Graphic display method for displaying a perspective view of an o

Details Graphic display method for displaying a perspective view of an o Graphic display method for displaying a perspective view of an o

1985-10-31

1988-06-28

Brigance, Gerald L.

Communications: electrical

Land vehicle alarms or indicators

Internal alarm or indicator responsive to a condition of the...

340724, 340727, 364521, 364522, G09G 102

Patent

active

047542691

DESCRIPTION:

BRIEF SUMMARY
BACKGROUND OF THE INVENTION

This invention relates to a graphic display method and, more particularly, to a graphic display method for transforming the three-dimensional coordinate values of an object to be displayed into the coordinate values of a two-dimensional display coordinate system, and displaying a perspective view of the object on a CRT display screen by using the two-dimensional coordinate values obtained by the transformation, wherein the position at which the perspective view is displayed can be shifted, and the perspective view rotated, in a simple manner.
Graphic display units are in use everywhere as means for implementing CAD/CAM (computer aided design and manufacturing). It is essential that these graphic display units be capable of displaying the perspective view of a three-dimensional object on a display screen (CRT screen). To this end, conventional graphic display units are adapted to display a perspective view of a three-dimensional object and are capable of enlarging and reducing the size of the displayed view.
There are situations where it is desired to shift the position at which the perspective view is displayed on the CRT screen or to display the perspective view on the CRT screen upon changing the position from which the three-dimensional object is observed. In other words, there are times when one wishes to display the perspective view on the CRT screen while the view is rotated. In such cases, the conventional practice is to enter the display position and the angle of rotation from a keyboard to change the position at which the perspective view is displayed or to display the perspective view upon rotation.
With the conventional practice however, operation is troublesome, the display position cannot be changed continuously, and the perspective view cannot be displayed while it is being continuously rotated.
In addition, specialized hardware such as a joystick is provided and the joystick is used to change the display position or the angle of rotation of the perspective view. Thus, extra hardware is required, which is undesirable in view of cost.


SUMMARY OF THE INVENTION

An object of the present invention is to provide a graphic display method whereby the position at which a perspective view is displayed can be changed, and the perspective view rotated, through simple operations.
Another object of the present invention is to provide a graphic display method whereby the position at which a perspective view is displayed on a CRT screen can be changed continuously and, moreover, whereby the perspective view can be displayed while being continuously rotated.
A further object of the present invention is to provide a graphic display method in which use is made of numeric keys provided on a keyboard, as well as the arrangement of the keys. The keys constituting the numeric keys are employed as display position change keys and rotation angle change keys, and the display position or the angle of rotation of a perspective view is changed by a predetermined amount whenever these keys are pressed.
The present invention provides 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 a perspective view of the object on the CRT display screen by using the two-dimensional coordinate values obtained by the transformation. Let .beta. represent an angle between x and y axes among the 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 the reference), .alpha. 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 the reference), and (X.sub.o, Y.sub.o) the coordinate values of the three-dimensional coordinate origin of the perspective view in the display coordinate system. The three-dimensional c

REFERENCES:
patent: 3621214 (1971-11-01), Romney et al.
patent: 3731299 (1973-05-01), Bouchard et al.
patent: 4127849 (1978-11-01), Okor
patent: 4222048 (1980-09-01), Johnson
patent: 4467412 (1984-08-01), Hoff
patent: 4490781 (1984-12-01), Kishi et al.
patent: 4600919 (1986-07-01), Stern

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