JPH0614336B2 - Design support method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a design support method, and more particularly to a design support method suitable for displaying a perspective view of an object from an arbitrary position.

[Background of the Invention]

When designing a three-dimensional object, it may be necessary to display the object three-dimensionally on a two-dimensional screen in a perspective view or the like for confirmation. For example, in a plant piping layout, it is difficult to confirm in a two-dimensional drawing whether the designed piping does not interfere with each other, whether there is a problem in connection with equipment, etc., when the piping is complicated. Becomes In this case, the above confirmation is facilitated by displaying the plant three-dimensionally in a perspective view.

A method for displaying a three-dimensional object on a two-dimensional screen in a perspective view has been proposed (“Principles of interactive”).
computer graphics ”, by William M. Newman, Mc Graw H
Published by ill). The parameters (input data) necessary for creating the perspective view are the coordinates of the object, the coordinates of the viewpoint and the gazing point (or the coordinates of the viewpoint and the direction of the line of sight), and the field of view (width of field of view). When the object is fixed, one perspective view is obtained for one set of viewpoint, gazing point, and field of view value.

When actually using a perspective view, it is not easy to obtain a desired perspective view. This is because the coordinates of the viewpoint and the like must be given as numerical values. For example, when a perspective view from a certain viewpoint is obtained, even if one wants to obtain a perspective view with the viewpoint position moved to the upper right part to some extent from the result, the position of the actual optimum viewpoint or gazing point It is difficult to grasp the coordinates numerically.

Therefore, in the past, it was necessary to repeat trial and error until a desired perspective view was obtained while giving a numerical value that was estimated to be appropriate and seeing the result, which was a disadvantage of inefficiency.

[Object of the Invention]

It is an object of the present invention to provide a design support method capable of easily setting a viewpoint, a viewing direction, and a field of view and obtaining a three-dimensional figure of an object based on these in a short time.

[Outline of Invention]

A feature of the present invention is that the first graphic information of the designated object is selected from the storage means by the calculating means and displayed on the display device, and the first viewpoint information of the designated viewpoint is displayed with respect to the displayed first graphic information. Based on the position information, the information on the viewing direction based on the position of this viewpoint, and the information on the field of view, the second graphic information indicating these pieces of information is created by the calculating means, and the first graphic information and the Displaying on a display device, using the displayed first and second graphic information, three-dimensional third graphic information of the object with respect to the viewing direction and the field of view is created by a computing means, and It is to display on one of the display device and the other display device.

Example of Invention

The design support apparatus according to the exemplary embodiment of the present invention, in addition to the first screen (referred to as a main screen) that displays a perspective view,
A second screen (referred to as an auxiliary screen) that displays the gazing point and the field of view is provided, and the viewpoint, gazing point, and field of view are input on the auxiliary screen using various input devices called light pen, joystick, tablet, and mouse. By doing so, it becomes easy to specify parameters for obtaining a desired perspective view. Next, the position coordinates of the input viewpoint gazing point and the field of view in the three-dimensional space are automatically calculated, and a perspective view corresponding to these parameters is created and displayed on the main screen.

FIG. 1 shows the configuration of the design support apparatus according to the present embodiment.

The storage device 1 stores the coordinate data of the object, the perspective drawing creation program, and the coordinate conversion program necessary for creating the perspective view. The viewpoint, the gazing point, and the field of view are input using the input device 2. The viewpoint and the like input by the input device 2 are displayed on the auxiliary screen on the CRT 6. For this purpose, the auxiliary screen creating function 3 creates an auxiliary screen from the object data in the storage device 1 and the input points. On the other hand,
A perspective view corresponding to a viewpoint, a gazing point, and a field of view is created by the main screen creating function 4 from the view field data and the object data in the storage device 1. The main screen and the auxiliary screen are displayed by the display function 5 in a mode according to the request. The auxiliary screen creation function 3 and the main screen creation function 4 described above are calculation means.

The processing means of this embodiment is shown in FIG. The processing contents will be described below.

(1) Reading of object data and coordinate conversion program Object data (three-dimensional coordinates) and coordinate conversion program are read from the storage device. This program is a program for converting three-dimensional coordinates into two-dimensional coordinates in order to display an object on a two-dimensional auxiliary screen.

(2) Creation of auxiliary screen background image The above-mentioned three-dimensional coordinates of the object are converted into two-dimensional coordinates by a conversion program. Since the display view of the auxiliary screen is a perspective view from a fixed viewpoint, the coordinate conversion coefficient can always use a value that has been pre-filled.

The coordinate transformation consists of the following two steps.

(i) Conversion from original three-dimensional coordinates to three-dimensional coordinates with the viewpoint as the origin and the direction of the line of sight as the z-axis (x'y'z ') ^T = T ₁ T ₂ T ₃ T ₄ (x ₀ y ₀ z ₀ 1) ^T (1) x ₀ , y ₀ , z ₀ : Original three-dimensional coordinates x ′, y ′, z ′: New three-dimensional coordinates T ₁ : Transformation matrix (translation) T ₂ , T ₃ , T ₄ : Transformation matrix (rotation around each axis) For example, when (t _x , _ty , _tz ) is translated If we rotate θ around the z-axis, (ii) Conversion from three-dimensional coordinates to two-dimensional coordinates x = Dx ′ / z ′ y = Dy ′ / z ′ (4) x, y: coordinates on a two-dimensional plane D: distance between two-dimensional plane and viewpoint ( 3) Display of auxiliary screen Display the auxiliary screen background image created in step 2 on the CRT.

(4) Input of viewpoint, gazing point, and field of view The position of the window showing the viewpoint, gazing point, and field of view is input on the auxiliary screen by the input device. First, when the viewpoint and the gazing point of the auxiliary screen are moved by the input device, the arithmetic function in the input device calculates the three-dimensional coordinates of the input point.
Next, the size of the window showing the field of view is input. The size is picked up from the values input in advance. The set viewpoint, gazing point, and visual field data are stored in the intermediate data storage device. When displaying a viewpoint or the like on the auxiliary screen, in order to clarify the three-dimensional position of the point, the surface where the point exists is also displayed. When the y-axis direction is the depth direction, the xz plane is displayed.

(5) Reading of viewpoint, gazing point, and visual field data The viewpoint, gazing point, and visual field data are read from the intermediate data storage device.

(6) Reading of Object Data Perspective View Creation Program The object data and perspective view creation program are read from the storage device.

(7) Creation of perspective view A perspective view is created from the data of viewpoint, gazing point, and view target. The principle of the perspective drawing program will be described below. now,
The coordinate system of the three-dimensional space in the presence of the object S coordinate system _{(x s, y a, z} s) and. The coordinate system having the z-axis as the line-of-sight vector connecting the viewpoint and the gazing point is the E coordinate system (x _e , y _e ,
z _e) to. When the plane showing the field of view is P _v , the field of view is defined as a space surrounded by a plane extending from the side surface of the quadrangular cone formed by the origin of the E coordinate system and the plane P _v . (FIG. 3) A perspective view is an object in the field of view.
It can be considered as a diagram projected on the plane P _{v of the} E coordinate.
The point A _s (X _s , y _s , Z _s ) of the S coordinate system is the transformation matrix V
The _e, point _A e of E coordinate system _{(X e, y e, Z} e) are converted to.

(X _e y _e, z _e 1) ^T = V _e (x _s y _s z _s 1) ^T (5) V _e = T ₁ · T ₂ · T ₃ · T ₄ (6) T ₁ : conversion matrix ( _{translation) T 2, T 3, T} 4: transformation matrix (rotation about the respective axes) Next, _{a e} is converted points on a plane _{P v a} p (x p, the y _p).

The coordinate transformation matrix V _e is calculated by the relative positional relationship between the S coordinate system and the E coordinate system. Therefore, when the positions of the viewpoint and the gazing point change, T _i changes, and V _e becomes V _e ′.

V _S ′ = T ₁ ′ · T ₂ ′ · T ₃ ′ T ₄ ′ (8) Further, when the surface showing the field of view is moved, D changes. In either case, the x and y coordinates on the two-dimensional screen change, and as a result, the perspective view changes.

(8) Display of main screen The perspective view obtained in the above step is displayed on the main screen. When displaying the auxiliary screen and the main screen on the same CRT, the position and size of both screens are controlled by the display function and displayed.

After finishing the above step 8, if it is desired to obtain a perspective view with a changed viewpoint, the process returns to step 4.

Example 1 of the auxiliary screen is shown in FIG.

The purpose of the auxiliary screen is to display the position of the viewpoint / gazing point on the screen so that the positional relationship between the viewpoint / gazing point and the object can be intuitively grasped. On the auxiliary screen,
A viewpoint 8, a gazing point 9, a window 10 showing a field of view, and an object 11 are displayed. When the viewpoint and the gazing point are displayed on the two-dimensional screen, the depth of the point in the three-dimensional space cannot be grasped by displaying only the points, so the plane 12, 1 on which the viewpoint and the gazing point exist.
3 is displayed to make it easy to grasp the three-dimensional existence position.
The planes 12 and 13 are moved by the input device in the direction of the arrow in the figure, and the viewpoint and the gazing point are the planes 12 and 13, respectively.
13 Move up. When the positions of the viewpoint and the gazing point are determined, the direction 14 of the line of sight connecting the viewpoint and the gazing point is displayed. The window 10 showing the width of the visual field is installed so that its center position overlaps with the line of sight 14. The window 10 is moved to the line of sight 14 by the input device.
Move up in the direction of the arrow. The size of the window (width of the field of view) is input as a numerical value, or patterns of a plurality of sizes are set in advance and stored in a storage device, and the size is selected from them.

Input devices for the auxiliary screen include a light pen, a joystick, a doublet, and a mouse.

The object displayed on the auxiliary screen can be simplified. As described above, since the object of the auxiliary screen is for the purpose of grasping the positional relationship with the viewpoint, it may not be necessary to display it in detail like the main screen. In the present embodiment, the object is simplified in the auxiliary screen creating function.
That is, the minimum value and the maximum value of x, y, z coordinates are selected from the coordinates of the object, and (x _min , x _max ), (y _min , y
_The object is displayed as a rectangular parallelepiped having ( _max ) and ( _zmin , _zmax ) as boundaries.

The embodiment of FIG. 1 equipped with the CRT 6 having the auxiliary screen described above is (1) the positional relationship between the object, the viewpoint, and the gazing point can be easily recognized with the eyes, (2) the gazing point on the screen It is possible to move and easily enter the position, and (3) the perspective view corresponding to the positions of the viewpoint and the gazing point can be automatically displayed, so that the target perspective view can be obtained efficiently in a short time. it can.

The main screen and the auxiliary screen can be displayed on different CRTs, but here, as an embodiment, one CRT is used.
An example of displaying the main screen and the auxiliary screen on the RT is shown. FIG. 6 shows a screen configuration example.

A main screen 15 and an auxiliary screen 16 are displayed on the CRT. On the auxiliary screen, the simplified object 17 and viewpoint 1
8, the gazing point 19, and the field of view 20 are displayed. A perspective view 21 of the object 17 viewed from the viewpoint 18 is displayed on the main screen. The perspective view of the main screen changes according to the movement of the viewpoint.

The size of the auxiliary screen is changed on demand as needed as shown in FIG. When moving the viewpoint,
The auxiliary screen is enlarged and used, and when the position of the viewpoint for obtaining a desired perspective view is determined, the auxiliary screen is reduced or deleted.

In the embodiment of FIG. 7, the position of the auxiliary screen is the upper right of the screen, but the position of the auxiliary screen can be set to any position on the CRT. It can also be set to. Next, how the perspective view on the main screen changes when the position of the viewpoint is changed on the auxiliary screen of the first embodiment will be described.

FIG. 8 shows perspective views of the object viewed from the viewpoints A, B, and C shown in FIGS. 9, 10, and 11, respectively. Here, the position of the gazing point, the distance between the viewpoint and the window showing the field of view, and the size of the window are constant.

The movement of the viewpoint from A to B is an operation of moving the viewpoint away from the object on the line of sight connecting the viewpoint and the gazing point. In the conventional method, the user needs to input the position coordinates of the viewpoint, so when the point is moved in a certain vector direction in the three-dimensional space, the user needs to calculate each time to determine the coordinate position. However, in the present embodiment, the viewpoint can be input only by moving the viewpoint on the auxiliary screen. Similarly, the viewpoints A to C can be easily moved. In the present embodiment, the positional relationship between the viewpoint and the object can be visually confirmed, and the viewpoint can be efficiently searched for to obtain a desired perspective view.

Regarding the auxiliary screen, some examples different from the first embodiment will be shown below.

When setting a viewpoint, there may be a case where it is desired to set the viewpoint at a point considerably distant from the object. If the scale of the auxiliary screen was fixed, it would be impossible to deal with it. In the present embodiment, as shown in FIG. 12, the scale is automatically enlarged when the viewpoint 22 reaches the outer frame 23 forming the auxiliary screen. For the scale, some patterns are stored in advance in a storage device and are gradually changed.

The above example is an example in which the size of the auxiliary screen is made constant and only the scale is changed.However, when the scale is made constant and the viewpoint reaches the outer frame that constitutes the auxiliary screen, the outer frame, namely, It is also possible to increase the size of the auxiliary screen.

In order to realize these, in the auxiliary screen creation function, the two-dimensional coordinates of the viewpoint on the screen are compared with the position coordinates of the outer frame of the auxiliary screen stored in the storage device, and the viewpoint comes into contact with the outer frame. If it is determined, the scale is enlarged or the screen is enlarged. In this embodiment, steps 1 to 4 in FIG.
Is changed to steps 1 to 4- ^c in FIG.

Enlarging the scale twice means that the coordinates of the display point on the screen change to 1/2.

That is, x ₀ : x coordinate on the screen of the origin x, x ′: x coordinate of the display point before and after the scale conversion on the screen Therefore, if the scale conversion factor is α, x ′ = 1 / α (x−x ₀ ) + x _A scale expansion of ₀ (10) is performed. Several types of α are stored in the storage device.

When enlarging the screen, the position of the display point on the screen does not change, but the display range is simply expanded. That is, x of x ° _min ≤x≤x ° _max , y ° _min ≤y≤y ° _man x
゜_mix , x ゜_max , y ゜_min , y ゜_max change.

Since the target object shown on the auxiliary screen is displayed for the purpose of grasping the positional relationship with the viewpoint, it is sufficient to display a diagram from a certain fixed viewpoint. However, when the viewpoint moves to the back side of the object, it becomes difficult to grasp the positional relationship between the viewpoint and the object. Therefore, in the present invention, for each quadrant in which the viewpoint exists,
Change the figure of the object on the auxiliary screen. In the example of FIG. 14,
The case where the viewpoint A moves up to B while raising the yz plane is shown. In the case of three dimensions, xy plane, yz plane, z-
The x-plane divides the space into eight quadrants, and a maximum of eight case object views are displayed on the auxiliary screen.

In order to carry out the present embodiment, a conversion program (conversion coefficient) for converting three-dimensional coordinates into two-dimensional coordinates is stored in the storage device for each quadrant, and the input point is the xy plane, y. −
When passing through either the z plane or the z-x plane and moving to another quadrant, a conversion coefficient corresponding to the quadrant is read and a new auxiliary screen is created. Specifically, the conversion formula
Of (1) and (4), D in equation (4) is constant, and T ₁ and T in equation (1) are
Prepare ₂ , T ₃ and T ₄ for each quadrant. However, the absolute value of the rotation angle θ of the absolute value of the movement width _t x of the respective _{T 1} of the respective quadrant _(t y, t _s), and _{T 2 (T 3, T 4} ) , the quadrant is changed Even though they are equal. In this case, steps 1 to 4 in FIG. 2 become steps 1 to 4-d in FIG.

〔The invention's effect〕

According to the present invention, the position information of the specified viewpoint with respect to the displayed first graphic information of the specified object, and the information of the viewing direction based on the position of this viewpoint. , And the second graphic information indicating the information based on the visual field information is displayed on the display device together with the first graphic information, it is possible to easily visually confirm the set viewpoint position, viewing direction, and visual field. , These settings can be done easily. Further, it is possible to obtain a three-dimensional figure of the object corresponding to the set viewpoint position, viewing direction, and visual field in a short time.

[Brief description of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG. 2 is
FIG. 3 is a procedure diagram of the processing of the present invention, FIG. 3 is a principle diagram of a perspective view, FIG. 5 is an explanatory diagram of an example of an auxiliary screen, and FIGS. 6 and 7 are explanatory diagrams of a screen configuration example. FIG. 8 is an explanatory diagram of an example of an auxiliary screen, FIGS. 9, 10, and 11 are explanatory diagrams of an example of a main screen, FIG. 12 is an explanatory diagram of an example of an auxiliary screen, and FIG. FIG. 14 is a procedure diagram of processing, FIG. 14 is an explanatory diagram of an embodiment of an auxiliary screen, and FIG. 15 is a procedure explanatory diagram of processing. 1 ... storage device, 2 ... input device, 3 ... auxiliary screen creation function, 4 ... main screen creation function, 5 ... screen display function, 6
…… CRT.

Claims (1)

[Claims] 1. A first graphic information of a designated object is selected from a storage means by a computing means and displayed on a display device, and a position of a designated viewpoint with respect to the displayed first graphic information. Based on the information, the information on the viewing direction based on the position of the viewpoint, and the information on the field of view, the second graphic information indicating the information is created by the computing means, and the first graphic information and the display are generated. Displaying on a device, using the displayed first and second graphic information, three-dimensional third graphic information of the object with respect to the viewing direction and the field of view is created by the computing means, and A design support method characterized by displaying on one of a display device and another display device.