JP3317464B2 - Deformed shape generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shape deformation or deformed shape image generating apparatus for defining a new shape model by continuous deformation between two shapes.

[0002]

2. Description of the Related Art Conventionally, this type of shape deformation method includes:
The vertex list and the linked list for constructing a face (line) between the two shapes have exactly the same structure, and the structure is not changed at all during continuous deformation between the two shapes. Interpolation was performed between the vertices of two shapes.

For this reason, when a simple shape is transformed into a complicated shape, a vertex list and a linked list of vertices are prepared which are exactly the same as those representing a complicated shape, even for a simple shape. However, there is a disadvantage that the shape expression constraint is large (for example, Terzopoulo
s, D., and K. Fleischer, “Modeling Inelastic Defromat
ion: Viscoelasticity, Plasticity, Fracture, ”SIGGRAP
H'88,269-278).

[0004]

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and an object of the present invention is to generate an intermediate shape model by continuous deformation between shape models. It is an object of the present invention to provide a technique capable of facilitating a shape deformation process in a deformed shape generating apparatus.

[0005] The above object, other objects and a novel structure of the present invention will become apparent from the description of the present specification and the accompanying drawings.

[0006]

SUMMARY OF THE INVENTION The present invention is disclosed in the present application.
A brief description of typical inventions will be given below.
It is as follows. That is, the present onset Ming, to represent the shape of an object, generating an intermediate shape model by a continuous deformation between two geometric model with a linked list constituting the surface or line connects the vertex list and the vertex a modified shape generation apparatus, and pair to each shape model,
Performed once the alignment of the common basic shape, a first means for determining a characteristic quantity for expressing their respective geometric model,
When deforming from one shape model to the other shape model, using the vertex list of the common basic shape, a second means for interpolating both feature amounts, and A third means for creating a vertex list of the intermediate shape model representing a shape and a linked list connecting the vertices to form a face or a line.

Further, in the above means, a vertex list defining a shape and shape energy at each vertex are used as feature quantities of the shape model.

[0008]

According to the above-mentioned means, matching of two shape models from a common basic shape is performed to obtain a feature amount for expressing the two shape models.
When transforming to the other shape model, interpolation is performed on the feature values of both, so it is necessary to hold a shape model directly connected to both shapes and perform interpolation based on that shape model as in the past. Absent.

[0009]

An embodiment of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a block diagram showing a schematic configuration of a deformed shape generating apparatus according to an embodiment of the present invention.

In FIG. 1, reference numeral 301 denotes shape data A, 3
02 is shape data B, 304 is basic shape data, 310
Is deformation shape data, 305 is a feature value A, 306 is a feature value B, 303 is a feature value analysis unit, 307 is a feature value corresponding unit, and 309 is a feature value synthesis unit.

The deformed shape generating apparatus of this embodiment shown in FIG. 1 is constituted by, for example, an information processing apparatus such as a computer.

Shape data A301 and shape data B3
In step 02, a feature value A 305 and a feature value B 306 are generated from the basic shape data 304 by the feature value analysis unit 303.

These characteristic amounts A305 and B3
In step 06, the feature amount correspondence unit 307 uses the basic shape data 304 to make correspondence, and the interpolation amount 308 is given, so that the feature amount synthesis unit 309 generates deformed shape data 310 composed of both features.

Next, the operation of the feature amount analysis unit 303 will be described with reference to FIGS.

In the following description, an example in which a vertex list and a set of shape energy parameters at the vertices are used as feature quantities in the case of a three-dimensional shape will be described.

For a simple vertex list and a shape energy parameter at a vertex, a shape model having three vertices around one vertex is used as a shape model expressing a feature value.

Further, as an example of a modification for obtaining a feature quantity, a case where a spherical shape is used as basic shape data will be described.

FIG. 2 shows that, in a shape model in which three vertices exist around one vertex, the angle between the adjacent vertices and the adjacent surface with respect to the point Pi is defined as an energy parameter.
It is a figure showing that the feature can be expressed.

As shown in FIG. 2, in a shape model in which three vertices (P _{N1 (i)} , P _{N2 (i)} , P _{N3 (i)} ) exist around one vertex (Pi), for a point Pi, Using the angle between the adjacent vertex and the adjacent surface as an energy parameter, the feature amount can be expressed by the following equation.

[0021]

## EQU1 ## Pi = F + L (ri, di, φi) Ni FIGS. 3 and 4 are diagrams showing a modification of the vertex list expressing the feature amount.

The vertex lists expressing the features are shown in FIGS.
As shown in FIG.

In FIG. 3, 100 denotes two small faces, 1
01 is one slightly larger surface, and two small surfaces 100 are converted into one slightly larger surface 101 by edge deletion 104, and one slightly larger surface 101 is converted to a smaller surface 2 by surface division 105. Is converted into one hundred.

In FIG. 4, reference numeral 102 denotes a small remote surface 2
103 is a large surface, and two small surfaces 102 separated from each other are converted into a large surface 103 by the structure synthesis 106, and the large surface 103 is
It is divided into two separate small faces 102.

Next, referring to FIGS. 5, 6, and 7, a method of obtaining a characteristic amount from a basic shape will be described.

FIG. 5, FIG. 6, and FIG. 7 are diagrams for explaining how to obtain a characteristic amount from a basic shape in the present embodiment.

In FIG. 5, reference numeral 200 denotes a human head shape which is shape data, and 201 denotes a spherical shape which is basic shape data.

In FIG. 6, reference numeral 204 denotes an object shape surface;
5 is a basic shape surface, and 206 is energy.

In FIG. 7, reference numeral 207 denotes a matching surface, 208 denotes a feature vertex, and 209 denotes a shape energy parameter.

By matching the spherical shape 201, which is the basic shape data shown in FIG. 5, with the human head shape 200, which is the shape data, a shape 202 based on the feature is obtained, and the side deletion shown in FIGS. A shape 203 by the transformation can be obtained through 104, division of the surface 105, structure composition 106, and structure division 107.

Here, the spherical shape 2 which is the basic shape data
01, the surface of the human head shape 200 is aligned with the target shape surface 20 shown in FIG.
4 and a spherical surface 201 as basic shape data
Is the basic shape surface 205 shown in FIG.

When the surface of the shape 203 obtained by the transformation is the matching surface 207 shown in FIG. 7 and the vertices constituting the surface are the feature vertices 208, the shape energy parameter 209 is expressed as a vertex list in this way. When the shape energy is minimized, the intersection angle of the surface created by the adjacent vertex at each vertex is set.

As described above, the shape data A301 is
In the case of the human head shape 200, the spherical shape 201 which is the basic shape data is replaced with the human head shape 20 which is the shape data.
0, the spherical shape 20 which is the basic shape data.
1 and the human head shape 200 do not match, so the energy amount 206 is large, but by matching the energy 206 so as to be in the minimum state, the energy amount 206 passes through the shape 202 based on the feature corresponding to the human head shape. And feature 2 by conversion
03, which is a set of vertex lists and shape energy parameters.

Similarly, for the shape B, a vertex list and a set of shape energy parameters are created.

These become a feature value A 305 and a feature value B 306.

FIG. 8 shows the characteristic amounts A305 and B3.
It is a figure which shows the table of 06.

In FIG. 8, feature values A 305 and B 306 are represented based on a vertex list of basic shape data.

Next, the operation of the feature quantity correspondence unit 307 and the feature quantity synthesis unit 309 will be described.

From the shape data A301, the shape data B3
02, the vertex list and the shape energy parameter of the feature value A305 representing the shape data A301 are converted into the feature value B30 representing the shape data B302.
Consider moving to a vertex list and shape energy parameter of 6.

In this embodiment, since the shape energy parameter 209 is the intersection angle between the surfaces of the adjacent vertices, the number of elements of the shape energy parameter in the characteristic amount A 305 and the number of elements of the shape energy parameter in the characteristic amount B 306 Are different and the shape data A30
Interpolation cannot be performed with the elements of the vertex list and the set of shape energy parameters of the feature quantity A 305 representing “1”.

Therefore, the feature data corresponding unit 307 expresses the shape data A301 by using the vertex list of the basic shape data 304 so that the elements of the feature data A305 and the feature data B306 can be accessed. Interpolation can be performed with elements of the vertex list of the feature amount A305 and the set of shape energy parameters.

In the feature amount synthesizing unit 309, the interpolation amount 3
Interpolation in the feature amount is performed by the ratio of 08.

That is, assuming that the interpolation amount is α (0 ≦ α ≦ 1),
A new feature value C is obtained by the following equation.

[0044]

## EQU2 ## Feature value C = α feature value A + (1−α) Feature value B FIG. 9 shows a table of feature value C.

In this embodiment, as described above, since the shape energy parameter 209 is the intersection angle between the surfaces of adjacent vertices, the number of elements of the shape energy parameter in the feature amount A 305 and the shape energy parameter in the feature amount B 306 Is different from the number of parameters
This interpolation alone is not enough.

For this reason, the feature amount A30 is converted in the feature amount synthesizing unit 309 by the conversion shown in FIGS.
That is, interpolation is performed on the number of elements expressing 5 and the number of elements expressing the feature amount B306.

Thus, a set of feature points (vertex list and shape energy parameter) having an appropriate number of elements can be generated.

By performing the reverse operation of the feature amount analysis unit 303 from the feature points generated in this way, the deformed shape data to be obtained is generated.

It should be noted that other than the vertex list and the shape energy parameter may be used as the feature quantity.

As described above, the present invention has been specifically described based on the embodiments. However, it is needless to say that the present invention is not limited to the above-described embodiments, and can be variously modified without departing from the gist thereof.

[0051]

As described above, according to the present invention,
Matching of two shape models from a common basic shape is performed, and a feature amount for expressing the two shape models is obtained. When one shape model is transformed into the other shape model, the characteristics of the two shape models are compared. Since interpolation is performed in terms of quantity, it is not necessary to hold a shape model directly connected to both shapes and perform interpolation based on the shape model as in the related art.

Therefore, in the conversion between shapes,
The calculation amount can be defined by a process based on a continuous change of the feature amount, and it is possible to avoid the restriction on the expression of the shape model in the generation of the deformed shape.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a deformed shape generating apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing that, in a shape model having three vertices around one vertex, a feature amount of a point Pi can be expressed using an angle between an adjacent vertex and an adjacent surface as an energy parameter.

FIG. 3 is a diagram illustrating a deformation of a vertex list expressing a feature amount.

FIG. 4 is a diagram showing a deformation of a vertex list expressing a feature amount.

FIG. 5 is a diagram for explaining how to obtain a feature amount from a basic shape in the present embodiment.

FIG. 6 is a diagram for explaining how to obtain a feature amount from a basic shape in the present embodiment.

FIG. 7 is a diagram for explaining how to obtain a feature amount from a basic shape in the present embodiment.

FIG. 8 is a diagram illustrating a table of a feature amount A305 and a feature amount B306 in the present embodiment.

FIG. 9 is a diagram illustrating a table of a feature amount C according to the present embodiment.

[Explanation of symbols]

100: two small faces, 101: slightly larger face, 102
... Two separated small faces, 103. Large faces, 104. Deletion of sides, 105. Division of faces, 106.
... Structural division, 200 ... Human head shape, 201: Basic shape, 202: Shape by feature, 203: Shape by transformation, 204: Surface of target shape surface, 205: Basic shape surface,
206: energy amount, 208: feature vertex, 301: shape data A, 302: shape data B, 303: feature amount analysis unit, 304: basic shape data, 305: feature amount A, 306: feature amount B, 307: feature Unit for quantity,
308 ... interpolation amount, 309 ... feature amount synthesis unit, 310
... Deformed shape data.

Claims (2)

(57) [Claims] 1. A deformation for generating an intermediate shape model by continuous deformation between two shape models having a vertex list and a connected list connecting the vertices to form a surface or a line in order to represent the shape of an object. a shape generation apparatus, and pair to each shape model, from a common basic shape
Aligning once performed, a first means for obtaining a feature quantity of <br/> for representing their respective geometric model, when the deformation from one shape model to the other of the shape model, the common base A second means for interpolating both feature amounts using a shape vertex list; and connecting the vertex list of the intermediate shape model expressing a deformed shape and the vertices from the interpolated feature amounts to a surface. Or a third means for creating a linked list forming a line. As the feature amount of claim 2, wherein said shape model, the vertex list to define the shape and, according to claim 1 which comprises using a shape energy in each vertex
Deformed shape generation apparatus.