JPH04114204A - Rounding deformation operating method for three-dimensional shape - Google Patents

Abstract

PURPOSE:To simplify a system and to execute the rounding deformation of a three-dimensional shape with a small data amount by preparing a loop by repeatedly tracing from a rigid line to an apex and from the apex to the rigid line. CONSTITUTION:When executing the rounding processing of the three-dimensional shape, the history of the rounding deformation processing is added to the constitutive element of a shape to be newly generated as a number corresponding to the accumulation of the rounding deformation processings and further, only the changed part of a shape data is preserved. In the backing processing of the rounding deformation, the preceding shape is reproduced by deleting the data added in the latest rounding processing, restoring data preserved by the rounding processing and arranging those data. Thus, the backing processing of the rounding deformation can be executed while preventing the overlapped increase of the data amount and further without separately managing the history data of the rounding deformation.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for processing a rounded deformation of a three-dimensional shape, and more particularly to a rounded three-dimensional shape of an edge line obtained from three-dimensional shape data. On the other hand, the present invention relates to a backtracking process in a rounding deformation operation in, for example, a CAD/CAM system for molds, in which the original shape is obtained again in order to make rounding corrections.

[Prior Art] Conventionally, as a method for performing backtracking processing in a rounding deformation operation of a three-dimensional shape, for example, Modif (
In a system called ``Modif'', the history of each transformation process constituting the rounding transformation process is memorized, and at the time of backtracking, the history is traced in reverse to perform the opposite transformation process for each individual transformation process.

Furthermore, a method is known in which the shape before rounding is saved during the rounding transformation operation.

[Problems to be Solved by the Invention] In the conventional mod system described above, the program for reverse transformation processing performed during backtracking processing becomes large, and the system becomes complicated because the history of transformation processing must be managed. There were problems such as the In addition, with the method of saving the previous shape, when repeating the backtracking process,
There was a problem that the number of saved previous shapes increased and the amount of data increased.

This invention was made to solve the above problems, and when performing backtracking processing of rounding deformation operation,
A rounding transformation operation method for three-dimensional shapes with a simple system and a small amount of data is proposed, which avoids redundant increases in the amount of data during rounding transformation processing and eliminates the need to manage historical data of rounding transformations. This is what we provide.

[Means for Solving the Problems] A three-dimensional shape rounding deformation operation method according to the present invention includes, in a three-dimensional shape rounding deformation process, a number corresponding to the accumulation of rounding deformation processes, which is generated in the rounding deformation process described above. The first step is to add edges to faces, edges, and vertices, the second step is to save unnecessary rounded edges and vertices in the shape after the rounding deformation process, and generation on faces adjacent to the rounded edges. The third step of referring to the edge line to be rounded from the edge line to be rounded is performed, and in the backtracking process in the rounding transformation operation of the three-dimensional shape, the faces, edges, and vertices to which numbers corresponding to the latest rounding transformation process are added are The fourth step to be taken out is referred to by the ridgeline to which the number corresponding to the latest rounding deformation processing is added.
a fifth step of restoring the saved edges and vertices touching them; a sixth step of deleting the faces, edges and vertices to which numbers corresponding to the latest rounding deformation processing have been added; A seventh step is performed to reconstruct the loop on the surface remaining in the shape after completion.

[Operation] In the rounding deformation operation of a three-dimensional shape in this invention, when rounding a three-dimensional shape, the history of the rounding deformation process is used as a number corresponding to the accumulation of rounding deformation processes to be used as a component of a newly generated shape. In addition, only the changed part of the shape data is saved. In the backtracking process in the rounding deformation operation, the shape of -steps before is reproduced by deleting the data added by the latest rounding process, restoring the data saved by the rounding process, and organizing the data.

Therefore, it is possible to backtrack the rounding transformation operation without redundantly increasing the amount of data, and without separately managing historical data of rounding transformations.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the flow of a molding stem in which a rounding deformation operation of a three-dimensional shape is applied according to an embodiment of the present invention.

In step (1), a three-dimensional wire frame shape is manually input into the computer based on the three-view diagram of the mold.In step (2), the input wire frame shape is
eps, (Boundary Representat
ion) is converted into a solid model of representation. In step (3), the converted solid model is subjected to modifications such as rounding deformation and merging to which the present invention is applied. In step (4), the cutting process interval and tool path are calculated from the corrected solid model, and finally tool path data is output.

Next, FIG. 2 shows the flow of the rounding deformation operation in the modification of the solid model in step (3) to which the present invention is applied. In step (5), first, the stack number LR for rounding deformation is set to O. LR=0 indicates that the stacked number of rounding deformations is Ol, that is, the shape is in its original state before undergoing rounding deformation. In step (6), it is checked whether a rounding transformation operation is necessary.
If necessary, proceed to step (7). In step (7), the operator selects the edge line to be rounded and specifies rounding values at both ends of the edge line.
Rounding deformation processing is performed on the ridgeline portion selected in step 7). Then, in step (9), LR is increased by one, that is, the number of stacked rounding processes is increased by one. Step (10
) checks whether the resulting shape is correct, and if so, ends the rounding process. If it is not good, go back to step (6) and perform further rounding, or else go to step (11).
Checks whether to return the current shape to the previous state. If there is no need to go back, the process proceeds to step (10). If it is necessary to go back, proceed to step (I2).

In step (12), 1. It is checked whether R>0, that is, there is an accumulation of rounding in the current shape. If not, it is impossible to go back and the process proceeds to step (10). If there is an accumulation of rounding processes in the current shape, the process proceeds to step (13), where backward processing is performed to return the shape to the previous state. Then, in step (14), 0 or more, which reduces LR by one, that is, reduces the number of stacked rounding processes by one, is the flow of rounding transformation operations.

The flow of the rounding deformation process shown in FIG. 3 will be explained with reference to the example shown in FIG. 4. In FIG. 3, steps (15) to
(20) correspond to FIGS. 4(a) to (f), respectively. In step (15), surfaces are generated corresponding to the edges to be rounded and the vertices touching them. In FIG. 4(a), the edges e1, C2, and C3 are the edges to be rounded, and C
Surfaces f(eI), f(C2), f(ez), and f(vlI) are generated corresponding to 4, C3, and the vertex v8 that is in contact with each of them. The new rounding number LR+1 is added to these generated faces. Edges dependent on these generated surfaces do not yet exist at this step. In step (16),
New vertices are generated around the vertices that are in contact with the edge line to be rounded. In FIG. 4(b), around the vertex ve that is in contact with the rounded edge, the surface C1 for el and C2 is
It shows the generation of a vertex V+ where the upper edge line touches, a vertex v2 where the edge line on plane C2 touches C2 and C3, and a vertex v3 where the edge line on plane C3 touches C3 and eI. vl, C2, and C3 have the new rounding number 1 as described above.
．． R+1 is added. In step (17), edges are generated on surfaces adjacent to the edges to be rounded. Figure 4 (c
), the surface f3 and the surface f adjacent to the rounded edge &le+
, each edge line eI (eI) and e, (el) on the surface f1 and surface C2 adjacent to the edge line e2 to be rounded, each edge line e+(C
2> and er (C2), and each edge line e+ (C3) and er (
ea) is generated. A new rounding number LR+1 is added to each generated edge. Ridge line e1,
C2, C3 are in this step f1, C2, I
It is separated from 3 and saved. Also, at this time, the ridgeline eI(
The saved edge line e can be referenced from e, ) and e, (e:) (i=1.2.3). Step (18) creates a loop of the existing surface. If there is a rounded edge line among the edges that make up the loop of the existing surface, a staggered edge line is created on the existing surface in step (17). Therefore, a loop is created using one of these edges. In Fig. 4(d), a loop is created on the existing surfaces f1, C2, and I3. In step (19), a loop is created using one of these edges. Generates directional edges.

In FIG. 4(e), the ridge lines eq (eI) and cq (C2
), C9 (C3) is generated. The new rounding number LR+1 is added to these generated edges eg(eI), e, (C2), and eg(ei).

In step (20), loops are created in the newly generated surface corresponding to the edges and vertices to be rounded.

In Fig. 4(f), this newly generated surface f(eI),
A loop is created at f(C2), f(C3), and f(ve). The above is the flow of the rounding transformation process.

Next, the backtracking process of the rounding deformation operation will be explained. FIG. 5 shows the flow of the backtracking process, and FIG. 6 shows an example of the backtracking process. In step (2I), the surface section f to which the latest stack number, ie, LR, is added.

, edge group en, and vertex group V are extracted. Figure 6 (
In a), the surface fne-fnx to which LR is added, the edges e-n1 to en6 and eg1 to eg3, and the vertex Vn I
”” Vn 3 is taken out. In step (22), a previously rounded edge group e, which is referenced by an edge in the edge group en, is extracted from the saved edges. In step (23), the vertex V that is saved as the vertex touching the Ni line in e.

is being taken out. Figure 6(b) shows enl and en2
The edge line ep+ that was referenced and saved by en3 and en4 is
+r6 and e. Edge line ep referenced and saved by 6
3 is roughly connected to ep+, eo2, and ep3, and the saved vertex vp! + is taken out. Step (24
), LR is added to the surface fl, and the edge group e. ,
The vertex group Vn is deleted, and as a result, all the elements necessary for the -participation shape are present. Figure 6 (C
), the plane fnlI-fn3, the edge e. +~en6 and es+~esi, vertex V. 1 to Vn3 are deleted, and surfaces f1, f2, f3, edge e+[, eD2, eo3, and vertex vp remain. However, in this state, although the edges belonging to the surface are known, there is no order data between the edges, that is, loop data that limits the region of the surface. In step 25), a loop is created on the surface that remains in the shape, thereby allowing the shape to be returned to the previous shape.

In FIG. 6(d), a loop is created by extracting the edges belonging to each of f1, f2, and f3, and tracing the edges from the edge to the apex and from the apex to the edge.

[Effects of the Invention] As described above, in the rounding deformation process of a three-dimensional shape, numbers corresponding to the accumulation of rounding deformation processes are added to the faces, edges, and vertices generated in the rounding deformation process. A first step, a second step of preserving unnecessary rounded edges and vertices in the shape after rounding deformation processing, and a second step of saving the rounded edges and vertices that are unnecessary for the shape after the rounding deformation process, and the rounded edge line from the edge line generated on the face adjacent to the rounded edge line. a fourth step for performing a third step that refers to the three-dimensional shape, and extracting faces, edges, and vertices to which numbers corresponding to the latest rounding transformation processing are added in the backtracking processing in the rounding transformation operation of the three-dimensional shape; The fifth step is to restore the saved edge line and the vertices touching it that are referenced by the edge line to which the number corresponding to the latest rounding transformation process has been added. Rounding the three-dimensional shape by performing a sixth step of deleting added faces, edges, and vertices, and a seventh step of reconstructing loops on the surfaces remaining in the shape after the sixth step. Compared to conventional methods, this method eliminates the need for managing the history of rounding deformation processing and complex reverse deformation processing programs, and avoids redundant increases in shape data, making the system more efficient. This method has the effect of being able to perform rounding and deforming operations on three-dimensional shapes easily and with a small amount of data.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing the processing flow of a molding system to which rounding deformation of a three-dimensional shape is applied according to an embodiment of the present invention, and FIG. 2 is a flowchart showing the rounding deformation of a three-dimensional shape according to an embodiment of the present invention. A flowchart showing the flow of operations,
FIG. 3 is a flowchart showing the flow of rounding deformation processing according to an embodiment of the present invention, FIGS. A flowchart showing the flow of backtracking processing of a rounding deformation operation according to an embodiment of the invention, and FIGS. 6(a) to 6(a).
(d) is an explanatory diagram illustrating backtracking processing of the rounding deformation operation in FIG. 5; In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] In the rounding deformation process of a three-dimensional shape, the first step is to add numbers corresponding to the accumulation of rounding deformation processes to the faces, edges and vertices generated in the rounding deformation process, and to add unnecessary numbers to the shape after the rounding deformation process. A second step of saving edges and vertices to be rounded, and a third step of referencing the edge line to be rounded from an edge line generated on a face adjacent to the edge line to be rounded, rounding the three-dimensional shape. In the backtracking process in the transformation operation, the fourth step is to extract the faces, edges, and vertices to which numbers corresponding to the latest rounding transformation process have been added; Referring to
a fifth step of restoring the saved edges and vertices touching them; a sixth step of deleting the faces, edges and vertices to which numbers corresponding to the latest rounding deformation process have been added; A method for operating a rounding deformation of a three-dimensional shape, which performs a seventh step of reconstructing a loop on a surface remaining in the shape after completion of the process.