JPH064680A - Device and method for displaying graphic - Google Patents

Abstract

PURPOSE:To provide a method and a device for erasing and displaying the hidden surfaces of plural prism graphics expressed by two-dimensional information with a simple processing. CONSTITUTION:The graphic display device displaying the plural prism-shaped graphics expressed by two-dimensional information is provided with a means 2 calculating position information becoming reference points on the respective graphics, a means 3 calculating the direction of a vector showing the display direction of the plural graphics as angle information, a means 4 rotating position information on the respective reference points based on vector angle information, a means 5 comparing coordinate information after rotation and a means 6 deciding a display order between the respective graphics from the compared result of rotary coordinate information. The plural prism-shaped graphics are displayed based on the display order.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graphic display device and method for displaying a plurality of three-dimensional graphics created by two-dimensional information.

[0002]

2. Description of the Related Art In a material for presentation such as a catalog or a pamphlet, three-dimensional patterns are often used in order to improve visibility and comprehension.
When such a design is created by a general user in the office, it is desirable that it can be created as easily as possible.

A common method for creating a solid figure is 3
Although there are two-dimensional graphics and two-dimensional graphics, the former is not suitable for office use in terms of operability and calculation cost, and the latter is not practical in terms of functions.

As another method, there is an attempt to generate and display the coordinate information of a figure so that it looks like a three-dimensional figure even though it is two-dimensional. One of the supports for this method is Japanese Patent Application No. 3-181166 filed by the present applicant.
There is a graphic processing method for performing hidden surface elimination display on a prismatic graphic as described in Japanese Patent No.

[0005]

SUMMARY OF THE INVENTION The above graphic processing method is a hidden surface erasing display process for a single prismatic graphic itself. Therefore, that method cannot be applied to the hidden surface erasing display between the figures when generating and displaying a plurality of figures.

If the graphics are displayed in an overlapping order in the order in which they were created, they may not be displayed in consideration of the three-dimensional context and may be unnatural. The context can be changed and corrected using the up / down change function as in 2D graphics,
As the number of figures increases, the labor of the operation increases, which is troublesome. Therefore, there has been a demand for a method of performing this change process easily.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a graphic display device and method for performing a hidden surface erasing display of a plurality of prismatic figures expressed by two-dimensional information by a simple process.

[0008]

In order to achieve the above-mentioned object, a graphic display device of the present invention is a graphic display device for displaying a plurality of prism-shaped graphics expressed by two-dimensional information, and a reference on each graphic. Means for calculating position information of points, means for calculating the orientation of a vector representing the display direction of a plurality of graphics as angle information, means for rotating the position information of each reference point based on vector angle information, and after rotation It is possible to display a plurality of prism-shaped figures based on the display order by providing a means for comparing the coordinate information of the two and a means for determining the display order between the figures from the comparison result of the rotation coordinate information. Characterize.

Further, in order to achieve the above-mentioned object, the graphic display method of the present invention is a graphic display method for displaying a plurality of prismatic figures expressed by two-dimensional information, and a position serving as a reference point on each graphic. Information is calculated, the direction of the vector representing the display direction of multiple figures is calculated as angle information, the position information of each reference point is rotated based on the vector angle information, the coordinate information after rotation is compared, and the rotation coordinates It is characterized in that the display order between the figures is determined based on the result of the information comparison, and a plurality of prismatic figures are displayed based on the display order.

[0010]

The operation of the present invention will be described with reference to specific examples.

The processing unit for displaying the hidden surface in displaying the graphic of the present invention stores the vertex coordinate values of the graphic and the information necessary for the hidden surface display processing as shown in FIG. Information storage means 1, reference point position calculation means 2 for calculating a position serving as a reference point on each figure, vector angle calculation means 3 for calculating the direction of a vector representing the display direction of a plurality of figures, and each reference. The coordinate information rotating means 4 for rotating the position of the point, the coordinate information comparing means 5 for comparing the coordinate values, the display order determining means 6 for determining the display order between the figures based on the comparison result of the coordinate values, and each of the above. And a control means 7 for controlling the means.

According to the present invention having the above-mentioned configuration, the graphic information storage means 1 stores information on the vertex coordinate values of the prismatic figure, information on the type of display method, information by a vector representing the display direction of a plurality of figures, and the like. Then, the reference point position calculation means 2 calculates the position information serving as the reference point on each figure, the vector angle calculation means 3 calculates the direction of the vector input as the angle information, and the coordinate information rotation means 4 is calculated.
At the reference point on each figure, the rotation processing based on the vector angle information is performed, the coordinate information comparing means 5 compares the magnitudes of the coordinate values after the rotation, and the display order determining means 6 compares the coordinate values. The display order between the figures is determined by.

[0013]

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

First, an example of a prismatic figure handled by two-dimensional information and the contents of information expressing it will be described. FIG. 2 shows an example in which prismatic figures expressed by two-dimensional coordinate information are arranged on a two-dimensional plane. The figure (a) is displayed by wire frame, and the figure (b) is hidden surface erased display. Is. In the figure, P ₁ , P ₂ , P ₃ , P ₄ , Q ₁ , Q ₂ ,
Q ₃ and Q ₄ are the names of vertices. Vertices P ₁ , P ₂ ,
P _3, P ₄ and the vertex _{Q 1, Q 2, Q 3} , Q 4 corresponds respectively, for convenience of explanation, the figure composed of vertices P ₁ to P ₄ visible when viewing the hidden surface removal For convenience, the upper surface and the figure on the invisible side composed of the other vertices Q _{1 to} Q ₄ will be referred to as the lower surface. The faces other than these two faces of the figure will be called side faces. The shape is a quadrangular prism, but this is an example in this embodiment.

FIG. 3 shows the contents of the above-mentioned graphic information. The figure (a) shows the two-dimensional coordinate values of each vertex of the top figure, the figure (b) shows the two-dimensional coordinate values of each vertex of the bottom figure, and the figure (c) uses the top figure side. The vertex numbers at both ends of each side are shown. A prismatic figure can be obtained by inputting a plane figure and copying it by associating each vertex.

Now, consider the case where the number of figures becomes plural. FIG. 4 is an example in which two prismatic figures are displayed in a wire frame. An example of FIG. 5 shows the hidden surface erase display. Since these two figures do not overlap two-dimensionally, the hidden surface erase display may be performed without worrying about the context between the figures.

FIG. 6 shows the figure of FIG. 4 arranged in a two-dimensional manner and displayed in a wire frame. The two figures in the figure do not give three-dimensional context information, and the context cannot be determined from the figure. FIG. 7 shows the two figures shown in FIG. 6 in a hidden surface erased display by changing the state of the three-dimensional context. In the figure (a), it can be interpreted that the left figure is three-dimensionally on the front side, and the right figure is three-dimensionally on the front side. Two-dimensionally, the vertical relationship is opposite.

An outline of a process for performing hidden surface elimination display for a plurality of prismatic figures overlapping each other on such a two-dimensional plane will be described. Since the display order of the figures cannot be automatically determined only by the coordinate information of the figures, the operator gives information for supporting the decision. FIG. 8 shows a state of the operation, and information representing the three-dimensional positional relationship between the figures is set by a two-dimensional vector. For example, in order to make the figure on the left side to the front side like the figure in FIG. 7A from the figure in FIG. 6, two-dimensionally from the diagonally upper right to the diagonally lower left as shown in FIG. 8A. The target vector is drawn and the figure is displayed along the direction. This two-dimensional vector will be called an instruction vector. In the case of FIG. 8B, a two-dimensional vector is drawn from diagonally upper left to diagonally lower right, and a graphic is displayed along that direction.

The positional relationship of the graphic with respect to the direction along the vector changes depending on which position on the graphic is taken. Although the position is referred to as a reference point, the position of the reference point of each figure is selected by selecting either the center point of the top figure, the center point of the bottom figure, or the center point of the whole figure in the present invention. And For the center point, select either the center of gravity of the selected figure or the center of the smallest rectangle surrounding the figure.

FIG. 9 shows a processing flow of the operations performed up to the display of the figure. In step 1 (indicated by S1 in the figure; the same applies hereinafter), coordinate value information of the graphic is input. In step 2, a wireframe display or hidden surface removal display is selected as the type of display method. If the wire frame display is selected here, the operations after step 3 are not performed. Step 3
Then, automatically decide the order of hidden surface removal display between figures,
Select whether the operator decides manually. In the case of manual determination, the operations after step 4 are not performed, but the operation of designating the display order of the graphics is performed as necessary. Step 4
Then, the instruction vector in the two-dimensional direction is set so as to determine the order of display in units of figures. In step 5, the type of reference point of each figure is selected. Here, an operation of selecting the figure to be used from the upper surface, the lower surface, and the whole and an operation of selecting the type of the center point are performed. When the number of figures is one, the processing from step 3 onward may not be performed.

FIG. 1 shows an overall processing flow for displaying a figure.
It shows in 0. In step 11, the type of display method is determined, and in step 12, it is checked whether or not the type is hidden surface elimination display. If YES, the process proceeds to step 13 and NO.
In the case of, the process proceeds to the wire frame display process after step 21. In step 13, the type of mode that determines the display order of the figures is determined, and in step 14, it is checked whether or not the type is automatic. If YES, the process proceeds to step 15, and if NO, the process proceeds to step 17. . In step 15, the display order of all the figures is determined. The process of step 15 will be described in detail later. In step 16, selection of the graphic according to the display order determined in step 15 is started. If the order determination mode is not automatic, in step 17, the selection of the graphic according to the order in which the graphic is stored is started. The order in which the figures are stored means the order in which the coordinates for representing the figures are input by the user. In step 18, one figure is selected and the information is read. Here, one figure means a figure recognized as one prismatic figure. Step 1
At 9, the hidden figure is erased and displayed on the selected figure. In step 20, it is determined whether or not all the figures have been selected. If YES, the whole process is terminated, and if NO, the process returns to step 18.

If it is not the hidden surface elimination display, that is, if it is the wire frame display, in step 21, the selection of the graphic is started in the order in which the graphic is stored. In step 22, one figure is selected and the information is read. In step 23, the selected figure is displayed in wireframe.
In step 24, it is determined whether or not all the figures have been selected. If YES, the whole process is terminated, and if NO, the process returns to step 22. The coloring associated with displaying a graphic is not particularly mentioned in this processing flow, but may be performed during the hidden surface erasing display.

Step 1 in the display processing flow of FIG.
The processing flow of FIG. 11 shows the processing for determining the display order of the figures 5 in a slightly more detailed manner. At step 31, the instruction vector data is read. In step 32, the direction of the instruction vector data on the two-dimensional plane is obtained as angle information. This is shown in FIG. Arranged so that the end point of the instruction vector V is the origin position on the two-dimensional plane, and the change angle θ with respect to the + direction line segment of the Y axis from the origin to the position of the start point of the instruction vector V is obtained. .
In step 33, the selection of figures is started in accordance with the storage order. In step 34, one figure is selected and the information is read. In step 35, the position of the reference point of the selected figure is obtained. In step 36, the coordinate value of the reference point is rotated about the origin by the minus amount of the angle θ obtained in step 32, and the position information is stored. The state of the rotation processing is shown in FIG. In the figure, points Qc and Qc 'are 2
It is a reference point of two figures, and is rotated counterclockwise from the angle of FIG. 12 as shown in FIG. Yc and Yc ′ are −θ
It is the coordinate value (position information) in the Y direction after rotation. In step 37, it is determined whether or not all the figures have been selected, and YES
If NO, the process proceeds to step 38, and if NO, the process returns to step 34. In step 38, the magnitudes of the coordinate values in the Y direction of the rotated positions of the reference points are compared with each other, and the order is determined such that the larger value is displayed first.

FIG. 1 is a detailed block diagram of the process of obtaining the position of the reference point in step 35 in the process flow of FIG.
4 shows the processing flow. In step 41, the type of the figure to be used as the reference point is determined. In step 42, it is determined whether or not the type is calculated from the entire figure. move on. In step 44, it is determined whether or not the reference point is calculated from the upper surface of the figure. If YES, the process proceeds to step 45, and if NO, the process proceeds to step 46. Step 43
Now read the coordinates of the whole figure. In step 45, the coordinate value of the figure on the upper surface side is read. Step 46
Then, the coordinate value of the figure on the lower side of the figure is read. In step 47, the type of use position of the reference point is determined, and in step 4
In 8, it is determined whether or not the position of the center of gravity of the read graphic is used as the type. If YES, the process proceeds to step 49. Step 4
At 9, the coordinate value of the barycentric position is obtained from the read coordinate value. In step 50, the minimum rectangle surrounding the read figure is obtained. In step 51, the position of the center of gravity of the smallest rectangle is obtained. The method of obtaining such a reference point does not need to be limited to the above processing, for example, using a specific vertex position on the figure.

FIG. 15 shows a schematic block diagram of a configuration for performing the process of inputting graphic information to the process of displaying a graphic. The coordinate information input means 11 inputs coordinate value information of a graphic.
Generally, the figure inputting operation is often performed interactively by using a mouse or the like while looking at the screen of the display device, and corresponds to a portion for receiving coordinate information input from the pointing device.
The attribute information input means 12 inputs the information necessary for the hidden surface erasing display process, including the type of graphic display method. The graphic information storage unit 13 stores various input information. The hidden surface removal processing means 14 performs processing for hidden surface removal display. The drawing processing means 15 performs processing for expanding graphic information into raster information. The display memory 16 is a portion where the drawn graphic image and the like are developed. Control means 17
Controls the above means. The processing unit that performs the hidden surface removal processing in FIG. 1 corresponds to the graphic information storage unit 13 and the hidden surface removal processing unit 14 in FIG.

FIG. 16 shows an example of a hardware configuration for implementing the present invention. In the figure,
21 is a computer, 22 is a central processing unit, 23 is a graphic information processing device, 24 is an information storage memory, 25 is an image memory, 26 is an input device, 27 is a display memory, 28 is a display, 29 is a scanner, 30 is a printer. , 31 are buses.

The central processing unit 22 controls the entire processing unit and performs general calculations. The graphic information processing device 23 performs processing for generating / displaying a graphic. The information storage memory 24 stores various kinds of information including graphic coordinate information and information necessary for hidden surface removal processing. Image memory 2
Reference numeral 5 stores image data. Input device 26
Is for inputting graphic information and giving instructions to a computer. The display memory 27 expands data to be displayed, and the display 28 outputs and displays an image including a figure. The scanner 29 is for inputting an image, and the printer 30 is for outputting an image. The bus 31 plays a role of passing image data, graphic data, and control information. Graphic information processing device 23
The information storage memory 24 includes a processing unit for performing the hidden surface removal processing shown in FIG.

[0028]

As described above, according to the present invention, since a plurality of prismatic figures represented by two-dimensional information can be hidden and displayed by a simple operation, a plurality of prismatic figures can be displayed in a two-dimensional graphic. It is possible to create a three-dimensional figure as a result, and as a result, it is possible to create a three-dimensional figure with a simple operation and a low calculation cost.

[Brief description of drawings]

FIG. 1 is a block diagram of a processing unit that performs hidden surface removal processing of a figure.

FIG. 2 is an explanatory diagram illustrating an example of a prismatic figure.

FIG. 3 is an explanatory diagram illustrating the contents of prismatic figure information.

FIG. 4 is an explanatory diagram illustrating an example in which two prismatic figures are displayed in a wire frame.

FIG. 5 is an explanatory diagram illustrating an example in which two prismatic figures are hidden and displayed.

FIG. 6 is an explanatory diagram illustrating an example in which two overlapping prismatic figures are displayed in a wire frame.

FIG. 7 is an explanatory diagram illustrating an example in which two overlapping prismatic figures are hidden and erased and displayed.

FIG. 8 is an explanatory diagram illustrating a state of an operation that assists in determining the display order of the figures.

FIG. 9 is a processing flow of an operation performed until a figure is displayed.

FIG. 10 is a processing flow for displaying a figure.

FIG. 11 is a processing flow for determining the display order of figures.

FIG. 12 is an explanatory diagram for explaining how to determine the angle of the instruction vector.

FIG. 13 is an explanatory diagram illustrating a manner of rotating the position of the reference point.

FIG. 14 is a processing flow for obtaining the position of a reference point.

FIG. 15 is a block diagram of a processing unit that performs input to display of graphic information.

FIG. 16 is an explanatory diagram illustrating an example of a hardware configuration for implementing the present invention.

[Explanation of symbols]

1 ... Graphic information storage means, 2 ... Reference point position calculation means, 3 ...
Vector angle calculating means, 4 ... Coordinate information rotating means, 5 ... Coordinate information comparing means, 6 ... Display order determining means, 7 ... Control means, 11 ... Coordinate input means, 12 ... Attribute information input means, 1
3 ... Graphic information storage means, 14 ... Hidden surface removal processing means, 15
... drawing processing means, 16 ... display memory, 17 ... control means,
21 ... Calculator, 22 ... Central processing unit, 23 ... Graphic information processing unit, 24 ... Information storage memory, 25 ... Image memory, 26 ... Input device, 27 ... Display memory, 28 ... Display, 29 ... Scanner, 30 ... Printer , 31 ... Bus

Claims (2)

[Claims] 1. A graphic display device for displaying a plurality of prismatic figures expressed by two-dimensional information, a means for calculating position information serving as a reference point on each figure, and a vector representing a display direction of the plurality of figures. To calculate the orientation of each as the angle information, to rotate the position information of each reference point based on the vector angle information, to compare the coordinate information after rotation, and to compare each figure from the comparison result of the rotation coordinate information. A graphic display device, characterized in that a plurality of prismatic figures are displayed based on the display order by providing a means for determining a display order between them. 2. A graphic display method for displaying a plurality of prismatic figures expressed by two-dimensional information, in which position information serving as a reference point on each figure is calculated, and the direction of a vector indicating the display direction of the plurality of figures. Is calculated as angle information, the position information of each reference point is rotated based on the vector angle information, the coordinate information after rotation is compared, and the display order between each figure is determined from the comparison result of the rotated coordinate information. A method for displaying a figure, comprising displaying a plurality of figures in the shape of prisms based on the display order.