JP2003196320A - Data conversion method for cad (computer aided design), program and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable conversion of history type data into non-history type data requiring only a small amount of data while making use of operation easiness of history type data. <P>SOLUTION: The history type data in which a model is expressed by feature information indicating the geometrical shape and its components is converted into the non-history type data in which the model is expressed in the geometrical shape. In the conversion of the history type data into the non-history type data, pieces of attribute information indicating correspondence to the components are extracted from the feature information and added for each element shape constituting the geometrical shape of the model. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is for CAD for converting a history type data in which a three-dimensional model or the like is expressed by a geometric shape and feature information indicating its constituent parts into a non-history type data in which the model is expressed only by the geometric shape. The present invention relates to a data conversion method, a program, and a recording medium, and particularly to a CAD data conversion method, a program, and a recording medium that can process non-history type data in feature units at the time of editing.

[0002]

2. Description of the Related Art A conventional three-dimensional CAD system manages history-type data in which a three-dimensional model is represented by geometric shape and feature information indicating its constituent parts.
It is roughly divided into a system and a non-history type CAD system that manages non-history type data in which a three-dimensional model is expressed only by geometric shapes.

Further, the conventional history type CAD system is
In order to reduce the weight of data, it is often equipped with a function that deletes information related to features from history type data and converts it to non-history type data of only geometric shapes.

[0004]

However, since the history type data has the information such as the geometrical shape of the component, the dimensional constraint, the cross section, the parent-child relationship, the type, the name, the element ID, and the group ID for each feature, Although it has the advantage of being easy to edit, it also has the disadvantage of enormous data volume.

On the other hand, the non-history type data requires only a small amount of data because it is only a geometrical shape, but when editing, for example, if one hole is to be deleted,
The work becomes complicated, for example, the editing operator must determine which surface constitutes the hole and give a deletion instruction for each surface.

Therefore, in order to reduce the weight of data in the conventional history type CAD system, history type data is converted into non-history type data, but after the conversion, the shape of the model is edited by moving or deleting faces. In order to process several shapes collectively, it is necessary to make geometric data into a feature by a feature recognition technique or to make a group by a plurality of operations by a user to process.

For example, in the case of non-history type data,
Even if you want to delete one hole from the model, the editing operator must determine which surface constitutes the hole and issue a deletion instruction for each surface. Will end up.

It is an object of the present invention to provide a CAD data conversion method, a program and a recording medium which make it possible to convert history type data into non-history type data which requires a small amount of data while making the operation easy. And

[0009]

SUMMARY OF THE INVENTION The present invention is a CAD data conversion for converting from history type data in which a model is represented by geometrical shape and feature information indicating its constituent parts into non-history type data in which the model is represented by geometrical shape. The method is characterized in that, when converting into non-history type data, attribute information indicating a correspondence with a component is extracted from feature information and added for each element shape forming the geometric shape of the model. To do.

Therefore, according to the non-history type data obtained by the data conversion of the present invention, the components that the history type data has as the feature information are included for each geometric element such as a surface or a ridge line that constitutes the geometrical shape of the model. Since it has attribute information indicating correspondence, using this attribute information, the parts corresponding to the "holes" and "projections" that are the component parts of the model are searched from the entire model and collectively processed in feature units. Work becomes possible.

Here, the element shape forming the geometrical shape of the model includes faces, ridgelines and vertices. For each of the faces, ridgelines and vertices, attribute information indicating a correspondence with a component is extracted from the feature information. Add. Further, as the attribute information, it is also possible to extract a plurality of different attribute information indicating the correspondence with the constituent parts from the feature information and add them hierarchically. The attribute information to be added is, for example, information indicating the type and / or group of component parts.

The present invention provides a CAD program for converting history type data into non-history type data. This program inputs into the computer the history type data that represents the model with geometric information and the feature information indicating the constituent parts of the model, and the component information from the feature information for each element shape that constitutes the geometric shape of the model. A step of extracting and adding attribute information indicating a correspondence with, and a step of generating non-history type data by deleting all other information except the geometric shape of the history type data and the added attribute information. It is characterized by being executed.

The present invention provides a computer-readable recording medium storing a CAD program for converting history type data into non-history type data. The program stored in this recording medium includes a step of inputting to a computer history-type data representing a model with a geometric shape and feature information indicating its constituent parts, and for each element shape forming the geometric shape of the model. , A step of extracting attribute information indicating correspondence with a component from feature information and adding it, and deleting all other information except the geometric shape of the history type data and the added attribute information The step of generating and the step of generating are performed.

Other features of the program and the recording medium are basically the same as those of the data conversion method.

[0015]

1 is a block diagram of a functional configuration of a history type CAD system to which a CAD data conversion method according to the present invention is applied.

In FIG. 1, a history CAD system 10 includes a database 12, a shape creating section 14 functioning as a modeler, an element managing section 16 for managing ridge lines, faces, vertices, etc., which are element shapes constituting a geometric shape, and dimensions. A constraint management unit 18 that manages the constraint, a feature management unit 20 that manages the components of the three-dimensional model as feature information,
The database control unit 22 and the display unit 24 are provided.

The history type CAD system 10 stores the three-dimensional model created by the shape creating section 14 in the database 12 as history type data 26.

In addition to this, in the present invention, the data conversion unit 30 is provided in the history type CAD system 10.
The data conversion unit 30 converts the history-type data 26 of the created three-dimensional model stored in the database 12 into the non-history-type data 28.

Here, the history type data 26 is data in which a three-dimensional model is represented by a geometric shape and feature information indicating its constituent parts. On the other hand, the non-history type data 28 is the data in which the three-dimensional model is expressed only by the geometrical shape. In the present invention, when the data type converting unit 30 converts the history type data 26 into the non-history type data 28. To the ridges that make up the geometrical shape of the 3D model,
The feature is that attribute information indicating correspondence with a component is extracted from feature information for each element shape such as a face and a vertex and added.

FIG. 2 shows an example of a three-dimensional model composed of the history type data 26 of the database 12 created by the history type CAD system 10 of FIG. Figure 2
In the above, the three-dimensional model 32 has a structure in which two small holes 36-1 and 36-2 having a rectangular cross section are penetrated from the front of the rectangular parallelepiped 34.

Such a three-dimensional model 32 is created from the three components shown in FIG. The three components in FIG. 3 are a rectangular parallelepiped 34 and holes 36-1 and 36-2. The history type data 26 stored in the database 12 of FIG. 1 includes, in addition to the geometrical shape of the three-dimensional model 32 of FIG. 2, a rectangular parallelepiped 34 and holes 36-1 and 36, which are components of the three-dimensional model 32 of FIG. It is composed of feature information representing -2.

FIG. 4 is an explanatory diagram of the history type data 26 corresponding to the three-dimensional model 32 of FIG. This history type data 26, as shown by extracting the format of the basic structure on the upper side, shows the geometrical shape 38 of the three-dimensional model 32 in FIG. 2, the entire part management information 40 in FIG.
In the rectangular parallelepiped 34, the feature 01 information 42-1 and the feature 02 information 42 corresponding to the holes 36-1 and 36-2.
-2, feature 03 information 42-3.

The geometrical shape 38 of the three-dimensional model 32 is extracted below to show the details of the geometrical data structure 45.
Is equipped with. The geometrical data structure 45 includes the element shapes “edge-1” to “edge-M” of the surfaces indicated by “Face-1” to “Face-L” in the three-dimensional model 32.
The element shape of the ridge shown by, and further "Vertex-1" ~
It is configured by the element shape of the apex indicated by "Vertex-N".

For example, the surface element shapes "Face-1 to L"
Corresponds to the surface defined for the rectangular parallelepiped 34 and the holes 36-1 and 36-2 as shown in FIG. Also, geometric data structure 4
Each element shape in 5 has a geometric data structure 44 which is extracted and shown on the left side of the first "Face-1".

This geometric data structure 44 has coordinates (x, y, z) of a reference point in the surface element shape "Face-1".
And the vertices that make up the surface and their coordinate values. Further, the geometric data structure 44 has the element shapes “edge-1 to
"M" may be the coordinates of the end points of the ridge. Further, regarding the vertex element shapes “Vertex-1 to N”, vertex coordinates may be used.

The next part overall management information 40 is composed of an in-part feature management structure 46 as shown in the lower side. The in-part feature management structure 46 includes the total number of features, the total number of feature types, and the total number of feature groups.

In the case of the constituent parts shown in FIG. 3, the total number of features is "3", and the total number of feature types is "2" because of the rectangular parallelepiped and the hole, and the total number of feature groups is, for example, each part. If a component group is configured for each configuration, the value is “3”.

Feature 0 corresponding to the rectangular parallelepiped 34 of FIG.
The 1 information 42-1 is composed of a feature structure 48-1 as shown on the lower side. This feature structure 48-1 includes geometric shapes, dimensional constraints, cross sections, parent-child relationships,
It is composed of a type, a name, an element ID, and a group ID.

In the case of the feature 01 information 42-1, the geometrical shape is the geometrical information of the rectangular parallelepiped 34 in FIG. 3, and the content thereof is the same as the geometrical data structure 45 extracted below for the geometrical shape 38 of the three-dimensional model 32. Is.

Dimensional constraints are the vertical X, horizontal Y, and
The depth Z is set. The cross section is rectangular in this case. In the parent-child relationship, in the case of FIG. 3, since the rectangular parallelepiped 34 is the parent and the holes 36-1 and 36-2 are the children, the element ID “ID0 of the holes 36-1 and 36-2 that are the children is”.
02, ID003 ”is stored.

The next type is that the rectangular parallelepiped 34 of FIG. 3 is constructed by sweeping out a rectangular cross section,
“Type 1” indicating “sweep” is used. The names are given in order for the components of FIG. 3, and the rectangular parallelepiped 34 is, for example, “01”. The element ID is, for example, “ID001” and is used for setting the parent-child relationship.
The group ID is “GP001”, for example.

Subsequently, the feature 02 information 42-2 is shown in FIG.
Hole 36-1 of FIG. 3 and has a feature structure 48-2 shown in the lower right. This feature structure 48-2 also includes geometric shapes, dimensional constraints, cross sections, parent-child relationships,
It is composed of a type, a name, an element ID, and a group ID.

Among these, the parent-child relationship stores the element ID “ID001” of the parent because the rectangular parallelepiped 34 becomes the parent. Since the type is a hole, "Type2" indicating this is stored. Further, the name is “02”, the element ID is “ID002”, and the group ID is “GP002”.

The feature 03 information 42-3 is the same as the feature 02 information 42-2 having the same hole, and has the name “03”, the element ID “ID003”, and the group ID “GP003”. Is different.

In the data conversion section 30 of FIG.
The history type data 26 as shown in FIG. 4 is input, and the whole part management information 40, the feature 01 information 42-1, the feature 02 information 42-2, and the feature 03 information 42 that constitute the feature information other than the geometric shape 38 in FIG. -3
From the feature information, the attribute information indicating the correspondence with the constituent parts is extracted from the feature information and added to each element shape of the surface, the ridgeline, and the vertex in the geometric shape 38, and then the whole part management information 40, which is the feature information, The feature 01 information 42-1, the feature 02 information 42-2, and the feature 03 information 42-3 are deleted, and the non-history type data 28 of FIG. 1 is generated.

FIG. 5 is an explanatory diagram of the data conversion processing according to the present invention for generating the non-history type data 28 from the history type data 26 of FIG.

In FIG. 4, the geometrical shape 3 of the three-dimensional model
8 has a geometrical data structure 45 which is taken out and shown on the lower side, and this geometrical data structure 45 is composed of element shapes of faces, edges and vertices.

Therefore, the element shapes in this geometrical data structure 45, that is, the surface element shapes "Face-1 to L", the ridge element shapes "edge-1 to M", and the vertex element shape "Ve".
For each of the “rtex-1 to N”, the attribute information indicating the correspondence with the component is extracted from the subsequent feature information.

In this embodiment, attribute information about the surface element shapes “Face-7” and “Face-8” forming the hole 36-1 in FIG. 3 in the geometrical data structure 45 is extracted. Take the example of addition by. That is, the face “Face-7” in the hole 36-1 is stored data “Type 50” of type 50 from the feature structure 48-2.
“E2” is extracted and added, and “GP002” is further extracted and added from the group ID 52.

Also for the next surface element shape "Face-8", the "Type" corresponding to the type 50 and the group ID 52 is selected from the feature structure 48-2 of the same hole 36-1.
2 ”and“ GP002 ”are extracted and added. Regarding the element shapes in the remaining geometrical data structure 45, the corresponding type 50 and group I are similarly obtained from the feature information.
Each data of D52 is extracted and added.

If the attribute data structure 54 including the attribute information extracted from the feature information can be created for each element shape in the geometric data structure 45 that constituted the geometric shape 38, the whole part management information 4 in FIG.
0, the feature 01 information 42-1, the feature 02 information 42-2, and the feature 03 information 42-3 are all deleted.

For this reason, the converted non-history type data 28 has a structure in which the attribute data structure 54 extracted and added in FIG. 5 is added to the geometric shape 38, and the data amount is larger than that of the history type data 26 in FIG. Is significantly reduced.

FIG. 6 is a flow chart showing the procedure of data conversion processing by the data conversion unit 30 according to the present invention provided in the history type CAD system 10 of FIG.
This flowchart constitutes a program for data conversion according to the present invention.

Referring to FIG. 6, in the data conversion process, the three-dimensional model for which data conversion is to be performed is selected in step S1, and the history type data 2 of the three-dimensional model selected in step S2.
6 is input from the database 12.

The input of the history type data 26 is not limited to the input from the database 12, and for example, the history type data of another history type CAD system may be input by transfer, or the portable type such as a CD-ROM. It may be read from a recording medium.

Next, in step S3, as shown in FIG. 5, for each element shape such as a surface, a ridge, and a vertex forming a geometric shape, attribute information indicating a correspondence relationship from the feature information to the constituent parts is obtained. Is extracted and added. One piece of attribute information may be extracted from this feature information, or two kinds of attribute information may be extracted and hierarchically added as shown in FIG.

Subsequently, in step S4, non-history type data 28 is generated by deleting information other than the geometric information and the added attribute information from the history type data 26.
Then, in step S5, the generated non-history type data 28 is stored in the database 12.

FIG. 7 shows an example of editing processing using the non-history type data 28 with attribute information of the present invention created by the processing procedure of FIG. In FIG. 7, the three-dimensional model 32 has two holes 36-1 and 36-2,
For example, one hole 3 using the non-history type data 28
Consider the case where 6-1 is deleted.

Regarding the deletion of the hole 36-1, the hole 36-1 is selected from the attribute information added to the element shapes of the faces, edges and vertices constituting the hole 36-1 of the non-history type data 28. When the deletion is designated using the identifiable group ID “GP002”, the surface element shape “Face-7 to 10” is targeted for deletion as shown on the right side.
Is selected and this is deleted so that holes 36-
1 can be deleted.

On the other hand, if a similar operation is to be performed on root non-history type data, "Face 7 to 10"
Must be specified and then deleted.

When it is desired to delete both the holes 36-1 and 36-2, the attribute indicating that the component is a hole is included from the attribute information added to the element shapes of the face, the ridge and the vertex. The holes 36-1 and 36-2 can be collectively deleted by selecting the information "Type 2" and instructing the deletion.

Next, an embodiment of a computer-readable recording medium storing the data conversion program according to the present invention will be described. A history CAD system to which the data conversion program of the present invention is applied is installed in a computer, and the computer has a CPU, a RAM, and an R.
It is equipped with OM, hard disk drive HDD, CD-ROM drive, FD drive, keyboard, mouse, display, LAN interface, modem and the like.

The program for data conversion of the present invention is a CD-ROM, a floppy disk (R), a DV.
It is stored in a portable recording medium such as a D disc, an optical disc, an IC card, a database connected through a line using a modem and a LAN interface, or a database of another computer system, and is executed after being installed in a computer. .

Therefore, as a recording medium for storing the program of the present invention, a portable recording medium such as a CD-ROM, a floppy disk (R), a DVD disk, an optical disk, an IC card, or the like is provided inside or outside the computer. In addition to a storage device such as a hard disk, a database that holds a program via a line, another computer system and its database, and a transmission medium on the line are also included.

Although the above embodiment has been described by taking the three-dimensional model as an example, it is needless to say that the two-dimensional model may be used.

Further, the history type data to be converted in the present invention is not limited to the data structure of the above-mentioned embodiment, and any appropriate data structure may be used as long as it includes the geometrical shape of the model and the feature information about its constituent parts. The conversion to the non-history type data of the present invention can be applied to the target.

Further, the present invention includes appropriate modifications that do not impair the objects and advantages thereof, and is not limited by the numerical values shown in the above embodiments.

(Supplementary Note) (Supplementary Note 1) CA for converting a model from history type data represented by a geometric shape and feature information indicating its constituent parts into non-history type data representing the model by a geometric shape.
In the data conversion method for D, when converting to the non-history type data, attribute information indicating a correspondence with a component is extracted from the feature information for each element shape forming the geometric shape of the model. A data conversion method for CAD, characterized in that (1)

(Supplementary Note 2) In the CAD data conversion method according to Supplementary Note 1, the element shapes forming the geometrical shape of the model include faces, ridgelines and vertices. A CAD data conversion method, characterized in that attribute information indicating a correspondence with a component is extracted from the feature information and added. (2)

(Supplementary note 3) In the CAD data conversion method according to supplementary note 1 or 2, as the attribute information, a plurality of different attribute information indicating the correspondence with the component parts is extracted from the feature information and hierarchically extracted. A data conversion method for CAD, characterized in that (3)

(Supplementary Note 4) In the CAD data conversion method according to any one of Supplementary Notes 1 to 3, the attribute information is
A CAD data conversion method, which is information indicating the type and / or group of the component parts.

(Supplementary Note 5) A step of inputting history type data in which a model is represented by feature information indicating a geometrical shape and its constituent parts to a computer, and the feature for each element shape constituting the geometrical shape of the model is added. Non-history data is generated by extracting attribute information indicating correspondence with components from information and adding it, and deleting all other information except the geometric shape of the history data and the added attribute information. A program characterized by causing the steps of: (4)

(Supplementary Note 6) In the program according to Supplementary Note 5, the element shapes forming the geometrical shape of the model are:
A program including a face, a ridge, and a vertex, wherein attribute information indicating a correspondence with a component is extracted from the feature information and added to each of the face, the ridge, and the vertex.

(Supplementary note 7) In the program according to supplementary note 5 or 6, as the attribute information, a plurality of different attribute information indicating the correspondence with the component parts is extracted from the feature information and hierarchically added. A program characterized by.

(Supplementary Note 8) In the program according to any one of Supplementary Notes 5 to 7, the attribute information is information indicating the type and / or group of the constituent parts.

(Supplementary note 9) A step of inputting history type data in which a model is represented by feature information indicating a geometric shape and its constituent parts to a computer, and the feature for each element shape constituting the geometric shape of the model is added. Non-history data is generated by extracting attribute information indicating correspondence with components from information and adding it, and deleting all other information except the geometric shape of the history data and the added attribute information. And a computer-readable recording medium that stores a program for executing the steps. (5)

[0067]

As described above, according to the present invention, when converting from history-type data to non-history-type data, each element shape such as a surface, a ridge line, and a vertex forming a geometric shape is converted. , Since the feature information is deleted after the attribute information indicating the correspondence with the component parts is extracted from the feature information and added, even after the conversion to non-history type data, the component unit editing is added. Non-history type data that can be edited in large units such as holes and protrusions using the existing attribute information, and can be used with the ease of operation in editing that history type data has, while the amount of data is small. Can be obtained.

[Brief description of drawings]

FIG. 1 is a block diagram of a mechanical configuration of a CAD system to which the present invention is applied.

FIG. 2 is an explanatory diagram of a three-dimensional model which is a target of data conversion in the present invention.

FIG. 3 is an explanatory diagram of components that generate the three-dimensional model of FIG.

FIG. 4 is an explanatory diagram of history type data for generating the three-dimensional model of FIG.

5 is an explanatory diagram of a non-history type data generation process by the data conversion of the present invention for the history type data of FIG.

FIG. 6 is a flowchart showing a procedure of data conversion processing according to the present invention.

FIG. 7 is an explanatory diagram of an editing process using attribute information of non-history type data obtained by the present invention.

[Explanation of symbols]

10: History type CAD system 12: Database 14: Shape creation department (modeler) 16: Element management section 18: Restraint management department 20: Feature management department 22: Database control unit 24: Display 26: History type data 28: Non-history type data 30: Data converter 32: Three-dimensional model 34: rectangular parallelepiped 36-1, 36-2: holes 38: Geometric shape 40: Management information for all parts 42-1 to 42-3: Feature 01 to 03 information 44: Geometric data structure 45: Geometric data structure 46: In-part feature management structure 48-1, 48-2: Feature structure 50: Type 52: Group ID 54: Attribute data structure

Claims (5)

[Claims] 1. A method for converting a model from history type data represented by a geometrical shape and feature information indicating its constituent parts into non-history type data represented by a geometrical shape.
In the AD data conversion method, when converting to the non-history type data, attribute information indicating a correspondence with a component is extracted from the feature information for each element shape forming the geometric shape of the model. A data conversion method for CAD, characterized in that 2. The CAD data conversion method according to claim 1, wherein the element shape forming the geometrical shape of the model includes a face, a ridgeline, and a vertex, and the face, the ridgeline, and the apex of each of the elements. CAD characterized by extracting and adding attribute information indicating correspondence with constituent parts from feature information
Data conversion method. 3. The CAD data conversion method according to claim 1, wherein, as the attribute information, a plurality of different attribute information indicating a correspondence with the component is extracted from the feature information and hierarchically. CAD characterized by adding
Data conversion method. 4. A step of inputting to a computer history type data in which a model is expressed by feature information indicating a geometric shape and its constituent parts, and from each of the feature information for each element shape forming the geometric shape of the model, A step of extracting and adding attribute information indicating correspondence with a component, and a step of generating non-history type data by deleting all other information except the geometrical shape of the history type data and the added attribute information A program characterized by causing and to be executed. 5. A step of inputting to a computer history type data in which a model is represented by feature information indicating a geometric shape and its constituent parts, and from each of the feature information for each element shape forming the geometric shape of the model, A step of extracting and adding attribute information indicating correspondence with a component, and a step of generating non-history type data by deleting all other information except the geometrical shape of the history type data and the added attribute information And a computer-readable recording medium that stores a program for executing the following.