JPH07113928B2 - Figure layout display method - Google Patents

Description

The present invention relates to shape input in geometric modeling, which is the core of a mechanical design support system, and is particularly suitable for displaying a certain image on a display device. Figure layout display method.

[Conventional technology]

Various attempts have been made to support the design of mechanical structures and the like using a computer, and many effects have been achieved. Such a design support system is realized as a dialogue system between a designer and a computer. The designer advances the design work while interacting with the computer. This design work always targets a three-dimensional shape, and it is important that the designer can easily input the three-dimensional shape into the computer.
However, in the conventional three-dimensional shape input, a method in which a predetermined numerical value is input using a keyboard or the like to generate a three-dimensional shape in a computer is the mainstream. In addition, conventionally,
Since the designer is accustomed to drawing drawings, it is easier to input in two dimensions. 2 for such shapes
A method of creating a three-dimensional drawing or a three-dimensional drawing and using it to make it three-dimensional has also been attempted. This method is also the same as inputting the already determined numerical value.

Also, if there is an actual shape or scale model, to capture it in the calculator, photographic technology or ultrasound,
A method using a three-dimensional coordinate reader using a laser beam and a method using a kit with a scale to input a model into a computer [Japanese Patent Laid-Open No. 51-21227] are known. It is not possible to easily input the three-dimensional shape drawn in the designer's head.

[Problems to be solved by the invention]

In the above-mentioned conventional example, when moving individual figures created by numerical input with the keyboard or input using the actual model on the screen, the coordinate data etc. of the moving destination are calculated and the numerical value is input. There was a problem in operability.

It is an object of the present invention to provide a method for displaying and arranging a graphic that can favorably move a graphic displayed on the screen.

[Means for solving problems]

In order to achieve the above object, the present invention provides a graphic layout display method for displaying a three-dimensional shape to be displayed on a display device connected to a computer by using a plurality of basic graphics, which are graphic elements. A predetermined basic figure forming the three-dimensional shape is displayed from among the basic figures, a specific surface of the predetermined basic figure is selected, and another basic figure parallel to the display screen and to be overlapped with the predetermined basic figure The intersection line between the plane passing through the coordinate origin of the and the specific surface is obtained, the other basic figure is displayed on the intersection line, and the light is transmitted from the coordinate point (46) on the plane input on the display screen. Characterized in that the origin of coordinates of the other basic figure is moved to the perpendicular foot (47) on the intersection line by obtaining the foot (47) of the perpendicular drawn on the line, and the basic figure is displayed on the display device. To do.

[Action]

According to the above-mentioned means of the present invention, the coordinate origin of the other basic figure is obtained by obtaining the foot (47) of the perpendicular line drawn down on the intersection line from the coordinate point (46) on the plane input on the display screen. Is displayed by moving to the perpendicular leg (47) on the intersection line, it is possible to easily move the basic figure while looking at the display screen.

〔Example〕

An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows an interactive system between a designer (operator) 1 and a graphic display device 2 or a host computer (application system) 3. The command 4 from the designer 1 is input from the tablet 5, the stylus pen 6, the function key 7 and the keyboard 8, is interpreted by the graphic display device 2, and is processed by the host computer 3 if necessary. The command 4 is transferred to the host computer 3 via the means 9. The application program 10 is loaded in the host computer 3, and performs processing that cannot be performed by the graphic display device 2. For example, the host computer 3 manages various design information that cannot be managed by the graphic display device 2 or the entire mechanical structure. If necessary, these various kinds of information can be registered in the file 11 or searched. The graphic display device 2 manages graphic information input by the host computer 3 or the designer 1, creates drawing information as necessary, and creates a graphic display.
Display on 12. Designer 1 is a graphic display 12
Determine the next action by looking at the results displayed in. The screen of the graphic display 12 and the tablet 5 have a one-to-one correspondence, and the stylus pen 6 can identify the drawing information displayed on the screen of the graphic display 12.
The designer 1 looks at the result displayed on the graphic display 12, inputs the next command 4 from the tablet 5, the stylus pen 6, the function key 7, and the keyboard 8,
Repeat the same operation. In this way, the designer 1 interacts with the graphic display control device 2 or the host computer 3 to generate a desired three-dimensional shape in the memory of the graphic display device 2. The generated three-dimensional shape is transferred to the host computer 3 through the interface means 9 and managed by the application program 10 based on the judgment of the designer 1.
It is stored in the file 11 as needed.

The above is the description of the interactive means for generating a figure inside the computer, but the following describes how to input a shape.

FIGS. 2 (A) and 2 (B) show a three-dimensional shape designed by such a dialogue system. The shape of the pipe 13 is a cylinder,
This is an example described as an aggregate of basic figures 14a to 14d such as a cone and a torus. The designer 1 creates the basic figures 14a to 14d in the figure display device 2, arranges the basic figure at an appropriate position and posture by using the movement and rotation commands, and constructs a desired three-dimensional shape. In the case of the device 15, the basic figures 14e and 14f.

Next, how to generate a basic graphic in the graphic display device 2 will be described with reference to FIG. Graphic display device 2
In order to model a three-dimensional shape, a model space 16 as shown in FIG. 3 is automatically set therein. The model space 16 has a model coordinate system 17. The model coordinate system 17 is a rectangular coordinate system and is represented by (X, Y, Z). Alternatively, the basic figure 14 also has a primitive coordinate system 18 as shown in FIG. Primitive coordinate system 18 is also a Cartesian coordinate system,
It is indicated by (x, y, z). When the basic figure 14 is generated in the figure display device 2, the model coordinate system 17 and the primitive coordinate system 18 are in a matched state. The movement and rotation of the basic figure 14 in the model space 16 is performed by the amount of movement P ₀ (X ₀ , Y ₀ , Z ₀ ) and the amount of rotation F of the primitive coordinate system 18 with respect to the model coordinate system 17.
(3 × 3 matrix), and one point P ′ (x, y, z) in the primitive coordinate system 18 is 1 in the model coordinate system 17.
The point P (X, Y, Z) can be converted into P = [F] P '+ P ₀ (1). When formula (1) is expressed by components, Becomes In the figure display device 2, the shape information, the movement amount, and the rotation amount are stored for each individual basic figure 14.

Next, grouping of the basic figures 14 will be described with reference to FIGS. A general three-dimensional structure is described as an aggregate of a plurality of parts, and a part is a plurality of basic figures 14
Can be thought of as a collection of. FIG. 4 shows such a concept. There are a plurality of basic figure aggregates 19a to 19d in the model space 16, and each basic figure aggregate 19a to 19d is a basic figure 14a to 14d. It shows the place described as a collection of. Piping 1 in Figure 2 above
3. The device 15 corresponds to this basic figure aggregate 19. FIG. 5 shows an example in which the basic figure aggregate 19 is described as an aggregate of basic figures A and B. The basic figure aggregate 19 arranges the basic figure A in the model space 16 and then The figure B is generated and aligned, and is described as a union of the basic figure A and the basic figure B. The aggregate description modes 20 to 24 are the union mode 20, the difference set mode 21, the intersection set mode 22, the arrangement mode 23, and the interference check mode 24, respectively, in the figure display device as shape information for each basic figure unit. Managed. Arrangement mode 23 is a mode in which only the arrangement of basic figure 14 is described. The interference check mode 24 is used when defining the shape 25 for the interference check. This is the shape of interest only when the interference check is required. FIG. 6 shows a set operation.
Figure (i) shows the positional relationship between the basic figures A and B. Figure 6 (ii) is the union of the basic figures A and B (A + B)
Is the result of doing. FIG. 6 (iii) shows basic figures A and B.
It is the result of performing the difference set (A-B) of. Figure 6 (iv)
Is the result of performing the intersection (A * B) of the basic figures A and B. An arbitrary shape is generated in the computer by using these aggregate description modes in combination.

The three-dimensional shape generated in the computer as described above must be displayed on the graphics display 12. This will be described with reference to FIG. FIG. 7 (A),
(B) shows an example in which a plurality of windows 26a to 26c can be simultaneously displayed on the screen of the graphic display 12.
The graphic display 12 has a display coordinate system (X ',
Y ', Z') 27 is set, and the front side of the screen is Z '.
Is the positive direction. A window coordinate system (X ″, Y ″, Z ″) 28 is also set in the windows 26a to 26c, and the origin 0 ″ of the window coordinate system 28 is the viewpoint position for viewing the model space 16. The three-dimensional shape generated in the model space 16 is described by the projection-converted window coordinate system 28.
A projected shape is created on the X ″, Y ″ plane of the screen and displayed on the screen of the graphic display 12. The negative direction of the Z ″ axis of the window coordinate system 28 coincides with the line-of-sight direction 29. The designer can set the window coordinate system 28 at any position and orientation, and the window control information is managed in the computer.

Next, regarding data management in the graphic display device 2, FIG.
This will be described with reference to FIG. FIG. 8 shows the overall structure in the one-dimensional memory in the graphic display device 2, and the information to be managed is large (i) window control information, (ii) basic graphic aggregate information, (iii) basic graphic. Divided into three types of information,
Each has a cell structure. Each piece of information is linked by a pointer, and the first pointer to each piece of information is managed at the head of the one-dimensional memory. First, the pointer to the window control information is managed, and the window information can be sequentially retrieved by searching the address i of the pointer. A pointer j to the basic figure aggregate information is stored in the second word from the head of the one-dimensional memory,
The basic figure aggregate information can be retrieved by searching the address j. Similarly, basic graphic information can be sequentially extracted.
A pointer to an empty area is stored in the 4th word and is used for reproducing the deleted area. Figure 9 (A)
(C) shows management items of the window control information, which are information managed on a window 26 unit basis displayed on the graphics display 12. Among the window control information, the internal name is a consistent number in the graphic display device 2, and the external name is a name freely decided by the designer. The type of projection can satisfy either parallel projection or perspective projection. The viewpoint is the origin of the coordinate system of the window that looks at the model space 16. The projection matrix transforms one point in the model coordinate system 17 into one point in the window coordinate system 28. The window display range is the window relative to the display coordinate system 27.
These are the coordinate values of the lower left and upper right corners of 26. Further, the display range of the model space represents a part of the model space to be displayed by the window 26, and is described in parallel with the axis of the model coordinate system 17 by diagonal points representing a rectangular parallelepiped.

FIG. 10 shows the data items of the basic figure aggregate information, and the first 1st word manages the pointer to the next basic figure aggregate information. The internal name and external name are the same as the window control information. The pointer to the basic graphic information is a pointer to the information of the basic graphic forming the basic graphic aggregate, and by tracing the pointer, the information of all the basic graphic forming the basic graphic aggregate can be obtained.

FIG. 11 shows the data items of the basic graphic information, and the first three items are the same as described above. Also, the aggregate description mode, the movement amount, and the rotation amount are as described above. The pointer to the next basic figure information of the seven items is a pointer to the basic figure information that constitutes the basic figure aggregate, and by tracing this, all basic figure information that constitutes the basic figure aggregate can be obtained. it can. The pointer to the basic figure aggregate information is provided so that the aggregate to which the basic figure belongs can be easily identified. The following constrained basic figure name and constituent surface number are the surface information that constrains the origin of the basic figure of this cell, the constrained basic figure name is the external name of the basic figure having the constrained surface, and the constituent surface number is The surface number of the basic figure. The data amount of the next basic figure shape parameter indicates the number of words of the next basic figure shape parameter. The shape parameter of the basic figure is dimension data that characterizes the basic figure.

Next, regarding the basic graphic 14 that can be handled by the graphic display device 2,
This will be described with reference to FIGS. 12 to 17. The basic figure 14 can be classified into four (i) line segment elements, (ii) plane elements (iii) curved surface elements, and (iv) three-dimensional elements. FIG. 12 shows the line segment elements. As the basic figure 14, points, straight lines, circles / arcs, ellipses / ellipses and free curves can be defined, and the geometric information describing the basic figure is also shown. Shows. The geometric information includes shape parameters for describing the shape and basic figure types for identifying the shape, which are managed in the basic figure shape parameter portion of the basic figure information cell in FIG. The point is generated at the origin of the primitive coordinate system 18 and has no shape parameter. The straight line segment is described by the line segment length and is generated on the x axis of the primitive coordinate system 18. A circle / arc is described by a radius R and an angle θ from the x-axis. The ellipse / ellipse is similarly described by the major axis A, the minor axis B, and the angle θ. The free-form curve shall consist of multiple smoothly connected segments,
One segment is represented by a cubic Bezier curve. A cubic Bezier curve R (t) (t is an auxiliary variable, 0t1) is R (t) = (1 when P ₁ , P ₂ , P ₃ , P ₄ are control points, as shown in FIG. _{^{-t) 3 P 1 +3 (1}} -t) 2 tP 2 + (1-t) t 2 P 3 + t 3 P 4 and expressed. This curve is (i) the tangent direction at the start and end points is ▲
Matches ▼ and ▲ ▼.

(Ii) t = 0, t = the 1 respectively through the P _1, P _4.

(Iii) The curve represented by R (t) is included within the convex polygon of the control point (hatched portion in FIG. 13).

(Iv) An arbitrary curve can be generated by moving the control point.

It has characteristics such as, and has a property suitable for graphic processing by a computer.

Further, in FIG. 12, the local coordinate system (which can be freely generated in the model space 16) is also treated as one basic figure. The shape parameters are the lengths A, B, and C of each axis. The local coordinate system is used for arranging figures, and is made to coincide with either the primitive coordinate system or the model coordinate system, which will be described in detail later.

Fig. 14 shows the plane elements, and parallelograms, circles, ellipses, regular polygons and arbitrary shapes surrounded by free-form curves can be defined. This element describes the area on the plane as shown by the shaded area in Fig.14.
It is generated in the xy plane. A parallelogram is described by a shape parameter consisting of width A, height B, angle θ, and option IOPT. The option is to change the normal direction of the plane. IOPT = 1: The basic figure is generated. The normal direction of the plane matches the positive direction of the z axis of the primitive coordinate system. IOPT = −1: Plane The normal direction of is in agreement with the negative direction of the z-axis. A circle is described by radius R, rotation angle θ, and option. The ellipse is described by major axis A, minor axis B, angle θ, and option. A regular polygon is described by the circumscribed radius R, the division number N, and the option. An arbitrary shape is described by a closed loop of the shape defined by the line segment element. Specifically, the shape parameter is the number N of line segment elements forming the closed loop, and the name of the line segment element A _i (i =
1 to N), an option. Closed loop direction is 14th
In the figure, when the line segment element advances from the start point to the end point, the left side thereof is defined as the area of the plane element.

FIG. 15 shows a curved surface element, which is a basic figure that often appears in mechanical structures. As the basic figure, it is possible to handle a cylindrical surface, a conical surface, a spherical surface, a torus surface, and a free-form surface. The basic figure type of the cylindrical surface is 31, and the shape is described by the shape parameters consisting of radius (R), height (H), and option (IOPT). The option indicates the front and back of the surface, and is the same as in the case of the planar element described above. The basic shape type of the conical surface is 32, and the radius is 1 (R ₁ ), the radius is 2 (R ₂ ), the height (H), the eccentricity (D), and the option (IO
PT) is used as the shape parameter. The eccentricity amount D is an amount for representing the eccentric conical surface, and is shown by the x-axis coordinate of the primitive coordinate system. The sphere has a basic figure type of 33, and the shape parameters include a radius (R), a cut amount (D), and an option (IOPT). Cut amount (Only D is represented by the coordinate value on the z axis of the primitive coordinate system (-
R ≦ D <R). The torus surface has a basic figure type of 34 and is described by shape parameters including a large diameter (R _l ), a small diameter (R _s ), an angle (θ), and an option (IOPT). The angle is a quantity indicating the defined area of the torus surface. The free-form surface has a basic figure type of 35, and the free-form surface shape is expressed by a plurality of smoothly connected cubic Bezier surfaces S (u, v) (u, v are auxiliary variables, 0u, v1). I decided. 16th
The figure shows the cubic Bezier surface, which is P ₀₀ , P ₀₁ , ......, P
If the ₃₃ control points, S (u, v) = ((1-u) 3 3 (1-u) 2 u3 (1-u) u 2 u 3) · Can be expressed as This curved surface has the same properties as the Bezier curve and is suitable for graphic processing by a computer. As the shape parameters of the free-form surface, the number of Bezier surfaces in the u and v directions (the number of patches N _u , N _v ), the patch control points (P _{1 to} P ₁₆ ) corresponding to N _u × N _v, and the option (IOPT) Consists of.

Next, the three-dimensional element will be described. A three-dimensional element is a three-dimensional subspace surrounded by a surface, and a point P on the three-dimensional space.
Is given, it can be determined whether or not the point P is included in the subspace. FIG. 17 shows three-dimensional elements in this example, and a rectangular parallelepiped, a cylinder, a cone, a sphere, a torus, a column, a cone, a rotating body, an arbitrary solid, and the like were prepared.
A rectangular parallelepiped, a cylinder, a cone, a sphere, and a torus can be thought of as special cases of a cylinder, a complex, and a rotating body, but they are shapes that often appear in mechanical structures and should be prepared to reduce the amount of data. did. The rectangular parallelepiped has a basic figure type of 41 and is described by a shape parameter including a width (A), a depth (B), a height (C), and an option (IOPT). The option is to invert the front and back of the surfaces forming the three-dimensional element, and is the same as the case of the above-mentioned two-dimensional element. Cylinder, cone,
The sphere and torus are the same as the shape parameters for surface elements, and the basic figure types are 42,43,44,45 respectively.
Is. The column is a basic figure type 46, and the number (N) of line segment elements included in the xy plane of the primitive coordinate system and the name (A _i , i = 1 to N) of the line segment element corresponding to N and the height (H) and option (IOPT). The name of the line segment element is the internal name of the basic figure aggregate in FIG. 10 or the internal name of the basic figure in FIG. The cone has a basic figure type of 47, and the shape parameters are the number of line segment elements (N) and the name of the line segment elements (A _i , i = 1 to 1).
N), the convergence point (P) of the complex, the height (H), and the option (IOPT). Similarly for the rotating body, the basic figure type is 48
And the number of line segment elements (N) on the xy plane of the primitive coordinate system, the names of the line segment elements (A _i , i = 1 to N), the rotation angle (θ, 0 ° θ360 °), and the option ( IOPT) is used as the shape parameter. Although it is common to columns, cones, and rotating bodies, figures described in the xy plane of the primitive coordinate system are treated as if they were described in the same way in the case of the plane element in FIG. An arbitrary solid has a basic figure type of 49 and is treated as a shape closed by a surface. The shape parameter includes the number of surfaces (N), the name of the surface (A _i , i = 1 to N), and the option (IOPT). The name of the face is the internal name of the basic figure aggregate in Fig. 10 or
The internal names of the basic figures in Fig. 11 are shown.

Next, a method of moving / rotating the substrate graphic 14 will be described with reference to FIG. Fig. 18 shows the screen of the graphic display 12 divided into four parts.
Is the plan view of the model space 16 and the split screen 31 is the model space
16 shows a front view of 16, a side view of the model space 16 is displayed on the split screen 32 by trigonometry, and a three-dimensional view of the model space 16 is displayed on the split screen 33. The view information is managed by the data structure shown in FIG. The designer 1 utilizes such plural pieces of view information to generate and arrange a figure. Next, the generation and arrangement of graphics will be specifically described. The designer 1 inputs a necessary command using the function key 7. For example, description will be made assuming that a command for generating a cylinder is input. Parameters required to generate a cylinder are a radius and a height, and the graphic display device 2 requests these pieces of information. Specifically, the guidance is output on the graphic display 12. The designer 1 inputs necessary parameters: radius and height according to the request. If the radius and height are omitted, the default value is automatically set in the graphic display device 2. When the input is completed, the graphic information is managed by the graphic display device 2 and at the same time, the drawing data is created and displayed on the graphic display 12. In this case, it is displayed according to the view information. For example, in the case of FIG. 18, cylinder drawing data for four views is created and displayed on each split screen. The designer 1 confirms the result displayed on the graphic display screen and moves to the next operation. Next, the designer 1 for explaining the method of moving the cylinder generated in the graphic display device 2 in the model space 16 inputs a movement command from the function key 7. When the move command is input to the graphic display device 2, the graphic display device 2 inquires which graphic to move. The designer 1 uses the stylus pen 6 to specify the figure to be moved. The graphic display 12 is used by dividing the screen, but you can specify on any screen. In the case of a cylinder, the stylus pen 6 is used to select the display shape of the cylinder. The designer 1 then uses the stylus pen 6 to indicate the place where the cylinder is to be moved, using the four split screens. For example,
When the stylus pen 6 is moved in the split screen 30, the reference point of the cylinder is automatically updated in the graphic display device 2 so that the movement point and the origin of the primitive coordinate system of the cylinder coincide with each other, and at the same time the drawing of that state is performed. Recreate the data and redisplay it on Graphite Display 12. The screen of the graphic display 12 is divided into four parts, and the movement of the cylinder can be confirmed on each divided screen. This moving operation is continued unless the stylus pen 6 is in the pen-up state or it is not projected outside the split screen, and dynamic placement can be performed. If the stylus pen 6 is moved within the split screen 30, the X and Y values among the reference points of the cylinder are dynamically changed. If the stylus pen 6 is moved in the split screen 31, the coordinate values of the reference points X and Z of the cylinder are dynamically changed, and in the split screen 32, the Y and Z coordinate values are also dynamically changed. . Also, when the stylus pen 6 is moved within the divided image, it is assumed that the stylus pen 6 can be moved within a plane passing through the origin of the primitive coordinate system of the cylinder and having the vertical direction vector (line-of-sight vector) of the divided image as a normal line. . By these methods, the figure can be placed at any position in the model space. In the arrangement method described above, the coordinate values detected by the stylus pen 6 are not well separated.
Therefore, a method of rounding the coordinate values detected by the stylus pen 6 was prepared. FIG. 19 illustrates a method of rounding the coordinate values detected by the stylus pen 6, displaying a grid on the split screen 31, determining the grid point 34 closest to the coordinate value detected by the stylus pen 6, and stylus. It was used as the coordinate value with pen 6. The distance between the lattices can be freely designated by the designer 1.

Next, the operation of rotating a figure will be described with reference to FIG. First
FIG. 20 shows an enlarged view of the split screen 33 of FIG. Assuming that the stylus pen 6 is located at the coordinate point 35 in the split screen 33, the angle 38 formed by the line segment 36 connecting the coordinate point 35 and the center of the segmented screen 33 and the horizontal axis 37 of the screen is obtained. be able to. If this angle 38 is θ and the vector 39 perpendicular to the split screen 33 is (l, m, n), the coordinate transformation matrix [F] when the figure is rotated using the split screen 33 is However, a ₁₁ = COSθ + (1-COSθ) · l·l a ₁₂ = −n · Sinθ + (1-COSθ) · l · ma ₁₃ = m · Sinθ + (1-COSθ) · l · n a ₂₁ = n・ Sinθ + (1-COSθ) ・ l ・ ma ₂₂ = COSθ + (1-COSθ) ・ m ・ ma ₂₈ = −l ・ Sinθ + (1-COSθ) ・ m ・ n a ₃₁ = −m ・ Sinθ + (1- COS θ) · l · n a ₃₂ = l · Sin θ + (1-COS θ) · m · n a ₃₃ = COS θ + (1-COS θ) · n · m. In this rotation operation, the coordinate transformation matrix of the formula (2) is applied to the coordinate transformation matrix which is the reference of the figure. If the stylus pen 6 is not in the pen-up state or if it does not extend to the outside of the split screen, the coordinate conversion matrix is updated and at the same time the drawing data of each split screen is changed to enable dynamic rotation. At this time, when the stylus pen 6 is extremely close to the center of the split screen, an error is involved in the calculation of the angle 38, and therefore the rotation operation is excluded from the target. Further, as in the case of the moving operation, there are cases where it is desired to obtain a rotation angle with good division. In such a case, a radial grid as shown in FIG. 21 is displayed and the angle is calculated from the grid with the closest angle.

When arranging figures, there is a case where the figures are desired to be overlapped with each other or to be placed on the constituent surfaces of the figures and other figures. Next, a method for satisfying these needs will be described. FIG. 22 (A) shows that the local coordinate system 41 is on the rectangular parallelepiped 40, and the local coordinate system 41 is moved and rotated only on the plane 42. The local coordinate system 41 is also considered as one basic figure, and the constraint condition can be defined. Surfaces that can be specified as the constraint condition are a flat surface, a cylindrical surface, a conical surface, a spherical surface, and a torus surface. For the rotation on the surface, the aforementioned method is applied as it is, and in the method of arranging on the surface, it is often desired to take out the normal direction of the surface. Therefore, the local coordinate system 41
And the model space 16
And an arrangement corresponding to each axis of. Next, the movement operation on the surface will be described. Basically, it is the same as the above operation, but it is necessary to consider the constraint of riding on the surface. First
FIG. 22A shows a state where the local coordinate system 41 is constrained on the plane 42. The plane 44 is a plane parallel to the target divided screen, a plane passing through the center 0 ′ of the local coordinate system 41, and a plane perpendicular to the view vector 43. As described above, in the moving operation, the figure (local coordinate system 41) can be moved on the plane 44, but in this case, it must be able to move on the plane 42 of the rectangular parallelepiped 40. It is considered that this moves on the intersection line 45 between the plane 42 and the plane 44. The movement position of the local coordinate system corresponding to the coordinate point 46 designated by the stylus pen 6 is the foot 47 of the perpendicular line from the coordinate point 46 to the plane 42. This vertical foot 47 is the intersection of the two planes
I'm on the 45. When there is a constraint on the plane 42, the movement position is decided by the above-mentioned method and the movement amount which is the management information is changed, and at the same time, the drawing data is recreated and displayed on each divided screen to perform the dynamic arrangement. The above is the case where the constraint condition is a plane, but a cylindrical surface, a conical surface,
In the case of a spherical surface or a torus surface, the method of obtaining the moving position is slightly different. This will be described with reference to FIG. 22 (B) is almost the same as FIG. 22 (A), and shows a state in which the local coordinate system 41 is constrained on the spherical surface 49. The movable portion of the local coordinate system 41 is on the line of intersection 45 between the plane 44 and the spherical surface 49. Local coordinate system 41 corresponding to the coordinate point 46 specified by the stylus pen 6
The moving position of is the intersection 47 of the line segment 51 obtained by projecting the perpendicular 50 from the coordinate point 46 to the spherical surface on the plane 44 and the spherical surface 49. The intersection 47 lies on the ray 45 of the plane 44 and the sphere 49. Although the above is the description of the spherical surface, similar perpendicular lines can be obtained for the cylindrical surface, the conical surface, and the torus surface. In addition, the vertical line
The intersection of the line segment projected on 44 and the cylindrical surface, conical surface, or spherical surface can be easily obtained. The straight line equation is In general, the quadric surface of a cylindrical surface, a conical surface, or a spherical surface can be expressed as ax ² + by ² + cz ² + dxy + eyz + fzx + gx + hy + iz + j = 0 (4). By substituting the equation (3) into the equation (4), a quadratic equation regarding the auxiliary variable t can be obtained and easily solved. Further, in the case of a torus surface, the equation (4) becomes a quartic equation, and by substituting the equation (3), a quartic equation regarding t can be obtained, which can also be solved algebraically. Then, when the target position is determined, the local coordinates are replaced with another basic figure, so that the figures can be overlapped with each other or placed on the constituent surface of another figure.

According to the above-described embodiment, by using an arbitrary split screen, it is possible to arrange the figure at an arbitrary position and posture by moving and rotating the figure, and to facilitate the three-dimensional design of the mechanical structure. Become. In addition, when arranging figures, they can be arranged on a flat surface, a quadric surface, or a torus surface, so that parts and the like can be easily attached.

Further, in the above-mentioned embodiment, only the quadric surface is explained as the constraint condition. However, by obtaining the penetration line between the free-form surface and the plane and the perpendicular foot from any one point to the penetration line. The coordinate values on the free-form surface and the normal direction of the surface can be obtained and can be used to constrain the figure. Further, if the constituent surface numbers in FIG. 11 are meaningless, it is possible to restrict the figure to the entire basic figure or the entire basic figure group.

〔The invention's effect〕

According to the present invention, a basic figure can be moved with a stylus pen or the like while looking at the screen to form a three-dimensional figure, so that operability is improved.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a dialogue system using a computer. FIG. 2 is an explanatory diagram of basic figures forming a mechanical structure. FIG. 3 is an explanatory view showing a coordinate system for arranging basic figures in a three-dimensional space, FIG. 4 is an explanatory view of an assembly of basic figures, and FIG. 5 is an explanatory view of an assembly description mode of basic figures. , FIG. 6 is a concrete explanatory diagram of the aggregate description mode, FIG. 7 is an explanatory diagram of the coordinate system with the window displayed on the display screen, and FIG. 8 is a data structure managed in the graphic display device. , FIG. 9 is an explanatory view of window control information, FIG. 10 is an explanatory view of basic graphic aggregate information, FIG. 11 is an explanatory view of basic graphic information, and FIG. 12 is a basic graphic. 13 is an explanatory view of a line segment element, FIG. 13 is an explanatory view of a free curve, FIG. 14 is an explanatory view of a plane element of a basic figure, FIG. 15 is an explanatory view of a curved surface element of a basic figure, a 16 Figure is an explanatory view of Bezier curved surface, Figure 17 is about three-dimensional elements in basic figures FIG. 18, FIG. 18 is an explanatory view of a plurality of windows, FIG. 19 is an explanatory view of lattice points, FIG. 20 is an explanatory view of rotation of a figure, and FIG. 21 is an explanatory view of a radial lattice. First
Figure 22 is an explanatory view of the restraint method on the surface. 1 ... Designer, 2 ... Graphic display device, 3 ... Host computer, 4 ... Command, 5 ... Tablet, 6 ... Stylus pen, 7 ... Function key, 8 ... Keyboard,
9 ... Interface means, 10 ... Application program, 11 ... File, 12 ... Graphic disk press, 13 ... Piping, 14 ... Basic figure, 15 ... Equipment,
16 …… Model space, 17 …… Model coordinate system, 18 …… Primitive coordinate system, 19 …… Basic figure aggregate, 20 …… Union mode, 21 …… Differential set mode, 22 …… Intersection mode, 23 …
… Arrangement mode, 24 …… Interference check mode, 25 …… Shape for interference check, 26 …… Window, 27 …… Display coordinate system,
28 …… Wind coordinate system, 29 …… Line of sight, 30 …… Split screen, 31 …… Split screen, 32 …… Split screen, 33 …… Split screen, 34 …… Lattice point, 35 …… Coordinate point, 36 ...... Line segment, 37 ……
Horizontal axis, 38 …… Angle with horizontal axis, 39 …… Vector,
40 …… cuboid, 41 …… local coordinate system, 42 …… plane, 43
…… View vector, 44 …… plane, 45 …… intersection line, 46 ……
Coordinate point, 47 ... Vertical foot, 48 ... Center of sphere, 49 ... Sphere.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Miya Nio 4026 Kuji Town, Hitachi City, Hitachi, Ibaraki Prefecture Hitachi Research Laboratory, Hitachi, Ltd. (56) References JP 60-186967 (JP, A) JP Sho 59 -154569 (JP, A) JP-A-57-66474 (JP, A) JP-A-60-163162 (JP, A) JP-A-60-186967 (JP, A) "Introduction to CAD / CAM" edited by Fujio Yamaguchi P ． 75-77, p. 189-197, Published by S57 Industrial Research Committee

Claims (1)

[Claims] 1. A display device connected to a computer, which should be displayed 3
In a method for displaying and arranging a three-dimensional shape by using a plurality of basic figures that are graphic elements, a predetermined basic figure that constitutes the three-dimensional shape is displayed from among the plurality of basic figures, A specific plane of the basic figure is selected, an intersection line between the plane and the plane which is parallel to the display screen and passes through the coordinate origin of another basic figure to be overlapped with the predetermined basic figure is obtained, and the other line is placed on the intersection line. Is displayed, and the coordinate origin of the other basic figure is obtained by obtaining the foot (47) of the perpendicular line drawn from the coordinate point (46) on the plane input on the display screen to the intersection line. A method for displaying and arranging a graphic, characterized by moving to a foot (47) of the perpendicular on the intersection and displaying a basic graphic on a display device.