JPH07168947A - Stereoscopic graph plotting system - Google Patents

Abstract

PURPOSE:To provide a stereoscopic graph plotting system which can execute easily and speedily the plotting and the rotational plotting processing of a stereoscopic graph by two-dimensional processing. CONSTITUTION:In this stereoscopic graph plotting system, one of four kinds of reference rotation angles set for every angle range is selected by a reference rotation angle judging part 20 in accordance with the angle range obtained by quadri-secting 360 deg. to which the rotation angle to designate the viewpoint direction of the stereo-scopic graph belongs, and as procedure to read in the height data of the graph from the two-dimensional array of MXN of a stereoscopic graph image height storage area 60, graph image height data is read in by a data read-in control part 30 in conformity with four kinds of data reading-in sequence set for every reference rotation angle, and simultaneously, the graph image height data read in by a plotting control part 40 is arranged on a plotting pattern constituted of MXN pieces of grids on a plotting memory 80 in conformity with definite plotting sequence, and the plotting data of a stereoscopic graph image is generated, and the stereoscopic graph is outputted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional graph drawing system, and more particularly to a three-dimensional graph drawing system capable of drawing and outputting a three-dimensional graph at high speed by two-dimensional data processing.

[0002]

2. Description of the Related Art Conventionally, this type of three-dimensional graph drawing system has been incorporated into an information processing system as a statistical application program and is often used as one of means for visually displaying data. This system has a function of rotating the entire graph to display a hidden portion that cannot be seen when it is displayed on the output device.

In order to realize a function of rotating and drawing a three-dimensional graph, a polar coordinate conversion process of drawing data and a hidden line control process (a process of erasing a drawing line that appears more backward) can be performed in the program. It is commonly done.

That is, in the polar coordinate conversion processing of the drawing data, the polar coordinate values (in the case of a quadrangular prism, eight polar coordinate values are required) of individual prismatic column-shaped or columnar-shaped stereoscopic graph images forming a stereoscopic graph are used. Save it in memory,
The polar coordinate value of each stereograph image is recalculated according to the rotation angle. Further, in the hidden line control processing, the front-rear relationship with other stereograph images for each of the prismatic column shape and the columnar column-shaped stereograph image forming the stereograph is checked, and the drawing line located in the rear is erased. .

[0005]

The conventional solid graph drawing system described above requires three-dimensional polar coordinate conversion processing for the rotation angle and hidden line control processing after rotation.
The program is special and complicated compared to other planar graphs. As a result, there are problems that the execution program is enlarged, the drawing process is slowed down, and maintenance is not easy.
Further, in the three-dimensional coordinate conversion processing, since the drawing data becomes large, there is a drawback that the memory required by the system, such as a work memory for saving the drawing coordinates, becomes large.

An object of the present invention is to easily perform three-dimensional graph drawing and rotation drawing processing by two-dimensional data processing without performing three-dimensional polar coordinate conversion processing for rotation angles and hidden line control processing after rotation. Another object of the present invention is to provide a three-dimensional graph drawing system that can be executed at high speed. In addition, the processing program is simple and small, and a stereographic graph drawing system that can be easily maintained is provided.

Another object of the present invention is to provide a three-dimensional graph drawing system which can be realized with a small system resource by eliminating the three-dimensional coordinate conversion processing and eliminating the need for a work memory for saving large drawing data. To do.

[0008]

In order to achieve the above object, the present invention stereoscopically creates M × N (M and N are integers of 1 or more) two-dimensional graph data in a perspective view format. In a three-dimensional graph drawing system for drawing and outputting, graph image height storage means for storing only height data of individual graph images corresponding to M × N graph data, corresponding to M × N two-dimensional array. , It is determined which range of the angle range in which the viewpoint direction of the three-dimensional graph is designated is divided into four equal to 360 degrees, and four types of criteria are set corresponding to each of the angle ranges. The height data of the graph image is obtained from the reference rotation angle selection means for selecting the reference rotation angle corresponding to the angle range to which the designated rotation angle belongs from the rotation angle and the M × N two-dimensional array of the graph image height storage means. As the reading order, the reference rotation angle Data reading control means for setting one of four types of data reading order set for each according to the selected reference rotation angle, and reading and reading graph image height data in accordance with the set data reading order. Drawing control means for generating drawing data of a solid graph image by arranging the graph image height data in a drawing pattern composed of M × N grids on the drawing memory in a fixed drawing order; An output unit that reads the drawing data from the memory and outputs the drawing data as a three-dimensional graph is provided.

Further, according to the present invention, M × N (M and N are 1
In a stereoscopic graph drawing system that stereoscopically draws and outputs two-dimensional graph data of the above integer) in a perspective view format, only height data of individual graph images corresponding to M × N graph data is M A graph image height storage means stored corresponding to a two-dimensional array of × N and a plurality of types of reference rotation angles preset as a reference rotation angle for designating the viewpoint direction of a three-dimensional graph are selected. The reference rotation angle selection means for determining one reference rotation angle and the order of reading the height data of the graph image from the M × N two-dimensional array of the graph image height storage means are set for each reference rotation angle. Data reading control means for setting one of the four types of data reading order according to the selected reference rotation angle, and reading the graph image height data according to the set data reading order. Drawing control means for generating the drawing data of the stereoscopic graph image by arranging the read graph image height data in the drawing pattern composed of M × N grids on the drawing memory in a fixed drawing order. And an output means for reading the drawing data from the drawing memory and outputting it as a three-dimensional graph.

According to another preferred aspect, the drawing pattern formed on the image memory is set as a predetermined drawing order for drawing the read graph image height data by the drawing control means on the drawing pattern on the drawing memory. The order in which the graph images are sequentially overlapped and drawn from the rear side to the front side is set. Further, the angle range obtained by dividing 360 degrees into four equal parts is a range of 315 degrees to 45 degrees, a range of 45 degrees to 135 degrees, a range of 135 degrees to 225 degrees, and a range of 225 degrees to 31 degrees.
Four angle ranges of 5 degrees are set, and 0 degrees, 90 degrees, and 180 degrees are set as reference rotation angles with respect to the respective angle ranges.
The degree is set to 270. Further, as initial information for drawing the solid graph in the image memory, the origin coordinates of the drawing pattern of the image memory for drawing the solid graph, the unit lengths in the X-axis and Y-axis directions of the grid forming the drawing pattern, the drawing A storage unit for storing the value of the grid M × N forming the pattern and the drawing order when drawing the graph image height data on the drawing pattern is provided.

[0011]

Embodiments of the present invention will now be described in detail with reference to the drawings. Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a block diagram showing the configuration of an embodiment of a stereograph drawing system of the present invention. In FIG. 1, a stereoscopic graph drawing system 10 of the present embodiment is a system that stereoscopically draws and outputs two-dimensional graph data in a state of a perspective view.
0, the data reading control unit 30, and the drawing control unit 40
A rotation angle storage area 50, a stereograph image height storage area 60, an initial information storage area 70, and an image memory 8
0 and an output device 90.

The rotation angle storage area 50 is an area for storing the rotation angle input by the operator in order to specify from which direction the stereoscopic graph to be drawn should be viewed as an image, and it is from 0 to 360 degrees. Hold any angle up to.

The solid graph image height storage area 60 is a prismatic (quadrangular prism or triangular prism) shape or a cylindrical solid graph image (a unit solid shape) that constitutes a solid graph drawn on a virtual scale plane of M rows × N columns to be described later. This is an area for storing height data of the graph image (unit graph image height data) as an array “A” of M rows × N columns.

The reference rotation angle determination unit 20 determines where the rotation angle input and stored in the rotation angle storage area 50 is included in a preset angle range, and the reference rotation angle corresponding to the included angle range. Is a means for selecting.
The reference rotation angle determination unit 20 is provided in the rotation angle storage area 5
It is determined which one of the angular ranges obtained by dividing 360 degrees into four equal parts, and the reference rotational angle corresponding to the belonging angular range is selected. In this embodiment, 36
0 degree is a range of 315 degrees or more and less than 45 degrees, 45 degrees or more 1
Less than 35 degrees, more than 135 degrees and less than 225 degrees,
Divide into four angle ranges of 225 degrees or more and less than 315 degrees, 0 degree, 90 degrees, 180 degrees,
A reference rotation angle of 270 degrees is assigned.

Therefore, when it is included in the range of 315 degrees or more and less than 45 degrees (315 degrees ≦ Φ <45 degrees), 0 degrees is set to 45 degrees.
If the angle is included in the range of not less than 135 degrees and less than 135 degrees (315 degrees ≤
Φ <45 degrees) includes 90 degrees, and 18 is included in the range of 135 degrees or more and less than 225 degrees (135 degrees ≦ Φ <225 degrees).
When 0 degree is included in the range of 225 degrees or more and less than 315 degrees (225 degrees ≦ Φ <315 degrees), 270 degrees is selected as the reference rotation angle.

The angle range corresponding to the reference rotation angle is set based on the fact that the front-rear relationship between unit stereograph images from a certain viewpoint does not change in each rotation angle range. For example, when two unit stereoscopic graph images are located in front of and behind the viewpoint of an angle of 0 degree, the viewpoint is 315 degrees or more.
Within the range of less than 5 degrees, the standard is that the context does not change.

The data reading control unit 30 is means for setting the data reading order of the unit graph image height from the stereoscopic graph image height storage area 60 based on the reference rotation angle selected by the reference rotation angle determination unit 20. The data read control unit 30 has four reference rotation angles (0 degree, 90 degree, 1 degree).
The data reading order of the unit stereograph image height is preset for each 80 degrees and 270 degrees.

The drawing control unit 40 reads the unit stereograph image height data from the stereograph image height storage area 60 in accordance with the reading order set by the data reading control unit 30, and also reads the read unit stereograph image height data and drawing. It is means for generating drawing data of a graph based on the drawing information set in the information storage area 70 and drawing a three-dimensional graph in the image memory 80.

The drawing information storage area 70 stores initial information for drawing a three-dimensional graph in the image memory 80.
In the drawing information storage area 70, as initial information of drawing, the origin coordinates of a virtual scale plane on which a stereoscopic graph to be described later is drawn, the unit lengths (dx, dy) in the X-axis and Y-axis directions of the lattice forming the virtual scale plane. ), The number of grids forming the virtual scale plane (value of M × N), and the drawing order (drawing direction and drawing rule) when drawing the unit graph image on the virtual scale plane are stored.

The output device 90 is a CRT device or a printer device that visually displays the stereoscopic image drawn in the image memory by the drawing control unit 40.

FIG. 2 is a virtual scale plane (virtual drawing pattern) for drawing a solid graph on the image memory 80.
The image pattern of is shown. As shown in the figure, this virtual scale plane is composed of M × N (M and N are both positive integers of 1 or more) lattices.

Here, the reference rotation angle is 0 °, 90 °, 1
The image pattern of the virtual scale plane for each reference rotation angle of 80 degrees and 270 degrees is shown. Reference rotation angle is 0
In the case of degrees and 180 degrees, the pattern is shown by the solid line in the figure. In this way, when the reference rotation angle is 0 ° and 180 °, the drawing patterns have the same shape. Also, when the reference rotation angles are 90 degrees and 270 degrees, the pattern is shown by the dotted line in the figure. Even if the reference rotation angle is 90 degrees and 270 degrees, the drawing pattern has the same shape. Therefore, four types of three-dimensional graphs with reference rotation angles of 0 °, 90 °, 180 °, and 270 ° are drawn with two types of patterns.

Here, the coordinates of each lattice constituting the scale plane are, as shown in FIG. 3, which is an enlarged view of the portion surrounded by the alternate long and short dash line in FIG. 2, a unit in the X-axis and Y-axis directions of the lattice. It is calculated using the lengths dx and dy. The unit length d
X and dy are stored in advance in the drawing information storage area 70.

For example, the coordinates of the point Q given at the intersection of the grid lines represented by m and n in FIG. 2 are ((m-n) d
x, (m + n) dy), and the coordinates of a point Q ′ obtained by rotating this point by 90 degrees are expressed by (m, n) ((n−
m) dx, (m + n) dy).

The individual stereograph images (hereinafter, unit stereograph images) representing the data values in the stereograph are the drawing position data consisting of the coordinates of the intersections of the grid lines on the scale plane and the height of the unit stereograph image. Drawing is performed by drawing data generated by combining the unit graph image height data shown. Then, the drawing of the entire solid graph is completed by the drawing data of the unit solid graph image of M × N lattices on the virtual scale plane.

At this time, the data read control unit 30 determines the order of reading the unit graph image height data from the stereograph image height storage area 60 based on the reference rotation angle, corresponding to the drawing position on the virtual scale plane. Then, in the drawing control unit 40, the unit graph image height data read from the stereograph image height storage area 60 in the reading order,
From the drawing position on the scale plane, the drawing data of the stereograph viewed from the reference rotation angle is created.

FIG. 4 is a diagram showing an example of a drawing sequence for drawing the unit stereograph image on the virtual scale plane shown in FIG.

X from the origin (0,0) of the virtual scale plane
When a graph is drawn on a scale plane in which (M + 1) grid lines are drawn along the axis and (N + 1) grid lines are drawn along the Y axis, the origin (0, 0) is always applied from the point P (Mdx, Ndy) side.
It is possible to draw a graph image of a stereoscopic projection image without needing the hidden line control processing by drawing the unit stereo graph image in the direction indicated by the arrow in (0).

Here, the point P (Mdx, Ndy) is the coordinate of the drawing open position of the graph, and the drawing information storage area 70.
Is determined by the drawing control unit 40 based on the values of M and N, the unit lengths dx and dy, and the drawing order stored in the.
In addition, the unit solid graph image drawn with the drawing start point P (Mdx, Ndy) as the drawing coordinates has coordinates (Mdx, Nd).
y), ((M + 1) dx, Ndy), (Mdx, (N +
1) dy), ((M + 1) dx, (N + 1) dy) are drawn in a range (lattice). The lattice position on the scale plane of the unit solid graph image at this time is [M]
It will be represented as [N].

Therefore, the unit solid graph image drawn with the origin (0,0) as the drawing coordinate is expressed as [0] [0] based on the grid position, and the m-th grid line and the n-th grid line on the scale plane. Intersection points Q ((m-n) dx, (m +
A unit stereograph image drawn with n) dy) as drawing coordinates is represented by [m] [n] based on the grid position. In FIG. 4, the drawing order of the individual unit stereograph images at the reference rotation angle of 0 degree is expressed as follows based on the grid position. [M] [N] → [M] [N-1] → …… [M] [0] → [M-1] [N] → [M-1] [N-1] → …… [M- 1] [0] → ... → [m] [n] → …… [0] [N] → [0] [N−1] → …… [0 [0] This order is referred to as (drawing order A). To do.

Regarding the drawing order of the unit solid graph image,
Even when the reference rotation angle is 180, it is exactly the same as the above order A.

Further, FIG. 5 shows a state in which the scale plane is rotated 90 degrees from the state of FIG. Here, the grid line in the X-axis direction is N compared to the case of FIG. 4 in which the rotation angle is 0 degree.
+1 and the number of grid lines in the Y-axis direction is M + 1, and the values of M and N are opposite to those in FIG. Here, the drawing start point is P '(Ndx, Mdy), and drawing is performed in the same direction as in FIG.

The unit solid graph image drawn with the point Q '((n-m) dx, (n + m) dy) obtained by rotating the intersection Q shown in FIG. 4 by 90 degrees as the drawing coordinates is [n] [m]. expressed. In FIG. 5, the drawing order of the individual unit stereograph images at the reference rotation angle of 90 degrees is represented as follows based on the grid position. [N] [M] → [N] [M-1] → …… [N] [0] → [N-1] [M] → [N-1] [M-1] → …… [N- 1] [0] → …… → [n] [m] → …… [0] [M] → [0] [M−1] → …… [0] [0] This order is (drawing order B) And

Regarding the drawing order of the unit solid graph image,
When the reference rotation angle is 270, the order B is exactly the same.

Substituting M'for N and N'for M in the drawing order B, [M '] [N'] → [M '] [N'-1] → ... [M'] [0] → [M′−1] [N ′] → [M′−1] [N′−1] → ... [M′−1] [0] → …… → [m ′] [n ′] → …… [0] [N ′] → [0] [N′−1] → …… [0] [0], and it can be seen that drawing is performed in the same order as the order A.
Therefore, when the reference rotation angle is 90 degrees, the drawing order B can be obtained by mutually exchanging the values of M and N with respect to the drawing order A when the rotation angle is 0 degrees.

Regarding the drawing order on the virtual scale plane, if only the direction is determined, the drawing start position and the end position for each reference rotation angle are determined according to the origin of the virtual scale plane, the unit lengths dx, dy, and the values of M and N. The position is easily calculated.

That is, the drawing order of the solid graph on the scale plane with respect to each reference rotation angle is the same as the drawing starting position and the ending position, but the direction and order are constant because the values of M and N are interchanged.

The drawing unit control unit 40 of the three-dimensional graph drawing system 10 sequentially draws unit three-dimensional graph images only in the predetermined drawing order as described above, regardless of the rotation angle. Also, it is possible to draw a solid graph without performing hidden line control processing.

That is, as described above, the drawing position at the end of the virtual scale plane (point P in FIG. 4, point P'in FIG. 5).
The unit stereograph images are sequentially drawn in a certain direction (the lower right direction in FIGS. 4 and 5) from. In this way, the unit stereoscopic graph images are drawn so as to sequentially overlap from the rear to the front on the virtual scale plane.

In FIG. 4 and FIG. 5, the drawing direction is the lower right direction in the drawings, but it may be the direction from the rear to the front, and therefore the drawing direction may be the lower left direction in the drawings.

Next, the reading order of the unit graph image height data set by the data reading control unit 30 will be described. FIG. 6 shows an array pattern of unit graph image height data stored in the solid graph image height storage area 60. The unit graph image height data is stored in a two-dimensional array A of M rows × N columns as shown in the drawing, and each unit graph image height data is stored in the array along the directions of 0 to M and 0 to N, respectively. It is assumed that Here, the storage position of the unit graph image height data in the array A is shown in association with the grid position of the scale plane of FIGS. 4 and 5. That is, the unit graph image height data stored at the position of M row and N column of the array A is A
Represented as [M] [N].

When the reference rotation angle is 0 °, in order to draw the unit stereograph image at the drawing position [m] [n] indicated by the intersection Q in FIG. 4, the stereograph image height storage area 60 shown in FIG.
(1), that is, the unit graph image height data stored at the position of the array A [m] [n] is read.

Here, when a stereograph is drawn on the scale plane shown in FIG. 4 at a reference rotation angle of 0 degree, the unit graph image height data is read from the array A of the stereograph image height storage area 60 in the following order. Is set. A [M] [N] → A [M] [N−1] → …… A [M] [0] → …… → A [m] [n] → …… A [0] [N] → A [0] [N-1] → ... A [0] [0] This is the reading order.

Here, in the case of drawing a three-dimensional graph drawn at the reference rotation angle of 0 degrees as viewed from the opposite direction, in other words, when 180 degrees is selected as the reference rotation angle, in FIG. In order to draw the unit stereograph image at the drawing position [m] [n] indicated by the intersection point Q, the data of the position (3) in FIG. 6 in the stereograph image height storage area 60, that is, the array A [M-m ] The unit graph image height data stored in [N-n] is read.

Here, when a stereograph is drawn on the scale plane shown in FIG. 4 at a reference rotation angle of 180 degrees, the unit graph image height data is read from the array A of the stereograph image height storage area 60 in the following order. Is set to. A [0] [0] → A [0] [1] → …… A [0] [N] → …… → A [Mm] [Nn] → …… A [M] [0] → A [M] [1] → ... A [M] [N] This is the reading order.

Further, when 90 degrees is selected as the reference rotation angle, the unit to be read must be read in order to draw the unit solid graph image at the drawing position [n] [m] indicated by the intersection Q'in FIG. As the graph image height data, the data at the position (1) in FIG. 6, that is, the unit graph image height data stored in the array A [m] [n] is read. However, since the arrangement of the grids drawn on the scale plane has changed, when drawing a stereograph on the scale plane at a reference rotation angle of 90 degrees on the scale plane shown in FIG. The order of reading data is different from the order of reading and is set as follows. A [M] [0] → A [M−1] [0] → …… A [0] [0] → …… → A [m] [n] → …… A [M] [N] → A [M-1] [N] → ... A [0] [N] This is the reading order.

Here, in the case of drawing the three-dimensional graph drawn at the reference rotation angle of 90 degrees as viewed from the opposite direction, in other words, when 270 degrees is selected as the reference rotation angle, in FIG. In order to draw the unit stereoscopic graph image at the drawing position [n] [m] indicated by the intersection Q ′ of, the data at the position (3) in FIG. 6 in the stereographic image height storage area 60, that is, the array A [M− The unit graph image height data stored in m] [N-n] is read.

Here, when a solid graph is drawn on the scale plane shown in FIG. 5 at a reference rotation angle of 180 degrees, the unit graph image height data is read from the array A of the solid graph image height storage area 60 in the following order. Is set to. A [0] [N] → A [1] [N] → …… A [M] [N] → …… → A [Mm] [Nn] → …… A [0] [0] → A [1] [0] → ... A [M] [0] This is the reading order.

In this way, the pseudo drawing function of the stereoscopic graph is realized by changing the order of reading data according to the reference rotation angle with respect to the graph drawing position on the scale plane. That is, in order to draw a three-dimensional graph, only two-dimensional data (drawing position and unit graph image height data) is used instead of the conventional three-dimensional data. Therefore, complicated polar coordinate conversion processing and The hidden line control process is unnecessary.

The processing contents of the solid graph drawing system 10 of FIG. 1 will be described with reference to the flowchart of FIG.
Here, the desired rotation angle “Φ” is input and stored in the rotation angle storage area 50, and the stereoscopic image height storage area 60 is stored.
In the unit graph image height data, as shown in FIG.
It is assumed that they are stored as a two-dimensional array A of rows × N columns.

First, the reference rotation angle determination unit 20 reads the rotation angle "Φ" input from the rotation angle storage area 50 (step 701). The read rotation angle "Φ" is
If 315 ° ≦ Φ <45 °, 0 ° is set, and 315 ° ≦ Φ <
90 degrees in the case of 45 degrees, 180 degrees in the case of 135 degrees ≦ Φ <225 degrees, and 27 degrees in the case of 225 degrees ≦ Φ <315 degrees
0 degree is selected as the reference rotation angle (step 102).

Next, the data read control unit 30 checks the value of the reference rotation angle selected by the reference rotation angle determination unit 20, and if the reference rotation angle is "0 degree", the reading of the stereograph image height storage area 60 is performed. The reading order described in FIG. 5 is read when the reference rotation angle is “90 degrees”, when the reference rotation angle is 180 degrees, and when the reference rotation angle is 270 degrees. Set the order respectively (step 703, step 7)
04-707).

Next, the drawing control unit 40 starts from step 704.
According to any reading order set in 707,
The unit graph image height data stored in the array A of the three-dimensional graph image height storage area 60 is read one by one (step 70).
8). Here, every time the unit graph image height data is read from the array A, the column value and the row value of the read unit graph image height data are counted.

Next, based on the reading order of the read unit graph image height data and the drawing order (drawing order A or B) on the scale plane according to the reference rotation angle, the scale plane shown in FIGS. The drawing position of the above-mentioned read unit graph image height data is determined (step 70).
9). Then, based on the unit graph image height data and the drawing position, drawing data of the unit stereograph image is generated and drawn in the drawing memory 80 (step 710).

At this time, if the input rotation angle of the rotation angle storage area 50 is different from the reference rotation angle, step 7
In 10, the drawing control unit 40 changes the unit lengths dx and dy of the scale plane according to the input rotation angle, thereby changing the lattice shape of the scale plane and the ratio of the left and right sides of the unit stereograph image. The drawing data of the unit stereograph image in this state is generated and drawn in the drawing memory 80. As a result, drawing data of the unit solid graph image corresponding to the input rotation angle is generated. The input rotation angle is
If it is the same as the reference rotation angle, these processes are unnecessary.

Until all the unit graph image height data stored in the array A of the solid graph image height storage area 60 is read,
That is, the count value of the column of the unit graph image height data is N,
The processing from step 708 to step 710 is repeated until the count value of the row reaches M (steps 711, 71).
2).

When all the M-row × N-column unit stereograph images are drawn in the image memory 80, the output device 90 reads the drawing data in the image memory 80 and outputs the stereograph. That is, when the output device 90 is a display device,
A three-dimensional graph is displayed, and when the output device 90 is a printer, the three-dimensional graph is printed out.

FIG. 8 shows an example of a three-dimensional graph drawn by the present three-dimensional graph drawing system 10 at the reference rotation angle "0 degree". Further, FIG. 9 shows an example of a graph drawn by rotating the solid graph of FIG. 8 by “90 degrees”.

In the above embodiment, the reference rotation angle determination unit 20 determines the reference rotation angle based on the angle range including the arbitrary rotation angle input to the rotation angle storage area 50 by the operator. If the rotation angle input by the operator is limited to the reference rotation angle, the reference rotation angle determination unit 20 only needs to determine the selected reference rotation angle, and the determination process (step 702) described above is unnecessary. . If the rotation angle that can be input is limited to the reference rotation angle, in step 710, the drawing control unit 40 changes the unit lengths dx and dy of the scale plane according to the input rotation angle, and the scale plane grid is displayed. A process of generating drawing data of a unit stereograph image in a state in which the left and right ratios of the surface of the unit stereograph image are changed is also unnecessary, and a higher speed drawing process is realized.

The present invention has been described above with reference to the preferred embodiments, but the present invention is not necessarily limited to the above embodiments, and various modifications can be made within the scope of the gist of the present invention. .

[0061]

As described above, in the three-dimensional graph drawing system of the present embodiment, after the viewpoint direction of the graph to be drawn is determined, it is stored in the graph height storage area corresponding to the viewpoint direction (rotation angle). One of the order of reading the unit graph image height data is determined, and based on the unit graph image height data read according to this order, the drawing data of the unit stereoscopic graph image is created and drawn in the image memory. It is possible to easily and quickly execute the three-dimensional graph drawing and rotation drawing processing by the two-dimensional data processing without performing the three-dimensional polar coordinate conversion processing for the rotation angle and the hidden line control processing after the rotation. In addition, the processing program is simple and compact, and maintenance can be easily performed.

Further, since the three-dimensional polar coordinate conversion processing for the rotation angle is not performed, a large work memory for saving the coordinate values for drawing as in the conventional case is not required, and thus a solid graph is drawn with a small system resource. The system can be realized.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a stereoscopic graph drawing system according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example of an image pattern on a virtual scale plane used for drawing a three-dimensional graph according to the embodiment.

3 is an enlarged view of a part of a virtual scale plane shown in FIG.

FIG. 4 shows a rotation angle of 0 ° or 18 in the embodiment.
It is a figure explaining the drawing order which draws a unit solid graph image on a scale plane when it is set to 0 degree.

FIG. 5 shows a rotation angle of 90 degrees or 2 in the embodiment.
It is a figure explaining the drawing order which draws a unit solid graph image on a scale plane when it is set to 70 degrees.

FIG. 6 is a diagram showing a storage array of stereograph image height data stored in a stereograph image height storage area according to the embodiment.

FIG. 7 is a flowchart illustrating a graph drawing process by the three-dimensional graph drawing system according to the embodiment.

FIG. 8 shows an example of a three-dimensional graph drawn at a reference rotation angle of “0 degrees” by a three-dimensional graph drawing system.

FIG. 9 shows an example of a stereograph drawn by rotating the stereograph of FIG. 8 by “90 degrees”.

[Explanation of symbols]

 10 Solid Graph Drawing System 20 Reference Rotation Angle Judgment Unit 30 Data Read Control Unit 40 Drawing Control Unit 50 Rotation Angle Storage Area 60 Stereograph Image Height Storage Area 70 Drawing Information Storage Area 80 Image Memory 90 Output Device

Claims (5)

[Claims] 1. A three-dimensional graph drawing system for three-dimensionally drawing and outputting M × N (M and N are integers of 1 or more) two-dimensional graph data in a perspective view format. Corresponding to the data, the graph image height storage means that stores only the height data of each graph image corresponding to the two-dimensional array of M × N, and the rotation angle that specifies the viewpoint direction of the three-dimensional graph are 36
It is determined which one of the angular ranges obtained by dividing 0 degrees into four equal parts, and a reference corresponding to the angular range to which the designated rotational angle belongs from the four types of reference rotational angles set corresponding to each of the angular ranges. Reference rotation angle selection means for selecting a rotation angle, and four types set for each reference rotation angle as the order of reading the height data of the graph image from the M × N two-dimensional array of the graph image height storage means. Data reading control means for setting one of the data reading orders according to the selected reference rotation angle, and the graph image height data is read in accordance with the set data reading order, and the read graph image height data is read. Drawing control means for generating drawing data of a stereoscopic graph image by arranging the drawing pattern composed of M × N grids on the drawing memory in a fixed drawing order. Stereo graph drawing system and an outputting means for outputting a three-dimensional graph reads drawing data from the drawing memory. 2. A three-dimensional graph drawing system for three-dimensionally drawing and outputting M × N (M and N are integers of 1 or more) two-dimensional graph data in a perspective view format. Corresponding to the data, only the height data of each graph image is stored corresponding to the M × N two-dimensional array, and as a reference rotation angle for designating the viewpoint direction of the three-dimensional graph. A reference rotation angle selection unit that determines one selected reference rotation angle from a plurality of preset reference rotation angles and a M × N two-dimensional array of the graph image height storage unit, Data reading control means for setting one of four types of data reading order set for each of the reference rotation angles according to the selected reference rotation angle, as the order of reading the height data, and the set data. reading The graph image height data is read in accordance with the loading order, and the read graph image height data is arranged in a drawing pattern composed of M × N grids on the drawing memory in a fixed drawing order to obtain a three-dimensional graph image. A three-dimensional graph drawing system comprising: a drawing control unit that generates drawing data; and an output unit that reads the drawing data from the drawing memory and outputs the drawing data as a three-dimensional graph. 3. The drawing pattern height data read by the drawing control means is drawn in a drawing pattern on a drawing memory as a fixed drawing order from a rear side to a front side of a drawing pattern formed on the image memory. The three-dimensional graph drawing system according to claim 1 or 2, wherein an order in which the graph images are sequentially overlapped and drawn is set. 4. An angle range obtained by dividing 360 degrees into four equal parts,
315 to 45 degree range, 45 to 135 degree range, 135 to 225 degree range, 225 to 315 degree range
Four angle ranges of degrees are set, and 0 °, 90 °, 180 °, and reference rotation angles are set for the respective angle ranges.
The stereoscopic graph drawing system according to claim 1, wherein 270 is set. 5. As initial information for drawing a three-dimensional graph in the image memory, origin coordinates of a drawing pattern of the image memory for drawing the three-dimensional graph, unit lengths of X-axis and Y-axis directions of a grid forming the drawing pattern. 3. The storage unit according to claim 1, further comprising a storage unit that stores a value of a grid M × N that forms the drawing pattern and a drawing order when drawing the graph image height data on the drawing pattern. 3D graph drawing system.