JPH07192144A - Method and device for cutting and editing polyhedral solid - Google Patents

Abstract

PURPOSE:To make it possible to perform the cutting and editing processing on a plane even if data quantity is a little by cutting and editing a solid model by the number of the crossing points of a specified edge line and a cut plane. CONSTITUTION:Based on the data registered in a solid model data part 1, a solid model processing part 7 performs the cutting and editing processing of a solid model by utilizing plane (cut plane) data to be inputted from the outside. In this case, one of the surfaces of the solid model composed of a polyhedron is defined as a first surface and the other surface of the solid model facing this first surface each other is defined as a second surface. The crossing point of the set column of plural points composing each contour of the first surface and the second surface and the cutting surface for cutting and editing the solid model and the crossing point of the edge line connecting the point composing the set column of the first surface and the point composing the set column of the second surface facing this point each other and the cutting surface are determined, respectively. By the number of each crossing point, the cutting direction for the solid model is determined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyhedral solid cutting / editing method and apparatus for creating / editing a polyhedral solid model by cutting along a cutting plane.

[0002]

2. Description of the Related Art A computer treats a three-dimensional shape of an object as a solid model and creates a solid model.
As a processing system having an edit processing function, that is, a CAD system, there is, for example, one described in Japanese Patent Laid-Open No. 2-41573. This system requires the following data for one solid model. (1) Shape data for solid model (2) Two-dimensional auxiliary data including two-dimensional drawing and character data for solid model (3) Three-dimensional auxiliary data used by application for solid model (4) Solid model is placed Graphic data on a plane in three-dimensional space

[0003]

By the way, in general, CA
In the D system, the smaller the amount of data given, the faster the processing speed, and the more advanced and reliable the system will be. However, in the conventional technology described above,
As shown in (1) to (4) for the solid model, an extremely large amount of data is required, and there is room for improvement as a CAD system.

On the other hand, in such a CAD system, assuming that the processing for cutting and editing on a plane is performed on a solid model made up of polyhedra, one solid model made up of, for example, a cube or a rectangular parallelepiped is used.
Since surface data consisting of point data at one corner and ridge line data connecting the corners is necessary, and the mutual positional relationship of the six surfaces formed by a cube (rectangular parallelepiped) is also necessary as data. However, the amount of data becomes large, the processing speed becomes slow, and the reliability of the system decreases. Conversely, if the amount of data registered for one polyhedral solid is small,
Even if a large amount of data is obtained, the processing speed does not slow down, but on the other hand, the cutting and editing processing on the plane of the polyhedral solid cannot be performed.

Therefore, an object of the present invention is to enable cutting and editing processing on a solid model in a plane even if the amount of data relating to the solid model composed of a polyhedron is small.

[0006]

In order to achieve the above-mentioned object, the present invention firstly sets one surface of a solid model composed of a polyhedron as a first surface, and faces the first surface. The other surface of the solid model is
Of the first surface and the second surface, and an intersection of a set of a plurality of points forming the contours of the first surface and the second surface and a cutting plane for cutting and editing the solid model, and the first surface. And a point that constitutes the set sequence of
The ridgeline connecting the points forming the set sequence of the surface of, and the intersection points with the cutting plane are respectively obtained, and by the number of these intersection points,
This is a method for determining the cutting direction for the solid model.

Secondly, one surface of the solid model made up of polyhedra is the first surface, and the other surface of the solid model facing the first surface is the second surface, and the first surface is the second surface. A solid model data section for storing a set sequence data of a plurality of points forming respective contours of the first face and the second face, and points constituting the set sequence and the set sequence of the first face. A cutting edit process for determining the cutting direction for the solid model by the number of intersections of the ridge line connecting the point and the point forming the set sequence of the second surface facing this point and the cutting plane for cutting the solid model. It is configured to include a section.

[0008]

According to the first method or the second configuration, the first facing each other in the solid model composed of the polyhedron.
Based on the set sequence data of a plurality of points forming the contours of the respective faces and the second faces, and the set of these set sequences and the points forming the set sequence of the first faces and the set of the second faces facing this point. The solid model can be cut and edited by the number of intersections of the ridge line connecting the points forming the column and the cutting plane for cutting the solid model.

[0009]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic block diagram of the same editing apparatus including a CPU and a memory used in the method for cutting and editing a polyhedral solid according to an embodiment of the present invention. Hereinafter, a solid model composed of a polyhedron will be treated as a rectangular parallelepiped or a cube as shown in FIG. As the data necessary for cutting this solid model in a plane, as seen in the solid model data part 1 shown in FIG. 1, the upper surface 3 as the first surface of the solid model composed of a hexahedron and this upper surface 3 Is the vector of the bottom surface 5 as the second surface facing to.

As the vector of the upper surface 3, the number of points forming the contour of the upper surface 3 (when a representative corner point in FIG. 2 is shown, starting point U ₁ is U ₂ , U ₃ , U ₄ and , The end point is U ₅ point) and the coordinate values (x, y, z) of the plurality of points in the three-dimensional space. As for the vector of the bottom surface 5, as in the case of the top surface 3, the number of points forming the contour of the bottom surface 5 (D ₂ , D ₃ , D ₄ with the same D ₁ point as the start point and D ₅ point as the end point) and this It includes coordinate values (x, y, z) in a three-dimensional space of a plurality of points.

Based on the data registered in the solid model data section 1 described above, the solid model processing section 7
Cuts and edits a solid model using plane (cutting plane) data input from the outside. The processing method will be described below.

FIG. 3 is a flow chart showing a process for determining from which direction a solid model is cut by a cutting plane. As the cutting direction, see FIG.
As shown in (a) to (e), the cutting direction of the cutting plane 11 with respect to the solid model 9 is in five ways: side surface-side surface, bottom surface-side surface, top surface-side surface, top surface-bottom surface, and top surface-side surface-bottom surface. Be divided. In determining each such cutting direction, first, with respect to the cutting plane 11, the solid model 9
A process of obtaining an intersection of a set sequence of points (hereinafter, simply referred to as a sequence of points) constituting the cutting plane and the cutting plane 11 is performed (step 30).
3). As the sequence of points forming the solid model 9, in addition to the sequence of points forming the contours of the top surface 3 and the bottom surface 5 described above, a ridge line L connecting the point on the top surface 3 and the point on the bottom surface 5 facing this point.
There are point sequences at ₁ , L ₂ , L ₃ , L ₄ , and L ₅ .

In the following processing, corner points U ₁ , U ₂ , U ₃ , U ₄ , U _{5 on} the upper surface 3 and corner points D ₁ , D ₂ , D ₃ , D ₄ , D
₅ is treated as included on the ridge lines L ₁ , L ₂ , L ₃ , L ₄ , and L ₅ sides, respectively.

As the processing for obtaining the above-mentioned intersections, as shown in the next step 305, A: judgment whether or not there are two intersections between the point plane on the upper surface 3 and the cutting plane B: the point sequence on the bottom surface 5 Judgment whether or not there are two intersections with the cutting plane C: It is judged whether or not there is at least one intersection between the ridgeline on the side surface and the cutting plane. The cutting direction shown in is determined.

First, the side-to-side cutting of FIG.
This is a case where only the judgment result of C is “present”. here,
The case where the ridgeline of the side surface and the cutting plane 11 intersect at one point is also included, but this is the case where the cutting plane is in contact with the corner portion, and in this case as well, it is regarded as the side-side cutting.

The bottom-side cutting of FIG. 4B is when the judgment results of B and C are "present". That is, this is the case where the cutting plane 11 intersects the point sequence on the bottom surface at two points, and intersects the ridgeline on the side surface at one or more points (here, two points).

The cutting from the upper surface to the side surface in FIG. 4 (c) is when the judgment results of A and C are "present". That is, this is the case where the cutting plane 7 intersects the point sequence on the upper surface at two points and intersects the ridgeline on the side surface at one or more points (here, two points).

The top-bottom cutting in FIG. 4D is the case where the judgment results of A and B are "Yes", and the cutting plane 1
This is the case where 1 intersects both the point sequence on the top and the point sequence on the bottom at two points.

The top-side-bottom cut of FIG.
When all the judgment results of A, B, and C are “Yes”, the cutting plane 11 intersects both the point sequence on the top surface and the point sequence on the bottom surface at two points, and the ridgeline on the side surface and one or more points. This is the case where they intersect at two points here.

Other combinations, namely A, B and C
When all the judgment results of “No” are “No”, only the judgment result of “B” is “Yes” and only the judgment result of “A” is “Yes”
In the case of, error processing is performed.

Next, the processing method in each of the cutting directions shown in FIGS. 4A to 4E will be described step by step.

FIG. 5 shows a flow chart for side-to-side cutting. First, the coordinate value of the intersection of the ridgeline of the side and the cutting plane 11 is obtained (step 505). The coordinate value of the intersection is input to the bottom surface of the upper solid 9a after cutting (step 507), and the coordinate value of the intersection is input to the upper surface of the lower solid 9b after cutting (step 509). As a result, the side-to-side cutting process is completed by the cutting plane 11 for the solid model 9.

FIG. 6 is a flow chart for bottom-side cutting, and FIG. 7 is an explanatory view of the processing operation in the cutting process. The intersection points D ₁₁ and D ₁₂ of the bottom surface are projected in the sweep direction (the direction perpendicularly connecting the top surface and the bottom surface, here, the direction toward the top surface) (step 601), and the intersection points D ₁₁ and D of the bottom surface are projected.
_A plane is defined by ₁₂ and four projection points U ₁₁ and U _{12 on} the upper surface (step 603). The solid model 9 is cut along the defined plane 13 by the top-bottom cutting process (step 605). 2 caused by cutting the top-bottom
Intersection points L ₁₁ and L _{12 on the} sides of the two solids 15 and 17
The side-to-side cutting processing is performed on the solid 15 on the side having the first cutting plane 11 (step 607). As a result, the bottom surface-side surface cutting edit processing is completed by the cutting plane 11 for the solid model 9.

FIG. 8 shows a flowchart for cutting from the upper surface to the side surface, and FIG. 9 is an explanatory view of the processing operation in the cutting processing process. The intersections U ₁₃ , U ₁₄ of the upper surface are projected in the sweep direction (the direction perpendicularly connecting the upper surface and the bottom surface, here, the direction toward the lower surface) (step 801), and the intersections U ₁₃ , U of the upper surface are projected.
_A plane is defined by four points of ₁₄ and projection points D ₁₃ and D _{14 on} the bottom surface (step 803). The solid model 9 is cut along the defined plane 19 by the top-bottom cutting process (step 805). 2 caused by cutting the top-bottom
Intersection points L ₁₃ and L _{14 on} one side of the two solids 21 and 23
The side 21 of the solid 21 on the side where there is is subjected to side-to-side cutting processing at the first cutting plane 11 (step 807). As a result, the cutting / editing process of the top surface-side surface of the solid model 9 is completed by the cutting plane 11.

FIG. 10 shows a flowchart for the above-described bottom-side cutting and top-side cutting used in the top-side cutting. The solid model 9 is cut at the cutting plane 11 at the plane connecting the two intersections of the top surface and the two intersections of the bottom surface, which is caused by the cutting shown in FIG.
For the two solids 23 and 25 shown in (1), the point sequences on the respective upper surfaces are rearranged and newly set (step 1001), and the point sequences on the respective bottom surfaces are rearranged and newly set (step 1003). The point sequence data of the top and bottom of the two solids 23 and 25 set to
Input to the solid model data section 1.

FIG. 11 is a flowchart for cutting the top surface, the side surface, and the bottom surface, and FIG. 12 is an explanatory view of the processing operation in the cutting processing process. The intersection points D ₁₅ and D ₁₆ on the bottom surface are projected onto the upper surface in the sweep direction (step 1201), and the plane is defined by the intersection points D ₁₅ and D ₁₆ on the bottom surface and the projection points U ₁₅ and U _{16 on} the upper surface ( Step 1203). Defined plane 2
In step 7, the solid model 9 is cut by the top-bottom cutting process (step 1205).

Next, the intersection points U ₁₇ and U ₁₈ on the upper surface are projected on the bottom surface in the sweep direction (step 1207) and the intersection point U on the upper surface is projected.
_A plane is defined by four points ₁₇ and U ₁₈ and projection points D ₁₇ and D _{18 on} the bottom surface (step 1209). The solid model 9 is cut along the defined plane 29 by top-bottom cutting processing (step 1211).

The central solid 3 on the side where the intersections L ₁₅ and L ₁₆ are on the sides with respect to the three solids 31, 33 and 35 generated by the cutting process by the two planes 27 and 29.
3 is subjected to side-to-side cutting processing on the first cutting plane 11 (step 1213). As a result, the cutting / editing process of the top surface / side surface / bottom surface of the solid model 9 is completed by the cutting plane 11.

FIG. 13 shows a polyhedral solid model,
It is a flow chart which shows processing operation at the time of making a hole, and Drawing 14 is an explanatory view in the same processing operation. First, it is judged whether it is a polyhedron, or a rectangular parallelepiped or a cube (step 1301), for example, as shown in FIG.
In the case of a polyhedron as shown in (a), the solid model 3 of a rectangular parallelepiped (cube) is cut as shown in FIG.
5 (step 1303).

Next, it is judged whether or not the drilling direction is the same as the sweep direction, that is, the direction perpendicularly connecting the mutually facing top and bottom surfaces provided with point sequence data (step 13).
05), as shown in FIG. 14 (c), when the sweep direction S is the vertical direction and the drilling direction is the direction indicated by the arrow H orthogonal to the side surface and the two are different, the coordinate axes are exchanged and the sweep direction is changed. The side face and the side face facing each other are perpendicularly connected to each other, and are the same as the drilling direction H (step 1
307).

Next, a plane 37 that passes through the center O of the hole and is parallel to the top surface and the bottom surface is cut (step 1309), and the upper solid 39 and the lower solid with a semicircular hole opened by the cutting. For 41, each point sequence on a pair of side surfaces facing each other in the sweep direction S is defined (step 1311), and thereby the solid model with the holes 43 opened is completed (step 131).
3).

As described above, when the cutting and editing process is performed on the cutting plane 11 for the solid model 9 formed of a rectangular parallelepiped or a cube, the point sequence forming the outline of the upper surface 3 and the outline of the bottom surface 5 are formed. Since each data of the point sequence is sufficient, the cutting and editing process can be performed with a small amount of data, the processing speed is increased, and the reliability of the system is improved. In addition, as for the drilling process, the necessary data is only the point sequence data of the surfaces facing each other in the sweep direction as in the cutting process.
Perforation edit processing is possible with a small amount of data.

In the above embodiment, a cubic or rectangular parallelepiped solid has been described as an example. However, in the case of a polyhedron having at least two surfaces facing each other, the points forming the contours of these two surfaces respectively. The present invention can be applied by having columns as data.

[0035]

As described above, according to the present invention, when the cutting edit processing is performed on the solid model composed of a polyhedron by using the cutting plane, the necessary data regarding the solid model is the first facing each other. Of a plurality of points forming the contours of the surface of the first surface and the second surface, and a small amount of data is only required for the set string of points and the points forming the set string of the first surface and the points facing this point. The solid model can be cut and edited by the number of intersections of the ridgeline connecting the points forming the set sequence of the two surfaces and the cutting plane.

[Brief description of drawings]

FIG. 1 is a schematic block diagram of the same editing apparatus including a CPU and a memory used in a method for cutting and editing a polyhedral solid according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a sequence of points for defining a polyhedral solid.

FIG. 3 is a flowchart showing a process for determining from which direction a cutting plane is cut for a solid model.

FIG. 4 is an explanatory diagram showing a cutting direction by a cutting plane with respect to a solid model.

FIG. 5 is a flowchart showing a side-to-side cutting processing operation.

FIG. 6 is a bottom-side flow chart.

FIG. 7 is an explanatory diagram of an operation in the cutting process of FIG.

FIG. 8 is a flowchart showing an upper surface-side surface cutting processing operation.

9 is an operation explanatory diagram in the disconnection processing process of FIG. 8;

FIG. 10 is a flowchart showing a top-bottom cutting operation.

FIG. 11 is a flowchart showing a cutting processing operation of top surface / side surface / bottom surface.

FIG. 12 is an explanatory diagram of the operation in the disconnection process of FIG.

FIG. 13 is a flowchart showing a punching processing operation for a solid model.

FIG. 14 is an operation explanatory diagram in the process of punching processing of FIG. 13;

[Explanation of symbols]

 1 Solid Model Data Section 3 Top Surface (1st Surface) 5 Bottom Surface (2nd Surface) 7 Cutting / Editing Processing Section 9 Solid Model 11 Cutting Plane

Claims (2)

[Claims] 1. A surface of a solid model comprising a polyhedron is defined as a first surface, and another surface of the solid model facing the first surface is defined as a second surface.
An intersection of a set of a plurality of points forming each of the contours of the first surface and the second surface and a cutting plane for cutting and editing the solid model, and a set of the first surfaces. The intersections of the ridgeline connecting the constituent points and the points constituting the set sequence of the second surface facing this point and the cutting plane are obtained, and the cutting direction for the solid model is determined by the number of these intersections. A method for cutting and editing a polyhedral solid, characterized by: 2. One surface of a solid model comprising a polyhedron is used as a first surface, and the other surface of the solid model facing the first surface is used as a second surface.
A solid model data unit that stores set string data of a plurality of points that respectively configure the contours of the first surface and the second surface is provided, and the set string and the set string of the first surface are configured. Cutting for determining the cutting direction for the solid model by the number of intersections of the ridge line connecting the point to be cut and the point forming the set sequence of the second surface facing this point and the cutting plane for cutting the solid model A polyhedral solid cutting / editing device having an editing processing section.