JP3205403B2 - Shape restoration device for shape modeler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is constituted by a computer-aided design (CAD) device or the like, and creates a shape model by repeatedly performing an operation for generating one figure from two figures. The present invention relates to a shape restoring device that is used for a shape modeler capable of recovering a shape that has been deleted by the calculation by the shape modeler in the created shape model. The present invention relates to a shape restoring device suitable for a shape modeler for creating a simple shape model.

[0002]

2. Description of the Related Art When a shape model is created by a shape modeler as described above, repair when a figure operation error is found during creation, handling when a design change is required after creation, counterbore Due to the necessity of erasing only shape features such as holes, it may be necessary to restore a shape that has been eliminated by calculation in the created shape model. Once the model is calculated, the method of re-executing from the beginning to the time before the above-mentioned shape disappearance calculation using the execution record at the time of creation (re-execution method), and the procedure of creating the shape model are saved in the form of an Euler operator etc And a method of undoing the procedure and returning to the stage before the above operation (undo method) (see Japanese Patent Application Laid-Open No. 2-83610)
Also, there is known a method in which the above operation is regarded as performing creation and aggregation of a basic figure, and the shape is returned to the shape in the case where the operation of adding or canceling the figure is not performed in units of the basic figure (cancellation operation method). .

[0003]

However, when creating a complex shape model for a shaped material or the like,
The shape model is usually a set of many figures. Therefore, when the shape is to be restored by the above-described re-execution method, it is necessary to create execution records for all stages of the creation of the shape model. In addition, in this method, even a slight change requires a redo from the beginning, so that when the creation of the shape model has reached the final stage, there is a problem that a great deal of man-hour is required.

In the undo method, there is a problem that it takes a relatively long time to execute a command for tracing backward before the annihilation operation. Further, if an attempt is made to cope with a design change of a shape given in an early stage of the shape model creation, Since almost all the work is redone, the re-execution method requires less man-hours. Moreover, with this method, even if the influence of one shape is small,
The calculation has to be performed again only because a part irrelevant to the operation has been executed after the operation, so that there is a problem that waste is increased.

In the above-mentioned cancellation operation method, for example, when a basic figure forming the shape of a groove in a shape model having a hole at the bottom of the groove is canceled, only an invisible hole remains in the shape model. In some cases, a graphic that does not exist may be created, and such a graphic may cause confusion to the user. In addition, in this method, it is necessary to perform a calculation of a geometric figure that takes a long time even in an operation of returning, and when returning to the original state, omitting the calculation of such a geometric figure saves time.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus which can solve the above-mentioned problem advantageously by enabling the above-mentioned undo method to be performed locally only on a necessary portion. The shape restoration device for a shape modeler of the present invention comprises:
A shape model is created by repeatedly performing an operation for generating one figure from two figures, used for a shape modeler capable of handling a solid or a curved surface, and a shape in which the shape modeler has disappeared by the calculation is created. When the shape modeler deletes the shape by the calculation, the shape model to be deleted is formed among the edges and faces that the shape model after the calculation has. An edge forming a boundary between a region to be formed and a face connected to the edge, and a pointer providing unit for providing a pointer capable of specifying the edge forming the boundary of the region forming the shape to be eliminated. While holding the region forming the shape to be extinguished as a dead shell, the face in the region formed as the dead shell and other In the case where another pointer is given to the pair with the cartridge, the pointer is also held together, so that a dead shell holding means capable of holding a plurality of dead shells in a hierarchically related manner, Of the edges and faces of the shape model, when a pair of an edge serving as a boundary between a region forming a shape to be restored and a face connected to the edge is specified,
The dead shell having the edge specified by the pointer given to the specified pair of face and edge is searched for from the dead shells held by the dead shell holding means, and is determined to be the dead shell. The shape formed by the region is connected to the region having the face out of the two regions divided by the specified edge of the created shape model through the specified edge by the connection operation. And shape coupling means for restoring the shape.

[0007] In the apparatus of the present invention, the shape combining means may include a step of closing the edge of the set of the designated face and the edge among the edges and the faces of the created shape model in an annular shape. If not, or if it does not connect the two points on the ring-shaped closed edge of the created shape model, it prevents the ring from closing or connecting the two points Yes,
It may be characterized in that the lost shape is sequentially restored from the hierarchically related dead shells by sequentially searching for the edge to which the pointer to the dead shell is assigned. In the present invention, “edge” means an edge row.

[0008]

In the above-mentioned shape restoring device, when the shape modeler deletes the shape by calculation, the pointer giving means deletes the edge and the face of the edge of the shape model after the calculation. An edge forming a boundary between a region forming a shape and a pair of a face connected to the edge is provided with a pointer capable of specifying the edge forming the boundary of the region forming the shape to be eliminated,
When the dead shell holding means holds the region forming the shape to be erased as a dead shell, and another pointer is assigned to a set of a face and another edge in the dead shell region. By holding the pointers together, a plurality of dead shells are held in a hierarchically related manner as needed.

[0009] Then, the edge of the edge and the face of the created shape model, which is the boundary between the edge and the area forming the shape to be restored, and the edge of the edge by the user of the apparatus. When a pair of a face to be connected is specified, the shape combining unit specifies a dead shell held by the dead shell holding unit with a pointer assigned to the specified pair of a face and an edge. A dead shell having a given edge is searched for, and the shape formed by the dead shell region is subjected to a joint operation, and the face in the two regions divided by the designated edge of the created shape model is searched for. Is connected to the area having the shape via the specified edge to restore a required shape.

Therefore, according to the apparatus of the present invention, when it is desired to change a location of a created shape model, a set of an edge related to the location and a face connected to the edge is designated. Therefore, the local undo method of restoring the shape once erased only for the relevant portions while leaving the portions irrelevant to the relevant portion as it is can be performed. Even if a complex shape model is created for the object, the man-hour for creating the shape model itself does not increase, and
The shape can be restored, and the change can be made easily and without waste. According to this apparatus, the deleted graphics are taken out from the dead shell held hierarchically and restored, so that the sequential graphics are sequentially traced while reversing the local execution order when creating the shape model. Can be restored,
When restoring a shape, there is no possibility that a figure unintended by the user will be created, and since the restoration is performed using the topological relationship between figures without performing the operation of geometric figures, the restoration of figures should be performed in a short time. Can be.

Here, the edge of the set of the designated face and edge among the edges and faces of the created shape model is not closed in a circular shape, or the created shape model is not closed. The shape-coupling means, when not connecting two points on an annularly closed edge, has a pointer to a dead shell which prevents annularly closing or connecting the two points. By sequentially retrieving the added edges and sequentially restoring the disappeared shapes from the hierarchically related dead shells, it is possible to have edges that are not closed in a ring or created shape models. Even if you specify an edge that does not connect two points on the closed edge
Restoration can be continued without falling into an unexecutable state.

[0012]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of a shape restoring device for a shape modeler according to the present invention. Specifically, FIG. 1 operates based on a program given in advance and data inputted by a user. A shape modeler constituted by a conventional computer-aided design (CAD) device, and 2 in the figure, is incorporated in the shape modeler.
The shape restoring devices of the above embodiments are respectively shown.

The shape modeler 1 performs a set operation, a division and join operation, a separation of a surface, and a fillet operation as necessary to generate one figure from two figures, and the surface and the solid coexist. A geometric model that expresses vertices, edges (edges) and faces (planes) as geometrical data, and a topological element consisting of the vertices, edges, and faces. Having phase data representing the connection relationship of, based on the geometric data and the phase data,
As an external expression model (shape model), which is a graphic range handled by the user, a two-dimensional manifold model that is allowed to have a boundary is formed. On the other hand, since the shape modeler 1 includes the shape restoring device 2 of the above-described embodiment, a non-manifold model including a dead shell, which will be described later, is configured as an internal expression model that is a figure range handled internally. Such a shape modeler 1 is described, for example, by the present inventors in a journal of the Japan Society of Precision Engineering.
He is known for his work published in August 1991, "Topological Model and Set Operation of Surface Modeler".

The phase data handled by the shape modeler 1 has a winged edge structure. The winged edge structure is, as shown in FIG.
Against the sides of the face F _R and F _L, the vertex V ₁ and V ₂ across the edge E _1R connecting to the edge E with respectively adjacent to both sides of the face F _R and F _L, E _1L, A data structure attached to data indicating the adjacency between E _2R and E _2L to represent a three-dimensional topological structure centered on edges, first reported by Stanford University's Baumgart in 1975 Although the details of the data structure are described in several other papers already published, they are not directly related to the present invention, and thus description thereof is omitted here.

The shape restoration device 2 here is
As shown in FIG. 1, the apparatus includes a pointer providing means 3, a dead shell holding means 4, and a shape combining means 5, wherein the pointer providing means 3 causes the shape modeler 1 to erase the shape by the above calculation. At this time, of the remaining edges and faces of the shape model after the calculation, the edge forming the boundary between the region forming the shape to be erased (the shape model after the calculation and the shape model after the calculation) A pair of a pointer (an edge shared by a region forming a shape) and a face connected to the edge has a pointer (a search side that can specify the edge forming the boundary of the region forming the shape to be vanished). (Address indicating the location of the data to be searched for). As a result, the pair of the edge and the face has a one-to-one correspondence with a region forming a specific vanishing shape sharing the edge with the pair.

That is, for example, two figures P ₁ (P ₁ = A ₁₁ ∪A ₁₂ ) and P ₂ (P ₂ = A ₂ ) as shown in FIG.
₂₁ {A ₂₂ ) is performed, and a figure P ₃ (P ₃ = A ₁₁ } whose central part is broken as shown by a solid line in FIG.
When creating A ₂₁ ), looking at figure P ₁ ,
The right area A ₁₂ divided by the edge E ₁ , which is the intersection of the two figures P ₁ and P ₂ , forms a shape to disappear, and the left area A ₁₁ divided by the edge E ₁ is calculated. after remaining, but comes to have the shape P _3, when the pointer imparting means 3 that operation, set between the edge E ₁ and the face F ₁₁ connected thereto in the region a ₁₁ wing the phase data forming the Doejji structure imparts a pointer B ₁ to specific area a ₁₂ that forms a shape to the disappearance, the edge E ₁ that is shared between the region a ₁₁ remaining. Thus the phase data of the edge E _1, the edge E ₁
Preparative example will accompanying the pointer B ₁ assigned to the set of the face F ₁₁ serving as a face F _L.

[0017] the other hand, looking at the figure P _2, the upper area A ₂₂ that is divided by the edge E ₁ forms a shape to eliminate, also lower area A ₂₁ that is divided in its edge E ₁ the remaining even after the operation, but comes to have the shape P _3, when the pointer imparting means 3 of the operational set of the face F ₂₁ connected to it and the edge E ₁ of the area a ₂₁ to the winged phase data which forms an edge structure, to impart a pointer B ₃ to identify the areas a ₂₂ to form a shape that is the disappearance, the edge E ₁ that is shared between the region a ₂₁ remaining. Thus, the phase data of the edge E ₁ will additionally incidental pointer B ₃ assigned to the set of the face F ₂₁ serving as the edge E ₁ for example a face F _R.

The dead shell holding means 4
When the shape modeler 1 eliminates the shape by the above calculation,
In the case where the area forming the shape to be erased is attached with the attribute of dead shell DS and another pointer is assigned to a pair of a face and another edge in the area that is the dead shell, By holding the pointers together, a plurality of dead shells are stored in a hierarchically related manner. The remaining area is given an attribute called a live shell LS, and the live shell LS forms a shape model.

That is, for example, in the example shown in FIG.
The dead shell holding means 4 holds the regions A ₁₂ and A ₂₂ forming the shape to be annihilated as dead shells DS ₁ and DS ₃ , respectively, as shown by broken lines in FIG. for example the set of the face F ₁₂ and the edge E ₂ in the region a ₁₂ in which the dead shell DS _1, other example dead shell
Another pointer B identifying the edge E ₂ shared with DS _{2
When 2} is assigned, the pointer B ₂ is also held. Thereby, the dead shell holding means 4 can hold a plurality of dead shells DS, for example, DS ₁ and DS ₂ in a hierarchically related manner. The live shell LS to be formed has a tree-type connection relationship, for example, as shown in FIG. 4, and they constitute a non-manifold as a whole.

Accordingly, the dead shell DS can be different from each other in the first hierarchy connected to the live shell LS and in the subsequent hierarchies if the designated face and edge pair is different. For example, between dead shells DS belonging to different trees extending from DS ₁ and DS _{3 in} FIG. 4, for example, between DS ₂ and DS _{4 in} FIG. Does not exist.

By the way, since the live shell LS here forms a manifold, a pair of one edge and a face normally always has only one pointer, and therefore specifies only one dead shell. However, in the case where another region is eliminated using the same edge as a boundary in the previous graphic operation, it is necessary to specify two dead shells for a pair of the edge and a face connected to the edge. In such a case, it is considered that there is a dummy face at the position of the face combined with the edge serving as the boundary in the region which is eliminated by the current calculation and becomes the dead shell, and the combination of the dummy face and the edge serving as the boundary is considered. In addition, a pointer for specifying a region that has become a dead shell in the previous graphic operation may be added, and this method is called a dummy face method. According to this method, the dead shell holding means 4 can be easily configured as an extension of the conventional configuration of the two-dimensional manifold modeler.

Here, the shape combining means 5 includes, among the edges and faces of the created shape model, an edge serving as a boundary between a region forming a shape to be restored and the edge thereof. Is specified, a pointer assigned to the specified pair of face and edge from the dead shell DS held by the dead shell holding means 4 is attached. The dead shell DS having the edge specified in the above is searched for, and the shape formed by the dead shell region is determined by a joint operation between the two regions divided by the specified edge of the created shape model. The original shape is restored by connecting to the area having the specified face through the specified edge.

[0023] That is, for example, in the example shown in FIG. 3, when restoring the shape region A ₁₂ is formed, the user of the device, figure P ₃ has a shape model created edge and of the face, an edge E ₁ at the boundary between the region a _12, by specifying a set of the face F ₁₁ which is connected to the edge E _1, form-locking means 5, a dead shell possesses means 4 Among the dead shells held by the user, the edge E specified by the pointer B ₁ assigned to the pair of the designated face F ₁₁ and the edge E ₁
Dead shell DS ₁ with ₁ locates as shown in FIG. 3 (b) arrow, a shape that dead shell DS ₁ and area A ₁₂ is formed by binding operation, the said pattern P _3, is the designated Two regions A ₁₁ divided by the edge E ₁ ,
Area A _{11 of} A ₂₁ having face F _1.
To bind via the edge E ₁ specified above, to restore the original shape.

[0024] In the course of the join operation, figure P ₃ area A ₁₁ prior to the coupling between the region A ₁₂ to restore, figure P ₃ that will overlap with the region A ₁₂ to its restoring other Region A ₂₁ is removed. Conversely, when the area A ₂₂ is restored from the figure P ₃ , the area A ₂₂ of the figure P ₃ is combined with the area A ₂₂ to be restored before the area A ₂₁ of the figure P ₃ is combined with the area A _{22 in} the course of the combining operation. Figure P ₃ that overlaps with ₂₂
The other regions A ₁₁ is the removal of. This operation is realized while guaranteeing the phase integrity by using the cell operator (refer to the above-mentioned paper published in the Journal of the Japan Society of Precision Engineering in August 1991, "Topological Model and Set Operation of Surface Coexistence Modeler"). can do.

FIGS. 5A to 5C are explanatory views showing another example of performing the shape restoration using the shape restoration device 2 of the above embodiment. Here, FIG. Like figure S ₁
To obtain the set sum of the figure and the figure S ₂ (S ₁ ∪S ₂ →
S _A ) to perform a two-story figure S as shown in FIG.
Create an _{A (S A = S A1 ∪S} A2), then obtains the set union of the figure S _A and elongated shapes S _B operation (S _A ∪S _B →
S _C ), the figure S as shown in FIG.
_{From C} (S _C = S _C1 ∪S _C2 ), the graphics S _A and S _B are restored, and the graphics S ₁ and S ₂ are restored.

In such a case, first, the figure S ₁ and the figure S ₂
During operation for obtaining a set sum of, as shown in FIG. 5 (b), the pointer application means 3, the pointer b ₁ to identify the figure S ₁₂ to disappear from the graphic S _1, figure S ₁ and the figure S ₂ the boundary between the edge e _1, figure S _A1 connected thereto
With conferring to the combination of the face f ₁ of the pointer b ₂ to identify the figure S ₂₂ to disappear from the graphic S _2, and its edge e _1, face f ₂ of figure S _A2 connected thereto
And on the other hand, the dead shell holding means 4
But they held their shapes S ₁₂ and graphics S ₂₂ as dead shell respectively.

When calculating the set sum of the graphic S _A and the graphic S _B , as shown in FIG. 5C, the pointer assigning means 3 specifies the graphic S _AX which disappears from the graphic S _A. the pointer b ₃ to, figure S and the edge e _a of the boundary between the _a and the figure S _B, face f of figure S _C1 connected thereto
with conferring to the combination of the _a, a pointer b ₄ to identify the figure S _BX disappear from the graphic S _B, and the edge e _a,
Given to a set of the face f _b of figure S _C2 connected thereto, the other hand, a dead shell possesses means 4, to retain their shapes S _AX and graphics S _BX as dead shells, respectively.

When restoring the graphic S _A or S _B from the graphic S _C , the shape combining means 5 selects the graphic S from the plurality of dead shells held by the dead shell holding means 4. _{Using the} pointer b ₃ or b ₄ determined based on the designation of one of the two areas S _C1 and S _C2 divided by the edge e _a of _C and the edge e _a , the graphic S
A dead shell forming _AX or S _BX is searched for, and a shape formed by the dead shell is determined by a joint operation (S _C1 + S _AX).
By → S _A or _{S C2 + S BX → S B} ), said pattern S _C
Of the one having the designated face in the two areas S _C1 and S _C2 of the above-mentioned two are connected via the edge e _a to restore the original figure S _A or S _B.

Further, from the above described graphic S _A to the graphic S ₁ or S
When reconstructing ₂ , the shape combining means 5 selects two areas S _A1 , divided by the edge e ₁ of the graphic S _A from a plurality of dead shells held by the dead shell holding means 4. using the pointer b ₁ or b ₂ determined based on a set of specified between one and its edge e ₁ of S _A2, locate the dead shell to form a shape S ₁₂ or S _22, the shape of the dead shell forms, Combination operation (S _A1 + S ₁₂ → S
₁ or S _A2 + S ₂₂ → S ₂ ), the area having the designated face of the two areas S _A1 and S _A2 of the figure S _A is connected via the edge e ₁ to the original area. to restore the shapes S ₁ or S _2.

FIG. 6 shows the shape restoring device 2 of the above embodiment.
This shows an example in which the present invention is applied to shape recovery when designing an oil pump housing of an automatic transmission. In this example, a housing shape model M ₁ once created (shown in the upper right in the figure)
During, after adding one radial rib L ₁ was quenched by being created (shown in the lower left in the figure), remove the cylindrical portion C ₁ provided in another rib L ₂ in the shape model M ₂ to restore the shape of the wall and bottom of the original rib L ₂ (shown in the lower right in the drawing),
We have created the desired housing shape model M _3. In FIG. 6, the created model is shown in the form of a wire frame on the display for easy understanding.

As described above, according to the shape restoring apparatus 2 of this embodiment, when it is desired to change a location of a created shape model, an edge related to the location and a face connected to the edge are determined. By specifying a set of, it is possible to perform a local undo method in which a part irrelevant to the relevant part is left as it is and only the relevant part is restored with the shape once erased. Even when creating a complex shape model for a shaped material or the like, the man-hour for creating the shape model itself does not increase, and furthermore, the shape can be restored and the change can be made easily and without waste. be able to.

According to the apparatus of this embodiment, the deleted figure is taken out from the dead shell held hierarchically and restored, so that the local execution order when creating the shape model is reversed. The figure can be sequentially restored while tracing to the figure, and a figure not intended by the user is not generated when restoring the shape, and the restoration is performed using the phase relationship between the figures without performing the calculation of the geometric figure. Therefore, restoration of figures can be performed in a short time, and the apparatus can be easily added by extension from the conventional shape modeler without newly creating a non-manifold modeler, so that the addition can be performed at low cost. It can be carried out.

According to the shape modeler 1 here,
The shape features such as the through-holes, drill holes, and bearing surfaces described above are once deleted from the created shape model by the shape restoring function of the shape restoring device 2, and are not realized as a shape model. Refers to operation data stored as an implicit expression (implicit representation in shape feature theory), which is an expression that can unambiguously define the shape, for example, a set of an operation capable of generating a shape feature and its parameter, and the like. Is changed and the operation is re-executed, so that the shape feature can be easily changed or moved.

By the way, the shape restoration device 2 of the above embodiment is
When performing shape restoration, the created shape model (live shell LS) is divided into two regions by the specified edge, and the edge and the face are divided into the region having the specified face. since dead shell traced from the set of pointers couples shape to form its original designated edge, so as to divide the live shell LS into two, the edge e ₁₀ shown in FIG. 7 (a) such or annular closed ones, or it is necessary that such things edge e ₁₂ connecting two points on the edge e ₁₁ closed annularly live shell LS has shown in FIG. (b).

[0035] However some shapes user of the device is trying to restore, in the example shown in the edge, such as e _13, or 5 shown in FIG. 7 (c), the edge part by the edge e _a cut away such as e _1, or not closed in a ring shape,
Alternatively, an edge that does not connect two points on the circularly closed edge of the created shape model may be designated, and in such a case, the shape cannot be restored as it is.

In such a case, in the shape restoring device 2 of this embodiment, the shape connecting means 5 is provided with a pointer to a dead shell which prevents the ring from closing or joining two points. Edges are sequentially searched, and the disappeared shapes are sequentially restored from the hierarchically related dead shells held by the dead shell holding means 4.

[0037] That is, for example, to restore the shape S ₂ from the shape model S _C shown in FIG. 5 (c), the edge e ₁
And the set of the face f ₁ is specified, but the edge e ₁ is not closed in a ring, since its winged edge data are written connection relationship between edge e _a, form-locking means 5 , then searches the edge e _a, its because the edge e _a is closed, the edge e _a an edge e ₁ to restore the shape S _AX joint annularly from and thereafter the edge e ₁ from figure S ₂ To restore.

Therefore, according to the shape restoring device 2 of this embodiment, the edges of the created shape model and the set of specified faces among the faces are closed in a ring shape. Even if there is no connection, or if the created shape model does not connect two points on an annularly closed edge, the restoration can be continued without falling into an infeasible state.

Although the present invention has been described with reference to the illustrated examples, the present invention is not limited to the above-described example. For example, instead of the above-mentioned winged edge structure, a split An edge structure or a half-edge structure may be used, and alternatively, a ring structure or the like may be used.

[0040]

As described above, according to the shape restoring apparatus of the present invention, even when a complicated shape model for a raw material or the like, which is an aggregate of a large number of figures, is created, the shape model creation itself can be performed. Man-hours do not increase, and the shape can be restored, and the change can be easily and easily made. According to this apparatus, the deleted graphics are taken out from the dead shell held hierarchically and restored, so that the sequential graphics are sequentially traced while reversing the local execution order when creating the shape model. It can be restored, and there is no possibility that a figure unintended by the user is created when restoring the shape.Moreover, since the restoration is performed using the topological relationship between the figures without performing the operation of the geometric figure, the restoration of the figure can be performed. It can be done in a short time.

Further, the edge of the set of the specified face-to-edge among the edges and the faces included in the created shape model is not circularly closed, or the created shape model has The shape-coupling means is provided with a pointer to the dead shell, which prevents the annular closing or joining the two points when the two points on the closed annular edge are not connected. By sequentially retrieving the lost edges from the hierarchically related dead shell by sequentially searching for the lost edges, there is an edge that is not closed circularly, and the created shape model has Even when an edge that does not connect two points on an edge closed in a ring is specified, restoration can be continued without falling into an unexecutable state.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing an embodiment of a shape restoring device for a shape modeler of the present invention.

FIG. 2 is an explanatory diagram showing a structure of phase data handled by the apparatus of the embodiment.

FIG. 3 is an explanatory diagram showing a method for assigning a pointer by a pointer assigning means of the apparatus of the embodiment.

FIG. 4 is an explanatory diagram showing a state in which the dead shell holding means of the apparatus of the above embodiment holds a dead shell.

FIGS. 5A to 5C are explanatory views showing a procedure of shape restoration by the apparatus of the embodiment.

FIG. 6 is an explanatory view showing another example of the shape restoration by the apparatus of the embodiment.

FIGS. 7A to 7C are explanatory diagrams showing examples of edges designated for shape restoration.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Shape modeler 2 Shape restoration device 3 Pointer giving means 4 Dead shell holding means 5 Shape combining means

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masato Honda 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Motor Co., Ltd. (72) Inventor Shigeki Tanimoto 2--17-51 Akasaka, Minato-ku, Tokyo Japan (56) References JP-A-2-19975 (JP, A) JP-A-2-132573 (JP, A) JP-A-2-83610 (JP, A) JP-A-63-3375 (JP) , A) Tetsuhiko Suzuki and three others, "Topological mathematical model of curved surface coexistence modeler and" set operation "(1st report)", Journal of the Japan Society of Precision Engineering, August 1991, Vol. 57, No. 8, p. 1393-1398 (58) Field surveyed (Int. Cl. ⁷ , DB name) G06F 17/50 622 G06F 17/50 626 G06T 17/40 JICST file (JOIS)

Claims (2)

(57) [Claims] 1. A shape modeler (1) capable of handling a solid or a curved surface, wherein a shape model is created by repeatedly performing an operation for generating one figure from two figures, and the shape modeler is used by the calculation. In the shape restoring device (2) for restoring a lost shape into a created shape model, when the shape modeler deletes the shape by the calculation, an edge that the shape model after the calculation has An edge (E ₁ ) which forms a boundary between the face (A ₁₂ ) forming the annihilating shape and a face (F ₁₁ ) connected to the edge (E ₁ ). Pointer assigning means (3) for assigning a pointer (B ₁ ) capable of specifying the edge (E ₁ ) defining the boundary of the area (A ₁₂ ) forming the shape to be erased; The area (A ₁₂ ) to be formed is held as a dead shell (DS ₁ ), and a pair of a face (F ₁₂ ) and another edge (E ₂ ) in the area (A ₁₂ ) formed as the dead shell is added to another area. When the pointer (B ₂ ) is given, the dead shell holding means (4) which can hold a plurality of dead shells (DS ₁ , DS ₂ ) in a hierarchical manner by holding the pointer together. When, of the edges, and it faces the created shape model has a boundary to become edge between the region for forming a shape restoring _{(a 12) (E 1)} , the edge (E ₁ If) set of the face (F ₁₁₎ to be connected is specified, the dead shell the designated face from among the dead shell held unit is held (F ₁₁₎ and an edge (E ₁₎
A dead shell (DS ₁ ) having an edge (E ₁ ) specified by the pointer (B ₁ ) assigned to the pair
The shape formed by the region (A ₁₂ ) that is set as the dead shell (DS ₁ ) is subjected to a joint operation, and the two shapes of the two regions divided by the specified edge (E ₁ ) of the created shape model are combined. in the region of the person having the face (F _11), the bound via a specific edge (E _1), characterized in that it comprises a shape coupling means (5) to restore the shape, Shape restoration device for shape modeler. 2. The method according to claim 1, wherein said shape combining means (5) is configured to include, among the edges and faces of the created shape model, an edge (E ₁ ) of the set of the designated face and edge, If it is not closed circularly, or if it does not connect two points on the closed circular edge of the created shape model, close the ring or connect the two points By sequentially searching for the edge given the pointer to the dead shell, which is preventing the dead shell (DS ₁ ,
_{2. The} shape restoring device for a shape modeler according to claim 1, wherein the disappeared shapes are sequentially restored from DS ₂ ).