JP2001357084A - Device and method for optimizing voxel dividing coordinates, and computer-readable storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a high-accuracy analysis by reducing the difference be tween form data provided by voxel division and form data prepared by CAD or the like concerning a device and a method for optimizing voxel dividing coordinates for determining an optimal coordinate axis to the form data when dividing the form data prepared by CAD or the like into voxels. SOLUTION: This device is provided with a geographical information extracting means 2 for extracting the geographical information of the form data prepared by CAD or the like, a first vector extracting means 3 for extracting a first vector specifying the direction of a first surface selected on the basis of the geographical information, a second vector extracting means 4 for extracting a second vector specifying the direction of a second surface selected out of surfaces different from the first surface, and a voxel dividing means 5 for determining the coordinate axis to be uniquely determined with respect to the form data on the basis of the first and second vectors and dividing the form data into voxels with this coordinate axis as a reference.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a voxel.
) Using three-dimensional pixels called CAD (computer-
voxel division coordinate optimization apparatus for determining the optimal coordinate axis for this shape data when performing analysis by dividing arbitrary three-dimensional shape data created by aided design or the like, voxel The present invention relates to a divided coordinate optimization method and a computer-readable storage medium.

[0002] In general, a voxel is an object to be analyzed.
It is defined as a small cube volume element used to divide the dimensional shape data into a grid (called voxel division). According to the present invention, the shape data obtained by voxel division (hereinafter, abbreviated as “shape data after voxel division” as necessary) and the original shape data created by CAD (hereinafter, “CAD shape data"
This method refers to one method for obtaining relatively accurate analysis results by minimizing the difference from the above.

[0003]

2. Description of the Related Art When a general computer system is used to perform a voxel division of three-dimensional CAD shape data created by CAD and analyze the shape data,
A voxel set based on a three-dimensional coordinate axis including an X coordinate, a Y coordinate, and a Z coordinate is used.

FIG. 8 is a diagram showing a state in which shape data is divided into voxels by a conventional method. However, here, only a plane defined by the X coordinate and the Y coordinate in the three-dimensional coordinate axes is shown. Further, here, using voxels V each represented by a mesh having the same shape, three-dimensional CAD shape data C having a square plane is used.
It is assumed that one voxel division is performed.

In the conventional method shown in FIG. 8, the direction of voxel division is determined on the basis of a coordinate axis at the time of generating CAD shape data, and the voxel V set according to the voxel division direction is used to generate CAD shape data. Voxel division was performed. More specifically, according to the conventional method, even when the straight line edge of the square plane of the CAD shape data C1 is oblique to the X coordinate and the Y coordinate (shown by a solid line in FIG. 8A). The voxel V is set based on the X coordinate and the Y coordinate, and the voxel V is used to obtain shape data D after voxel division (in FIG. 8 (b), a solid line is used). Shown). As a result, as is apparent from FIG. 8B, the shape data obtained by the voxel division has a larger edge than the original CAD shape data (shown by a thick broken line in FIG. 8B). The jagged portions are larger.

[0006]

SUMMARY OF THE INVENTION As described above, CAD
In the case of performing voxel division of CAD shape data created by the above, conventionally, voxels set based on coordinate axes at the time of creating CAD shape data have been used. Therefore, C
Depending on the relationship between the shape of the AD shape data and the coordinate axes, the difference between the shape data obtained by voxel division and the original shape data created by CAD increases, and the analysis result of the shape data becomes inaccurate. Problems arise.

[0007] The present invention has been made in view of the above-mentioned problems, and has the following features: shape data obtained by voxel division;
A voxel division coordinate optimization device, a voxel division coordinate optimization method, and a voxel division coordinate optimization method capable of executing shape data analysis with high accuracy by minimizing the difference from the original shape data created by CAD or the like. It is an object of the present invention to provide a computer-readable storage medium.

[0008]

FIG. 1 is a block diagram showing the principle configuration of the present invention. However, here, the configuration of the voxel division coordinate optimizing device of the present invention is simplified and shown. In order to solve the above problems, the voxel division coordinate optimizing device 1 of the present invention, as shown in FIG. 1, uses a voxel-based geometrical analysis of an arbitrary three-dimensional shape data to be analyzed. There is provided geometric information extracting means 2 for extracting scientific information (geometry information). More specifically, the geometric information extracting means 2 is configured to output geometric information (for example, a shape having a plane, a cylindrical surface, or a curved surface) which is a feature of the shape data such as CAD shape data held by the shape data reading means 6. Data).

Further, the voxel-divided coordinate optimizing device 1 shown in FIG.
A first vector extracting means 3 for extracting a first vector for specifying the direction of the surface, and a second vector for specifying the direction of a second surface selected from the surfaces different from the first surface. Second vector extracting means 4 for extracting a vector.

Further, the voxel division coordinate optimizing device 1 shown in FIG. 1 includes a first vector extracted from the first vector extracting unit 3 and a second vector extracted from the second vector extracting unit 4. And voxel dividing means 5 for determining a coordinate axis (that is, a direction of voxel division) uniquely determined with respect to the shape data based on the vector. In the voxel dividing means 5, the voxel divides the shape data into voxels based on the coordinate axes determined as described above, and outputs the shape data after the voxel division.

Preferably, in the voxel division coordinate optimizing apparatus of the present invention, the first vector extracting means 2 comprises:
The direction vector that specifies the direction of the plane with the largest area is
The first vector is extracted as the first vector, and the second vector extracting means 3 is a direction vector that specifies the direction of the plane having the largest area among the planes other than the plane from which the first vector is extracted. Then, a direction vector orthogonal to the first vector is extracted as the second vector.

Further, preferably, in the voxel division coordinate optimizing apparatus of the present invention, when the first surface selected based on the geometric information is a curved surface,
Vector extraction means extracts a plurality of direction vectors respectively specifying the directions of the plurality of surface elements constituting the curved surface, and for each direction vector having a common direction, calculates the area of the surface element corresponding to the direction vector. The direction vector in which the area of the surface element obtained as a result of such addition is maximized is extracted as the first vector.

The geometric information extracting means 2, first vector extracting means 3, second vector extracting means 4, and voxel dividing means 5 are preferably realized by software of a computer as described later. With this software, features of shape data such as CAD shape data are extracted in the computer system, and a coordinate axis uniquely determined based on the extraction result is determined as an optimal coordinate axis for voxel division.

In summary, according to the present invention, geometric information which is a feature of the original shape data created by CAD or the like is extracted, and based on the geometric information, an optimal coordinate axis for performing voxel division is automatically determined. Can be determined
The difference between the shape data obtained by voxel division and the original shape data created by CAD is relatively small, and the shape data can be analyzed with high accuracy.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The construction and operation of a preferred embodiment of the present invention will be described below with reference to the accompanying drawings (FIGS. 2 to 7). FIG. 2 is a block diagram showing a configuration of an embodiment according to the voxel division coordinate optimizing device of the present invention. Here, the configuration of the computer system 10 for voxel division coordinate optimization in which the voxel division coordinate optimization device of the present invention is applied to a general computer system is shown as a representative. Hereinafter, the same components as those described above will be denoted by the same reference numerals.

In the computer system 10 for optimizing voxel division coordinates shown in FIG. 2, the geometric information extracting means 2, first vector extracting means 3, second vector extracting means 4 and voxel dividing means 5 shown in FIG. Is realized by a CPU (Central Processing Unit) 7 of a computer system. In other words, the geometric information extracting means 2, first vector extracting means 3, second vector extracting means 4, and voxel dividing means 5 are realized by software of a computer.

Further, the computer system of FIG.
A program storage unit 20 for storing a program for executing the voxel division coordinate optimization of the present invention is provided. The program storage unit 20 stores a RAM (random acc.
ess memory) or ROM (read-only memory). In addition, as the program storage unit 20, the CP
It is also possible to use a built-in RAM or ROM in U7. Here, the programs stored in the program storage unit 20 are for executing the functions of the geometric information extracting means 2, the first vector extracting means 3, the second vector extracting means 4, and the voxel dividing means 5. It is.

More specifically, the above program is:
Extracting geometric information relating to the geometric shape of the three-dimensional shape data such as CAD shape data; and generating a first vector specifying the direction of the first surface selected based on the geometric information. Extracting; and extracting a second vector specifying a direction of a second surface selected from among surfaces different from the first surface.
Determining a coordinate axis uniquely determined for the shape data based on the second vector and the second vector, and performing voxel division of the shape data by voxels based on the coordinate axis.

Further, the computer system of FIG.
Shape data such as CAD shape data to be analyzed,
A storage unit 70 is provided for storing data such as shape data or boundary conditions such as loads and constraints added to voxels after voxel division of the shape data and analysis results. This storage unit 70 is also constituted by RAM or ROM.

Further, the computer system of FIG.
An OS (operating system) unit 30 for controlling the operation of the CPU 7 is provided. The OS unit 30 has a function of causing the CPU 7 to execute a program stored in the program storage unit 20 and controlling exchange of various data between the storage unit 70 and the CPU 7. The OS unit is
It is realized by software and hardware of a computer.

Further, in the embodiment of the present invention, when the computer system 10 for voxel division coordinate optimization is operated using a computer-readable storage medium,
It is preferable to prepare a storage medium holding the contents of the program as described above, for example, a hard disk H. The hard disk H is driven by a hard disk drive 25. Here, the CAD shape data and the boundary conditions described above can be loaded from the hard disk H.

Further, in the computer system of FIG. 2, a mouse 60 and a keyboard 65 are provided as the shape data reading means 6 of FIG. By operating the mouse 60 or the keyboard 65, original shape data such as CAD shape data to be analyzed, and boundary conditions such as load and constraints added to the shape data or voxels obtained by dividing the shape data into voxels are obtained. Is input and stored in the storage unit 70 (FIG. 2). Note that these shape data and boundary conditions can also be loaded from the hard disk H.

Further, the computer system of FIG. 2 is provided with a display device 40 for displaying original shape data such as CAD shape data and for displaying shape data after voxel division. FIG. 3 is a flowchart for explaining the procedure of voxel division coordinate optimization according to the present invention. Here, a description will be given of a processing flow executed by the CPU 7 of FIG. 2 when determining an optimal coordinate axis for performing voxel division and analyzing CAD shape data based on the coordinate axis.

As shown in the flowchart of FIG. 3, first, when the user operates a mouse, a keyboard, or the like, the original CAD shape data created by the CAD is read and input to the computer system (step). S1). The CAD shape data can be loaded from a hard disk. Next, the CPU in the computer system extracts geometric information (eg, shape data having a plane, a cylindrical surface, or a curved surface) which is a feature of the CAD shape data (step S2).

Further, a CPU in the computer system
Searches for a surface having the maximum area from a plurality of surfaces (surfaces) constituting the CAD shape data (step S).
3). Further, the CPU in the computer system extracts a first vector specifying the direction of the surface from the surface searched as described above (step S4). For example, the direction vector of the straight line edge, the normal vector of the plane, and the direction vector of the center of the cylindrical surface that form the surface having the maximum area are extracted as the first vector.

Further, a CPU in the computer system
Searches for a surface having the maximum area from among the surfaces other than the surface having the maximum area (step S5). Further, the CPU in the computer system extracts a second vector specifying the direction of the surface from the surface searched as described above (step S6). Preferably, the second vector is
The relationship is orthogonal to the first vector.

Further, a CPU in the computer system
Creates a new coordinate axis uniquely determined for the shape data based on the first and second vectors as an optimal coordinate axis for voxel division (step S).
7). For example, when the plane having the largest area is a square, the directions of the two types of linear edges constituting the square plane are automatically determined as the X coordinate and the Y coordinate of the optimal coordinate axes. Note that the remaining Z coordinates of the coordinate axes are uniquely determined as coordinates orthogonal to both the X coordinate and the Y coordinate.

Further, a CPU in the computer system
Executes voxel division of the CAD shape data based on the newly created coordinate axes, and outputs and displays the data after the voxel division (step S8). FIG. 4 is a diagram showing a first specific example of voxel division coordinate optimization according to the present invention. However, here, as in the case of FIG. 8A, a three-dimensional CAD created by CAD is used.
In the shape data, only a square plane defined by the X coordinate and the Y coordinate is shown.

FIG. 4 (a) shows a C created by CAD.
The relationship between the AD shape data C1 and the X coordinate and the Y coordinate at the time of creating the CAD shape data is shown. FIG. 4A is exactly the same as FIG. 8A described above, and a detailed description of FIG. 4A is omitted. On the other hand, FIG. 4B shows the relationship between the shape data when performing voxel division and the X and Y coordinates newly created by the voxel division coordinate optimization method according to the present invention. . In the voxel division coordinate optimization method according to the present invention, as shown in FIG. 4B, instead of the coordinate axes at the time of generating the CAD shape data, the directions of the two types of straight edges in the square plane of the CAD shape data C1 are used. The vector is automatically determined as the X and Y coordinates of the optimal coordinate axis.

As a result, the straight edges of the square plane of the CAD shape data C1 are arranged in parallel with the X coordinate and the Y coordinate, respectively. Further, the direction of the voxel division is determined based on the optimal coordinate axes including the automatically determined X coordinate and Y coordinate, and the CAD shape is set using the voxel V set according to the voxel division direction. Voxel division of data is performed. Finally, shape data obtained by voxel division, that is, shape data E after voxel division (FIG. 4)
(B) indicated by a solid line) is closer to the original CAD shape data without jagged edges. Therefore, it is possible to obtain a more accurate analysis result.

FIG. 5 is a diagram showing a second specific example of voxel division coordinate optimization according to the present invention. In FIG.
A state in which an optimal direction vector is extracted when voxel division is performed on the CAD shape data C2 in which the plane S2 having the largest area is an arbitrary plane is shown. As shown in FIG. 5, when the plane S2 having the maximum area is an arbitrary plane, a normal vector perpendicular to this plane is extracted as the first vector V1 specifying the direction of the plane S2 having the maximum area. Is done. This second
Is determined as the X coordinate, the Y coordinate, or the Z coordinate of the optimal coordinate axis.

FIG. 6 is a diagram showing a third specific example of voxel division coordinate optimization according to the present invention. In FIG.
FIG. 8 shows how an optimal direction vector is extracted when voxel division is performed on CAD shape data C3 in which a plane S3 having a maximum area is a cylindrical surface. As shown in FIG. 6, when the surface S3 having the maximum area is a cylindrical surface, a direction vector perpendicular to the cylindrical surface and passing through the center of the cylindrical surface specifies the direction of the surface S3 having the maximum area. It is extracted as the first vector V1. The first vector V1 in the third specific example is determined as the X coordinate, the Y coordinate, or the Z coordinate of the optimal coordinate axis.

FIG. 7 is a diagram showing a fourth specific example of voxel division coordinate optimization according to the present invention. In FIG.
An optimal direction for performing voxel division of CAD shape data C4 such that surface S4 selected based on the geometric information of the CAD shape data is a curved surface sandwiched between two straight lines L1 and L2. This shows how to extract a vector. FIG.
As shown in (2), when the surface S4 is a curved surface, a plurality of direction vectors V11 to V1n (n is a positive integer of 2 or more) that respectively specify the directions of a plurality of surface elements constituting the curved surface are extracted. . Furthermore, these direction vectors V11
For ベ ク ト ル V1n, directional vectors having a common direction are put together, and the areas of the surface elements corresponding to these directional vectors are added. The direction vector in which the area of the surface element obtained as a result of such addition is maximized is extracted as the first vector. The direction vector extracted in this manner is the optimum coordinate X coordinate, Y coordinate
It is determined as coordinates or Z coordinates.

[0034]

As described above, according to the present invention,
Geometric information, which is a feature of original shape data such as CAD shape data, is extracted, and based on this geometric information, an optimal coordinate axis for voxel division is automatically determined. The shape data after the division is closer to the CAD shape data, so that a relatively accurate analysis can be performed.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the principle configuration of the present invention.

FIG. 2 is a block diagram showing a configuration of an embodiment according to the voxel division coordinate optimizing device of the present invention.

FIG. 3 is a flowchart illustrating a procedure of voxel division coordinate optimization according to the present invention.

FIG. 4 is a diagram showing a first specific example of voxel division coordinate optimization according to the present invention.

FIG. 5 is a diagram showing a second specific example of voxel division coordinate optimization according to the present invention.

FIG. 6 is a diagram showing a third specific example of voxel division coordinate optimization according to the present invention.

FIG. 7 is a diagram showing a fourth specific example of voxel division coordinate optimization according to the present invention.

FIG. 8 is a diagram showing a state in which shape data is divided into voxels by a conventional method.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Voxel division coordinate optimization apparatus 2 ... Geometric information extraction means 3 ... 1st vector extraction means 4 ... 2nd vector extraction means 5 ... Voxel division means 6 ... Shape data reading means 7 ... CPU 10 ... Voxel division coordinates Computer system for optimization 20 Program storage unit 25 Hard disk drive 30 OS unit 50 Display device 60 Mouse 65 Keyboard 70 Storage unit

Claims (5)

[Claims] 1. An arbitrary 3 to be analyzed using voxels
Geometric information extracting means for extracting geometric information relating to the geometric shape of the dimensional shape data; and extracting a first vector for specifying a direction of a first surface selected based on the geometric information. 1 vector extraction means, 2nd vector extraction means for extracting a second vector specifying the direction of a second plane selected from among the planes different from the first plane, and Voxel dividing means for determining a coordinate axis uniquely determined for the shape data based on a second vector, and dividing the shape data by the voxel based on the coordinate axis. Voxel division coordinate optimization device. 2. The method according to claim 1, wherein the first vector extraction unit extracts a direction vector that specifies a direction of a plane having a maximum area as the first vector, and the second vector extraction unit performs the first vector extraction. The direction vector that specifies the direction of the surface having the largest area among the surfaces other than the extracted surface is extracted as the second vector, and the direction vector is orthogonal to the first vector. The device according to claim 1. 3. When the first surface selected based on the geometric information is a curved surface, the first vector extracting unit specifies directions of a plurality of surface elements constituting the curved surface. A plurality of direction vectors to be extracted, for each direction vector having a common direction, add the area of the surface element corresponding to the direction vector, and determine the direction vector in which the added area of the surface element is the largest, 2. The apparatus according to claim 1, wherein the extraction is performed as a first vector. 4. An arbitrary 3 parsed using voxels
Extracting geometric information related to the geometric shape of the dimensional shape data; extracting a first vector specifying a direction of a first surface selected based on the geometric information; Extracting a second vector that specifies the direction of a second surface selected from among surfaces different from the first surface; and extracting a second vector specifying the shape data based on the first and second vectors. Determining a uniquely determined coordinate axis, and dividing the shape data by the voxel with reference to the coordinate axis. 5. A means for extracting geometric information relating to a geometric shape of arbitrary three-dimensional shape data, and a first vector specifying a direction of a first surface selected based on the geometric information. A means for extracting a second vector specifying a second direction selected from a plane different from the first plane; and a means for extracting a second vector based on the first and second vectors. Means for determining a coordinate axis uniquely determined with respect to the shape data, and dividing the shape data by voxels with reference to the coordinate axis.