JP2001307132A - Method for processing three-dimensional shape and storage medium storing program for executing the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a three-dimensional(3D) shape processing method capable of displaying segments having 3D directions and lengths such as a normal, a tangent and a visual line direction on 3D space so that a user can easily understand the directions and lengths in the case of displaying the segments on a two-dimensional(2D) screen. SOLUTION: Cubes Q (cubes whose respective faces are displayed) whose directions are shown are additionally displayed correspondingly to segments b, c indicating directions concerned with a line L to be a 3D shape to be displayed. Namely the start point coordinates and end point coordinates are found out in each of the segments b, c, a distance D between the start point coordinates and the end point coordinates is found out, a cube having the start point coordinates as an origin, the same inclinations as the segments b, c and height and width of D is generated, and projection processing similar to other display elements is applied to the generated cubes and the processed images are displayed on a screen.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional shape processing method for projecting and displaying a line segment indicating a three-dimensional direction related to a target three-dimensional shape on a two-dimensional surface, and a method for implementing the method. The present invention relates to a storage medium storing a program.

[0002]

2. Description of the Related Art Conventionally, a three-dimensional shape processing system such as a CAD system or a CAM system using a graphics display device and a computer generates a three-dimensional shape and deforms the generated three-dimensional shape. 3
Various decisions are made on the dimensional shape. The three-dimensional shape (three-dimensional solid) refers to a shape generated as, for example, solid model data in a boundary expression format. A solid model in the boundary expression format is a model in which a closed area in a three-dimensional space is defined by elements such as ridge lines, vertices, and faces, and a solid body is expressed. Such 3
In a two-dimensional shape processing system, a line segment indicating a three-dimensional direction related to a target three-dimensional shape is projected and displayed on a two-dimensional surface. The line segment indicating the direction is, for example, a line segment visualizing the direction of the normal line of the surface forming the three-dimensional shape, the direction of the tangent line of the ridge line, and the like. By setting the line segments at the required positions, they were displayed on the screen. However, in such a case,
When displaying a tangent line, a normal line, or the like having three-dimensional information on a display device of a two-dimensional screen, there is a problem that information in a depth direction is lost, and it is difficult for a user to recognize the indicated direction. Was. For example, in the case of the example of FIG.
It is impossible to accurately determine whether the upper line a is toward the front, toward the back, or perpendicular to the viewing direction. In addition, there are cases where it is desired to display not only the direction but also the size of the direction vector, but a line segment that is at an angle relatively close to the line of sight will be displayed short, and the exact size from the figure will be displayed. Is difficult to determine (see FIG. 9). When performing the three-dimensional shape processing, the position of the viewpoint and the direction of the line of sight are frequently changed. In such a case, it is desirable to use a pointing device such as a mouse input device to move the viewpoint and line of sight in real time, and to display on the screen an indication of the direction for the user to operate at this time. When the line-of-sight direction is processed in the reference world coordinate system, it is difficult to accurately recognize the line-of-sight direction with a simple line display (see FIG. 10).

[0003]

In the prior art, when a line segment having a three-dimensional direction and size such as a normal, a tangent, and a line of sight in a three-dimensional space is displayed on a two-dimensional screen, There was a problem that the direction and size were difficult for the user to understand. An object of the present invention is to solve such a problem of the related art. That is, an object of the present invention is to use a direction and a size when displaying a line segment having a three-dimensional direction and size such as a normal, a tangent, and a line of sight in a three-dimensional space on a two-dimensional screen. Another object of the present invention is to provide a three-dimensional shape processing method which is easy for a user to understand, and a storage medium storing a program for executing the method.

[0004]

According to a first aspect of the present invention, there is provided a two-dimensional processing method for projecting and displaying a direction in a three-dimensional shape on a two-dimensional surface. A cubic or rectangular parallelepiped whose direction is known is additionally displayed in association with a line segment indicating a direction related to the three-dimensional shape. According to a second aspect of the present invention, in the three-dimensional shape processing method according to the first aspect, when a vector line segment having a significant magnitude is displayed, the magnitude of the vector is the same as that of the side of a cube or the vector of a rectangular parallelepiped. The cubic or rectangular parallelepiped is displayed with the size of the side in the direction. According to a third aspect of the present invention, in the three-dimensional shape processing method according to the first or second aspect, the direction of one side of the cube or the rectangular parallelepiped is matched with the direction of a line segment indicating the direction. And According to a fourth aspect of the present invention, in the three-dimensional shape processing method according to the first aspect,
A cubic or rectangular parallelepiped whose direction is known is additionally displayed in association with a line segment indicating the line of sight of the displayed three-dimensional shape. According to a fifth aspect of the present invention, in the three-dimensional shape processing method according to the fourth aspect, when the direction of the line of sight is changed, the direction of one side of the cube or the rectangular parallelepiped is changed in accordance with the direction of the line of sight. And Claim 6
According to a third aspect of the present invention, a program for executing the three-dimensional shape processing method according to any one of the first to fifth aspects is stored.

[0005]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing a three-dimensional shape processing apparatus for performing a three-dimensional shape processing method according to one embodiment of the present invention. As shown in FIG. 1, the three-dimensional shape processing apparatus includes a data processing unit 1
, An input device 2, a display device 3, a plotter 4, a data memory (for example, RAM) 5, an external storage device (for example, hard disk device) 6, a storage medium drive device 7, and the like. The data processing unit 1, the input device 2, the display device 3, the plotter 4, the data memory 5, the external storage device 6, and the storage medium driving device 7 are interconnected. The data processing unit 1 includes a memory for loading a program and a CPU that operates according to the program.
A dimensional shape model is generated, and a display process according to the present invention is performed. The input device 2 includes a mouse input device and a keyboard input device, and is used by a user to input an instruction content and the like. The display device 3 displays a three-dimensional shape model and the like. The plotter 4 outputs a three-dimensional shape model (hereinafter abbreviated as a three-dimensional shape) on a sheet.
The data memory 5 temporarily stores various data. The external storage device 6 stores a plurality of three-dimensional shape model data (hereinafter abbreviated as shape data), a program, and the like. The storage medium drive 7 drives a removable storage medium. FIG. 2 is an explanatory diagram for describing a three-dimensional shape processing method according to the first embodiment of the present invention regarding display under the same conditions as in FIG. As shown in FIG. 2, in the first embodiment, the cube Q whose direction is known in association with a line segment (tangent line in the illustrated example) indicating a direction related to a line L which is a three-dimensional shape to be displayed. (It may be a rectangular parallelepiped).
Thereby, the inclination of the cube Q is known, and from the inclination,
It can be seen that the line a starts from the line L and is approaching diagonally forward. This is because, in this embodiment, the starting point SP of the line a coincides with the center of one surface of the cube, and the inclination of the line a and the inclination of the cube coincide. That is, FIG.
Thus, it can be seen that the plane to which the start point SP belongs is the plane at the back of the cube, and the line a must be directed to the near side so that the line a and the cube have the same inclination. This direction is not clear in the prior art shown in FIG.

FIG. 3 is an explanatory diagram for explaining a three-dimensional shape processing method according to the second embodiment of the present invention, which is related to display under the same conditions as in FIG. As shown in FIG. 3, in the second embodiment, a line L which is a three-dimensional shape to be displayed is
A cubic Q (or a rectangular parallelepiped) whose direction is known is additionally displayed in association with a line segment (tangent in the illustrated example) indicating the direction related to. The size of the vector line segment is set to the size of the side of the cube or the side of the cube in the same direction as the vector, and the cube or the rectangle is displayed. Line B with start point on line L
And line C are the lengths determined in this way, and line B and line C
Is equal to the length of one side of the corresponding cube, and the cubes Qb and Qc have substantially the same size. Therefore, in FIG. 3, the lengths of the lines b and c are substantially equal. And the direction in which each faces is also a line b
It can be seen that the direction is obliquely toward the front of the figure, and that the line c is the upper right direction. FIG.
This is not clear in the prior art shown in FIG. FIG. 4 is a flowchart for explaining the second embodiment. Hereinafter, the operation of the second embodiment will be described with reference to FIGS. First, for the vector line segment V to be displayed, the data processing unit 1 obtains the start point coordinates SP and the end point coordinates EP (step S1). Then, a distance D between the start point coordinates SP and the end point coordinates EP is obtained (step S2). Subsequently, a cube having the same inclination as the vector line segment V, the height and the width D is generated with the starting point coordinates SP as the origin (step S3). At this time, the angle at which the cube is placed (the rotation angle when the axis of the cube in the direction of the vector line segment is used as the rotation axis) is not uniquely determined, and is freely determined. Next, the generated cube is subjected to the same projection processing as in the case of other display elements, and is displayed on the screen (step S4). In the above, a rectangular parallelepiped may be used instead of a cube. In this case, the length of the rectangular parallelepiped in the same direction as the vector line segment V is set to the same length as the vector line segment V. As described above, according to the second embodiment, when a line segment having a three-dimensional direction and size such as a tangent in a three-dimensional space is displayed on a two-dimensional screen, the direction and size are displayed. Is easy for the user to understand.

FIG. 4 is an explanatory diagram for explaining a three-dimensional shape processing method according to the third embodiment of the present invention, which is related to display under the same conditions as in FIG. In the third embodiment of the present invention, as shown in FIG. 6, a cubic or rectangular parallelepiped whose direction is known is additionally displayed in association with a line segment indicating the line of sight of the displayed three-dimensional shape. In the third embodiment of the present invention, a cube representing the direction of the line of sight is drawn with respect to the arrow indicating the line of sight, thereby avoiding the loss of the depth direction due to the two-dimensionalization. Further, when the direction of the line of sight changes due to the operation of the user, the direction at that time can be clarified by moving the cube or the rectangular parallelepiped in real time. FIG. 4 is a flowchart for explaining the second embodiment. Hereinafter, the operation when the cube is moved will be described based on FIG. 7 (the same applies to the case where the rectangular parallelepiped is moved). First, for the vector line segment V indicating the line of sight to be displayed, the data processing unit 1 obtains the start point coordinates SP and the end point coordinates EP at that time (step S11). Then, a distance D between the start point coordinates SP and the end point coordinates EP is obtained (step S12). Then, using the starting point coordinates SP as the origin,
A cube having the same inclination as the vector line segment V and a height and width D is generated (step S13). At this time, the angle at which the cube is placed (the rotation angle when the axis of the cube in the direction of the vector line segment is used as the rotation axis) is not uniquely determined, and is freely determined. Next, the generated cube is subjected to the same projection processing as that for the other display elements, and is displayed on the screen (step S14). In the above, when a rectangular parallelepiped is used instead of a cube, the length of the rectangular parallelepiped in the same direction as the vector line segment V is set to be the same as the vector line segment V. Subsequently, by monitoring information input by the input device 2, the data processing unit 1 determines whether the position of the vector line segment indicating the line of sight has been changed (step S15). If it is determined that the cube has been changed (Yes in step S15), the display of the cube displayed up to that point is ended (step S16), and the process is repeated from step S11 in the case of the position of the changed vector line segment. .

On the other hand, in step S15,
If it is determined that no change has been made (step S15
No), it is determined whether or not the work is completed (step S1).
7) If the work is not completed (No in step S17),
After the wait state for the predetermined time, the process returns to step S15 to determine the change of the position of the vector line segment. In the wait state, other processing can be performed. Step S
In 17, if it is determined that the work is finished (Yes in step S17), the operation is finished. Thus, according to the third embodiment, even when the displayed three-dimensional direction is the line-of-sight direction, the direction can be displayed on the two-dimensional screen in a manner that is easy for the user to understand. Even if the line of sight changes, it can be similarly displayed in an easily understandable manner. The case where the displayed three-dimensional direction is the tangent line or the line-of-sight direction has been described above. Similarly, the case where the displayed three-dimensional direction is the normal line is also described. The method can be performed. Further, the three-dimensional shape processing method according to the present invention has been described in the case of displaying on a display device, but the display according to the present invention also includes the case of displaying on paper by a plotter. Further, it is possible to obtain a machine-readable storage medium storing a program for performing the three-dimensional shape processing method according to the present invention as described above. The three-dimensional shape processing method according to the present invention can be performed by causing an information processing device such as a personal computer to read and execute the program stored in the storage medium.

[0009]

As described above, according to the first aspect of the present invention, a cube or a rectangular parallelepiped whose direction is known is additionally displayed in association with the line segment indicating the direction related to the three-dimensional shape of the display object. Therefore, when a line segment having a three-dimensional direction in a three-dimensional space is displayed on a two-dimensional screen, the user can easily understand the direction. According to the second aspect of the present invention, in the first aspect of the present invention, when a vector line segment having a significant size is displayed, the magnitude of the vector is set to the side of the cube or the vector of the rectangular parallelepiped. Since the cube or the rectangular parallelepiped is displayed with the size of the side in the same direction, when displaying a line segment having a three-dimensional direction and size in a three-dimensional space on a two-dimensional screen, the direction and size are displayed. Is easy for the user to understand. According to the invention described in claim 3, in the invention described in claim 1 or 2, the direction of one side of the cube or the rectangular parallelepiped coincides with the direction of the line segment indicating the direction. Alternatively, the direction of the line segment indicating the direction can be easily known from the direction of the rectangular parallelepiped. Also,
According to the invention described in claim 4, in the invention described in claim 1, a cube or a rectangular parallelepiped whose direction is known is additionally displayed in association with the line segment indicating the line of sight of the displayed three-dimensional shape. When a gaze direction having a three-dimensional direction in a three-dimensional space is displayed on a two-dimensional screen, the direction becomes easy for a user to understand. According to the invention described in claim 5, in the invention described in claim 4, when the line of sight is changed, the direction of one side of the cube or the rectangular parallelepiped changes in accordance with the line of sight. Even when it changes, when the gaze direction having the three-dimensional direction is displayed on the two-dimensional screen, the user can easily understand the direction. According to a sixth aspect of the present invention, there is provided a machine-readable storage medium storing a program for performing the three-dimensional shape processing method according to any one of the first to fifth aspects. Therefore, the effects of the first to fifth aspects of the present invention can be obtained by causing the information processing device to read and execute the program stored in the storage medium.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a three-dimensional shape processing apparatus that performs a three-dimensional shape processing method according to one embodiment of the present invention.

FIG. 2 is an explanatory diagram for describing a three-dimensional shape processing method according to the first embodiment of the present invention.

FIG. 3 is an explanatory diagram for describing a three-dimensional shape processing method according to a second embodiment of the present invention.

FIG. 4 is a flowchart for explaining a three-dimensional shape processing method according to a second embodiment of the present invention.

FIG. 5 is another explanatory diagram for describing the three-dimensional shape processing method according to the second embodiment of the present invention.

FIG. 6 is an explanatory diagram for describing a three-dimensional shape processing method according to a third embodiment of the present invention.

FIG. 7 is a flowchart for explaining a three-dimensional shape processing method in three-dimensional shape processing according to a third embodiment of the present invention.

FIG. 8 is an explanatory diagram for describing an example of a conventional three-dimensional shape processing method.

FIG. 9 is an explanatory diagram for explaining another example of the conventional dimensional shape processing method.

FIG. 10 is an explanatory diagram for explaining another example of a conventional three-dimensional shape processing method.

[Explanation of symbols]

1 data processing unit, 2 input device, 3 display device, 4
Plotter, 5 data memory, 6 external storage device.

Claims (6)

[Claims] In a two-dimensional processing method for projecting and displaying a direction in a three-dimensional shape on a two-dimensional surface, a three-dimensional object to be displayed is displayed.
A three-dimensional shape processing method characterized by additionally displaying a cube or a rectangular parallelepiped whose direction is known in association with a line segment indicating a direction related to a three-dimensional shape. 2. The three-dimensional shape processing method according to claim 1, wherein when a vector line segment having a significant size is displayed, the magnitude of the vector is set to a side of a cube or a side of a side of the cube in the same direction as the vector. A three-dimensional shape processing method characterized by displaying the cube or the rectangular parallelepiped in a size. 3. The three-dimensional shape processing method according to claim 1, wherein the direction of one side of the cube or the rectangular parallelepiped is matched with the direction of a line segment indicating the direction. Shape processing method. 4. The three-dimensional shape processing method according to claim 1, wherein a cube or a rectangular parallelepiped whose direction is known is additionally displayed in association with a line segment indicating a line-of-sight direction of the displayed three-dimensional shape. A three-dimensional shape processing method. 5. The three-dimensional shape processing method according to claim 4, wherein when the line-of-sight direction is changed, the direction of one side of the cube or the rectangular parallelepiped is changed in accordance with the line-of-sight direction. Shape processing method. 6. A machine-readable storage medium storing a program for executing the three-dimensional shape processing method according to claim 1. Description: