JPH07320089A - Line-hiding editing system - Google Patents

Abstract

PURPOSE:To facilitate the operation and shorten the time for a line-hiding process by providing a specific cover surface specification part and a specific line-hiding process part. CONSTITUTION:The cover surface specification part 5 is equipped with a function which accepts data on a cover surface as a line-hiding area inputted through an input part 4 and stores the data in a memory table 3 through a component arrangement part 6. The line-hiding process part 7 is equipped with an intersection decision part 7a, an intersection extraction part 7b, and a line- hiding execution part 7c. And, the intersection decision part 7a has a function which decides whether or not a figure element crosses an area line constituting the cover surface, and an intersection extraction part 7b a 1st flag to the start point of the figure element and the intersection with another figure element and a 2nd flag to the intersection with the area line when the intersection decision part 7a decides that there is the intersection. Further, the line hiding execution part 7c has a function for the line hiding process in the section of a part having the 2nd flag halfway and given the 1st flags at both the ends between the start point and end point of the figure element.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a figure hidden line editing system which performs a hidden line overlapping process.

[0002]

2. Description of the Related Art In a CAD system, various designs are made and various figures are arranged to create a predetermined drawing. And when such figures are arranged, a plurality of figures may overlap each other. In such a case,
It is necessary to perform hidden line processing such as erasing or making a broken line in the area of the back side graphic covered by the front side graphic.

[0003]

However, in the conventional hidden line processing system, the hidden line processing requires a complicated operation and a lot of time, so that the operation is easy and the hidden line processing is performed. There has been a demand for the realization of a hidden line editing system for figures that can reduce the time required.

[0004]

In order to solve the above-mentioned problems, the hidden line editing system for figures according to the present invention is a cover surface designating unit for designating a cover surface for designating an area to be covered. To provide. In addition, if any figure element that composes a figure intersects another figure element and the area line of the covering surface specified by the covering surface designating section intersects between the intersections, any figure The line between the intersections with other graphic elements in the element is hidden, and the end points of any graphic element are located in the area of the covering surface, and the end points, and the graphic elements and other graphic elements When the area line of the covering surface intersects with the intersection point of and, the line between the intersection points of the end points and other graphic elements is hidden, and the line between the When both end points of the graphic element are located, a hidden line processing unit for performing a hidden line processing on the entire graphic element is provided.

[0005]

In the figure hidden line editing system of the present invention, when the operator designates the covering surface, the covering surface designating section accepts the designation of the covering surface. As a result, the hidden line processing unit, if any figure element forming the figure intersects another figure element and the area line forming the covering surface intersects between the intersections, The line between the intersections of arbitrary graphic elements with other graphic elements is hidden. Also, the end points of arbitrary graphic elements are located in the area of the covering surface,
And if the area line of the covering surface intersects between the end point and the intersection of the graphic element and another graphic element, the line between the end point and the intersection of the other graphic element is hidden. To process. Furthermore,
When both end points of an arbitrary graphic element are located in the area of the covering surface, the entire graphic element is hidden.

[0006]

Embodiments of the present invention will now be described in detail with reference to the drawings. << Embodiment >> FIG. 1 is a block diagram showing an embodiment of a hidden line editing system for graphics according to the present invention. The system shown in the figure includes a drawing database 1, a drawing citation unit 2, a memory table 3, an input unit 4, a cover surface designation unit 5, a component placement unit 6, a hidden line processing unit 7, a hidden line table 8, and a display control unit 9. , Display monitor 10
Consists of.

The drawing database 1 is a drawing database that manages drawing data created by a CAD system in a file. The drawing citation section 2 retrieves an arbitrary drawing from the drawing database 1 and cites the drawing.
The memory table 3 is a memory for storing the drawings cited by the drawing citation unit 2 and the drawing data arranged by the component arranging unit 6. The input unit 4 is an input unit including a keyboard 4a for inputting numerical values and characters, a mouse 4b for inputting a position on the screen, and the like.

The cover surface designation unit 5 has a function of receiving data of the cover surface, which is a hidden line area, input by the input unit 4 and storing the data in the memory table 3 via the component placement unit 6. ing. The cover surface will be described later. The component placement unit 6 changes the component shape quoted on the screen to
It is configured to be designated based on the operator's instruction from the input unit 4 and to be arranged at the component mounting position.

The hidden line processing unit 7 determines that, when an arbitrary graphic element forming a graphic intersects with another graphic element, and a region line forming a covering surface intersects between the intersections. The line between the intersections of the arbitrary graphic element and other graphic elements is hidden, and the end point of the arbitrary graphic element is located in the area of the covering surface, and that end point and the above-mentioned arbitrary If the area line of the covering surface intersects between the intersection of the graphic element of and the other graphic element, the line between the end point and the intersection of the other graphic element is hidden, and further, When both end points of an arbitrary graphic element are located within the area of the covering surface, the function of performing the hidden line processing on the entire graphic element is provided.

Further, the hidden line processing unit is the intersection determination unit 7a.
And an intersection extraction unit 7b and a hidden line execution unit 7c. Here, the intersection determination unit 7a has a function of determining whether or not the graphic element intersects with a region line that forms the covering surface, and the intersection extraction unit 7b determines that the determination result of the intersection determination unit 7a intersects. If it is, the intersections of the graphic element and other graphic elements and the intersections of the area lines are extracted, and the first flag is set at the start and end points of the graphic element and the intersections with other graphic elements.
A second flag is added to the intersection with the area line.
Further, the hidden line execution unit 7c has a function of performing the hidden line processing on the section between the start point and the end point of the graphic element to which the first flag is added on both sides having the second flag in the middle. There is something.

The hidden line table 8 is a table used when the hidden line processing unit 7 performs the hidden line processing. Also,
The display control unit 9 is a control unit for displaying the graphic processed by the hidden line processing unit and the graphic stored in the memory table 3 on the display monitor 10.

Next, the operation of the cover surface designating section 5 will be described. FIG. 2 is an operation explanatory diagram of the covering surface designation unit 5. In the figure, 101 is a mouse cursor indicating the position of the mouse 4b on the display monitor 10, 102 is a rectangular area in which the covering surface is surrounded by a rectangle, and 103 is a polygonal area in which the covering surface is surrounded by a polygon. The cover surface designating unit 5 makes the part in which the part drawing A and the part drawing B overlap with each other by hidden lines (at this time, the part drawing A is arranged on the front side and the part drawing B is arranged on the rear side). As shown in FIG. 2A, when the surface shape of the overlapping portion is relatively simple, the diagonal line (P1, P2) of the rectangular area 102 is designated by the mouse cursor 101. Further, as shown in FIG. 2B, when the surface shape of the overlapping portion is oblique or complicated, each end point (P3 to P8) of the polygonal area 103 is designated by the mouse cursor 101. .

In this case, it is not necessary to exactly enclose the designated area of the covering surface, and if the line to be hidden is covered, it is only necessary to roughly enclose the inside of the actual surface. In addition, here, it is assumed that it can be arbitrarily selected whether it is surrounded by the rectangular area 102 or the polygonal area 103.

Next, the operation of this embodiment will be described.
FIG. 3 is an explanatory diagram of the cover surface designation in the hidden line processing. First, the part database C and the part diagram D are the drawing database 1
Stored in. Part diagram C shows a part having one rectangular hole (consisting of L5 to L8) and two round holes (C1 and C2) in a rectangular shape (consisting of L1 to L4),
Part diagram D shows a part having one rectangular hole (configured by L13 to L16) in a rectangular shape (configured by L9 to L12).

In such a state, the drawing reference unit 2 takes out the data of the parts drawing C and the parts drawing D and stores them in the memory table 3. Next, the operator operates the input unit 4 and arranges the component drawing C and the component drawing D by the component arrangement unit 6. As a result, the display control unit 9 causes the display monitor 10 to display a drawing in which the component drawing C and the component drawing D are combined, as shown in FIG.

After that, the operator designates the covering surface as shown in FIG. 3C by the operation of the covering surface designating section 5 described above. The designation in this case is the rectangular area 102.
a (composed of L17 to L20). Then, the graphic elements (L1 to L16,
C1, C2) coordinate data and rectangular area 102a (L
The coordinate data (17 to L20) are stored in the memory table 3.

Next, the operation of the hidden line processing unit 7 will be described.
FIG. 4 is an operation flowchart of the hidden line processing unit 7.
First, the intersection determination unit 7a of the hidden line processing unit 7 extracts one graphic element (L1 to L16, C1, C2) from the memory table 3 (step S1), and the graphic element covers the area line ( It is determined whether or not it intersects L17 to L20) (step S3). It is assumed here that the extraction of the graphic element from the memory table 3 has not been completed in step S2. In the step S3, in the case of intersecting graphic elements (L1, L3 and C1), the graphic elements are once erased from the memory table 3 (step S3).
4), the intersection extraction unit 7b displays the area lines (L17 to L) of the covering surface.
20) and the target graphic element and all the cross points of other graphic elements in the memory table 3 and the target graphic element are calculated (step S5).

FIG. 5 shows a straight line L that intersects the area line of the covering surface.
It is explanatory drawing at the time of performing a hidden line process of 1. Here, an intersection P9 with the area line L17 and an intersection P1 with the area line L19
0, the intersection point P11 with the straight line L9 of the part drawing D and the straight line L1
The intersection P12 with 3 is calculated. Next, the intersection calculated in step S5 and the start / end points of the graphic element are stored in the hidden line table 8 and rearranged from the start point to the end point direction (step S6).

That is, referring to FIG. 5, the straight line L
Coordinates of a total of 6 points including the start point P13 and the end point P14 of 1 and the intersection points P9 to P12 calculated in step S5 are stored in the hidden line table 8. Then, at this time, as a hidden line flag added to each point, "1" which is the first flag at the end point (start point or end point) and the intersection with another graphic element is set to the area line of the covering surface. A second flag "0" is stored at the intersection. Then, the contents of the hidden line conversion table 8 are rearranged so that the coordinate values are arranged from the start point to the end point.

Next, the hidden line execution unit 7c extracts one graphic element to be hidden from the hidden line table 8 (step S7) and determines whether it is a front graphic element or a rear graphic element (step S7). Step S9). This will be described with reference to FIG. 5. With the contents of the hidden line table 8 after rearrangement, the hidden line flag is searched from the beginning and the hidden line flag is “1” to “0” or “0” to “1”. A figure that connects the coordinates of the boundary that changes to (P1
3-P12, P12-P11 and P11-P14) are taken out, and the figure (P12-P11) having the hidden line flag "0" in the middle is the figure hidden on the rear side, and the others are the figures displayed on the front side. I know there is. In the flowchart of FIG. 4, the data extraction end determination in the hidden line table in step S8 assumes that the data to be extracted remains.

The graphic element determined to be the front graphic element in step S9 is newly registered in the memory table 3 as a solid line shape (step S10). On the other hand, the graphic element determined to be the rear surface graphic element is determined whether the current processing method is the erase mode or the broken line mode (step S11). It is newly registered in the memory table 3 (step S
12). Further, in the case of the erasing mode, the entire graphic element has already been erased in step S4, so that no special processing is required. It is possible to arbitrarily select whether the current processing method is the erasing mode or the broken line mode.

The above steps S7 to S12 are repeated until all the data in the hidden line table 8 are extracted. If it is determined in step S8 that there are no more graphic elements to be extracted, the process returns to step S1. The next graphic element is fetched from the memory table 3 and the above-mentioned processing is repeated. Then, similarly, step S1 to step S
By performing the processing of 12, the hidden line processing is performed on the linear graphic elements L1 and L3 and the circular graphic element C1 in the part drawing C. Even in the case of a circular graphic element, by considering that the start point and the end point are arcs with the same coordinates,
It can be processed in the same manner as the linear graphic element described above.

If it is determined in step S3 that the figure element does not intersect the area line of the covering surface,
In step S13, it is determined whether the graphic element is completely included in the area of the covering surface. even here,
If it is determined to be "no", the graphic element does not occupy the area of the covering surface, and the process returns to step S1. On the other hand, in step S13, when the figure element is completely included in the area of the covering surface, it is determined whether the current processing method is the erase mode or the broken line mode (step S14). In the case of the broken line mode, the graphic element is changed to the broken line shape (step S15). In the erase mode, the graphic element is erased from the memory table 3 (step S16). As described above, the rectangular holes (L5 to L8) in the component drawing C are erased or broken by the processing of steps S13 to S16.

In the above embodiment, the straight line L1 of the parts drawing C is used.
Although the end point of is on the front side, the hidden line can be processed by the same method as above even when this end point is on the rear side of the hidden line. FIG. 6 shows an example thereof. In such a case, the content of the hidden line table 8 of the straight line L1 becomes P13, P9, P11, P14 (after rearrangement) in correspondence with FIG. 5, and the hidden line flag is 1, 0, 1 It becomes 1.

Even in such a case, the hidden line processing unit 7
The end point P13 of the straight line L1 is located in the rectangular area 102a,
Moreover, the intersection point P between the end point and the straight line L1 and another graphic element
Since the area line L9 intersects with 11, the end point P
Line P13-P1 between intersection points P11 of 13 and other graphic elements
Hidden line 1 is processed. Further, the straight line L4 is the rectangular area 10
Since both end points of the straight line are located in 2a, the straight line L4 is also hidden by the processing of steps S13 to S16 described above.

As described above, the hidden line editing system for graphics of the present embodiment can easily and accurately perform the hidden line processing. However, in order to explain this in detail, the operator can visually perform the hidden line processing. A method of performing the processing will be described below as a comparative example.

<< Comparative Example >> FIG. 7 is a block diagram of a system of a comparative example. The drawing system is the drawing database 1
The drawing database 1 to the input unit 4, the component placement unit 6, the display control unit 9, the display monitor 10
The configuration of is the same as that of the above embodiment. Figure designator 11
Is for designating a graphic on the screen by the input unit 4. Further, the component placement unit 6 is configured to specify the component shape quoted on the screen by the graphic designating unit 11 and place the component shape at the component mounting position. The graphic cutting unit 12
The graphic erasing unit 13 has a function of cutting the graphic of the overlapping part of the component, and the graphic erasing unit 13 has a function of erasing the overlapping part of the component.
The graphic broken line forming section 14 has a function of making the overlapping portion of the parts into a broken line.

In the system configured as above, the hidden line processing is performed as follows. FIG. 8 is an explanatory diagram of the hidden line editing process. First, when drawing a drawing such as an assembly drawing, the drawing data of the necessary parts drawing (A, B) is quoted from the drawing database 1 by the drawing quoting unit 2 on the screen, and the shape designating unit 11 instructs the shape of the component. The component placement unit 6 places each component shape at an appropriate position. Here, in the part where the parts are overlapped, it is necessary to partially erase or make a broken line in the shape of the part drawing B arranged on the rear surface side.

There are various methods for erasing or making a part of the shape into a broken line depending on the system. Generally, however, each of the graphic elements constituting the shape of the component arranged on the rear surface side ( In this case, L20, L21, L2
2, C3), the graphic cutting unit 12 cuts at the intersections (P15 to P21) of the shapes of the components arranged on the front side, while instructing by the graphic designating unit 11. Then, after dividing into a shape of a portion displayed on the front side and a shape hidden on the rear side, the shape is erased or broken by the graphic erasing unit 13 or the graphic broken line forming unit 14.

Specifically, first, the graphic element L of the parts drawing B is shown.
20 is the intersection P1 of the graphic elements L23 and L24 of the part drawing A
5, the shape of the hidden part P15-P1 cut at P16
6 parts are erased or broken. Next, the graphic element L21
For, regarding P17 to P18, the P17-P18 portion is cut and then erased or broken. Similarly, L22 and C3 are erased or broken.

In such a method, it is necessary to cut, erase, or make a broken line for each figure element to be hidden, and it takes a very long time, while the figure hidden in the embodiment is hidden. In the line-editing system, the operator only needs to specify the area to be hidden by the covering surface, and therefore the hidden-line processing can be performed quickly.

In the above embodiment, the first flag is set at the start point and end point of the graphic element and at the intersections with other graphic elements.
Also, a second flag is added to the intersection with the area line on the covering surface, and the section between the start point and the end point of the graphic element where the first flag is added on both sides having the second flag in the middle is hidden. Since it is configured to perform the linearization processing, it is possible to accurately perform the hidden processing of the graphic element with a simple configuration.

In the above-described embodiment, the case of the straight line graphic element and the circular graphic element in the graphic element for performing the hidden line processing has been described, but the shape is not limited to these shapes, and various curved lines and the like can be used. Even if there is, it can be applied similarly.

[0034]

As described above, according to the figure hidden line editing system of the present invention, a covering surface is designated in an area to be hidden by overlapping figures, and any figure element is replaced with another figure. If it intersects with an element and the figure element and the area line that composes the covering surface intersect, the line between the intersections with other figure elements is hidden, and the area inside the covering surface If the end point of a graphic element is located and the area line of the covering surface intersects between that end point and the intersection of the graphic element with another graphic element, the end point and the other graphic element The line between the intersections is hidden, and if both end points of the graphic element are located in the area of the covering surface, the whole graphic element is hidden. It is possible to shorten the time and the burden on the operator.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a hidden line editing system for graphics according to the present invention.

FIG. 2 is an operation explanatory diagram of a covering surface operation unit in the hidden line editing system for graphics of the present invention.

FIG. 3 is an explanatory diagram of covering surface designation in the hidden line editing system for graphics of the present invention.

FIG. 4 is a flowchart of hidden line processing in the figure hidden line editing system of the present invention.

FIG. 5 is an explanatory diagram of a hidden-line processing of a straight-line figure in the figure hidden-line editing system of the present invention.

FIG. 6 is an explanatory diagram of another case of hidden line straightening processing in the figure hidden line editing system of the present invention.

FIG. 7 is a block diagram of a system of a comparative example.

FIG. 8 is an explanatory diagram of hidden line processing in the system of the comparative example.

[Explanation of symbols]

 3 memory table 4 input unit 5 covering surface designation unit 7 hidden line processing unit 7a intersection determination unit 7b intersection extraction unit 7c hidden line execution unit 8 hidden line table 10 display monitor

Claims (2)

[Claims] 1. A hidden line editing system for a figure, which performs a hidden line process on an area covered by overlapping figures, and a cover plane designating unit for designating a cover plane for designating the area to be hidden, In the case where any of the constituent graphic elements intersects another graphic element, and the area line forming the covering surface intersects between the intersections, the other graphic element in the arbitrary graphic element The line between the intersection points is hidden, and the end point of any figure element is located in the area of the covering surface,
And, when the area line of the covering surface intersects between the end point and the intersection of the graphic element and another graphic element, a line between the intersection of the end point and the other graphic element. Hidden line processing is performed, and when both end points of an arbitrary graphic element are located in the area of the covering surface, a hidden line processing unit for performing a hidden line processing on the entire graphic element is provided. A hidden line editing system for figures. 2. The hidden line editing system for a graphic according to claim 1, wherein the hidden line processing unit is an intersection determination unit that determines whether or not the graphic element intersects a region line forming a covering surface. When the determination result in the intersection determination unit is an intersection, the intersection of the graphic element and another graphic element and the intersection of the area line are extracted, and the start point and end point of the graphic element and other An intersection extraction unit that gives a first flag to an intersection with a graphic element and a second flag to an intersection with the area line, and both sides having a second flag in the middle between the start point and the end point of the graphic element And a hidden-line executing unit that performs a hidden-line process on a section of the part to which the first flag is added.