(b) transforming the three-dimensional coordinate values into the display coordinate system based on the formula ##EQU4## and (c) displaying the perspective view of the three-dimensional object while rotating the perspective view in accordance with the coordinate values in the display coordinate system obtained by said transforming step (b).
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Accused Products
Abstract
A graphic display method for transforming three-dimensional coordinate values (x, y, z) of an object to be displayed into coordinate values (X,Y) of a two-dimensional display coordinate system on a CRT display screen (DPS), and displaying a perspective view of the object on the CRT display screen (DPS) by using two-dimensional coordinate values obtained by the transformation. In the method, β represents an angle between x and y axes among three-dimensional coordinate axes of the perspective view displayed on the CRT screen (where the counter-clockwise direction is taken as positive with the x axis serving as a reference), α represents the angle between the x axis and an X axis of a display coordinate system (where the counter-clockwise direction is taken as positive with the X axis serving as a reference), and (Xo,Yo) represent coordinate values of a three-dimensional coordinate origin (DRP) of the perspective view in the display coordinate system. A keyboard is provided with keys for incrementing and decrementing the angle α. The method has a step of increasing α by pressing the increment key or decreasing α by pressing the decrement key, and a step of transforming the three dimensional coordinate values into the display coordinate system (X-Y) by the formula ##EQU1## The perspective view of the three-dimensional object is displayed while it is rotated by using the coordinate values in the display coordinate system obtained by the transformation.
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Citations
7 Claims
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1. A graphic display method for transforming three-dimensional coordinate values (x, y, z) of an object to be displayed into coordinate values (X, Y) of a two-dimensional display coordinate system on a CRT display screen, and displaying and rotating a perspective view of the object on the CRT display screen by using two-dimensional coordinate values obtained by the transformation, where β
- represents an angle between x and y axes among three-dimensional coordinate axes of the perspective view displayed on the CRT screen with the x axis serving as a reference and the counter-clockwise direction defined to be positive, where α
represents the angle between the x axis and an X axis of a display coordinate system with the X axis serving as a reference and the counter-clockwise direction defined to be positive, and where (Xo, Yo) represent coordinate values of a three-dimensional coordinate origin of the perspective view in the display coordinate system, and a keyboard is provided with keys for incrementing and decrementing the angle α
, said method comprising the steps of;(a) increasing α
by pressing the increment key or decreasing α
by pressing the decrement key;(b) transforming the three-dimensional coordinate values into the display coordinate system based on the formula ##EQU4## and (c) displaying the perspective view of the three-dimensional object while rotating the perspective view in accordance with the coordinate values in the display coordinate system obtained by said transforming step (b). - View Dependent Claims (2, 3, 4, 5)
- represents an angle between x and y axes among three-dimensional coordinate axes of the perspective view displayed on the CRT screen with the x axis serving as a reference and the counter-clockwise direction defined to be positive, where α
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6. A graphic display method for displaying and rotating a perspective view of an object on a CRT display screen having a display coordinate system with an X axis and a Y axis, comprising the steps of:
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(a) providing three-dimensional coordinate values (x, y, z) for an object to be displayed; (b) providing angle data representing a first angle which is between the x and y axes; (c) providing angle data representing a second angle which is between the x axis and the X axis; (d) providing a coordinate origin (Xo, Yo) representing coordinate values of a three-dimensional coordinate origin in the display coordinate system; (e) increasing the second angle by actuating an increment key or decreasing the second angle by actuating a decrement key; (f) transforming the three-dimensional coordinate values representing the object to be displayed into the display coordinate system of the CRT display; and (g) displaying the perspective view of the three-dimensional object while rotating the perspective view in accordance with the coordinate values in the display coordinate system obtained by said step (f). - View Dependent Claims (7)
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Specification