JP2776711B2 - How to create a 3D model - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for creating a three-dimensional model, and more particularly, to a method for converting a three-dimensional model of each surface from a rough wire frame model using a computer-aided design system (hereinafter referred to as a CAD system). The present invention relates to a method of creating a three-dimensional model to be created.

[0002]

2. Description of the Related Art Conventionally, when designing an automobile body using a CAD system, the body is represented as a set of a plurality of curved surfaces.

At this time, a ridge line of each curved surface is extracted from a mock-up model showing a vehicle body, and a wire frame model is created. Next, based on the wire frame model, data of a plurality of closed loops (hereinafter, referred to as “surface loops”) constituted by the respective wire frames is extracted, and further, a three-dimensional model of each surface is obtained from the data of the surface loop. Is generated. Based on the three-dimensional model of the surface, data (hereinafter referred to as NC data) to be input to the numerical control machine tool when a mold used for a press or the like is manufactured.

In this case, a rough wireframe model created by a CAD system based on a mockup model is created with priority given to design, and therefore has the inconvenience that ridge lines do not intersect. NC data cannot be obtained instantaneously.

[0005] For this reason, the operator verifies the CAD data of the rough wireframe model, and if it finds any inconvenience such that the end point of the ridge line does not intersect with another ridge line or another end point, the rough The correction is made while consulting with the creator of the appropriate wireframe model, and the data of the surface loop surrounded by each ridgeline is created from the complete wireframe model obtained by this correction.

As described above, the operator creates the data of each surface loop while verifying each edge of the ridge line of the rough wireframe model, and when the data of all the surface loops is obtained, the operator creates these surface loops. A three-dimensional model of the surface is generated based on the loop data.

[0007]

However, in the above-described method for generating a three-dimensional model of a surface according to the prior art, an operator verifies each end point of a ridge line of a rough wire frame model, and the end point is compared with another ridge line. If there was an inconvenience such as not intersecting, this was corrected and the data of the surface loop surrounded by the corrected edge was created each time,
When the wire frame model has a complicated shape, there is a disadvantage that it takes a huge amount of work time to create all the surface loops.

Further, the correction work is often performed by the judgment of the operator, and there is a problem that the accuracy of the generated three-dimensional model and the time required for the work differ depending on the degree of experience of the operator in charge.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and a three-dimensional model in which a shape surface is set from a rough wire frame model created with priority on design. Is to provide a method of creating a three-dimensional model that can easily obtain a three-dimensional model.

[0010]

According to the present invention, there is provided a CAD system comprising:
Wireframe Set shaped surface against a closed loop that is created from the model that provides a method of making a three-dimensional model to obtain a three-dimensional model, in the end points of the edge line constituting the rough wire frame model, other ridge or Have an intersection with another endpoint
A first step of extracting Tanai endpoints, and the extracted end point, a second step of determining whether or not within the allowable values away distance between the end points of the edge line or near the vicinity preset , Determined in the second step to be within the allowable value
Is closed, the distance between the end points is automatically corrected and the closed loop
Created the data of the group and determined that it was not within the allowable value
In this case, a third step of notifying the abnormality, Yu
Characterized in that it.

[0011]

In the method for creating a three-dimensional model according to the present invention, the distance between the end points of each ridge forming the wire frame model is calculated based on the distance between the end points.
The defective point at the end point is extracted, and it is determined whether or not the distance between the end points of the defective point is within a predetermined allowable value. If the determination result is not within the allowable value, the defective point is corrected.

Next, data of a plurality of closed loops surrounded by the respective edges forming the corrected wireframe model is created, and a predetermined shape surface is set for the data of the closed loops.

Therefore, every time a closed loop is designated, it is not necessary to correct the defect at the end point of the ridge line constituting the closed loop, and after correcting the defective point at the end point, a plurality of closed loop data can be created at once. The working time for creating closed loop data from a rough wireframe model can be reduced.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, a preferred embodiment of a method for creating a three-dimensional model according to the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 shows a CAD system 1 embodying the present invention.
FIG. 3 is a block diagram showing a configuration of a 0. CAD system 10
Is a controller 12 having a central processing unit for performing graphic calculation, display control, database management, etc., and a large-capacity storage device 14 capable of storing and updating a large amount of graphic information.
And a graphic-compatible display device 16 which is a central device for the interaction between the CAD system 10 and the operator.
And a keyboard 18 as an input device and a tablet 2
0, a mouse 22, a light pen 24, a floppy disk driver (hereinafter referred to as FDD) 26, and an XY plotter 28 as a graphic output device.

The controller 12 of the CAD system 10 has many programs as shown in FIG. Each program can be classified into the following modules according to the functions to be shared. (a) An operating system 30 and a control module 32 for controlling the processing of the controller 12 and the flow of information. (b) An input module 34 that assists various input devices, for example, an input operation corresponding to the keyboard 18 to be performed smoothly. (c) An input interpretation module 36 that interprets the input information according to the format of the command instruction. (d) A display module 38 that manages display information and performs display processing according to commands. (e) A command module 40 for performing graphic processing according to a command composed of sub-modules corresponding to the instruction. (f) CAD system 10 held in database 42
A database operation module 44 for efficiently searching and storing a large amount of information necessary for the operation. (g) A macro module 48 for executing a macro program 46 which is an automatic design program. (h) An external system interface 50 for exchanging information with other CAD systems and performing interlocking processing.

Further, in order to maintain expandability and maintainability, the controller 12 has a system control file 52 for storing the configuration and standard values of the CAD system 10, and a command control for storing operability of each command and a program control procedure. Auxiliary files such as a file 54 and a display control file 56 for storing the model and configuration of the display device are prepared. In addition, as other auxiliary components, a graphic processing library 58 for processing graphics, a display device 16
Display library 60 for displaying on the display
Release utility 6 for outputting to Y plotter 28
2. A program such as a data exchange utility 64 for coupling with another CAD system is provided.

Next, each module will be briefly described. The control module 32 integrates programs into modules and intervenes between the modules to centrally manage the control in the system and standardize the calling procedure.
The functions include start, end, abnormal processing, execution control of each module, recording of execution history, debugging function, special processing with the operating system 30, and the like.

The input module 34 provides the operator with a comfortable input procedure in accordance with a specification that unifies various input methods of various input devices. Its functions are to prompt the operator for the type of information to be input, the input method and the input device, select the input device, and convert the input information to a standard type.

The input interpretation module 36 unifies the input information interpretation method and the result display, thereby supporting various input instruction methods, improving input operability, and maintaining the expandability of the system. Its function is to interpret the input information and display the interpretation result.

The display module 38 uniformly processes various display operation requests and manages display information and display states. The function manages the display device, controls the display, manages the display information, and manages the display state.

The command module 40 centrally manages the format of input arguments, the calling of a processing program according to the command, and the processing method of the result, and maintains the maintainability and expandability of the system.

The database operation module 44 standardizes a request method from another module and provides recovery means when a failure occurs. The functions include management of database usage, operation of the database 42, processing when a failure occurs, and the like.

The external system interface 50 standardizes information exchange with other systems, and makes effective use of the CAD system 10. Its function is to exchange information with external systems and to control the operation of external programs.

The macro module 48 controls the execution of the CAD system 10 according to the created macro program 46. Its functions are translation of the macro program 46 and execution of the macro program 46.

The operation of generating a three-dimensional surface model from a rough wireframe model created from a mockup model by the CAD system 10 having the above-described program will be described with reference to FIGS. .

First, CAD data of a rough wire frame model created according to the mock-up model is
The data is input from the DD 26 and read by the controller 12 (step S1).

The CAD data is converted by the display module 38 and the display library 60 by the controller 12 and displayed on the display device 16 (see FIG. 4) (step S2).

Next, the controller 12 automatically inserts the minimum necessary auxiliary lines for creating a surface into the rough wire frame model displayed on the display device 16, and also inserts other ridge lines or other auxiliary lines. It is determined whether or not there is an end point a having no intersection with the end point (step S).
3), an end point a having no intersection with another ridge line or another end point
Is found, the distance d ₁ between the end point a and the nearby ridgeline or end point is obtained by calculation, and the distance d
₁ determines whether within the tolerance d ₀ set in advance (step S4).

If the separation distance d ₁ is within the allowable value d ₀ ,
The controller 12 performs an automatic correction for automatically relating the end point a to a nearby ridge line or end point (step S).
5) If the separation distance d ₁ is not within the allowable value d ₀ , the controller 12 determines that there is an abnormality, and
An abnormality is displayed at the end point a displayed in (step S6).

The operator operates the displayed abnormal part (FIG. 5 *).
(See mark), the end point a is corrected by manual operation in consultation with the designer and the designer of the rough wireframe model (step S7).

The operation of correcting the end point a by the operator will be described with reference to FIGS.

FIG. 6 is an enlarged explanatory view of the portion A shown in FIG. In FIG. 6, the end point a is separated from the link point b. Then, the operator selects the end point a and the link point b using the mouse 22, and further inputs an instruction to execute a correction from the keyboard 18, whereby the end point a is linked to the link point b. Thus, the ridge line c (d-a) is modified to ridge c ₁ (d-b).

When it is determined that the ridge line f having the end point e shown in FIG. 5 is excessive, it is deleted by the operator.

In this manner, data of each surface loop is created (see FIG. 8) from the completed secondary wire frame model after the end point mismatch is corrected and unnecessary edges are deleted (see FIG. 8). (Step S8) The respective surface loops are associated and stored in the mass storage device 14.

Next, three-dimensional data of each surface is created from the data of each surface loop, that is, so-called surface covering is performed (step S9). The three-dimensional data of the surface obtained by this surface setting is stored in the large-capacity storage device 14 as basic data when manufacturing a press die or the like.

As described above, according to this embodiment,
At the end points of all the ridge lines constituting the rough wireframe model displayed on the display device 16, it is searched whether or not there is an end point having no intersection with another ridge line or another end point. If it is found, and this end point, or to automatically correct the distance d ₁ between the edge line or end point in the vicinity, or by displaying the anomaly,
In order to prompt the operator to make a correction, a rough wireframe model can be easily corrected in a short time.

[0038]

According to the method of creating a three-dimensional model according to the present invention, it is not necessary to correct a defect at an end point of a ridge forming the closed loop every time a closed loop is designated. Since it is possible to create multiple closed-loop data at a time, it is possible to reduce the time required to create closed-loop data from a rough wireframe model,
This brings about an effect that it is possible to reduce the total work time from creation of a rough wire frame model to creation of a three-dimensional model of a surface.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a CAD system that implements the present invention.

FIG. 2 is a diagram illustrating a program module included in a controller in the embodiment shown in FIG.

FIG. 3 is a flowchart illustrating a method of creating a three-dimensional model of each surface from a rough wireframe model in the embodiment shown in FIG.

FIG. 4 is a diagram illustrating a rough wireframe model displayed on a display device in the embodiment shown in FIG. 1;

FIG. 5 is a diagram for explaining a method of displaying an abnormal portion of a rough wireframe model on a display device in the embodiment shown in FIG. 1;

6 is a diagram illustrating an operation of correcting an abnormal portion of the rough wire frame model shown in FIG.

FIG. 7 is a diagram showing a modified wireframe model in the embodiment shown in FIG. 1;

8 is a diagram illustrating each surface loop created from the wire frame model shown in FIG. 7;

[Explanation of symbols]

 Reference Signs List 10 CAD system 12 Controller 14 Mass storage device 16 Display device 18 Keyboard 22 Mouse 26 Floppy disk driver (FDD)

──────────────────────────────────────────────────続 き Continuing the front page (72) Inventor Ayumu Nakajima 1-10-1 Shinsayama, Sayama City, Saitama Prefecture Honda Engineering Co., Ltd. (72) Inventor Masaki Tokai 1-10-1 Shinsayama, Sayama City, Saitama Honda Engineering Inside (72) Inventor Hiroshi Sekine 1-10-1 Shinsayama, Sayama City, Saitama Prefecture Inside Honda Engineering Co., Ltd. (56) References JP-A-60-55483 (JP, A) JP-A-4-153886 (JP) (A) JP-A-3-105676 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) G06T 17/00 JICST file (JOIS)

Claims (1)

(57) [Claims] In 1. A CAD system, set the shaped surface against a closed loop that is created from the word <br/> ear frame model is CAD data, a method of making a three-dimensional model to obtain a three-dimensional model, rough The end point of each ridge line that composes the wireframe model
A first step of extracting an end point that does not have an intersection with another ridge line or another end point; and between the extracted end point and a nearby ridge line or a nearby end point.
If the release distance is determined in advance and a second step of determining whether or not within the tolerance which is set, to be within the allowable value in the second step of
In this case, the end points are automatically corrected to
Data is created, and if it is determined that the
Comprises a third step of notifying the user of an abnormal condition .