JPH0554151A - Stereoscopic graphic processor - Google Patents

Abstract

PURPOSE:To efficiently draw a sphere by calculating the contour of shadow formed in the case of irradiating a stereoscopic graphic with light in a direction designated by a direction designating means, and attaching shadow along the contour of the calculated shadow. CONSTITUTION:In the case of drawing the spere, a CPU 1 displays a message so as to designate the direction of irradiating the graphic with light while using a mouse 6 after drawing a circle as the origin of the sphere. A mouse cursor is moved to a suitable position and when a left button 6a of the mouse 6 is pushed, a position fixing code is outputted. Next, the CPU 1 calculates the current coordinate of the mouse cursor and when the coordinate is within the range of the drawn circle, an angle theta formed between a straight line, which connects a designated coordinate A and a center 0 of the drawn circle, and an X axis is calculated. Then, coordinate transformation is executed to rotationally move the coordinate only for the angle thetaand to set it on the X axis. Next, the contour of the shadow is calculated and drawn and afterwards, the contour is painted out so as to attach the gradation of the shadow. Then, the sphere attached the shadow is reversely rotationally moved only for the angle theta and defined as the shadow formed on the spherical face in the case of irradiating the coordinate with light.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a figure processing apparatus for drawing various figures, and more particularly to a three-dimensional figure processing apparatus for drawing three-dimensional figures.

[0002]

2. Description of the Related Art Conventionally, when a three-dimensional figure such as a sphere is drawn by a figure processing device, an operator appropriately casts a circle which is a base of the sphere and makes it look like the sphere, or it is registered in advance. I was drawing the sphere by calling the sphere data from the existing parts.

[0003]

However, when a shadow is cast on a curved surface such as the surface of a sphere in consideration of the direction of light, the outline of the shadow is not linear and the density of the shadow is not uniform. It was not easy due to the fact that it varied from place to place, and it took a lot of work.

The present invention has been made to solve the above-mentioned problems, and when the direction of light is designated, the outline of the shadow and the density of the shadow on the three-dimensional figure are calculated, so that the sphere can be efficiently projected. It is for drawing.

[0005]

In order to achieve this object, the graphic processing apparatus of the present invention draws a first drawing means A for drawing a three-dimensional figure before a shadow is cast, and the drawing means A. Direction designating means B for designating a direction of illuminating a figure, contour calculating means C for computing a contour of a shadow formed when light hits a three-dimensional figure in the direction designated by the direction designating means, and the contour calculation And a second drawing means D for drawing a shadow along the contour of the shadow obtained by the means C.

[0006]

The graphic processing apparatus of the present invention having the above-mentioned configuration is
The first drawing means A draws a solid figure before adding a shadow. The direction designating means B designates the direction in which light is applied to the three-dimensional figure. The contour calculating means C calculates the contour of the shadow formed when the light hits the solid figure in the direction designated by the direction designating means. The second drawing means 2 casts a shadow along the contour obtained by the contour calculating means.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram showing a hardware configuration of an embodiment embodying the present invention.

As shown in FIG. 1, a central processing unit (CPU) 1 that controls the entire apparatus has a read-only storage device (ROM) 2 and a readable / writable storage device (RAM).
3, auxiliary storage device (hard disk: HD) 4, key input device (keyboard: KB) 5, mouse 6, display device 7
(CRT) is connected.

As is well known, the CPU 1 executes the processing while decoding the data code read from the ROM 2 or the auxiliary storage device 4 into the RAM 3.

Next, FIG. 3 is a flowchart showing the operation of this embodiment, and the operation of the apparatus of this embodiment will be systematically described below with reference to this flowchart.

In step 1 (hereinafter abbreviated as S1; the same applies to the following steps), the CPU 1 draws a three-dimensional figure (here, a circle which is the origin of a sphere) before shadowing (see FIG. 4). In S2, the CPU 1 displays a message for designating the direction of the light (the position on the spherical surface where the light is perpendicular) using the mouse 6 (see FIG. 5). Next CPU
1 waits for the position confirmation code to be input from the mouse 6 (S3, S4: NO). Here the operator is mouse 6
When is moved, the mouse cursor corresponding to the movement of the mouse 6 moves on the screen of the CRT 7.

When the operator moves the mouse cursor to an appropriate position and presses the left button 6a of the mouse 6, the mouse 6 outputs a position fixing code. When the left button 6a of the mouse 6 is pressed and the position fixing code is output from the mouse 6 (S4: YES), the CPU 1 obtains the current coordinates of the mouse cursor and determines whether the coordinates are within the figure of the circle drawn in S1. Judge (S5). The coordinate specified by the mouse is S
If it is outside the range of the circle drawn in 1 (S5: NO), the process proceeds to S6, and if the coordinates designated by the mouse is within the range of the circle drawn in S1 (S5: YES), the process proceeds to S7. .. In S6, the CPU 1 displays an error message so as to specify the coordinates inside the figure, and returns to S3. CPU at S7
As shown in FIG. 6, 1 is the angle θ formed between the X-axis and the straight line connecting the designated coordinate (point A) and the center O of the circle drawn in S1 in order to facilitate the calculation in S8. , The specified coordinates are rotated by the angle θ with the center O of the circle as the center of rotation, and coordinate conversion is performed so that the specified coordinates are on the X axis.

In S8, the CPU 1 calculates the outline of the shadow. The brightness of the sphere varies depending on the place, and the place where the light hits the surface of the sphere perpendicularly is the brightest, and the place where the light hits the surface becomes darker as it becomes shallow. Actually, the brightness of the surface of the sphere changes continuously, but in this embodiment, the brightness from the gradually darker part to the darkest part where no light hits is divided into several levels. The boundary is calculated as the outline of the shadow. The apparent boundary of a sphere is an elliptical arc.

In S9, the CPU 1 draws the contour calculated in S8 (see FIG. 7). In S10, the CPU 1 paints along the contour drawn in S9 to shade the shadow (see FIG. 8). In S11, the CPU 1 rotationally moves the shaded sphere drawn in S10 in the opposite direction by the angle θ of the rotational movement performed in S7 with the center of the sphere as the center of rotation, and moves to the coordinates specified in S2 to S6. The shadow is formed on the spherical surface when light is applied (see FIG. 9).

The present invention is not limited to the embodiments described in detail above, and various modifications can be made without departing from the spirit of the invention.

For example, in the present embodiment, the outline of the shadow formed on the three-dimensional figure when the three-dimensional figure is illuminated is calculated and the shadow is cast on the three-dimensional figure. It is also possible to draw the shadow on the plane by obtaining the contour of the shadow of the solid figure projected on the plane when the solid figure is illuminated with light.

[0018]

As is clear from the above description,
The graphic processing apparatus of the present invention can easily draw a solid figure that is closer to the real thing by drawing a shadow formed when the solid figure is illuminated by illuminating the original figure.

[Brief description of drawings]

FIG. 1 is a configuration diagram of the present invention.

FIG. 2 is a block diagram showing a hardware configuration of a three-dimensional figure processing device.

FIG. 3 is a flowchart showing an operation of the three-dimensional figure processing device.

FIG. 4 is a diagram showing a screen during operation of the three-dimensional figure processing device.

FIG. 5 is a diagram showing a screen during operation of the three-dimensional figure processing device.

FIG. 6 is a diagram illustrating a process of rotating and moving a designated coordinate for convenience of calculation.

FIG. 7 is a diagram in which a contour of a shadow is drawn.

FIG. 8 is a diagram in which a shadow is drawn along the outline of the shadow.

FIG. 9 is a diagram in which a diagram of a sphere in which a shadow is drawn is rotated and moved.

[Explanation of symbols]

1 Central Processing Unit (CPU) (Drawing Means 1, Outline Calculation Means, Drawing Means 2) 6 Mouse (Direction Designating Means)

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ichiyo Takeuchi, 15-1 Naeshiro-cho, Mizuho-ku, Nagoya-shi Brother Industrial Co., Ltd. (72) Inventor Michiyo Amano, 15-1 Naeshiro-cho, Mizuho-ku, Nagoya-shi Brother Engineering Incorporated (72) Inventor Ritsuko Kagami 15-1 Naeshiro-cho, Mizuho-ku, Nagoya-shi Brother Industries Ltd.

Claims (1)

[Claims] 1. A first method for drawing a three-dimensional figure before applying a shadow
Drawing means, a direction designating means for designating a direction of illuminating the figure drawn by the drawing means, and a contour of a shadow formed when light hits the three-dimensional figure in the direction designated by the direction designating means. A three-dimensional figure processing device comprising: a contour calculating means for calculating; and a second drawing means for drawing a shadow along the contour of the shadow obtained by the contour calculating means.