JP3935997B2 - How to convert a drawing file to an intermediate format - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, when converting drawing data between different data formats in a CAD (Computer Aided Design) system or the like having a dimension measuring function, a phase line picture (hereinafter referred to as a dimension figure) in an intermediate format is topological. In particular, the present invention relates to a method for converting a drawing file subjected to geometric analysis processing into an intermediate format, and more particularly, to a method for converting an optimum drawing file into an intermediate format when measurement information necessary for re-measurement of dimensions is not in the format.
[0002]
[Prior art]
The CAD system can be freely selected by the user by comparing and examining its usage, function, and price. As a result, many CADs are distributed in the market, but these data are not compatible. Thus, when drawing data is actually converted between different CADs, a common data format called an intermediate format is required. DXF, BMI, IGES, STEP, etc. exist in the intermediate format, but DXF is the mainstream in the two-dimensional design. DXF is an intermediate format for CAD drawing conversion used by AutoCAD (trademark) of AutoDesk, and is currently used for converting drawing data between various CADs.
[0003]
By the way, the data structure inside such drawing data includes dimension line measurement information in coordinates and numerical data, but the dimension line data format depends on the dimension line command operation at the time of data reading. There are those having no dimension measuring function and those having a dimension measuring function (hereinafter referred to as automatic adjustment dimensions). The former is a data format for describing dimension lines, dimension extension lines, arrow graphics, and dimension characters in separate figures such as lines, solids (filled figures), and texts in DXF. In this case, the data relating to the dimension line, the dimension auxiliary line, the arrow graphic, and the dimension character are processed as a simple graphic even on the received CAD. On the other hand, the latter is a data format in which a dimension composite figure and a dimension element are paired in DXF. A dimension compound figure is a set of figure elements constituting a dimension figure. The dimension element is a dimension element having measurement information necessary at the time of re-measurement, and the main measurement information includes coordinates of an arbitrary point P1 on the dimension line or its extension line, as shown in FIG. The coordinates of the start points P2 and P3 of the two dimension extension lines and the inclination (hereinafter referred to as an angle) θ of the dimension line passing through the point P1. Data described in such automatic adjustment dimensions is converted into the received CAD data format.
[0004]
[Problems to be solved by the invention]
However, when a drawing file including the above-mentioned automatic adjustment dimensions is converted into a DXF file, even if the dimension composite figure itself is correctly created, depending on CAD, there is no start point P2 or angle θ, or the point P3 is shifted. Dimensional element data with problems such as being may be created. For this reason, CAD that reads such a DXF file does not interfere with the creation of a sample that does not have a measurement function (just a picture), but if you try to create a dimension line with a measurement function, a reading error will occur. Or as shown in FIG.24 (b) and (c), there exists a problem that a dimension line will deform | transform at the time of reading or subsequent dimension remeasurement.
In addition, the graphic elements in a dimensional composite graphic do not have information about which graphic element represents which part of the dimensional graphic (for example, dimension line, dimension extension line, terminal symbol, lead line, reference dimension box). In addition, since the writing order varies depending on the CAD, even if only the dimension composite figure is correctly created, the point or angle that the dimension element should originally have cannot be obtained.
[0005]
The present invention has been made in view of such problems, and to an intermediate format of a drawing file from which correct measurement information can be obtained by performing topological and geometric analysis processing on dimensions and figures in the intermediate format. The purpose is to provide a conversion method.
[0006]
[Means for Solving the Problems]
A method for converting a drawing file according to the present invention into an intermediate format is as follows: Used in CAD system When converting drawing data including dimension figures and dimension elements necessary for dimension measurement between different data formats through an intermediate format such as DXF, the dimension figures contained in the drawing data converted into the intermediate format are topological. Then, while analyzing geometrically, the inclination of the dimension line in the dimension figure and the point on the straight line including the dimension line, and the start point of the two extension lines in the dimension figure are obtained, and based on these points and inclination The dimension element on the intermediate format is reconstructed.
[0007]
More specifically, the analysis processing of the dimension graphic includes a first step of recording an angle of a line segment that is paired with a side in the dimension graphic, coordinates of two end points, and a connection relationship thereof; The second step of replacing the overlapping point with one point when the overlapping points are replaced with one point, and the overlapping line segment is replaced with one line when the infinite lengths are overlapped with each other. A third step of erasing the line segment and the end point paired with the closed graphic in the dimension graphic while replacing the line segment and the end point paired with the terminal symbol in the graphic with one vertex; Based on the vertex obtained in the step, the line segment and the end point obtained in the second step, the dimension line and the two extension lines in the dimension figure are determined, and the inclination of the dimension line and the straight line including the dimension line are determined. The fourth step to find the point and the previous Characterized by comprising a fifth step of obtaining a start point of the extension line.
[0008]
In addition, the present invention is a computer-readable storage medium (CD-ROM, floppy disk, etc.) in which a program for causing a computer to execute the above method is described.
[0009]
According to the method for converting a drawing file into an intermediate format according to the present invention, when converting drawing data between different data formats, the dimension figure contained in the drawing data converted into the intermediate format is topologically and geometrically. While analyzing, the inclination of the dimension line in the dimension figure, the point on the straight line including the dimension line, and the start points of the two dimension extension lines in the dimension figure are obtained, so that correct measurement information according to the format can be obtained.
[0010]
More specifically, based on the angle of the line segment that is paired with the side in the dimension figure, the coordinates of the two end points, and their connection relationship, and the vertex that is paired with the terminal symbol in the dimension figure. By determining the dimension line and the two dimension extension lines in the dimension figure, the inclination of the dimension line, the point on the straight line including the dimension line, and the start point of the dimension extension line can be obtained.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a block diagram showing a configuration of a CAD system to which a method for converting a drawing file into an intermediate format according to an embodiment of the present invention is applied.
[0012]
In this system, drawing data input via an input device 1 such as a keyboard and a mouse and drawing data input from another CAD system (not shown) via a LAN or the like are stored in a recording device 2 such as a hard disk. To be recorded. If the recorded drawing data has a different data format, the CPU 3 temporarily stores the drawing data in the RAM 4 and intermediate format according to the file conversion program installed in the recording device 2 and the microprogram written in the ROM 5. The measurement information P1, P2, P3, θ required at the time of remeasurement is obtained while analyzing the shape of the dimensional figure included in the drawing data via DXF, and data conversion is executed. The objects of graphic analysis are length dimension lines (including diameter dimension lines) and angle dimension lines, which are recorded in the recording device 2 as a meta graphic database. The meta graphic database is composed of topological data and geometric data in order to analyze the shape of the dimensional graphic topologically and geometrically. The phase data indicates which side is an end point and which side is an end point, and is configured such that one overlapping point is one point and multiple sides are one side. Further, the geometric data is configured to represent the coordinates (X, Y) of the point represented by the phase data and the angle θ of the side. The drawing data recorded in the recording device 2 is output as an image via an output device 6 such as a display, a printer, or a plotter based on the automatically adjusted dimensions.
[0013]
FIG. 2 is a diagram illustrating an example of a meta graphic database.
In this database, as geometric data, the angle θ of the metalines L1 to L8 paired with the sides LINE, POLYLINE, SOLID, and 3DLINE in the dimensional composite figure, and two end points of this line segment (assuming only the end points) Since the shape of the dimensional figure can be analyzed, the intersection points are excluded.) The coordinates (X, Y) of the meta points p1 to p16 paired with the terminal symbol INSERT (composite figure arrangement), CIRCLE ( The vertex (X, Y) of the meta terminal paired with a circle and a donut (special POLYLINE) is recorded. Further, in this database, connection relationships of the metalines L1 to L8 and the meta points p1 to p16 are recorded as phase data.
[0014]
Next, the dimension graphic analysis process in the CAD system configured as described above will be described.
FIG. 3 is a flowchart showing the procedure of the drawing file conversion method by the CPU 3.
First, the CPU 3 reads the drawing data converted into DXF by the operation of the input device 1 (S1), and executes topological and geometric analysis processing on the dimensional figure included in the drawing data (S2). Next, the CPU 3 reconstructs the dimension element of DXF using the measurement information P1, P2, P3, θ obtained by the dimension graphic analysis (S3).
[0015]
FIG. 4 is a flowchart showing the procedure of the dimension graphic analysis method by the CPU 3.
First, initialization processing described below is executed (S11). That is, as shown in FIG. 2, the CPU 3 uses the vertex coordinates (X, Y), which are DXF elements in the dimensional composite figure, as the meta points pi, and the line segment of the angle θ connecting these two points as the meta line Li. Register in the meta graphic database. At this time, INSERT, CIRCLE, and donut are registered in the meta graphic database as meta terminals. Next, the CPU 3 replaces the overlapping points with one point and the multiple sides with one side, and integrates the overlapping metalines Li into one when the length of the metaline Li is infinite (S12). Subsequently, the CPU 3 separates and removes the terminal symbol and the closed graphic in order to leave only the metaline of the dimensional graphic skeleton on the meta graphic database (S13). At this time, the terminal symbol is re-registered in the meta graphic database as a meta terminal. Subsequently, the CPU 3 executes a shape analysis process based on the terminal symbol and a shape analysis process based on the intersection code according to the number of the separated terminal symbols in order to determine the dimension line and the dimension auxiliary line (S14). . As a result, an arbitrary point P1 on the dimension line or its extension and the angle θ of the dimension line are obtained, but the CPU 3 determines the end points of the two metalines Li determined as the dimension extension line by the shape analysis. It is determined which is the start point P2 or P3, respectively (S15).
[0016]
FIG. 5 is a flowchart showing details of the above-described overlapping point erasing process and multiple side erasing / metaline integration process (S12).
That is, in the overlapping point erasing process, the CPU 3 first sorts the meta points pi in ascending order with respect to the X values as shown in FIG. 6, and sets the meta points pi having the same X values to the same item Xs (s = 1, 2). ,...) (S21). Next, the CPU 3 sorts the meta points pi in ascending order with respect to the Y values, and classifies the meta points pi having the same Y values into the same items Yt (t = 1, 2,...) (S22). Subsequently, if there is the same meta point pi belonging to the item Xs and meta point pi belonging to the item Yt, the CPU 3 moves the meta point pi to the item Xs * Yt (S23). Thereby, in the case of FIG. 2, the matrix shown in FIG. 6 is obtained. Subsequently, if there are meta points belonging to the same item, since the X value and the Y value are the same overlapping points, the CPU 3 deletes other points while leaving one point (S24). Therefore, in the case of FIG. 6, the meta points p3, p5, p7 and the meta points p10, p12, p14 are overlapping points, and by deleting the meta points p5, p7, p12, p14, the overlapping points are They are replaced by points p3 and p10, respectively.
[0017]
Further, in the multi-side erasure / metaline integration process, as shown in FIG. 7, the CPU 3 sorts the metalines Li in ascending order with respect to the angle θ, and sets the same lines θs (s = 1, 2, (S25). At this time, θ and θ + 180 ° are regarded as the same. Next, the CPU 3 sorts the metalines Li in ascending order with respect to the Y intercept (when X = 90 °, the X intercept is used), and the same metaline Li of the Y intercept is the same item At (t = 1, 2,... (S26). Subsequently, if there is the same metaline Li belonging to the item θs and the metaline Li belonging to the item At, the CPU 3 moves the metaline Li to the item θs * At (S27). At this time, the meta point pi that is no longer used as the end point of the metaline Li is deleted. Thus, in the case of FIG. 2, when the Y intercept is determined with the meta point p1 as the origin, the matrix shown in FIG. 7 is obtained. Subsequently, if there are metalines belonging to the same item, the angle θ and the Y-intercept are the same multiple sides or a metaline that can be integrated, so the CPU 3 determines the distance between two points in the metapoint group that the metaline that can be integrated has. Multiple edges are erased or metaline integration is performed using the two endpoints of the new metaline as the maximum of the two (S28). Therefore, in the case of FIG. 7, the metalines L4 and L5 can be integrated, and the meta point group is p3, p8, p9, and p10. Since the angle of the metalines L4 and L5 that can be integrated is θ = 0 °, the maximum point p3 of the X value and the X value are assumed to have the maximum distance between the two points in the meta point group p3, p8, p9, and p10. The minimum point p10 is selected, and the metalines L4 and L5 that can be integrated are integrated into one metaline. Further, when the dimensional figure is drawn with one stroke, that is, in the case of FIG. 8, the metalines L3, L4, the metalines L5, L6, etc. are multiple sides. For example, by deleting the metaline L4, the multiple sides become the metaline L3. Is replaced by
By such processing, the meta graphic database is as shown in FIG. Here, mpi represents a meta point, and mLi represents a metaline.
[0018]
FIG. 10 is a diagram illustrating an example of the terminal symbol and the closed graphic described above, and FIG. 11 is a flowchart illustrating details of the separation process (S13). In FIG. 10, the meta point is represented by V1 and the meta line is represented by ei (hereinafter, the same applies to those described later).
In the dimensional figure, as shown in FIG. 10, the number of sides and points is large in the terminal symbol portion. In addition to the LINE, POLYLINE, SOLID, and 3DLINE arrows (open and closed arrows; the two metalines representing these arrows are hereinafter referred to as V-shaped lines). There are regular n-gons by, and arbitrary figures by INSERT, which cause geometric data to be complicated.
[0019]
Therefore, if the metaline Li is connected to another metaline Lj at the end point, the CPU 3 moves to that metaline Lj (S31). Thereafter, the same processing is executed for the destination metaline Li (S31), and after returning to the original metaline Li (S32), the CPU 3 determines what the closed figure is (S33). As a result of the determination, if it is a closed figure that cannot be a terminal symbol such as a regular quadrangle, a rectangle, or an n-gon with different side lengths (hereinafter referred to as side lengths), the CPU 3 executes the removal process as it is. (S34). If it is a terminal symbol shape such as a regular n-gon (n = 3, n ≧ 5) or an isosceles triangle, the CPU 3 re-registers it as a meta terminal in the meta graphic database, and then executes a removal process. (S35).
[0020]
FIG. 12 is a flowchart showing details of the closed graphic determination process, and FIG. 13 is a diagram for explaining this determination.
First, the CPU 3 stores the side length R and the angle θi of the first metaline Li (S41). Hereinafter, until returning to the first metaline Li, the CPU 3 counts the number n of sides and compares it with the side length R and the angle θj of another metaline Lj constituting the closed figure (S42). At this time, if three or more metalines Lj are connected to the meta point pi constituting the closed figure, the angle between the side length R and the metalines Lj (hereinafter referred to as an inter-side angle) α is the immediately preceding one. A metaline Lj equal to the value is searched. If there is an equal metaline Lj, it is set as the next side, and if there is no metaline Lj, the graphic analysis is stopped. As a result of the comparison, if all the side lengths R of the closed figure are the same and the side-to-side angle α is also the same, it is determined as a regular n-gon. Further, if the side lengths are different but n = 4 and the side-to-side angles α are all the same, the rectangle is determined and excluded from the analysis target. For other closed figures, if n = 3, processing is left to terminal symbol removal described later, and if n ≧ 4, the figure does not appear on the normal dimension line, so the figure analysis is stopped (S43).
[0021]
FIG. 14 is a flowchart showing details of the terminal symbol removal process.
First, the CPU 3 checks how many pairs of meta-lines Li having the vertices of meta points pi having two or more sides connected are equal in length (S51). If it is one set (S52), it is regarded as a V-shaped line and added as a meta terminal, this V-shaped line is removed, and if there is a bottom line, it is also removed (S53). On the other hand, if there are two or more sets (S52), a unit vector from the vertex toward the midpoint of each base is obtained (S54). If all the unit vectors are the same (S55), it is regarded as a nested V-shaped line, a V-shaped line having the maximum apex angle is added as one meta terminal, and the V-shaped line sharing the vertex is removed ( S53). If there is an unequal unit vector passing through the vertex (S55), the graphic analysis is stopped.
[0022]
FIG. 15 is a flowchart showing details of the shape analysis process based on the terminal symbol and the shape analysis process based on the intersection code.
If there are two terminal symbols obtained by the above terminal symbol and closed figure separation processing (S61), the CPU 3 determines a metaline Li passing through both vertices as a dimension line and a metaline Li passing through only one vertex. Each is determined to be a dimension extension line (S62). At this time, the vertex of the terminal symbol is the placement position in the case of a composite figure, the center of gravity in the case of a regular n-gon (n ≧ 5), the vertex opposite to the base in the case of an isosceles triangle in the V-shaped line, and the center of gravity in the case of an equilateral triangle. As the temporary vertex, the vertex closest to the dimension line, the center of CIRCLE, and the donut are selected. On the other hand, if the number of terminal symbols is one or less, all the metalines Li are extended to obtain the intersection Ci (S63). For the metaline passing through the intersection Ci, the intersection code “1” is recorded if the intersection Ci is an end point, the intersection code “2” is recorded if it is an inner division point, and the intersection code “3” is recorded if it is an outer division point ( S64). Therefore, in the case of FIG. 16A, the intersection connection table shown in FIG. 16B is obtained.
[0023]
By the way, a dimension figure has the property that two dimension extension lines are parallel to each other, and the dimension line internally divides the dimension extension lines. Therefore, shape analysis can be performed by using these properties and the intersection connection table.
That is, as shown in FIG. 16, the intersection points C1 and C2 having the intersection point code “2” on the two parallel metalines e1 and e3 are also points on the metaline e2 connecting the metalines e1 and e3. The metalines e1 and e3 are determined as dimension extension lines, and the metaline e2 connecting them is determined as a dimension line (S65). At this time, as shown in FIG. 17, even if there are two sets of parallel metalines e1, e3 and e2, e5, the metalines e1, e3 are determined as dimension extension lines and metalines e2 by determining the same conditions as described above. Can be determined as a dimension line. Further, as shown in FIG. 18, at the intersection C2 where the intersection code is “2” for the metaline e2 which is a dimension line, the dimension line of that portion is determined to be the outer dimension. Similarly, for a metaline that is a dimension line, at the intersection point where the intersection code is “3” as shown in FIG. 16 or “1” as shown in FIG. As shown in FIGS. 19A and 19B, one of the reasons for not having two parallel metalines is that one dimension line auxiliary line is not displayed and two dimension line auxiliary lines. The case of non-display is considered. In this case, as shown in FIG. 19C, if there is one terminal symbol having directionality, the dimension line and the dimension extension line can be distinguished from each other. If there is no terminal symbol or there is no directionality even if there is only one terminal symbol, it is not possible to distinguish which line is a dimension line or a dimension auxiliary line, so the graphic analysis is stopped. On the other hand, as shown in FIG. 20, one of the reasons that there is no metaline connected by the intersection code “2” is that the dimension line is not displayed. In this case, if there is one terminal symbol having directionality, it is possible to distinguish the position and orientation of the dimension line. If there is no terminal symbol or there is no direction even if there is only one terminal symbol, it is not possible to distinguish between the time shown in FIG. 19B or the time shown in FIG.
By such processing, the coordinates (X1, Y1) of an arbitrary point P1 on the dimension line or its extension and the angle θ of the dimension line can be obtained.
[0024]
FIG. 21 is a flowchart showing details of the start point determination process that is subsequently performed on the dimension extension lines that are distinguished by the above determination.
First, the CPU 3 obtains the distance from the vertex of the terminal symbol to the end point of the dimension extension line passing through the point (S71), and checks whether there is a combination of end points that are not the same distance (S72). If there is a combination of end points that are not the same distance (S72), the CPU 3 determines that the combination is the starting point of the dimension extension line (S73). Therefore, in the case of FIG. 22A, the distance from the vertex V3 of the terminal symbol to the end point V1 is the same as the distance from the vertex V4 of the terminal symbol to the end point V5, and the distance from the vertex V3 to the end point V2 Since the distance from the vertex V4 to the end point V6 is different, the end point V2 and the end point V6 are determined as the start points of the dimension extension line.
[0025]
On the other hand, if there is no combination of end points that are not the same distance (S72), the CPU 3 checks whether there is a combination of end points that are far away (S74). If there is a combination of the far end points (S74), the CPU 3 determines that the combination is the starting point of the dimension extension line (S73). Accordingly, in the case of FIG. 22B, the distance from the terminal symbol vertex V3 to the end point V1 is the same as the distance from the terminal symbol vertex V4 to the end point V5, and the distance from the vertex V3 to the end point V2 Although the distance from the vertex V4 to the end point V6 is also the same, since the end points V2 and V6 are far from the end points V1 and V5, the end point V2 and the end point V6 are determined as the start points of the dimension extension line. As shown in FIG. 22C, if there is no combination of distant end points (S74), analysis as a dimensional figure is impossible, and conversion processing is executed as a normal figure (S75).
By such processing, the coordinates (X2, Y2) and (X3, Y3) of the starting points P2, P3 of the two dimension extension lines can be obtained.
[0026]
According to this embodiment, the measurement information of the dimension element is not in the format, that is, as shown in FIGS. 24B and 24C, there is no starting point P2 of the dimension extension line, and there is no angle of the dimension line. Even in this case, correct measurement information P1, P2, P3, θ according to the format can be obtained while analyzing topologically and geometrically the graphic elements included in the dimensional composite graphic. There will be no reading error, and the dimension line will not be deformed when the dimension is remeasured after reading.
[0027]
Further, in this embodiment, not only the measurement information possessed by the DXF dimension element but also the information generally possessed by the dimension line element other than DXF, that is, the terminal symbol, the size, type, orientation (inner dimension / outer dimension), dimension If the presence / absence of a line and the presence / absence of a drawing length and a dimension extension line in the case of parallel drawing are obtained, these pieces of information can be converted into data.
[0028]
In the above-described embodiment, the case where the dimension graphic relates to the length dimension line has been described, but the present invention can also be applied to the case where the dimension graphic relates to the angle dimension line. In this case, since the dimension line is an arc, integration is performed based on the center point and the radius. Further, as shown in FIG. 23, when the center angle of the V-shaped line 11 having an axial direction perpendicular to the dimension extension line is set to 60 ° and an angle dimension line having a center angle of 60 ° is written, the two V-shaped lines 11 are written. Since one side of each of the two becomes a straight line and is integrated into one metaline, it is preferable not to delete the multiple sides in the angular dimension line or to integrate the metalines between the metalines having a gap.
[0029]
【The invention's effect】
As described above, according to the present invention, when converting drawing data between different data formats through an intermediate format such as DXF, the graphic elements included in the data converted into the dimension elements and the dimension composite figure While analyzing topologically and geometrically, the points on the straight line including the dimension line that is the dimension figure, the start points of the two dimension extension lines that are the dimension figure, and the inclination of the dimension line are obtained. The correct measurement information can be obtained.
[Brief description of the drawings]
FIG. 1 is a block diagram showing the configuration of a CAD system to which a method for converting a drawing file into an intermediate format according to an embodiment of the present invention is applied.
FIG. 2 is a diagram showing an example of a meta graphic database.
FIG. 3 is a flowchart showing DXF dimension conversion processing;
FIG. 4 is a flowchart showing a procedure of a dimensional graphic analysis method.
FIG. 5 is a flowchart showing details of overlapping point erasing processing and multiple side erasing / metaline integration processing;
FIG. 6 is a diagram for explaining the elimination of overlapping points.
FIG. 7 is a diagram for explaining multiple side erasure and metaline integration;
FIG. 8 is a diagram showing a meta-graphic database of one-dimensionally drawn dimensional graphics.
FIG. 9 is a diagram showing a meta graphic database after overlapping points and multiple edges are erased and meta lines are integrated.
FIG. 10 is a diagram illustrating an example of a terminal symbol and a closed figure.
FIG. 11 is a flowchart showing details of a terminal symbol and closed graphic separation process.
FIG. 12 is a flowchart showing details of a closed figure determination process;
FIG. 13 is a diagram for explaining determination of a closed figure.
FIG. 14 is a flowchart showing details of a terminal symbol removal process.
FIG. 15 is a flowchart showing details of shape analysis processing based on terminal symbols and shape analysis processing based on intersection codes.
FIG. 16 is a diagram for explaining determination of a dimension line and a dimension auxiliary line based on an intersection code.
FIG. 17 is a diagram for explaining shape analysis when there are two sets of parallel metalines;
FIG. 18 is a diagram for explaining determination of an outer dimension and an inner dimension.
FIG. 19 is a diagram for explaining determination of a dimension extension line in a special case.
FIG. 20 is a diagram for explaining determination of a dimension line in a special case.
FIG. 21 is a flowchart showing details of a dimension auxiliary line start point determination process;
FIG. 22 is a diagram for explaining start point determination of a dimension extension line;
FIG. 23 is a diagram illustrating an example of an angular dimension line.
FIG. 24 is a diagram showing an example of measurement information held by a dimension element.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Input device, 2 ... Recording device, 3 ... CPU, 4 ... RAM, 5 ... ROM, 6 ... Output device.

Claims (2)

When converting drawing data including dimension figures and dimension elements necessary for dimension measurement between different data formats used in the CAD system through the intermediate format, the dimensions included in the drawing data converted into the intermediate format While analyzing the figure topologically and geometrically, the inclination of the dimension line in the dimension figure and the point on the straight line including the dimension line and the starting point of the two extension lines in the dimension figure are determined, and these points and A method for converting a drawing file into an intermediate format, wherein dimension elements on the intermediate format are reconstructed based on an inclination. The dimension graphic analysis process is:
A first step of recording an angle of a line segment paired with a side in the dimension figure, coordinates of two end points, and a connection relationship thereof;
A second step of replacing the overlapping points with one point when the end points overlap, and replacing the overlapping line segments with one line segment when the infinite length of the line segments overlaps;
A third step of erasing the line segment and the end point paired with the closed figure in the dimension figure while replacing the line segment and the end point paired with the terminal symbol in the dimension figure with one vertex;
Based on the vertex obtained in the third step, the line segment and the end point obtained in the second step, the dimension line and the two dimension extension lines in the dimension figure are determined, and the inclination of the dimension line and this A fourth step for obtaining a point on a straight line including:
5. The method for converting a drawing file into an intermediate format according to claim 1, further comprising: a fifth step of obtaining a starting point of the dimension extension line.

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