JP3744243B2 - 2D drawing creation method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for creating a two-dimensional drawing such as a front view, a side view, and a plan view from a three-dimensional model using CAD drawing data.
[0002]
[Prior art]
Conventionally, a method for creating a two-dimensional drawing such as a front view, a side view, and a plan view from a three-dimensional model using CAD drawing data is a front view of a surface viewed from an arbitrary direction in the three-dimensional model. Based on this, for example, what is called a side view or a plan view is added to create a so-called 3-side view or 6-side view.
[0003]
Specifically, when drawing a two-dimensional drawing (three-sided view) 20 as shown in FIG. 12B from a three-dimensional model 1 as shown in FIG. A side view and a plan view are added to this, and a three-sided view 20 is obtained. .
[0004]
[Problems to be solved by the invention]
By the way, when creating such a two-dimensional drawing, it is necessary to specify at least the following items.
▲ 1 ▼ Specify front view
This is a front view of a two-dimensional drawing that specifies in what coordinate direction the three-dimensional model is to be arranged and in what direction. Note that a surface drawn as a two-dimensional drawing is referred to as a view (VIEW) in the sense that a surface with a three-dimensional model is viewed.
[0005]
Usually, in the case of the three-dimensional coordinate axes of X, Y, and Z, the front view that can be specified is first an XY plane as a view viewed from the Z-axis direction, a Y-X plane obtained by rotating this 90 degrees clockwise, and further 90 -XY plane rotated 90 degrees, -YX plane rotated 90 degrees, -XY plane viewed from the opposite direction of the Z axis (from the -Z axis direction to + Z direction), and the YX plane rotated 90 degrees clockwise. Further, there are 8 types of X-Y plane rotated 90 degrees and -Y-X plane rotated 90 degrees further, as seen from the Y-axis direction and the X-axis direction and the -Y-axis direction and the -X-axis direction. Since the view is added, there are a total of 24 views. Therefore, the designation of the front view is to designate one of these 24 ways.
(2) Specify a surface other than the front view
This specifies the surface to be created other than the front view. For example, in the case of a three-view view, in addition to the front view, a side view and an upper plan view. A left side view, an upper plan view, a lower plan view, and a rear view are designated.
(3) Specify paper size for drawing 2D drawings
This is to specify the size of the paper for drawing each figure specified in (1) and (2) above. Specify from.
(4) Specifying the scale of the drawing to be created
This designates the scale (scale) of the drawing drawn on the paper, and is usually designated from standardized scales such as 2/1, 1/1, 1/2, 1/4.
(5) Layout of each figure on the paper,
Each figure designated in the above (1) and (2) is designated to be drawn at an appropriate position on the paper designated in the above (3) with the scale designated in the above (4).
[0006]
As described above, in order to create a two-dimensional drawing, at least five items must be specified, and among these, the front view is important.
[0007]
If the front view is specified, the other items will be determined automatically. For example, surfaces other than the front view will be the left and right sides and the top and bottom planes of the front view. The paper size and scale are determined to be a size and scale that allow the front view and other views to be entered. This is because it is only necessary to arrange the view of the area.
[0008]
On the other hand, the front view can basically be any view of the three-dimensional model as a front view, but is not completely free, and is usually specified according to some rule. For example, when drawing a drawing, it is preferable to draw the drawing so that there is little margin on the paper and each drawing has an easy-to-read scale. From this point of view, the designation of the front view is such that when the three-dimensional model is viewed from each axial direction (including when viewed from the (−) minus direction of each axis), the longitudinal direction of the largest surface is It is preferable to specify along the horizontal axis of the two-dimensional drawing. Thus, normally, when a two-dimensional drawing is created by placing a rectangular drawing sheet sideways, the drawing scale can be maximized within the sheet, and an efficient drawing arrangement with less margin can be achieved.
[0009]
However, since this type of front view view is judged by humans by viewing the 3D model, it is easy to make mistakes. For example, if it is specified correctly, it will be placed on the specified size on the specified scale. However, there is a case where a two-dimensional drawing cannot be drawn on a desired sheet or scale because of an incorrect specification. In such a case, the front view must be specified again from the beginning, or if it is worse, it will be necessary to repeat extremely complicated operations such as changing the paper size and scale without noticing the mistake in specifying the front view. It will be.
[0010]
In the first place, the specification of each item as described above is troublesome. Especially when creating a 2D drawing from many 3D models, it is necessary to repeat the specification for each 3D model. Such work is desired to be automated.
[0011]
Accordingly, the present invention provides a two-dimensional drawing creation method capable of automatically creating a two-dimensional drawing without specifying complicated items when creating a two-dimensional plan view from a three-dimensional model on a CAD system. In particular, as described above, it is to provide a two-dimensional drawing creation method capable of automatically specifying the most difficult front view.
[0012]
[Means for Solving the Problems]
The object of the present invention is achieved by the following means.
(1) CAD system automatically A method for creating a two-dimensional drawing from three-dimensional model data, comprising: creating a cubic model including the three-dimensional model from the three-dimensional model data; and A step of detecting a surface having the largest area and extracting the view of the three-dimensional model from the direction when the surface is viewed as a first front view candidate; and when extracting the first front view candidate A step in which the longitudinal direction of the surface of the cubic model is along the horizontal axis of the two-dimensional drawing to be created is extracted from the first front view candidates and is used as a second front view candidate; 3 detected in the step of detecting a surface in the three-dimensional model perpendicular to the longitudinal direction of the surface of the cube model when the front view candidate is extracted and the step of detecting the surface in the three-dimensional model. Of the faces in the dimensional model, A two-dimensional drawing having a step of extracting a second front view candidate from the second front view candidates when a larger face is present, and determining the final front view as a final front view. How to make.
(2) The step of detecting a plane in the three-dimensional model is to search the three-dimensional model data in the longitudinal direction of the plane of the cube model from both ends inward. Dimensional drawing creation method.
(3) CAD system automatically A method for creating a two-dimensional drawing from three-dimensional model data, comprising: creating a cubic model including the three-dimensional model from the three-dimensional model data; and A step of detecting a surface having the largest area and extracting the view of the three-dimensional model from the direction when the surface is viewed as a first front view candidate; and when extracting the first front view candidate When the lengths of the vertical and horizontal sides of the surface of the cube model are the same, the 3D model data is extracted inward from the top, bottom, left, and right directions of the cube model when the first front view candidate is extracted. A two-dimensional drawing created by a portion having the largest area among the surfaces in the three-dimensional model detected in the step of detecting a surface in the three-dimensional model and detecting the surface in the three-dimensional model. Also to the right It was extracted from the first front view candidate, 2-dimensional drawing generation method characterized by comprising the steps, a to determine this the final front view.
(4) The two-dimensional drawing creation method further includes a step of determining a paper size on which the final front view and a predetermined surface drawing are entered according to a predetermined scale. Drawing creation method.
(5) In the step of determining the paper size, a paper size on which the final front view and a predetermined surface figure are entered according to a predetermined scale from among drawing size candidates prepared in advance. At this time, when there is no paper size in which the final front view and the drawing of the predetermined surface are included in the drawing size candidates prepared in advance according to a predetermined scale. Is a method of creating a two-dimensional drawing, wherein the scale is changed.
[0013]
【The invention's effect】
According to the present invention, the following effects can be obtained for each claim.
[0014]
According to the first aspect of the present invention, a cubic model including the cubic model is created from the three-dimensional model data, the one having the largest area of the created cubic model is extracted as the first front view candidate, The one in which the longitudinal direction of the surface is horizontal is extracted as the second front view candidate, and then in the three-dimensional model perpendicular to the longitudinal direction of the surface of the cube model from which the first front view candidate is extracted. A surface is detected, and the surface with the largest area in the detected three-dimensional model facing right is extracted from the second front view candidates, and this is used as the final front view. As a front view, a view as viewed from the direction of the largest area is selected, and this is arranged sideways, so that a front view that can efficiently arrange a two-dimensional drawing on a sheet is provided. Can be determined automatically . In addition, since the side with a large area of the surface in the three-dimensional model is arranged on the right side, the center of gravity side of the three-dimensional model is always arranged on the right side.
[0015]
According to the second aspect of the present invention, when detecting a surface in the three-dimensional model perpendicular to the longitudinal direction of the surface of the cube model when the first front view candidate is extracted, the surface of the cube model is detected. In the longitudinal direction, the three-dimensional model data is searched inward from both ends thereof, so that the side serving as the center of gravity of the three-dimensional model can be detected simultaneously from the two directions.
[0016]
According to the third aspect of the present invention, a cubic model including the cubic model is created from the three-dimensional model data, and the largest area of the created cubic model is extracted as a first front view candidate. A surface in the three-dimensional model is detected from the top, bottom, left, and right directions of the cube model from which the first front view candidate is extracted, and the portion of the detected surface in the three-dimensional model that has the largest area faces the right side of the two-dimensional drawing. In the 3D model in which the front view is selected as the front view and the front view is a square with no difference in length and width, the side with the center of gravity is It will always be automatically placed to the right.
[0017]
According to the fourth aspect of the present invention, the method further includes the step of determining the paper size on which the finally determined front view and the drawings of the other surfaces are entered according to a predetermined scale. It is possible to automatically determine a sheet having a size that can accommodate a two-dimensional drawing drawn by a predetermined scale.
[0018]
According to the present invention as set forth in claim 5, a drawing size prepared in advance at the stage of determining the paper size on which the finally determined front view and the drawings of the other surfaces are entered according to a predetermined scale. The scale is changed when there is no size that can accommodate all the area drawings, so if there is no paper of a size that can accommodate all the faces with a predetermined scale, it will be prepared in advance. The scale is automatically changed so that it fits on the existing paper, and the optimum scale for the paper is determined.
[0019]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
[0020]
FIG. 1 is a main flowchart showing a processing procedure for creating a two-dimensional drawing according to an embodiment to which the present invention is applied. FIGS. 2 to 4 are subroutine flowcharts of main steps in the main flowchart.
[0021]
In the present embodiment, as shown in FIG. 12, a case where a three-dimensional model 1 of a clamp jig used in a production line for an automobile body is converted into a two-dimensional drawing as a three-dimensional view 20 will be described as an example.
[0022]
As shown in FIG. 1, the basic processing procedure of the two-dimensional drawing creation method according to the present embodiment is as follows. First, a three-dimensional model for creating a two-dimensional drawing from three-dimensional model data stored in advance in a CAD system. Is specified, and how many planes (for example, 3 planes and 6 planes) are to be created is specified (S1). At this time, a plurality of three-dimensional models may be selected. In this case, the following steps S2 to 5 are repeatedly executed for each selected model. In the present embodiment, as described above, a clamp jig is designated as the three-dimensional model, and a three-dimensional view is designated as the two-dimensional drawing to be created.
[0023]
Subsequently, a front view view determination process using the three-dimensional model data is performed (S2), a paper size and drawing scale determination process (S3), and a drawing layout process are performed (S4). A two-dimensional drawing is output from a printer (or plotter) connected to the CAD system (S5).
[0024]
Next, the procedure for determining the front view in the above basic procedure will be described with reference to FIG.
[0025]
First, the maximum value and the minimum value from the origin are determined for each of the X, Y, and Z axes of the three-dimensional coordinates from the data of one selected three-dimensional model (S201). From the minimum value, as shown in FIG. 5, the cubic model 10 including the entire three-dimensional model 1 and including a plane parallel to each coordinate axis is drawn (S202). In step S201, the maximum value and the minimum value are obtained because the size of the three-dimensional model is calculated from the origin on the three-dimensional coordinate based on the coordinate position. For example, one end of the three-dimensional model is obtained. When the part is placed at the origin of the three-dimensional coordinates, it is only necessary to obtain the maximum value. Further, a cube model including the three-dimensional model may be directly drawn from the dimension data of the three-dimensional model without going through S201.
[0026]
Subsequently, the areas of three planes (XY plane, YZ plane, ZX plane) viewed from each axial direction of the obtained cube model 10 are obtained (S203).
[0027]
Then, the same direction as the direction of viewing the surface having the largest area among the obtained areas is set as a first front view view candidate (first front view candidate) (S204). As a result, in the case of the three-dimensional model 1, the plane viewed from the Z-axis direction has the largest area, and therefore, the front view view candidates include the YX plane, the −XY plane, the −YX plane, and the −XY plane. Eight types of plane, YX plane, XY plane, and -YX plane are extracted.
[0028]
Subsequently, the lengths of the vertical and horizontal sides of the surface of the cubic model 10 from which the first front view candidate is obtained are compared (S205).
[0029]
As a result of the comparison, if it is determined that the vertical and horizontal lengths are different (S206), then a view in which the longitudinal direction of the surface of the cube model is horizontal is selected from the first front view candidates. It is selected as a figure view candidate (second front view candidate) (S207). In the three-dimensional model 1, since the Y-axis direction is longer than the X-axis direction, candidates for the second front view of the three-dimensional model are the -Y-X plane (FIG. 6A), Y-X, as shown in FIG. There are four views (VIEW) of the plane (FIG. 6B), the −YX plane (FIG. 6C), and the YX plane (FIG. 6D).
[0030]
Subsequently, the three-dimensional model data is searched simultaneously from the two positive and negative directions of the axis along the longitudinal direction from both longitudinal ends of the cube model 10 inward from the longitudinal end positions, A plane perpendicular to the longitudinal direction in the three-dimensional model is detected (S208). Therefore, in the three-dimensional model 1, as shown in FIG. 7, the search is started simultaneously from the two directions of the + Y axis direction and the −Y axis direction.
[0031]
On the other hand, in the comparison of the vertical and horizontal sides in step S205, when it is determined that there is no difference between the vertical and horizontal sides (S206), the four directions of the top, bottom, left and right of the surface when the candidate for the first front view is extracted. At the same time, a plane in the three-dimensional model is searched (S209). Therefore, in this case, if the first front view candidate is viewed from the Z-axis direction, the search is started simultaneously from the four directions of + X-axis direction, -X-axis direction, + Y-axis direction, and -Y-axis direction. Will do.
[0032]
Subsequently, as a result of searching for the faces in the three-dimensional model in step S208 or S209, the faces found first are compared (S210).
[0033]
Then, as a result of the comparison, when it is determined that the areas of the surfaces in the three-dimensional model are different (S211), a front view that faces the right as a two-dimensional drawing created by the one having the largest area. A view is selected from the second front view view candidates when the steps S207 and S208 have been performed, and this is determined as the final front view (S212). Thereby, in the case of the three-dimensional model 1, as shown in FIG. 8, the view of the YX plane is determined as the final front view. On the other hand, if step S209 has been performed, the first front view view candidate is selected and determined as the final front view.
[0034]
In the step 210, if the areas are the same as a result of comparing the first faces found (S211), either one of them may be the right side. For example, a code is attached to each view in advance. In the same manner as described above, the front view view candidate is selected so that the code number with the younger side is on the right side (S213).
[0035]
Here, the processing in steps S210 to S213 is processing for detecting the center of gravity position in the three-dimensional model. Usually, the center of gravity position of the three-dimensional model is on the side having the largest area. Judgment is made by detecting the inner surface. In particular, as in the present embodiment, when the 3D model is a clamp jig, the clamp jig has a pedestal on the ground side, so there is a clear difference in the size of the top and bottom direction as the shape of the 3D model, and Since there is a large area on the ground side, the ground side with the center of gravity of the clamp jig can be detected efficiently by such processing. In the case where the difference in area in the top-and-bottom direction of the three-dimensional model is small, instead of such processing, all of the searched surfaces may be compared and the one with the largest area may be the right side. .
[0036]
When the final front view is determined as described above, the process returns to the main routine.
[0037]
Next, a procedure for determining the paper size and the drawing scale will be described with reference to FIG.
[0038]
First, the drawing scale is set to 1/1 (S301). Note that the value 1/1 of the scale is set in advance, and other values may be set.
[0039]
Subsequently, the minimum required rectangle size of the drawing drawn on the paper is obtained from the finally determined front view, created view, and scale (S302). This process is a process performed to obtain a minimum size necessary for drawing creation. In addition, since the three views are created in this embodiment, the views to be created are two views of the left side view and the upper plan view in addition to the front view.
[0040]
The sizes of these views can be easily obtained from the above-described cube model because the front view is already determined at this point. In the case of the present embodiment, as shown in FIG. 9, the horizontal length of the front view on the drawing created by multiplying the length of A of the cubic model 10 including the three-dimensional model 1 by the scale value. The length of B multiplied by the scale value is the horizontal length of the left side view. Therefore, the minimum required horizontal length of the rectangle is (A + B) × scale value. On the other hand, the vertical length of the rectangle is obtained by multiplying the length of C in FIG. 9 by the scale value to obtain the vertical length of the front view, and the length of B multiplied by the scale value is the upper plane. This is the vertical length of the figure. Therefore, the minimum vertical length of the rectangle is (C + B) × scale value. FIG. 10 shows the positional relationship between A, B, and C when actually drawn as a drawing.
[0041]
Subsequently, a blank for entering dimensions and balloons is added to the size of the rectangle obtained in step S302 to obtain a size rectangle necessary for drawing creation (S302). For this, for example, a certain value as a margin may be added to the size of the rectangle obtained in step S302, or it may be increased at a certain magnification. The rectangular size obtained here is referred to as the final drawing size. Specifically, for example, it may be set in advance so as to take a 20-m margin on each side view, and this may be added to each view. As a result, as shown in FIG. 10, a final drawing size in which each surface view including a margin is included is obtained.
[0042]
Next, the final drawing size obtained is within the effective range in which a drawing in the paper can be created, and the smallest paper size is selected from among the paper size candidates prepared in advance. (S304). Here, the paper size candidates prepared in advance are, for example, JIS-A series paper, such as A3, A2, A1, A0, 1.5 AO, and 2A0. Therefore, for example, when A1, A0, 1.5A0, and 2A0 can be selected as the size of the final drawing size, the smallest A1 is selected. Here, if there is no paper size that can be selected, paper NG is output.
[0043]
Subsequently, it is determined whether or not the sheet NG is output (S305).
[0044]
Here, when the paper size can be selected, it is determined to use the selected paper size and the current scale value (S306), and the process returns to the main routine. On the other hand, when the paper size cannot be selected, the scale value is scaled down (S307). Therefore, for example, when the scale value is 1/1, the scale value is changed to 1/2, and when the scale value is 1/2, the scale value is changed to 1/4. Then, the process returns to step S302, and the subsequent processing is repeatedly executed. Finally, in step S307, the paper size and scale value in which all view drawings are included are determined.
[0045]
Next, a drawing layout procedure will be described with reference to FIG.
[0046]
First, the front view and each view drawing on the other surface are arranged with a preset margin (S401). Here, since the three-side view is created, the paper size and the drawing scale are determined based on the front view, the left side view, and the upper plan view that are finally obtained by the above-described front view determination process. The scale is determined by the scale value determined by the processing, and a margin set in advance in a rectangle of the final drawing size, for example, 20 mm is taken up and down on the left and right and up and down for each plan view. Thereby, the arrangement of each view as shown in FIG. 11A is determined.
[0047]
Subsequently, the center 7 of the rectangle 5 having the final drawing size obtained in the above-described paper size and drawing scale determination processing is obtained (S402) (see FIG. 11A).
[0048]
Subsequently, the center 27 within the effective range 23 for creating the drawing in the paper 21 having the paper size determined by the paper size and drawing scale determination processing described above is obtained (S403). As shown in FIG. 11B, the effective range 23 is usually provided with a column 25 for entering the title and number of the drawing in the sheet 21, so that the drawing is not applied to these columns 25. The range that can be drawn is referred to herein as the effective range 23.
[0049]
Subsequently, as shown in FIGS. 11A and 11B, the center 7 of the final drawing size 5 obtained in step S402 and the center 27 of the effective range 23 of the paper 21 are combined, and each view performed in step S401 is performed. According to the arrangement, a drawing layout for arranging each view in the sheet 21 is determined (S404). Then, the process returns to the main routine.
[0050]
Since the drawing layout of each view has been determined as described above, the main routine outputs the drawing of each view on a sheet according to this.
[0051]
In the present embodiment described above, the part that requires manual operation is basically only the designation of the three-dimensional model to be converted into a two-dimensional drawing and the designation of the plane view, and all other parts are automatically determined. Therefore, it is possible to create a two-dimensional drawing from the three-dimensional model data with a very simple operation and without mistakes.
[0052]
In the above-described embodiment, the clamp jig is described as an example of the three-dimensional model. However, the present invention is not limited to such a three-dimensional model, and can be suitably used for various three-dimensional models. can do. Further, the present invention is not limited to the three-view drawing, and can be applied to the creation of a six-view drawing or a larger number (or fewer) two-dimensional drawings.
[Brief description of the drawings]
FIG. 1 is a main flowchart showing a processing procedure for making a three-dimensional model into a two-dimensional drawing by applying the present invention.
FIG. 2 is a subroutine flowchart showing a procedure for determining a front view in the main flowchart shown in FIG. 1;
FIG. 3 is a subroutine flowchart showing a procedure for determining a scale in the main flowchart shown in FIG. 1;
4 is a subroutine flowchart showing a procedure of drawing layout processing in the main flowchart shown in FIG. 1. FIG.
FIG. 5 is a perspective view for explaining a cubic model including a three-dimensional model (X, Y, and Z in the figure indicate three-dimensional coordinates).
FIG. 6 is a drawing showing candidates for a front view.
FIG. 7 is a perspective view for explaining search of a surface in a three-dimensional model (X, Y, and Z in the figure indicate three-dimensional coordinates).
FIG. 8 is a drawing showing a front view that is finally determined.
FIG. 9 is a perspective view of a three-dimensional model for explaining a paper size and scale determination process (note that X, Y, and Z indicate three-dimensional coordinates in the figure).
FIG. 10 is a diagram showing a state in which the paper size and scale determination processing is actually arranged as a two-dimensional drawing for explaining the processing.
FIG. 11 is a drawing for explaining a drawing layout;
FIG. 12 is a diagram illustrating an example of creating a two-dimensional drawing from a three-dimensional model.
[Explanation of symbols]
1 ... 3D model,
2 ... 2D drawings,
10 ... Cube model.

Claims (5)

A CAD system for automatically creating a 2D drawing from 3D model data,
Creating a cubic model including the three-dimensional model from the three-dimensional model data;
A step of detecting a surface having the maximum area of each surface from the created cubic model and extracting a view of the three-dimensional model from a direction when the surface is viewed as a first front view candidate; ,
The one along the horizontal axis of the two-dimensional drawing created by the longitudinal direction of the surface of the cube model when the first front view candidate is extracted is extracted from the first front view candidates, A stage to be a front view candidate,
Detecting a surface in the three-dimensional model perpendicular to the longitudinal direction of the surface of the cube model when the first front view candidate is extracted;
Of the faces in the 3D model detected in the stage of detecting the faces in the 3D model, the one with the largest area is the one facing the right side from the second front view candidates. Extracting and determining the final front view as a two-dimensional drawing creation method. Detecting a surface in the three-dimensional model comprises:
2. The two-dimensional drawing creation method according to claim 1, wherein the three-dimensional model data is searched inward from both ends in the longitudinal direction of the surface of the cube model. A CAD system for automatically creating a 2D drawing from 3D model data,
Creating a cubic model including the three-dimensional model from the three-dimensional model data;
A step of detecting a surface having the maximum area of each surface from the created cubic model and extracting a view of the three-dimensional model from a direction when the surface is viewed as a first front view candidate; ,
When the lengths of the vertical and horizontal sides of the surface of the cube model when the first front view candidate is extracted are the same, the cube model when the first front view candidate is extracted from the three-dimensional model data. Detecting a surface in the three-dimensional model inward from the top, bottom, left, and right directions;
Of the faces in the three-dimensional model detected in the step of detecting the faces in the three-dimensional model, the first front view candidate is the one facing the right side of the two-dimensional drawing created by the portion having the largest area. Extracting from the above and determining the final front view. The method for creating a two-dimensional drawing. 2. The two-dimensional drawing creation method further comprises a step of determining a paper size on which the final front view and a predetermined plane view are entered according to a predetermined scale. Item 2. A method for creating a two-dimensional drawing according to Item 3. The step of determining the paper size is to determine a paper size in which the final front view and a predetermined surface figure are included according to a predetermined scale from among drawing size candidates prepared in advance. At this time, when there is no paper size that can be used for the drawing of the final front view and the predetermined plane according to a predetermined scale among the drawing size candidates prepared in advance, 5. The two-dimensional drawing creation method according to claim 4, wherein the scale is changed.

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