JP4788565B2 - Apparatus and method for creating three-dimensional shape data of object having seam on surface - Google Patents

Description

  The present invention relates to a technique for creating three-dimensional shape data of an object having a seam on a surface, and more particularly, to a technique for creating a sample image of a product having a seam on a surface by using a CG (computer graphics) technique. . The present invention also relates to a method for pseudo-determining a normal n with respect to an object surface at a position of a predetermined sample point defined on the surface of the object represented by three-dimensional shape data.

  Due to the improvement in computer performance, CG images are being used in various fields of industry. For example, in the design stage of buildings, furniture, automobiles, etc., many CG images are usually used. Also, various CG images of articles are indispensable for various video expressions such as product presentations and movies using computers. Furthermore, recently, there are many examples in which CG images are used instead of actual product photos in product catalogs and the like. In general, in the case of a product that has been commercialized through a design stage using CAD, it is possible to create a CG image using the CAD data used for the design. It becomes possible to prepare.

In the case of articles such as furniture such as sofas, interiors of automobiles, clothes, bags, shoes, bags, etc., the surface of which is decorated with fabric or leather, seams appear on the surface. Therefore, when expressing these articles as a CG image, it is preferable to create an image of the article including the seam. In particular, when the seam is an important element constituting the design of the article, it is indispensable to express it with a CG image including the seam. For example, in Patent Document 1 below, a three-dimensional effect such as a sewing line or stitch is expressed by applying a special optical shading process so that the finished state of the clothing can be confirmed with a CG image. Technology is disclosed.
JP 2000-235589 A

  In interior products such as furniture and automobile interiors, and apparel products such as clothes, bags, shoes, and bags, the seam has not only a meaning as a functional product but also a meaning as an important component in design, From the consumer's perspective, it becomes a significant factor that affects the value of the product. For this reason, in a CG image used for a product catalog or presentation, it is required to represent the shape of the seam as accurately as possible.

  However, conventionally, a method for efficiently creating high-quality three-dimensional shape data of an object including such a seam has not been proposed. It resulted in imposing a burden.

  For example, Patent Document 1 described above discloses a technique (so-called bump mapping technique) that artificially adds a shadow to a seam portion by correcting the normal direction of an object surface. According to this method, the seam can be expressed by a relatively simple process, but since it is a method of expressing the seam in a pseudo manner, high-quality three-dimensional shape data of the object cannot be created. Specifically, it is inappropriate for the close-up expression of the article, and when the texture is pasted, the distortion of the texture cannot be expressed, and it is only a simple concave or convex line expression, There is a problem that complicated shape expression peculiar to an actual seam cannot be performed.

  On the other hand, in the case of buildings, automobile interiors, furniture, etc., it is possible to efficiently create a CG image by diverting CAD data used in the design stage. However, the CAD data used in the design stage usually includes only information indicating the basic shape of the article, and does not include information on the stitches. For example, since seats of automobiles are designed using CAD, it is possible to create a CG image using CAD data. However, the CAD data of the seat sheet created at the design stage is the three-dimensional shape data of the urethane structure that constitutes the interior of the seat. Finally, information on the cloth or leather skin that wraps this urethane structure Is not included. Therefore, CAD data cannot be used as it is to create a CG image including a seam.

  Accordingly, an object of the present invention is to provide a technique that enables efficient creation of high-quality three-dimensional shape data of an object including a seam. The present invention corresponds to an invention obtained by further improving the prior invention disclosed in Japanese Patent Application No. 2005-124535. The improvement over the prior invention is in the method of defining normals that stand on the object surface, and the object of the present invention in this respect is the position of a predetermined sample point defined on the surface of the object represented by the three-dimensional shape data. It is an object of the present invention to provide a method for easily obtaining a pseudo normal line with respect to the object surface.

(1) A first aspect of the present invention is an apparatus for creating 3D shape data of an object having a seam on the surface, which creates 3D shape data including the seam for an object having a seam on the surface.
Basic shape data input means for inputting three-dimensional shape data of an object that does not include seam information as basic shape data;
First reference line defining means for defining a first reference line indicating a direction on the object surface of the seam on the surface of the object indicated by the basic shape data based on an instruction from the operator;
Thread section parameter definition means for defining a thread section parameter indicating the section shape of the thread constituting the seam and its size based on an instruction from the operator;
Based on an instruction from the operator, a sewing process parameter indicating the shape of the ups and downs of the object surface of the seam for one pitch is defined using a periodic function having a period λ corresponding to the length of one pitch of the seam. Sewing process parameter definition means,
For a plurality of sample points P on the first reference line, a pseudo normal n ^* of the first reference line at the position of the sample point P is obtained, and the sample point P is on the pseudo normal n ^*. A second reference indicating a direction in a three-dimensional space of a seam that causes ups and downs with respect to the surface of the object by a set of representative points Q. A second reference line creating means for creating a line;
Thread shape data creating means for creating the three-dimensional shape data of the thread constituting the seam based on the second reference line and the thread section parameter;
By combining the three-dimensional shape data of the thread with the basic shape data, synthetic shape data creating means for creating synthetic shape data that is the three-dimensional shape data of the object including the stitch information,
Is provided.

(2) According to a second aspect of the present invention, in the device for creating three-dimensional shape data of an object having a seam on the surface according to the first aspect described above,
In the second reference line creation means,
A sample point determination unit for determining a sample point P for which the pseudo normal n ^* is to be obtained;
The first reference point P ⁺ located at a position separated from the sample point P in the first direction along the first reference line, and opposite to the first direction from the sample point P along the first reference line A reference point determination unit for determining a second reference point P ⁻ located at a position separated in the second direction of
A first vector V ⁺ having a predetermined length directed from the sample point P toward the first reference point P ⁺ and a second vector having a predetermined length directed from the sample point P toward the second reference point P ⁻ . a vector determiner for determining a, ^- vector V
A sum vector determining unit for obtaining a sum vector Vsum of the first vector V ⁺ and the second vector V ⁻ ;
A normal determining unit that determines the direction opposite to the sum vector Vsum as the direction of the pseudo normal n ^* ;
A representative point determination unit for obtaining a representative point Q based on the sample point P;
Is provided.

(3) According to a third aspect of the present invention, in the apparatus for creating three-dimensional shape data of an object having a seam on the surface according to the second aspect described above,
The first reference line defining means defines the first reference line by a permutation of a plurality of discretely located sample points P;
When the reference point determination unit obtains the pseudo normal n (i) ^* for the i-th sample point P (i), the (i + a) -th sample point P (i + a) is used as the first reference point P. ⁺ a, and the (i-b) -th sampling point P (i-b) a second reference point P ^- and,
The vector determining unit determines a predetermined unit length in advance, sets a unit vector having a unit length in a direction from the sample point P (i) to the sample point P (i + a) as a first vector V ⁺ , the unit vector having the unit length direction in a direction toward the sample point P (i) sampling point from P (i-b) a second vector V ^- is obtained by the a determined manner.

(4) According to a fourth aspect of the present invention, in the device for creating three-dimensional shape data of an object having a seam on the surface according to the first to third aspects described above,
A first reference line defining means, based on an instruction from an operator, in a three-dimensional space in which an object indicated by basic shape data is defined, a reference line made of a straight line or a curve, and a projection direction indicating a predetermined projection direction A projection image formed on the surface of the object indicated by the basic shape data when the reference line is projected in the projection direction indicated by the projection direction vector is used as the first reference line. It is intended to be defined.

(5) According to a fifth aspect of the present invention, in the apparatus for creating three-dimensional shape data of an object having a seam on the surface according to the first to fourth aspects described above,
The sewing process parameter defining means has a function of defining a sewing process parameter using a length λ of one pitch of the stitches and a periodic function h (s) having a period λ,
The second reference line creation means is on the first reference line, and the sample point P is located at a position s along the first reference line from the predetermined start point P0 defined on the first reference line. , A pseudo normal n ^* at the position of the sample point P is obtained, and a representative point Q that is on the pseudo normal n ^* and is separated from the sample point P by a distance h (s) is obtained. The second reference line is created by the set of points Q.

(6) According to a sixth aspect of the present invention, in the device for creating three-dimensional shape data of an object having a seam on the surface according to the fifth aspect described above,
The sewing process parameter defining means has a length function λ represented by a length λ corresponding to one pitch of a stitch and h (s) = Asin ^γ (2πs / λ) (where A and γ are predetermined constants). s) and the sewing process parameters are defined.

(7) According to a seventh aspect of the present invention, in the device for creating three-dimensional shape data of an object having a seam on the surface according to the first to fourth aspects described above,
The undulation table in which the sewing process parameter defining means shows a combination of the length λ for one pitch of the seam, a plurality of discrete values s within a range of 0 to λ, and a predetermined value h (s) corresponding to each discrete value. And define sewing process parameters using
The second reference line creation means is on the first reference line, and the distance along the first reference line from the predetermined start point P0 defined on the first reference line is a position (kλ + s) (provided that k = 0, 1, 2, ...) respectively calculated pseudo normal line ^{n *} with respect to sample point P in, is in the pseudo normal line ^{n *} above, at a position away from the sample point P by a distance h (s) A certain representative point Q is obtained, and a second reference line is created by the set of representative points Q.

(8) According to an eighth aspect of the present invention, in the device for creating three-dimensional shape data of an object having a seam on the surface according to the seventh aspect described above,
The second reference line creation means performs an interpolation process on the discrete information based on the undulation table, and creates a second reference line using the information after the interpolation process.

(9) According to a ninth aspect of the present invention, in the device for creating three-dimensional shape data of an object having a seam on the surface according to the first to eighth aspects described above,
The thread shape data creation means defines the arrangement representative points at predetermined intervals on the second reference line, and the two-dimensional cross-sectional figure of the yarn indicated by the thread cross-section parameter at each arrangement representative point position The processing is performed in a direction orthogonal to the tangent vector of the two reference lines, and the three-dimensional shape data of the yarn is created using the arranged two-dimensional cross-sectional figure.

  (10) According to a tenth aspect of the present invention, there is provided a program for realizing the function on a computer, the apparatus for creating three-dimensional shape data of an object having a seam on the surface according to the first to ninth aspects described above. It is configured by incorporating.

(11) In an eleventh aspect of the present invention, in a method for creating three-dimensional shape data of an object having a seam on a surface, the three-dimensional shape data including the seam is created for an object having a seam on the surface.
A basic shape data input step in which three-dimensional shape data of an object not including stitch information is input as basic shape data to storage means in the computer;
The computer defines a first reference line indicating a direction on the object surface of the seam on the surface of the object indicated by the basic shape data based on an instruction from the operator, and stores the first reference line in the storage means. The baseline definition stage of
A computer defines a thread cross-sectional parameter indicating a cross-sectional shape and a size of a thread constituting the seam based on an operator's instruction, and stores the thread cross-sectional parameter in a storage unit;
The computer uses a periodic function having a period λ corresponding to the length of one pitch of the seam based on an instruction from the operator, and shows a sewing processing parameter indicating the shape of the ups and downs of the object surface of the stitch of one pitch. And a sewing process parameter definition stage for storing this in the storage means,
The computer obtains, for each of the plurality of sample points P on the first reference line, the pseudo normal n ^* of the first reference line at the position of the sample point P, and is on the pseudo normal n ^*. A representative point Q located at a predetermined distance determined by the periodic function from the sample point P is obtained, and a second point indicating the direction in the three-dimensional space of the seam that causes ups and downs with respect to the object surface by the set of the representative points Q. A second reference line creating stage for creating a reference line and storing the reference line in a storage means;
A computer that creates three-dimensional shape data of a thread constituting the seam based on the second reference line and the thread section parameter, and stores the data in a storage means;
The computer creates composite shape data that is the 3D shape data of the object including the stitch information by combining the 3D shape data of the thread with the basic shape data, and stores this in the storage means. The creation stage,
Is to do.

(12) In a twelfth aspect of the present invention, in the method for creating three-dimensional shape data of an object having a seam on the surface according to the eleventh aspect described above,
In the second reference line creation stage, the process of obtaining the pseudo normal n ^* for the sample point P
The first reference point P ⁺ located at a position separated from the sample point P in the first direction along the first reference line, and opposite to the first direction from the sample point P along the first reference line Determining a second reference point P ^{− at} a position spaced apart in the second direction of
A first vector V ⁺ having a predetermined length directed from the sample point P toward the first reference point P ⁺ and a second vector having a predetermined length directed from the sample point P toward the second reference point P ⁻ . and determining the ^- vector V
Determining a sum vector Vsum of, ^- the first vector V ⁺ and the second vector V
Obtaining a pseudo-normal n ^* oriented in the opposite direction to the sum vector Vsum;
It is something that is done by.

(13) According to a thirteenth aspect of the present invention, in the method for creating three-dimensional shape data of an object having a seam on the surface according to the twelfth aspect described above,
In the first reference line definition stage, a permutation of a plurality of discretely located sample points P is determined, and the first reference line is defined by sequentially connecting the plurality of sample points P.
When the second reference line creation means obtains the pseudo normal n (i) ^* for the i-th sample point P (i), the (i + a) -th sample point P (i + a) a reference point P ^+, the (i-b) -th sampling point P (i-b) a second reference point P ^- samples from the in advance determined beforehand predetermined unit length, sampling point P (i) A unit vector having an orientation unit length in the direction toward the point P (i + a) is defined as a first vector V ^+, and the direction from the sample point P (i) to the sample point P (ib) is defined as the unit length. a unit vector having a second vector V ^- is obtained by the a determined manner.

(14) In the fourteenth aspect of the present invention, the normal line n of the object surface at the position of a predetermined sample point defined on the surface of the object is obtained in a pseudo manner based on the three-dimensional shape data of the object. In the method for determining normals on the surface of a three-dimensional object,
A step in which the three-dimensional shape data of the object is input as basic shape data to storage means in the computer;
The computer defining the position of the sample point P of interest;
A computer defining a reference line through the sample point P on the surface of the object;
The computer has a first reference point P ⁺ located at a position separated from the sample point P along the reference line in the first direction, and a second opposite to the first direction from the sample point P along the reference line. Defining a second reference point P ^{− at} a position spaced in the direction of
The computer has a first vector V ⁺ having a predetermined length directed from the sample point P toward the first reference point P ⁺ and a predetermined length directed from the sample point P toward the second reference point P ⁻ . Determining a second vector V ⁻ ;
Computer, the first vector V ⁺ and the second vector V ^- and determining a sum vector Vsum and,
A computer determining a vector oriented in the opposite direction to the sum vector Vsum as a pseudo normal n ^* for the object surface at the position of the sample point P;
Is to do.

(15) In the fifteenth aspect of the present invention, based on the three-dimensional shape data of an object, a normal line n about the object surface at a position of a predetermined sample point defined on the surface of the object is obtained in a pseudo manner. In the method for determining normals on the surface of a three-dimensional object,
A step in which the three-dimensional shape data of the object is input as basic shape data to storage means in the computer;
A computer defining a permutation of a plurality of sample points discretely located on the surface of the object;
A computer determining an i-th sample point P (i) of a plurality of sample points as a sample point for which a normal is to be obtained;
Recognizing the (i + a) th sample point P (i + a) and the (ib) sample point P (ib) based on the permutation;
The computer determines a predetermined unit length in advance, sets a unit vector having a unit length in the direction from the sample point P (i) to the sample point P (i + a) as the first vector V ^+, and sets the sample point the unit vector having the unit length direction in a direction toward the P (i) sampling point from P (i-b) a second vector V ^- and the step of determining,
Computer, the first vector V ⁺ and the second vector V ^- and determining a sum vector Vsum and,
A computer determining a vector oriented in the opposite direction to the sum vector Vsum as a pseudo normal n (i) ^* for the object surface at the position of the sample point P (i);
Is to do.

  In the present invention, a first reference line is defined on the object surface that does not include information on the seam, and the first reference line is defined as a three-dimensional seam that causes ups and downs with respect to the object surface using a sewing processing parameter. Since it is converted into a second reference line indicating the direction in the space, and the cross-sectional shape figure of the thread is arranged along the second reference line, and the three-dimensional shape data of the thread is created, the seam It is possible to efficiently create high-quality three-dimensional shape data of the included object. Further, in the present invention, instead of defining the normal for the sample point on the surface, the pseudo normal for the sample point on the line is defined. Therefore, the pseudo normal for the object surface can be easily obtained. It becomes possible.

  Hereinafter, the present invention will be described based on the illustrated embodiments. As already described, the present invention should be an improved invention of the prior invention disclosed in Japanese Patent Application No. 2005-124535. Therefore, the contents of §1 to §7 described below are almost the same as those of the prior application invention. The improvements to the prior invention will be described in detail in §8 and §9.

<<< §1. Basic procedure >>>
In the present invention, three-dimensional shape data including a seam is created for an object having a seam on the surface. In this section 1, the basic procedure of the present invention will be described using a simple model.

  FIG. 1 is a flowchart showing the basic procedure of a method for creating three-dimensional shape data according to the present invention. The present invention is based on the premise that the computer is basically used, and each stage shown in the flowchart of FIG. 1 is developed exclusively by the computer using its hardware resources. The processing to be executed based on the software program is shown.

  As shown in the figure, this basic procedure is roughly classified into three processes: an input process (step S1), a definition process (steps S2 to S4), and a creation process (steps S5 to S7). The input process is a process for inputting the three-dimensional shape data of the object to be processed in this basic procedure, and the definition process is for defining parameters and the like necessary for creating the three-dimensional information of the seam. The creation process is a process for creating the three-dimensional information of the seam on the surface of the object indicated by the three-dimensional shape data input in the input process, using the parameters defined in the definition process. Hereinafter, the individual steps constituting each process will be described in order.

  First, the basic shape data input step shown in step S1 is a step of performing processing for inputting basic shape data to the storage means in the computer. Here, the basic shape data is the three-dimensional shape data of an object that does not include seam information. The basic procedure shown in the flowchart of FIG. 1 is a process for adding seam information to the basic shape data. It can be said. Here, for convenience of explanation, the following explanation will be given when the three-dimensional shape data for an object having a simple rectangular parallelepiped shape as shown in FIG. 2 is input as the basic shape data Db. The basic shape data Db shown in FIG. 2 is data that simply represents a rectangular parallelepiped, and does not include any stitch information.

  In the present application, for convenience of explanation, the three-dimensional shape data and the three-dimensional figure represented by the data are denoted by the same reference numerals. For example, the symbol “Db” illustrated in FIG. 2 indicates the three-dimensional form of the object itself, and also indicates basic shape data for expressing the object.

  The first reference line defining stage shown in step S2 is a first reference line indicating a direction on the object surface of the seam on the surface of the object Db indicated by the basic shape data Db input in step S1, based on an instruction from the operator. This is a stage in which one reference line is defined and stored in the storage means. In other words, a process of defining a projection line obtained by projecting the locus of the seam on the object surface as the first reference line is performed. FIG. 3 is a perspective view showing an example in which a first reference line L1 (shown by a broken line) is defined at the center position of the upper surface of the object Db. Here, for convenience of explanation, a simple example in which only one first reference line L1 is defined on the upper surface of the object is shown. Of course, the first reference line L1 may be defined across a plurality of surfaces. It is possible to define multiple lines.

The yarn cross-section parameter definition stage shown in step S3 is a stage in which a thread cross-section parameter Pc is defined on the basis of an operator instruction and stored in the storage means. Here, the thread cross-sectional parameter Pc is a parameter indicating the cross-sectional shape of the thread constituting the seam and its size. FIG. 4 is a plan view showing an example of the cross-sectional shape of the yarn defined by the yarn cross-section parameter Pc. In the example shown in the figure, a circular two-dimensional sectional figure C is defined. The cross section made of such a representative geometric figure can be defined by an equation, and in the case of the illustrated circle, x ² + y ² = r ² using the xy two-dimensional coordinate system. It can be defined by an equation. Here, since r is the radius of the circle, this equation defines both the cross-sectional shape of the yarn and its size.

  The sewing process parameter definition stage shown in step S4 is a stage in which the sewing process parameter Ps is defined based on an operator instruction and stored in the storage means. Here, the sewing processing parameter Ps is a parameter indicating the length of one pitch of the stitches and the shape of the ups and downs of the one stitch of the stitches with respect to the object surface. In the first place, a seam is a physical structure that is formed by alternately passing threads from the front to the back and back to the front of a cloth or leather sheet. The seam that appears on the surface of an article is the surface of the object. The thread is made to rise and fall at a predetermined cycle.

  The sewing processing parameter Ps is a parameter that defines the period and shape of the ups and downs. FIG. 5 is a plan view showing one definition form of the sewing processing parameter Ps. In this example, the sewing processing parameter Ps is composed of a graph indicating a rectangular wave ups and downs shape (indicated by a one-dot chain line) and information indicating a length λ (one period of the graph) for one pitch. That is, the sewing processing parameter Ps indicating the shape of the ups and downs with respect to the object surface of the seam for one pitch can be defined using a periodic function having a period λ corresponding to the length of one pitch for the seam. Here, the reference line S of the graph indicates the surface position of the object, and the alternate long and short dash line shown above the reference line S corresponds to the seam portion (visible part) exposed on the surface of the object. A one-dot chain line shown below S corresponds to a seam portion (invisible portion) hidden inside the object.

  This completes the definition process. Subsequently, the creation process is executed. First, in the second reference line creation stage shown in step S5, a seam that causes ups and downs on the object surface based on the first reference line L1 defined in step S2 and the sewing processing parameter Ps defined in step S4. The second reference line L2 indicating the direction in the three-dimensional space is created and stored in the storage means.

  FIG. 6 is a perspective view showing an example of the second reference line L2 created in the stage of step S5. The second reference line L2 shown in FIG. 6 is created based on the first reference line L1 shown in FIG. 3 and the sewing processing parameter Ps shown in FIG. 5, and the reference of the graph shown in FIG. 3 shows the position of the graph indicated by the alternate long and short dash line in the three-dimensional space when the line S is superimposed on the first reference line L1 shown in FIG. In short, the process of mapping the graph shown in FIG. 5 onto the first reference line L1 using the reference line S as a reference is performed.

  As described above, in the graph shown in FIG. 5, the portion of the alternate long and short dash line shown below the reference line S is an invisible portion. The invisible part is embedded in the object Db in FIG. The first reference line L1 is a two-dimensional line defined on the object surface, whereas the second reference line L2 is a three-dimensional line that causes ups and downs on the object surface. become.

  FIG. 6 shows an example in which the second reference line L2 is composed of two periods (two pitches) of stitches for convenience of illustration, but in practice, one pitch of the stitches is shown. The minute length λ is generally set sufficiently small with respect to the size of the object, and the second reference line L2 usually includes a larger number of periods. In the illustrated example, since the first reference line L1 is defined only on the upper surface of the object, the second reference line L2 is also created only on the upper surface of the object. When the reference line L1 is continuously defined also on the front surface of the object, the second reference line L2 is also continuously formed up to the front surface of the object.

  In the thread shape data creation stage of step S6, based on the second reference line L2 created in step S5 and the thread cross-sectional parameter Pc defined in step S3, 3D shape data of the thread constituting the seam is created, This is the stage where the process of storing this in the storage means is performed. FIG. 7 is a perspective view showing an example of the three-dimensional form of the yarn indicated by the three-dimensional shape data Ds of the yarn created in step S6. Here, for convenience, the three-dimensional form of the yarn indicated by the shape data Ds is also indicated by using the same symbol Ds. The yarn three-dimensional form Ds as shown in FIG. 7 can be created by continuously arranging the two-dimensional cross-sectional figure of the yarn shown in FIG. 4 along the second reference line L2 shown in FIG. it can.

  Specifically, the arrangement representative points are defined at predetermined intervals on the second reference line L2, and a process of arranging a two-dimensional cross-sectional figure of the thread at each arrangement representative point is performed. The three-dimensional shape data Ds of the yarn may be created as a surface that smoothly connects the contour lines of the two-dimensional sectional figure. For example, as shown in FIG. 4, when a two-dimensional cross-sectional figure C made of a circle is defined by the yarn cross-section parameter Pc, the center is located at each arrangement representative point position defined on the second reference line L2. In this way, a circular two-dimensional sectional figure C may be arranged. At this time, each two-dimensional sectional figure C is preferably arranged in a direction perpendicular to the tangent to the second reference line L2 at each arrangement representative point. Thus, the three-dimensional structure obtained by smoothly connecting the circumferences of a large number of circles (two-dimensional cross-sectional figure C) arranged along the second reference line L2 is the three-dimensional form Ds of the yarn shown in FIG. It turns out that. The three-dimensional form Ds of the yarn corresponds to a cylindrical pipe having a radius r arranged with the second reference line L2 as a central axis, and a part (invisible part) of the pipe is embedded in the object Db. It is in a state.

  In step S7, the composite shape data creation stage combines the basic shape data Db input in step S1 with the three-dimensional shape data Ds of the yarn created in step S6, so that the three-dimensional shape of the object including stitch information is obtained. This is a stage in which composite shape data Dbs, which is data, is created and stored in storage means. If the basic shape data Db and the three-dimensional shape data Ds of the yarn are data defined on the same three-dimensional coordinate system, the combined shape data Dbs is obtained simply by combining these data. Can do.

  The three-dimensional shape data Ds of the thread is data including both the visible part exposed on the upper surface of the object Db and the invisible part embedded in the object Db. In step S7, the invisible data in the three-dimensional shape data Ds of the yarn may be deleted and synthesized. However, in practice, even if the composite shape data Dbs includes the data of the invisible part of the three-dimensional shape data Ds of the yarn, the three-dimensional structure as shown in FIG. At the stage of obtaining a two-dimensional projection image showing the state observed from the above, the invisible portion of the three-dimensional form Ds of the yarn is hidden by the upper surface of the object Db by the hidden surface processing, so no problem occurs.

  As described above, according to the method for creating the three-dimensional shape data of the object having the seam on the surface according to the present invention, first, the three-dimensional shape data of the object not including the stitch information is input as the basic shape data Db. 1 reference line L1, thread section parameter Pc and sewing processing parameter Ps are defined, and based on these information, a second reference line L2 indicating the direction of the seam in the three-dimensional space is created. The yarn three-dimensional shape data Ds can be created by arranging the yarn cross-sectional shape figure along the reference line L2. Therefore, it is possible to efficiently create high-quality three-dimensional shape data of an object including a seam.

<<< §2. Basic configuration of equipment >>
Next, the basic configuration of a device for creating three-dimensional shape data of an object having a seam on the surface according to the present invention will be described with reference to the block diagram of FIG. As described above, the present invention is basically based on the assumption that a computer is used, and the apparatus shown in FIG. 8 is an apparatus realized by incorporating a dedicated program into the computer. Accordingly, the functions of the constituent elements shown as individual blocks are actually functions realized by a program incorporated in the computer.

  The apparatus shown in FIG. 8 has a function of creating three-dimensional shape data including a seam for an object having a seam on the surface, and is composed of components indicated by a total of seven blocks. These individual blocks correspond to the respective steps S1 to S7 of the flowchart shown in FIG. 1, and have a function of executing the processes shown in the corresponding steps.

  That is, the basic shape data input means 10 has a function of executing the basic shape data input stage shown in step S1, and the first reference line definition means 20 has a first shape shown in step S2. The thread section parameter defining means 30 has a function of executing the reference line defining stage, the thread section parameter defining means 30 has a function of executing the thread section parameter defining stage shown in step S3, and the sewing process parameter defining means 40 is step S4. The second reference line creation means 50 has a function of executing the second reference line creation stage shown in step S5, and the sewing process parameter definition stage shown in FIG. The yarn shape data creation means 60 has a function of executing the yarn shape data creation stage shown in step S6, and the composite shape data creation means 70 is shown in step S7. It has a function of executing a molded shape data creation step. Hereinafter, processing executed by each of these units 10 to 70 will be described in order with reference to specific examples shown in FIGS.

  First, the basic shape data input means 10 is a component having a function of inputting, as basic shape data, three-dimensional shape data of an object that does not include stitch information. The original shape data is input as basic shape data Db. In short, the basic shape data input means 10 is a general input device having a function of taking digital data given from the outside into the computer.

  As methods for expressing an object three-dimensionally, an expression using a polygon and an expression using a parametric curved surface are generally known. The former is a method of expressing the object surface as an aggregate of a large number of polygons (polygons). Usually, the position coordinates of the vertices constituting each polygon and the positional relationship of each vertex (which vertex is connected to which vertex) Thus, the three-dimensional shape of the object is defined by the information indicating whether a polygon is formed. On the other hand, the latter is a technique for expressing the surface of an object by a parametric surface represented by a Bezier surface, a spline surface, or a NURBS surface, and is based on a set of various parameters for defining the parametric surface. The original shape is defined.

  The basic shape data input by the basic shape data input means 10 may be data in the former form (three-dimensional shape data representing the object surface by a large number of polygons), or data in the latter form (by parametric curved surfaces). 3D shape data representing the surface of the object).

  As already described, in the case of buildings, automobile interiors, furniture, etc., design using CAD is generally performed, and CAD data created at this design stage usually includes basic shape data Db. It is included. For example, CAD data of an automobile seat seat is three-dimensional shape data of a urethane structure that forms the interior of the seat, and corresponds to the three-dimensional shape data of a seat that does not include stitch information. The actual sheet is obtained by covering the surface of this urethane structure with a cloth or leather skin with seams. For an object for which such CAD data is prepared, this CAD data may be supplied to the basic shape data input means as it is or after being subjected to necessary corrections. For example, in the case of clothes, data obtained by adding corrections for expressing wrinkles caused by contact with the human body surface to the CAD data of the pattern used at the time of design is used as the basic shape data Db of the clothes. What is necessary is just to give to the basic shape data input means 10.

  Of course, when the CAD data used in the design stage cannot be diverted, or in the case of an object for which CAD data does not exist in the first place, three-dimensional shape data of the object (data that does not include seam information) is created, It is necessary to give to the basic shape data input means 10. As described above, since various devices for creating three-dimensional shape data of an object that does not include stitch information have already been put into practical use, detailed description thereof is omitted here.

  The first reference line definition means 20, the thread section parameter definition means 30, and the sewing process parameter definition means 40 are all components having a function of setting predetermined data based on an instruction input from the operator. In order to input an instruction from the operator, a predetermined input screen is presented on the display, and the operator who views the input screen operates a computer input device such as a keyboard or a mouse, and inputs the operation result. Prepare a program to import as.

  First, the first reference line definition means 20 sets the direction on the object surface of the seam on the surface of the object indicated by the basic shape data Db input by the basic shape data input means 10 based on an instruction from the operator. This is a component having a function of defining the first reference line L1 shown. For example, when the basic shape data Db of the object as shown in FIG. 2 is input, the first reference line L1 as shown by the broken line in FIG. 3 is defined on the surface of this object. A specific method of defining the first reference line L1 will be described in detail in §3.

On the other hand, the thread cross-section parameter definition means 30 is a component that defines a thread cross-section parameter Ps indicating the cross-sectional shape and size of the thread constituting the seam based on an instruction from the operator. As shown, the shape and size of the two-dimensional cross-sectional figure C of the thread can be defined by the equation x ² + y ² = r ² of the circle in the xy two-dimensional coordinate system. Although it is possible for the operator to directly input such a specific equation and set the yarn section parameter Ps, in practice, by specifying or selecting various constant values included in the equation as parameters. It is preferable to set a desired cross-sectional shape and size. A specific method for setting the thread section parameter will be described in detail in §4.

  The sewing process parameter definition means 40 has a function of defining a sewing process parameter Ps indicating the length of one pitch of the seam and the shape of the ups and downs of the seam of the stitch for the object surface based on an instruction from the operator. It is a component with. For example, in the example shown in FIG. 5, the sewing processing parameter Ps is defined by a length (λ) corresponding to one pitch of the seam and a graph (indicated by a one-dot chain line) showing the shape of the ups and downs with respect to the object surface of this one pitch seam. The sewing processing parameter Ps is defined using a periodic function having a period λ corresponding to the length of one pitch of the stitches. In order to define the length λ, for example, a function for allowing an operator to input a desired numerical value in a predetermined unit (for example, mm) may be provided. In order to define the shape of the ups and downs, for example, a plurality of graphs may be prepared in advance, and a function for allowing the operator to select a desired graph from the graphs may be provided. A specific method for setting the sewing processing parameters will be described in detail in §5.

  The second reference line creation means 50 is based on the first reference line L1 defined by the first reference line definition means 20 and the sewing process parameter Ps defined by the sewing process parameter definition means 40. This is a component having a function of creating a second reference line L2 indicating the direction in the three-dimensional space of the seam that causes ups and downs with respect to the object surface. As described in §1, for example, by using the first reference line L1 as shown in FIG. 3 and the sewing processing parameter Ps shown in the graph as shown in FIG. 5, the first reference line L1 as shown in FIG. Two reference lines L2 are created. A specific algorithm for the process of creating the second reference line L2 will be described in detail in §6.

  The thread shape data creating means 60 is based on the second reference line L2 created by the second reference line creating means 50 and the thread section parameter Pc defined by the thread section parameter defining means 30. This is a component having a function of creating the three-dimensional shape data Ds of the constituent yarn. As described in §1, for example, the second reference line L2 as shown in FIG. 6 and the two-dimensional cross-sectional figure C of the yarn indicated by the yarn cross-sectional parameter Pc as shown in FIG. 4 (in this example, a circle) ), The three-dimensional shape data Ds of the yarn as shown in FIG. 7 is created. A specific algorithm for the process of creating the three-dimensional shape data Ds of the yarn will be described in detail in §7.

  The synthesized shape data creating unit 70 includes stitch information by synthesizing the three-dimensional shape data Ds of the yarn created by the yarn shape data creating unit 60 with the basic shape data Db input by the basic shape data input unit 10. This is a component that performs a process of creating composite shape data Dbs, which is three-dimensional shape data of an object. As described above, if the basic shape data Db and the three-dimensional shape data Ds of the yarn are made to be data using the same three-dimensional coordinate system, the synthesized shape data creating means 70 simply has two data Db and Ds. The combined shape data Dbs can be created.

  The synthesized shape data Dbs created in this way is outputted from the synthesized shape data creating means 70 to an external device and used for various purposes. For example, if the synthetic shape data Dbs is taken into a general apparatus capable of handling three-dimensional CG, a two-dimensional CG image when an object including information on stitches as shown in FIG. 7 is observed from a predetermined viewpoint. Can be created. At this time, as described above, the invisible portion of the three-dimensional form Ds of the yarn can be hidden by the hidden surface processing.

<<< §3. Definition of the first reference line >>>
Subsequently, an example of a specific definition method of the first reference line L1 performed in step S2 of FIG. 1 or the first reference line definition means 20 of FIG. 8 will be described. For example, as shown in FIG. 3, the first reference line L1 is a line indicating the direction on the object surface of the seam. If the line is defined on the object surface, the first reference line L1 may be a straight line. It doesn't matter if it's a curve.

  In §1 and §2 described so far, for the sake of convenience of explanation, an example in which the three-dimensional shape data of an object made of a rectangular parallelepiped as shown in FIG. 2 is input as the basic shape data Db has been described. Consider a case where the three-dimensional shape data of an object including a curved surface as shown in FIG. 9 is input as basic shape data Db.

  FIG. 10 is a perspective view showing a state where first reference lines L11 and L12 (shown by broken lines) are defined on the surface of the object shown in FIG. These reference lines L11 and L12 are defined on the curved surface near the left and right ends of the object Db. In order to define the first reference line based on the operation input of the operator, for example, a program that provides a function for performing drawing on the surface of a three-dimensional object is prepared, and this drawing function is used. It is also possible to take a method in which the first reference line is drawn directly on the surface of the object. However, in practice, it is preferable to define the first reference line using a projection process as described below.

  FIG. 11 is a perspective view showing the principle of the first reference line definition method using this projection processing. Now, as shown in the figure, two reference lines K11 and K12 are defined at positions away from the object Db, and a projection direction vector V indicating a predetermined projection direction is defined. Then, the reference lines K11 and K12 are projected in the projection direction indicated by the projection vector V, a projection image is formed on the surface of the object Db, and this projection image is defined as the first reference line. In the illustrated example, the projected image of the reference line K11 on the object surface is the first reference line L11, and the projected image of the reference line K12 on the object surface is the first reference line L12.

  If the reference lines K11 and K12 are constituted by straight lines, the positions of these reference lines on the three-dimensional coordinate system can be expressed by a very simple equation, and the reference line can be changed by changing the parameters of this equation. K11 and K12 can be moved in a desired direction. Although the equations are a little complicated, it is possible to define a reference line consisting of curves. On the other hand, since the three-dimensional shape of the object is given as the basic shape data Db, the projection images of the reference lines K11 and K12 on the object surface can be obtained by performing geometric calculation on the three-dimensional coordinate system. it can. If the operator inputs parameters that specify the shape and position of the reference line and the direction of the projection direction vector, and the projection image obtained based on the specified parameters is displayed in real time on the display screen, the operator Each time an operation input for changing the value of the parameter is performed, the position of the projected image displayed on the display screen changes in real time. Therefore, the operator can define the first reference line at a desired position while looking at the display screen.

  After all, on the basis of an instruction from the operator, on the three-dimensional space in which the object indicated by the basic shape data Db is defined, reference lines K11 and K12 made of straight lines or curves, and a projection direction vector V indicating a predetermined projection direction, And a first projection image L11, L12 formed on the surface of the object indicated by the basic shape data Db when the reference lines K11, K12 are projected in the projection direction indicated by the projection direction vector V. The function defined as the reference line may be given to the first reference line defining means 20 shown in FIG.

  As described above, the basic shape data Db may be three-dimensional shape data representing the object surface by a large number of polygons, or the object surface may be represented by a parametric surface represented by a Bezier curved surface, a spline curved surface, or a NURBS curved surface. The expressed 3D shape data may be used. In the former case, the projection images L11 and L12 of the reference lines K11 and K12 (that is, the first reference line) are usually expressed as straight lines or curves drawn on a specific polygon, and in the latter case, , A Bezier curve, a spline curve, and a NURBS curve.

  Note that the first reference line is not necessarily defined as a geometric line, and can be defined by a permutation of a plurality of discretely located points. For example, if the points P1, P2, P3,... Discretely located on the surface of the object Db are defined in this order, the plurality of points P1, P2, P3,... Are sequentially connected on the surface of the object Db. It is possible to define the first reference line as a line (for example, a line connecting at the shortest distance on the surface).

<<< §4. Definition of thread section parameter >>>
Next, an example of a specific method for defining the thread section parameter Pc performed in step S3 in FIG. 1 or the thread section parameter defining means 30 in FIG. 8 will be described. The thread cross-sectional parameter Pc is a parameter indicating the cross-sectional shape and the size of the thread constituting the seam. It doesn't matter.

FIG. 12 shows a superquadratic curve represented by an expression of (x / a) ^{2 / ε} + (y / b) ^{2 / ε} = 1 (where ε is a predetermined constant) in an xy two-dimensional orthogonal coordinate system. It is a figure which shows the example which performed the definition of the two-dimensional cross-sectional figure of a thread | yarn using. This expression is an expression showing a super quadratic function. When rewritten into an expression using a parametric variable θ, it becomes a form using a trigonometric function of x = a cos ^ε θ and y = b sin ^ε θ.

FIG. 13 is a plan view showing the shape of a two-dimensional sectional figure defined on the xy two-dimensional orthogonal coordinate system by the above equation when the value of the constant ε is changed. FIG. 13 (a) shows the shape when ε = 0.1, which is a figure close to a so-called rounded rectangle. FIG. 13B shows the shape when ε = 0.7, and the roundness of the corners becomes stronger. FIG. 13C shows the shape when ε = 1.0, and the figure obtained is a geometric figure represented by the formula (x / a) ² + (y / b) ² = 1, That is, it becomes an ellipse. The circle shown in FIG. 4 corresponds to the case where a = b = r is set. FIGS. 13D, 13E, and 13F are shapes when ε = 1.5, 2.0, and 3.0, respectively.

  After all, in the above equation, the constants a and b are parameters that define the cross-sectional size, and the constant ε is a parameter that defines the cross-sectional shape. Therefore, if the yarn cross section is defined using the super quadratic function shown in FIG. 12, the shape of the yarn cross section constituted by the super ellipse is determined by defining the constants a, b, and ε as the yarn cross section parameters. And size can be determined. Since the operator only needs to input an instruction to set the values of the three parameters a, b, and ε, the yarn cross section can be defined with a very light work load.

  Since the cross-sectional shape of a thread used for a general sewing process is substantially a shape based on a circle or an ellipse, it can be defined by setting ε to a desired value in the equation shown in FIG. However, in a special sewing process or the like, a thread having a cross-sectional shape that cannot be expressed by the equation shown in FIG. 12 may be used. In such a case, as shown in FIG. 14, in the rθ polar coordinate system, the relationship between the angle θ (0 ≦ θ <2π) and the distance r (θ) corresponding to this angle θ is defined as the yarn cross-section parameter. do it.

  Actually, since the value of the angle θ must be defined as a discrete value for each predetermined interval, a finite number of θ values given as the discrete values and the corresponding value of r (θ) A cross-sectional shape table showing the combination of the thread cross-sectional shape and the cross-sectional shape table may be used to define the thread cross-sectional parameters. For example, if θ is set as a discrete value every 10 °, the thread cross-sectional parameters can be defined by the cross-sectional shape table indicating a total of 36 combinations of “θ and r (θ)”, and a cross section of an arbitrary shape can be obtained. It can correspond to the thread that has.

  When a discrete value is used as the value of the angle θ, the contour line of the yarn cross section is not defined as a continuous line but is defined as a set of a finite number of points. For example, in the example shown in FIG. 14, one contour point K is defined by a specific combination of θ and r (θ). It is expressed as a set of contour points K. Therefore, when information on the contour line between adjacent contour points K is necessary, interpolation processing such as linear interpolation and spline interpolation may be performed.

<<< §5. Sewing process parameter definition >>>
Next, an example of a specific method for defining the sewing process parameter Ps performed in step S4 in FIG. 1 or the sewing process parameter defining means 40 in FIG. 8 will be described. The sewing process parameter Ps is a parameter indicating the length of one pitch of the seam and the shape of the ups and downs of the one pitch of the seam on the object surface. Here, the length λ for one pitch of the seam can be easily defined by designating a predetermined unit (for example, mm) and allowing the operator to designate a numerical value.

  On the other hand, it is convenient to define the shape of the ups and downs with respect to the object surface using a periodic function h (s) having a period λ. Here, s is a parameter indicating a distance along the first reference line L1 from a predetermined starting point position defined on the first reference line L1, and the function value h (s) is only the distance s. It is a parameter indicating the amount of ups and downs at a distant position. For example, the position on the object surface may be set to the reference value 0, the position floating outward from the object surface may be indicated by a positive ups and downs, and the position sinking in from the object surface may be indicated by a negative ups and downs.

FIG. 15 is a graph showing a function represented by an expression h (s) = Asin ^γ (2πs / λ) (where A and γ are predetermined constants) as a typical periodic function h (s). Here, when γ = 1 is set, the periodic function h (s) becomes a sine function as shown in the figure, and the shape of the graph can be adjusted by variously changing the value of γ. For example, it is also possible to define a periodic function close to a rectangular wave, as in the graph shown by the alternate long and short dash line in FIG. Note that A is an amplitude, and the value can be specified by the operator as an amount having a predetermined unit (for example, mm), similarly to λ.

  In the case of a general seam, since the visible part (the part located above the object surface) and the invisible part (the part located below the object surface) are alternately repeated, the periodic function h (s) is also positive. It is preferable to use a function that alternates between a value and a negative value. In the above formula, when γ is set to an even number, the function h (s) always takes a positive value. Therefore, if a shape in which γ is set to an even number is absolutely necessary, the function value is set every half cycle. It is advisable to perform processing that inverts the sign of. Of course, depending on the stitching method, there may be a stitch formed only of the visible portion and not having the invisible portion. In such a case, the function in which γ is set to an even number may be used as it is.

  It is also possible to define the visible part and the invisible part by separate functions. The ratio between the length of the visible portion and the length of the invisible portion does not necessarily have to be 1: 1, and the shape of the visible portion and the shape of the invisible portion do not necessarily have to be the same. In some cases, it is better to define the function that defines the shape of the visible portion and the function that defines the shape of the invisible portion separately. In short, any function may be used as long as it is a function that can define the shape of the ups and downs with respect to the object surface of the stitch for one pitch. Since the function h (s) is a periodic function, the function value h (s) only needs to be defined within the range of 0 ≦ s <λ.

  Of course, the shape of the stitches for one pitch is not necessarily defined by a function, but can be defined by a set of discretely arranged contour points. FIG. 16 is a plan view showing an example in which the shape of the seam is defined by a set of a large number of contour points Ki. Here, the i-th contour point Ki is a point defined by a combination of a distance si given as an i-th discrete value within a range of 0 to λ and a predetermined value h (si) corresponding thereto. It turns out that. Therefore, by creating a undulation table indicating a combination of the length λ for one pitch of the seam, a plurality of discrete values s within a range of 0 to λ, and a predetermined value h (s) corresponding to each discrete value, Sewing processing parameters can be defined using this undulation table.

  However, the shape of the seam for one pitch defined in this undulation table is not a continuous line, but a set of a finite number of points. If necessary, interpolation is performed for discrete information on this undulation table. It is preferable to carry out the treatment.

<<< §6. Creating a second reference line >>
Next, an example of a specific method for creating the second reference line performed in step S5 in FIG. 1 or the second reference line creating means 50 in FIG. 8 will be described. As shown in FIG. 6, the second reference line L2 is a line indicating the direction in the three-dimensional space of the seam where the ups and downs occur with respect to the object surface, and the first reference line L1 and the sewing process It is created based on the parameter Ps. Here, the sewing process defined as the first reference lines L11 and L12 defined on the object Db as shown in FIG. 10 and the periodic function h (s) having the predetermined period λ as shown in FIG. A specific method for creating the second reference line based on the parameter Ps will be described.

  First, consider a method of creating a second reference line based on the first reference line L12 shown in the perspective view of FIG. The second reference line created here should be a line obtained by mapping the graph of the periodic function h (s) shown in FIG. 15 along the first reference line L12. In this case, first, the starting point P0 is set at an arbitrary position on the first reference line L12. This starting point P0 serves as a reference for determining a phase in mapping the periodic function h (s). If it is necessary to accurately determine the phase of the seam, it is necessary for the operator to specify the position of the starting point P0 accurately. However, even if it is a general application that does not need to consider the phase of the seam. For example, the second reference line creation means 50 may be provided with an automatic setting function that sets an arbitrary point on the first reference line L12 (for example, the end point of the first reference line L12) as the start point P0.

  When the starting point P0 is determined in this way, as shown in FIG. 17, the point P is on the first reference line L12 and the distance from the starting point P0 along the first reference line L12 is at the position s. A normal line n about the object surface set at the position of the point P is obtained, and a point Q that is on the normal line n and is separated from the point P by a distance h (s) is obtained. What is necessary is just to perform the process which produces the 2nd reference line by a set. Since the function h (s) is a periodic function, if the value of the function value h (s) is defined within the range of 0 ≦ s <λ, the function value h (s) is obtained for any value of s. It is possible to create a second reference line corresponding to any length of the first reference line.

  The point Q constituting the second reference line is defined at a position separated from the point P by the function value h (s) along the direction of the normal line n set at the position of the point P. The generated second reference line is always a line that causes ups and downs with respect to the object surface. Of course, the function value h (s) can take both positive and negative values. When the function value h (s) takes a positive value, the point Q is separated from the point P in the outward direction of the object. When defined as a point and the function value h (s) takes a negative value, the point Q is defined as a point separated from the point P in the inner direction of the object.

When the sewing processing parameter Ps is defined by an expression and the first reference line is expressed by a relatively simple expression, the second reference line composed of a set of points Q can also be expressed by the expression. is there. For example, when the first reference line is a straight line, the second reference line is an expression given as the sewing processing parameter Ps, for example, an expression such as h (s) = Asin ^γ (2πs / λ). The represented periodic curve is arranged as it is in the three-dimensional space. Therefore, the second reference line can be obtained as an equation by converting the above equation defining the periodic curve on the two-dimensional plane into an equation on the three-dimensional space.

  Note that, as in the example shown in FIG. 16, the sewing processing parameter Ps includes a length λ corresponding to one pitch of the stitches, a plurality of discrete values s within a range of 0 to λ, and a predetermined value corresponding to each discrete value. When defined by the undulation table indicating the combination of h (s), the value h (s) is defined only for a finite number of variables s within the range of 0 ≦ s <λ. Therefore, although the value h (s) is not defined for the variable s greater than or equal to λ, there is no problem if the information of the undulation table is repeatedly applied with the period λ. That is, with respect to the point P on the first reference line L12 and having a distance (kλ + s) along the first reference line L12 from the starting point P0 (where k = 0, 1, 2,...). A normal line n about the object surface set up at the position of the point P is obtained, and a point Q that is on the normal line n and is separated from the point P by a distance h (s) is obtained. The second reference line may be created by Here, k is an integer such as k = 0, 1, 2,..., And is a parameter indicating the number of repetitions.

  Thus, since the point Q defined using the undulation table is a discrete point, when it is desired to obtain the second reference line as a continuous line, the discrete information based on the undulation table is used. The interpolation process is performed, and the second reference line may be created using the information after the interpolation process. For example, a plurality of discrete points Q may be obtained based on the undulation table, and interpolation processing such as linear interpolation or spline interpolation may be performed on the portion between adjacent points Q.

  On the other hand, when the sewing processing parameter Ps is defined not by the undulation table but by the periodic function h (s), the function value h (s) can be obtained for an arbitrary s. For any point P on the line, the corresponding point Q can be determined. Therefore, in principle, the second reference line can be created as a continuous line composed of an infinite number of points Q. However, practically, since it is not possible to perform an operation for obtaining the position of an infinite number of points Q, a finite number of sample points P (i) are defined at predetermined intervals on the first reference line and based on the sewing processing parameters. Thus, by raising and lowering each sample point P (i), a finite number of representative points Q (i) are obtained, and the second reference line is formed as a set of the finite number of representative points Q (i). That's fine. Specifically, a normal line n (i) is obtained for the object surface set at the position of the i-th sample point P (i) on the first reference line, and is on the normal line n (i). A process in which a point located at a position separated from the sample point P (i) by a predetermined distance determined based on the sewing processing parameter is the i-th representative point Q (i) is i = 1, 2, 3,. It only needs to be repeated as many times as necessary.

  FIG. 18 shows a method of creating the second reference line L2 based on a finite number of sample points P0, P1, P2,... Defined on the first reference line L1 (shown by a broken line). It is a front sectional view shown, and shows a section which cut a three-dimensional form of an object along the 1st standard line L1. The sample points P0, P1, P2,... May be defined, for example, as points that are arranged at equal intervals along the first reference line L1 from the start point P0 (of course, it is not always necessary to set them at equal intervals). . The straight lines n0, n1, n2,... Shown by broken lines in the figure indicate normal lines set on the object surface at the positions of the sample points P0, P1, P2,. The sample point P0 is the same point as the start point P0, and is a point where the distance s = 0 from the start point.

  The illustrated example is an example in which the value at s = 0 of the periodic function h (s) is h (0) = 0, and the sample point P0 at the start position and the representative point Q0 corresponding thereto are the same. It becomes the point. On the other hand, the sample point P1 defined at the position separated from the start point P0 by the distance s1 along the first reference line L1 is located on the normal line n1 and is separated from the sample point P1 by the distance h (s1). The point Q1 located at is obtained as a corresponding representative point. Similarly, the sample point P2 defined at the position separated from the start point P0 by the distance s2 along the first reference line L1 is on the normal line n2 and is separated from the sample point P2 by the distance h (s2). The point Q2 at the position is obtained as the corresponding representative point. Hereinafter, similarly, representative points Q3 to Q8 corresponding to the respective sample points P3 to P8 are obtained as illustrated.

  Thus, the second reference line L2 is configured by a set of representative points Q0 to Q8 obtained as a plurality of discrete points. Interpolation processing such as linear interpolation or spline interpolation may be performed on the portion between adjacent representative points Q as necessary.

  When the object surface is composed of a plurality of surfaces, and sample points are set at the intersections of the plurality of surfaces, the sample point position has a plurality of normal lines (methods for individual surfaces). Line) will be defined. For example, in the example shown in FIG. 3, the first reference line L1 is defined only on the upper surface of the object Db. However, if the first reference line L1 is a continuous line from the upper surface of the object Db to the front surface, Assuming that a sample point P is defined at an intersection position (a position bent at a right angle) between the upper surface and the front surface, with respect to the sample point P, the normal to the object upper surface and the front surface of the object The normal for can be defined. In such a case, only one of the normals may be adopted, and the representative point Q may be defined on the adopted normal, or an intermediate normal located between the two normals may be defined, The representative point Q may be defined as

<<< §7. Creation of three-dimensional shape data of yarn >>>
Next, an example of a specific method for creating the three-dimensional shape data of the yarn performed in step S6 in FIG. 1 or the yarn shape data creating means 60 in FIG. 8 will be described. The second reference line L2 shown in FIG. 6 is a geometric line having no thickness, whereas the three-dimensional shape data Ds of the yarn shown in FIG. 7 is like a cylindrical pipe. The data shows the three-dimensional form. In order to create such three-dimensional shape data Ds, arrangement representative points Q are defined at predetermined intervals on the second reference line L2, and the position of each arrangement representative point is defined by the yarn cross section parameter Pc. A process of arranging the two-dimensional cross-sectional figure in a direction orthogonal to the tangent vector T of the second reference line L2 at the arrangement representative point Q, and using the arranged two-dimensional cross-sectional figure, the tertiary of the yarn The original shape data Ds may be created. The “arrangement representative point Q” described in §7 may be the same as the “representative point Q” corresponding to each sample point described in §6, or may be separate. However, in practice, it is preferable to use the “representative point Q” described in §6 as it is as the “arrangement representative point Q” in this §7 as well, and the following description takes such a case as an example. Is.

  For example, as shown in FIG. 19, on the first reference line L1, the ith sample point P (i), the (i + 1) th sample point P (i + 1), and the (i + 2) th sample point. P (i + 2) is defined, and normals n (i), n (i + 1), n (i + 2) with respect to the object surface are defined at the respective sample point positions, and representative points Q (i) are defined on the respective normals. ), Q (i + 1), Q (i + 2) are considered. In this case, the second reference line L2 is defined as a line that smoothly connects the representative points. In FIG. 19, vectors T (i), T (i + 1), and T (i + 2) are tangents of the second reference line L2 at the representative points Q (i), Q (i + 1), and Q (i + 2), respectively. It is a tangent vector indicating the direction.

  On the other hand, it is assumed that a circle with a radius r is defined as the two-dimensional cross-sectional figure C of the yarn by the yarn cross-sectional parameter Pc as shown in FIG. In this case, in order to create the three-dimensional shape data of the yarn, first, at the position of each representative point Q (i), Q (i + 1), Q (i + 2), the two-dimensional sectional figure C of the yarn, that is, the radius r The process of arranging the circles may be performed. Specifically, a circle with a radius r may be arranged so that the center is at the position of each representative point Q (i), Q (i + 1), Q (i + 2). At this time, each circle is arranged in a direction orthogonal to the tangent vector of the second reference line L2 at each representative point.

  FIG. 20 shows a two-dimensional cross-sectional figure C (i), C (i + 1), C () of a thread made of a circle with a radius r at each representative point Q (i), Q (i + 1), Q (i + 2). It is a conceptual diagram which shows the state which has arrange | positioned i + 2). The circles C (i), C (i + 1), and C (i + 2) are arranged so that the representative points Q (i), Q (i + 1), and Q (i + 2) are centered, and They are arranged in a direction orthogonal to the tangent vectors T (i), T (i + 1), and T (i + 2).

  When the cross-sectional figure C to be arranged is a circle, there is no need to consider the position in the rotation direction (circumferential direction) at the time of arrangement, but in the case of other figures, the position in the rotation direction. Need to be considered. For example, when the two-dimensional cross-sectional figure C of the yarn is an ellipse, it is necessary to consider in which direction the major axis is arranged. Such a position reference regarding the rotation direction may be determined by using a tangent vector and a normal line for each representative point.

  For example, in the example shown in FIG. 21, a representative point Q (i) is defined on the normal line n (i) with respect to the sample point P (i), and the tangent vector T (( i) is defined. In this case, when the two-dimensional cross-sectional figure C (i) of the yarn is arranged at the position of the representative point Q (i), a projection plane that includes the representative point Q (i) and is orthogonal to the tangent vector T (i) is used. The tangent vector T (i) is projected in the direction of the normal n (i), and the position of the projection vector TT (i) obtained on this projection plane is used as a reference, and the two-dimensional cross-sectional figure C ( i) may be arranged. In other words, a projection plane that passes through the representative point Q (i) and is orthogonal to the tangent vector T (i) is defined, and the tangent vector T (i), the normal n (i), and the projection vector TT (i). The projection vector TT (i) is defined on the projection plane so that the person is included on the same plane. Then, the direction of the projection vector TT (i) is used as a position reference for the rotation direction in arranging the two-dimensional cross-sectional figure C of the yarn (for example, a reference for determining the direction of the major axis when an ellipse is arranged). It may be used as.

  As described above, when the process of placing the two-dimensional cross-sectional figure C (i) of the yarn at the position of the representative point Q (i) is performed, the tangent vector T (i) at the position of the representative point Q (i). It is necessary to ask. Here, three specific methods for obtaining the tangent vector T (i) are shown.

  First, when a second reference line L2 that can be expressed by an equation is created by the second reference line creating means 50, a tangent vector T is obtained using a differential value at a representative point Q (i) of this equation. (I) can be obtained. A differential value at a specific coordinate position in an equation indicating a straight line or a curve graph indicates the inclination of the graph at the coordinate position, and indicates the direction of the tangent vector at the coordinate position. Therefore, when the second reference line L2 is expressed by an equation, a tangent vector T (i) at an arbitrary representative point Q (i) can be obtained by performing a differentiation operation.

  On the other hand, when the second reference line L2 is expressed by a set of discretely defined representative points Q, the direct information expressing the second reference line L2 is the cubic of each representative point Q. Only the position coordinates in the original space. For example, in FIG. 19, for convenience of explanation, the second reference line L2 is drawn as a solid line, but actually only the position coordinates of each representative point Q (i), Q (i + 1), Q (i + 2) are shown. The second reference line L2 is merely a line conceptually defined as a curve that smoothly connects these representative points (of course, if interpolation processing such as linear interpolation or spline interpolation is performed, It is possible to materialize the second reference line L2 as a line connecting the representative points).

  Thus, when only the position coordinates of each representative point Q (i), Q (i + 1), Q (i + 2) are given, the direction toward the adjacent representative point is treated as the direction of the tangent vector. Thus, a tangent vector can be defined for each representative point. That is, the tangent vector T (i) of the second reference line at the i-th representative point Q (i) uses the (i + 1) -th representative point Q (i + 1) and the point Q (i). What is necessary is just to define as a vector along the line segment which ties Q (i + 1).

  FIG. 22 is a conceptual diagram showing an example in which tangent vectors T (i) and T (i + 1) are defined for the representative points Q (i) and Q (i + 1) by such a method. The tangent vector T (i) for the representative point Q (i) is a vector along the line segment connecting the representative points Q (i) and Q (i + 1), and the tangent for the representative point Q (i + 1). The vector T (i + 1) is a vector along a line segment connecting the representative points Q (i + 1) and Q (i + 2). The tangent vector defined by such a method does not indicate the exact orientation of the tangent at each representative point, but has sufficient accuracy in practice if the distance between adjacent representative points is small to some extent. A tangent vector can be defined.

  In order to define a tangent vector with higher accuracy, the following method is effective. That is, for each representative point Q (i), a proximity point QQ (i) that is a point on the second reference line L2 and is present closer to the adjacent representative point is defined, and each representative point Q ( The tangent vector T (i) in i) is obtained as a vector along a line segment connecting the representative point Q (i) and the adjacent point QQ (i) defined for the representative point.

  FIG. 23 shows an example in which the tangent vectors T (i), T (i + 1), and T (i + 2) for the representative points Q (i), Q (i + 1), and Q (i + 2) are defined by such a method. FIG. The tangent vector T (i) for the representative point Q (i) is a vector along the line connecting the representative point Q (i) and the adjacent point QQ (i), and the representative point Q (i + 1) Is a vector along a line segment connecting the representative point Q (i + 1) and the proximity point QQ (i + 1), and the tangent vector T (i + 2) for the representative point Q (i + 2). Is a vector along a line segment connecting the representative point Q (i + 2) and the adjacent point QQ (i + 2). In the figure, the distance between each representative point and its proximity point is relatively large for the sake of illustration, but in practice it is preferable to make this distance very small.

  The positions of the proximity points QQ (i), QQ (i + 1), and QQ (i + 2) are ultimately the proximity points PP (i), PP (i + 1), PP (i + 2) on the first reference line L1. Therefore, in practice, the positions of the adjacent points QQ (i), QQ (i + 1), and QQ (i + 2) may be determined by the following procedure.

  First, as shown in FIG. 23, in the step of creating the second reference line L2, a large number of sample points P (i), P (i + 1), P (i + 2) are formed on the first reference line L1 at predetermined intervals. ) Is set, the proximity points PP (i), PP (i + 1), and PP (i + 2) are also set on the first reference line L1 at positions separated from each sample point by a predetermined distance δ. Then, for each sample point P (i), P (i + 1), P (i + 2), each proximity is obtained by the same method as that for obtaining each representative point Q (i), Q (i + 1), Q (i + 2). For the points PP (i), PP (i + 1), and PP (i + 2), the proximity points QQ (i), QQ (i + 1), and QQ (i + 2) are obtained. That is, if the normals standing on the object surface at the positions of the proximity points PP (i), PP (i + 1), and PP (i + 2) are nn (i), nn (i + 1), and nn (i + 2), respectively. , Proximity points QQ (i), QQ (i + 1), and QQ (i + 2) are points on the normals nn (i), nn (i + 1), and nn (i + 2), respectively. i), PP (i + 1), and PP (i + 2) are obtained as points separated by a predetermined distance determined based on the sewing processing parameter Ps.

  Now, as shown in FIG. 20, at the positions of the representative points Q (i), Q (i + 1), and Q (i + 2), the two-dimensional cross-sectional figures C (i), C (i + 1), and C (i + 2) of the yarn, respectively. ), The data indicating the three-dimensional structure obtained by smoothly connecting the contours of these cross-sectional figures is the three-dimensional shape data Ds of the yarn. Here, a specific method for obtaining the three-dimensional shape data Ds of the yarn as polygon data will be described.

  First, as shown in the plan view of FIG. 24, a plurality of control points are defined on the outline of the two-dimensional cross-sectional figure C (circle in the illustrated example) of the yarn. In the illustrated example, twelve control points G0 to G11 are defined at equal intervals on the circumference. Once a cross-sectional graphic with such control points defined is placed at each representative point position, adjacent control points on the same cross-sectional graphic or control points on cross-sectional graphics arranged adjacent to each other are connected to each other Then, a polygon having these control points as vertices is formed, and the three-dimensional shape data Ds of the yarn may be constituted by a set of the polygons.

  FIG. 25 is a perspective view showing a method of forming such a polygon. The cross-sectional figure C (i) arranged at the i-th representative point Q (i) and the (i + 1) -th representative point Q ( A cross-sectional figure C (i + 1) arranged at i + 1) is shown. In this example, the two cross-sectional figures C (i) and C (i + 1) are both circles, and as described above, the arrangement using the projection vectors TT (i) and TT (i + 1) as the position reference regarding the rotation direction is used. Has been done. Accordingly, the 0th control point G0 (i) on the cross-sectional figure C (i) is defined in the direction indicated by the projection vector TT (i), and the 0th control point G0 on the cross-sectional figure C (i + 1). (I + 1) is defined in the direction indicated by the projection vector TT (i + 1). In FIG. 25, in order to avoid complication of the figure, the jth control point G (i, j) and the (j + 1) th control are also placed on the cross-sectional figure C (i). Only the point G (i, j + 1) is shown, and on the sectional figure C (i + 1), the jth control point G (i + 1, j) and the (j + 1) th control point G (i + 1, j + 1) are also shown. ) Only.

  Here, if four control points G (i, j), G (i, j + 1), G (i + 1, j + 1), and G (i + 1, j) are connected as shown in the figure, these four control points are apexes. A quadrangle can be formed. In this way, the jth control point G (i, j) and (j + 1) th defined for the two-dimensional sectional figure C (i) placed at the position of the i-th representative point Q (i). Control point G (i, j + 1) and the jth control point G (i + 1) defined for the two-dimensional sectional figure C (i + 1) arranged at the position of the (i + 1) th representative point Q (i + 1). , J) and the (j + 1) -th control point G (i + 1, j + 1), and defining a quadrangle having a total of four points, the three-dimensional shape data Ds of the yarn is constituted by a set of these quadrangles. (If the 0th control point G0 is also handled as the 12th control point G12, a quadrangle can be defined around the entire cross-sectional figure).

  Note that a polygon formed with a plurality of control points as vertices is not necessarily a quadrangle. For example, in the example shown in FIG. 25, if the control point G (i, j) and the control point G (i + 1, j + 1) are connected, two sets of triangles are formed instead of a quadrangle. After all, if extended as a general theory, one or more control points defined for the two-dimensional cross-sectional figure C (i) arranged at the position of the i-th representative point Q (i), and the (i + 1) -th control point. Three-dimensional shape data of a thread by a set of polygons having one or more control points defined for the two-dimensional sectional figure C (i + 1) arranged at the position of the first representative point Q (i + 1) as a vertex Ds can be created.

  Although the example in which the three-dimensional shape data Ds of the yarn is configured as a collection of polygons has been described above, it is needless to say that the three-dimensional shape data Ds of the yarn can be configured as a collection of parametric curved surfaces such as NURBS. In this case, a process for defining a NURBS curved surface that passes through each control point may be performed. Since the technique for performing such processing is a known technique in which various methods are already known, detailed description thereof is omitted here.

<<< §8. Basic principle of the technique using pseudo normals >>
§1 to §7 described so far have almost the same contents as the prior application disclosed in Japanese Patent Application No. 2005-124535. The feature of the present invention is an improvement related to the method for determining the normal in the prior invention.

  As described in §6, in the present invention, when creating the second reference line, it is necessary to determine the normal n to the object surface at the position of the sample point P on the first reference line. For example, FIG. 17 shows a normal line with respect to the object surface at the position of the sample point P on the first reference line L12 (the point at which the distance from the start point P0 along the first reference line L12 is at the position s). An example in which n is set is shown. As described above, in this example, the representative point Q constituting the second reference line is defined at a position separated from the sample point P by the function value h (s) along the direction of the normal line n. Will be. Here, the normal line n has direction information, and in the case of the example in FIG. 17, the direction indicated by the arrow is the direction of the normal line n. The function value h (s) can take both positive and negative values. When the function value h (s) takes a positive value, the representative point Q is defined as a point separated in the direction of the normal n, When the function value h (s) takes a negative value, the representative point Q is defined as a point separated in a direction opposite to the direction of the normal line n.

  By the way, the normal defined by the sample point P in the present invention is a normal for the surface of the three-dimensional object (region near the sample point P). Information on the surface to be located is required. Since various methods are already known for calculating a normal line for an arbitrary sample point P on the surface of the object based on the three-dimensional shape data representing the object, a specific description is omitted here. To do. However, both methods require a relatively complicated calculation, and when a procedure that requires a large number of normals as in the present invention is executed, the calculation burden cannot be ignored.

  In the present invention, the normal line needs to be obtained in order to determine the representative point Q on the second reference line by moving the sample point P on the first reference line by a predetermined distance in a predetermined direction. . Here, the normal n defined for the sample point P is used to indicate the moving direction of the sample point P. For example, in the case of the example shown in FIG. 18, the representative point Q1 is determined by moving the sample point P1 by a distance h (s1) in the direction of the normal line n1. Thus, the reason why the moving direction of the sample point P for determining the representative point Q is set as the normal direction is that it is considered that the seam is usually lifted and lowered in the direction perpendicular to the object surface. However, in practice, the thread is a material having a certain degree of elasticity, and the second reference line determined by the method described in §6 does not necessarily indicate the actual thread sewing path accurately. is not. In practical use, it is sufficient that the seam portion looks real in the three-dimensional shape data of the “object having a seam on the surface” created by the method according to the present invention.

  Considering such points, in the present invention, the normal line used for determining the representative point Q is not necessarily an accurate normal line. Therefore, the present inventor reduces the calculation burden by using a pseudo normal instead of the original normal as a normal necessary for creating the second reference line by the method described in §6. I got the idea to plan. Here, the pseudo-normal is not a geometrical normal, but in implementing the present invention, it should be a pseudo-normal that approximates to the extent that it can be substituted for the original normal. Is.

  The feature of the pseudo-normal in the present invention is that the line can be defined for one point on the “line”. As described above, the original normal for the surface of a three-dimensional object should be defined for one point on the “surface”, and the original normal is defined for one point on the “line” in the first place. Can not do it. In the present invention, a pseudo normal is defined for one point on the “line”, and the pseudo normal is substituted for the original normal. Hereinafter, a method of defining the pseudo normal will be described.

Now, let us define a pseudo normal n ^* at the position of an arbitrary sample point P on this line when there is a first reference line L1 made of a curve as shown in FIG. In the figure, for the sake of convenience, the first reference line L1 is drawn as a curve on the paper surface (plane), but the first reference line L1 does not necessarily have to be a curve on the plane.

First, a first reference point P ⁺ located at a predetermined distance from the sample point P in the first direction (right direction in the figure) along the first reference line L1 and the first reference line A second reference point P ⁻ located at a predetermined distance from the sample point P in the second direction (left direction in the figure) opposite to the first direction is determined along L1. The distance between the reference points P ⁺ and P ^{− from} the sample point P is set in advance so as to be within a predetermined range (practically, it is preferable to be within a very small distance compared to the size of the object). To keep. For example, a circle having a predetermined radius (a small radius) a is drawn around the sample point P, and the reference points P ⁺ and P ⁻ are defined at the intersections between the circle and the first reference line L1. Is possible.

Next, a first vector V ⁺ having a predetermined length directed from the sample point P toward the first reference point P ⁺ and a predetermined length directed toward the second reference point P ⁻ from the sample point P. second vector V of ^- obtaining a. Then, a sum vector Vsum of the first vector V ⁺ and the second vector V− is obtained, and a pseudo normal n ^* directed in the opposite direction to the sum vector Vsum is obtained. The pseudo normal n ^* is given as a vector, and the direction with an arrow in the figure is the direction of the pseudo normal n ^* . The size of the vector corresponding to the pseudo normal n ^* has no special meaning, but it can be handled as a unit vector having a unit length if necessary.

In the example shown in FIG. 26, the magnitude of the first vector V ⁺ is set equal to the distance between the sample point P and the first reference point P ^+, and the magnitude of the second vector V ⁻ is Although it is set equal to the distance between the sample point P and the second reference point P ⁻ , the sizes of the first vector V ⁺ and the second vector V ⁻ may be arbitrarily set. In short, the first vector V ⁺ may be defined as a vector having a predetermined size (predetermined length) that is directed in the direction from the sample point P toward the first reference point P ⁺ . The vector V ⁻ may be defined as a vector having a predetermined size (predetermined length) in the direction from the sample point P toward the second reference point P ⁻ .

However, as a result of various trials by the inventor of the present application, in practice, it is more normal to set the magnitude of the first vector V ^{+ and} the magnitude of the second vector V ⁻ to be equal. It was confirmed that a near pseudo normal n ^* can be defined. If the magnitudes of both vectors V ⁺ and V ⁻ are equal, the angle θ ⁺ and the angle θ ⁻ shown in FIG. 26 are equal, and the sum vector Vsum is a direction that bisects the angle between both vectors V ⁺ and V ^−. Will turn to. Practically, it is preferable to define the pseudo normal n ^* along the bisector of the angle between both vectors V ⁺ and V ⁻ in this way.

FIG. 27 is an example in which a pseudo normal n ^* is defined for a sample point P on the first reference line L1 having a different shape. Again, the first reference point P ⁺ located at a predetermined distance from the sample point P in the first direction (right direction in the drawing) along the first reference line L1 and the first reference line L1 along the opposite second direction to the first direction from the sample point P second reference point P in only spaced apart locations predetermined distance (to the left in the figure) ^- and it is defined, the sample points The distance between P and the first reference point P ⁺ is set to be considerably larger than the distance between the sample point P and the second reference point P ⁻ . In such a case, the magnitude of the first vector V ⁺ is set to the distance between the points P and P ⁺ , and the magnitude of the second vector V ⁻ is set to the distance between the points P and P ^−. Then, the vector V ⁺ becomes considerably longer than the vector V ⁻ , and the obtained pseudo-normal line n ^* is inclined to the left rather than the illustrated example. Therefore, in the case of the illustrated example, a predetermined unit length is determined in advance, the direction from the sample point P toward the first reference point P ⁺ is directed, and the first vector V ^{+ is set} as a unit vector having the predetermined unit length. , And a second vector V ⁻ is defined as a unit vector having a predetermined unit length in the direction from the sample point P toward the second reference point P ⁻ . As a result, the magnitudes of both vectors V ⁺ and V ⁻ are equal, and the sum vector Vsum is directed in a direction that bisects the angle between both vectors V ⁺ and V ⁻ (angle θ ⁺ and angle θ ^- are equal).

Pseudo normal line n ^* also shown in FIG. 26, the pseudo normal line n ^* also shown in FIG. 27, is a pseudo-normal defined for sample point P on the reference line L1, about a sample point P of the three-dimensional object It is not the normal normal. That is, any pseudo-normal line n ^* is defined based only on the information on the reference line L1, and information on the surface in the vicinity of the sample point P is not taken into consideration. In other words, the pseudo-normal line n ^* is obtained without considering any information on the object surface in the direction perpendicular to the paper surface of FIGS.

FIG. 28 is a perspective view showing the difference between the original normal line and the pseudo-normal line used in the present invention, and the intersection line 110 that appears in the contour portion of the cut surface when the spherical object 100 is cut along the cutting plane 200 (plane). An original normal n (shown by a solid line) and a pseudo normal n ^* (shown by a one-dot chain line) are drawn on the upper predetermined point. If this spherical object 100 is considered to be the earth, a normal line n indicated by a solid line is a vector directed vertically upward at each point. On the other hand, the pseudo-normal line n ^* indicated by the alternate long and short dash line is a vector included in the cut surface 200. This is because the original normal n is defined in consideration of the surface information of the spherical object 100, while the pseudo normal n ^* is a circle (intersection line) drawn on the cut surface 200. This is because it is defined taking into consideration only information relating to (110). Thus, the pseudo-normal line n ^* used in the present invention is not defined in consideration of information related to the surface of the object, and therefore does not necessarily match the original normal line.

However, in the present invention, a normal line n set at the position of the sample point P is required to determine the path (second reference line) of the seam on the object surface. Therefore, such a pseudo-normal line n ^* is used instead. However, there is no problem in practical use. This is because the first reference line L1 is a line indicating the direction on the object surface of the seam, and if it is a pseudo normal n ^{* in} which the information of the first reference line L1 is included, the seam This is thought to be because the function as a substitute for the normal to determine the route can be sufficiently achieved.

After all, in the present invention, in the model shown in FIG. 17, instead of the normal line n (original normal line on the surface of the object Db) set at the sample point P, it is determined only from the information of the first reference line L12. The pseudo normal line n ^* may be used. As described above, the pseudo normal n ^* takes a pair of reference points P ⁺ and P ⁻ on both sides of the sample point P on the reference line L12, and is directed from the sample point P toward the reference points P ⁺ and P ⁻ . A vector V ⁺ , V ⁻ having a predetermined length facing the direction V is defined, a sum vector Vsum is obtained, and can be defined as a vector facing the direction opposite to the sum vector Vsum. Since the operation for obtaining the pseudo normal n ^* defined by such a method is simpler than the operation for obtaining the original normal n, the operation load for obtaining the second reference line is greatly reduced in the present invention. be able to.

If the pseudo normal is defined by the above-described method, the pseudo normal cannot be defined if the reference line in the section between the reference points P ⁺ and P ⁻ is a straight line. That is, when the reference point P ⁺ , the sample point P, and the reference point P ⁻ are arranged on a straight line, the vectors V ⁺ and V ⁻ are arranged on a straight line, so that the sum vector Vsum is defined. I can't. As described above, the above-described method may not be able to define the pseudo-normal line. However, if the pseudo-normal line n ^* cannot be obtained for a specific sample point P, the sample point P may not be obtained. Since it is sufficient to obtain the original normal line n by a normal method, there is no problem.

<<< §9. Specific method using pseudo-normal >>>
When the pseudo normal n ^* described in §8 is used in place of the normal n in the second reference line generating process described in §6, the second reference line generating means 50 shown in FIG. , For a plurality of sample points P on the first reference line, the pseudo normal n ^* of the first reference line at the position of the sample point P (a pseudo value that can be determined in consideration of only the information of the first reference line) And a representative point Q located on the pseudo-normal line n ^* and located at a position separated from the sample point P by a “predetermined distance determined by a periodic function defined as the sewing processing parameter Ps”. The second reference line indicating the direction in the three-dimensional space of the seam that causes ups and downs with respect to the object surface by the set of representative points Q may be executed.

  FIG. 29 is a block diagram showing a more detailed configuration of the second reference line creating means 50 having such a processing function. As shown in the figure, the second reference line creating means 50 includes a sample point determining unit 51, a reference point determining unit 52, a vector determining unit 53, a sum vector determining unit 54, a normal determining unit 55, and a representative point determining unit 56. Have.

Here, the sample point determination unit 51 is a constituent element that determines the sample point P for which the pseudo normal n ^* is to be obtained, and the predetermined point on the first reference line is determined as the target sample point P (hereinafter referred to as “sample point P”). (Referred to as sample point of interest). For example, if a large number of sample points are defined on the first reference line at predetermined intervals, these sample points may be extracted as target sample points one by one in order.

On the other hand, the reference point determination unit 52 includes a first reference point P ⁺ located at a predetermined distance from the target sample point P in the first direction along the first reference line, and the first reference line. And a second reference point P ⁻ located at a predetermined distance from the target sample point P in a second direction opposite to the first direction. As described above, if the distance between the reference points P ⁺ and P ⁻ from the target sample point P is set to a predetermined value a in advance, a circle having a radius a around the sample point P is drawn. Reference points P ⁺ and P ⁻ can be defined as intersection positions between the circle and the first reference line L1.

However, in practice, the reference points P ⁺ and P ⁻ are not defined as points located at a predetermined distance from the target sample point P, but are defined as other sample points adjacent to the target sample point P. Is preferred. For example, in the example shown in FIG. 18, a large number of sample points P0, P1, P2, P3,... Are defined on the first reference line L1. In this case, for example, if the pseudo normal at the position of the sample point P1 is to be obtained, the sample point P1 is the sample point P of interest, so the sample point P2 adjacent to the right side of the sample point P of interest is the first reference point as P ^+, the sample points P0 adjacent to the left second reference point P ^- may be performed to define to. When a large number of sample points P0, P1, P2, P3,... Are defined, the coordinate values of the individual sample points have already been obtained, so these existing sample points can be used as reference points as they are. For example, the calculation for obtaining the coordinate value of the reference point becomes unnecessary, and the calculation burden is reduced.

Eventually, the first reference line definition means 20 shown in FIG. 8 has a function of defining the first reference line L1 by the permutation of a plurality of discretely located sample points P, and a large number of sample points P0. , P1, P2, P3,..., P (i-1), P (i), P (i + 1),. (I + 1) when obtaining the pseudo-normal n (i) ^* for the i-th sample point P (i) (that is, when the sample point P (i) becomes the sample point of interest). ) -th sampling point P (i + 1) as the first reference point ^{P +,} (i-1) th sampling point P (i-1) the second reference point P ^- be carried out to determine it can.

29 determines the first vector V ⁺ having a predetermined length in the direction from the target sample point P toward the first reference point P ⁺ and the second from the target sample point P. And a second vector V ⁻ having a predetermined length in the direction toward the reference point P ⁻ . If a common unit length is determined in advance as the predetermined length of each vector, the vectors V ⁺ and V ⁻ are always unit vectors.

As described above, an existing sample point is used as it is as a reference point, and the sample point P (i + 1) adjacent to one is set as the first reference point P ⁺ with respect to the sample point P (i). If the sample point P (i−1) adjacent to the second reference point P ⁻ is used, the vector determining unit 53 determines a predetermined unit length in advance and sets the sample point P (i) of interest. A unit vector having a unit length and a direction from the sample point P (i + 1) to the adjacent sample point P (i + 1) is defined as the first vector V ^+, and the sample point P (i) is directed to the adjacent sample point P (i-1). A unit vector having a direction and a unit length can be defined as the second vector V ⁺ .

The sum vector determination unit 54 has a function of performing an operation for obtaining a sum vector Vsum of the first vector V ⁺ and the second vector V ⁻ thus defined. Such an operation for obtaining the sum of vectors can be executed by a simple geometric operation. The normal determining unit 55 determines the direction opposite to the sum vector Vsum thus determined as the direction of the pseudo normal n ^* , and determines the normal n ^* at the sample point P of interest.

In addition, the representative point determination unit 56 performs processing for obtaining the representative point Q corresponding to the target sample point P using the normal line n ^* determined in this way. The specific method for obtaining the representative point Q is as already described in §6. Thus, if the second reference line creation means 50 shown in FIG. 8 is configured as shown in the block diagram of FIG. 29, it is possible to perform arithmetic processing using the pseudo normal n ^* instead of the original normal n ^. Become.

If a specific method using the pseudo-normal line is described with reference to the procedure shown in the flowchart of FIG. 1, the following process may be performed when performing the second reference line creation stage in step S5. That is, for a plurality of sample points P on the first reference line, the pseudo normal n ^* of the first reference line at the position of the sample point P is obtained, and the sample is on the pseudo normal n ^*. A representative point Q located at a predetermined distance determined by a predetermined periodic function (a function defined as a sewing processing parameter in step S4) from the point P is obtained, and the set of representative points Q causes the object surface to rise and fall. A second reference line indicating the direction in the three-dimensional space of the seam that generates the image may be created.

Further, if the method of using the existing sample points as they are as reference points is adopted, permutations of a plurality of discretely located sample points P are determined at the first reference line definition stage in step S2, and the plurality of these sample points are determined. The first reference line is defined by sequentially connecting the sample points P, and the pseudo normal n ((i) for the i-th sample point P (i) is determined by the second reference line creating means in step S5. i) When determining ^* , the (i + 1) th sample point P (i + 1) is the first reference point P ^+, and the (i-1) th sample point P (i-1) is the second reference point P ⁺ . reference point P ^- and then, predetermined advance defining a predetermined unit length, and a unit vector having a unit length direction in a direction toward the sample point P from the sample point P (i) (i + 1 ) the first vector V ⁺ , The direction from the sample point P (i) to the sample point P (i-1) Position vector second vector V ^- and it may be as defined.

<<< §10. Possibility of using pseudo normals >>
In §8 and §9, an example in which pseudo normals are used in the process of creating three-dimensional shape data of an object having a seam on the surface is described. However, the use of the pseudo-normal is not limited to such a process, and can be used in various fields that handle three-dimensional shape data of an object. For example, in a rendering process for a three-dimensional object, a normal line is usually obtained for each point on the object surface, and the reflected light for the incident light is calculated. In such a case, conventionally, an operation for obtaining an original normal line is performed based on information on a minute surface, so that the operation burden is extremely large. In this way, the concept of the pseudo normal used in the present application is introduced to an arithmetic process that requires some processing using the normal standing on the object surface, and the pseudo normal is used as a substitute for the original normal. By doing so, it is possible to significantly reduce the calculation burden.

  FIG. 30 is a flowchart showing the basic procedure of the method for determining the normal on the surface of the three-dimensional object according to the present invention (in practice, the pseudo normal is determined instead of the original normal), and this method is used. Then, based on the three-dimensional shape data of the object, it is possible to pseudo-determine the normal n with respect to the object surface at the position of a predetermined sample point defined on the surface of the object.

  First, in step S11, the three-dimensional shape data of the object is input as basic shape data to storage means in the computer. Hereinafter, the processes of steps S12 to S17 are all executed by the computer.

  First, in step S12, the position of the sample point P for which a pseudo normal is to be obtained is defined. In subsequent step S13, a reference line passing through the sample point P is defined on the surface of the object. As long as the reference line is a line on the object surface passing through the sample point P, any line may be defined. For example, a specific method for defining the first reference line described in §3 can be used.

In the next step S14, the first reference point P ⁺ located at a position separated from the sample point P along the reference line in the first direction and the first direction from the sample point P along the reference line are defined as follows. second reference point P in the position spaced in a second direction opposite ^- and are defined. The distance between the sample point P and each of the reference points P ⁺ and P ⁻ is determined so as to be within a predetermined range. For example, when the distance between the two points is determined to be a predetermined value a, each reference point P ⁺ , P ⁻ is a point on the reference line and is located at a distance a from the sample point P. Can be defined uniquely. The distance a may be defined not as the shortest distance between two points but as a distance along the reference line.

Subsequent step S15, the second reference point P from the first vector V ⁺ and the specimen point P of a predetermined length facing direction from the sample point P to the first reference point P ^{+ -} predetermined facing a direction toward the second vector V of length ^- and is defined, in step S16, the first vector V ⁺ and the second vector V ^- sum of vector Vsum is obtained. Then, in the last step S17, a process of determining a vector directed in the opposite direction to the sum vector Vsum as a pseudo normal n ^* with respect to the object surface at the position of the sample point P is performed.

  It should be noted that instead of the steps S12 and S13, a plurality of sample points P1, P2, P3,..., P (i−1), P (i), P (i + 1) discretely located on the surface of the object. ,... May be defined, and the i-th sample point P (i) of the plurality of sample points may be defined as a sample point for which a normal is to be obtained. In this case, the reference line is not directly defined as a geometric line, but can be grasped as a conceptual line in which a large number of discretely defined sample points are sequentially connected.

In this case, in step S14, based on the permutation of the sample points, the (i + 1) th sample point P (i + 1) is recognized as the first reference point P ⁺ , and the (i-1) th sample point. P (i-1) the second reference point P ^- well be recognized as, at step S15, advance predetermined predetermined unit length, direction toward the sample point P (i + 1) from the sampling point P (i) Is defined as a first vector V ^+, and a unit vector having a direction unit length in the direction from the sample point P (i) to the sample point P (i−1) is defined as the second vector V ⁺ . The vector V ⁻ may be determined.

Finally, a modification regarding the reference point determination method will be described. In §9 and §10, permutations of a plurality of sample points P1, P2, P3,..., P (i−1), P (i), P (i + 1),. The i-th sample point P (i) of these multiple sample points is the target sample point for which the normal is to be obtained, and the (i + 1) -th sample point P (i + 1) is the target sample point. The method of recognizing as the first reference point P ⁺ and recognizing the (i−1) th sample point P (i−1) as the second reference point P ⁻ has been described. However, the reference points P ⁺ and P ⁻ are not necessarily set to the sample points P (i + 1) and P (i−1) that are directly adjacent to the target sample point P (i). The adjacent sample points P (i + 2) and P (i-2) may be set, or the sample points P (i + 3) and P (i-4) may be set. In other words, with respect to focus sampling point P (i), the sample point P (i + a) as the first reference point ^{P +,} the sample point P (i-b) a second reference point P ^- and (A and b are arbitrary natural numbers). However, in practice, a = b = 1 is set, and the sample point P (i + 1) is set as the first reference point P ⁺ and the sample point P (i−1) is set to the first value as in the example described so far. A reference point P ^{− of} 2 is preferred.

It is a flowchart which shows the basic procedure of the production method of the three-dimensional shape data which concerns on this invention. It is a perspective view which shows an example of the object represented by the basic shape data Db input by step S1 of FIG. FIG. 2 is a perspective view showing an example in which a first reference line L1 (shown by a broken line) is defined at the center position of the upper surface of the object indicated by basic shape data Db in step S2 of FIG. It is a top view which shows an example of the cross-sectional shape of the thread | yarn corresponding to the thread | yarn cross-section parameter Pc defined in step S3 of FIG. It is a top view which shows one definition form of the sewing process parameter Ps defined in step S4 of FIG. It is a perspective view which shows an example of the 2nd reference line L2 produced in the step S5 of FIG. It is a perspective view which shows the three-dimensional form of the thread | yarn shown by the thread | yarn shape data Ds produced in the step S6 of FIG. It is a block diagram which shows the basic composition of the production apparatus of the three-dimensional shape data which concerns on this invention. It is a perspective view which shows an example of the object containing the object curved surface shown by basic shape data Db. FIG. 10 is a perspective view showing a state where first reference lines L11 and L12 (shown by broken lines) are defined on the surface of the object shown in FIG. 9; It is a perspective view which shows the principle of the definition method of the 1st reference lines L11 and L12 using a projection process. It is a figure which shows the example which defined the two-dimensional cross-sectional figure of the thread | yarn using the super quadratic function in xy two-dimensional orthogonal coordinate system. It is a top view which shows the shape of the two-dimensional cross-sectional figure defined on xy two-dimensional orthogonal coordinate system, when the value of the constant (epsilon) in the type | formula shown in FIG. 12 is changed. It is a top view which shows the example which defined the thread | cross-section parameter using the r (theta) polar coordinate system. It is a graph which shows typical periodic function h (s). It is a top view which shows the example which defined the shape of the seam by the collection of many outline points Ki. It is a perspective view which shows the specific method of producing a 2nd reference line. It is a front sectional view showing a method of creating a second reference line L2 based on a finite number of sample points defined on the first reference line L1. It is a conceptual diagram which shows the method of producing the three-dimensional shape data Ds of a thread | yarn based on the 2nd reference line L2. It is another conceptual diagram which shows the method of producing the three-dimensional shape data Ds of a thread | yarn based on the 2nd reference line L2. It is another conceptual diagram which shows the method of producing the three-dimensional shape data Ds of a thread | yarn based on the 2nd reference line L2. It is a conceptual diagram which shows an example of the method of defining the tangent vector in each representative point. It is a conceptual diagram which shows an example of another method of defining the tangent vector in each representative point. It is a top view which shows the state which defined several control points G0-G11 on the outline of the two-dimensional cross-sectional figure of a thread | yarn. It is a perspective view which shows the formation method of the polygon which comprises the three-dimensional shape data Ds of a thread | yarn. It is a figure which shows the basic method of defining the pseudo normal line used by this invention. It is a figure which shows another method of defining the pseudo normal line used by this invention. It is a perspective view which shows the difference between an original normal line and the pseudo-normal line used by this invention. It is a block diagram which shows the more detailed structure of the 2nd reference line preparation means 50 shown in FIG. It is a flowchart which shows the basic procedure of the normal-line determination method in the three-dimensional object surface which concerns on this invention.

Explanation of symbols

10: basic shape data input means 20: first reference line definition means 30: thread section parameter definition means 40: sewing process parameter definition means 50: second reference line creation means 51: sample point determination unit 52: reference point determination Unit 53: vector determination unit 54: sum vector determination unit 55: normal line determination unit 56: representative point determination unit 60: thread shape data generation unit 70: composite shape data generation unit 100: spherical object 110: intersection line 200: cutting plane a: Predetermined distance, predetermined radius C, C (i), C (i + 1), C (i + 2): Two-dimensional cross-sectional figure Db of thread: Basic shape data and three-dimensional form of object indicated by the data Ds: Yarn of thread Three-dimensional shape data and three-dimensional form Dbs of yarn indicated by the data: synthetic shape data G0 to G11, G (i, j), G (i, j + 1), G (i + 1, j), G (i + 1, j + 1) ) Control point h (s): periodic function and its value K, Ki: contour points K11, K12: reference lines L1, L11, L12: first reference line L2: second reference lines n, n0 to n8, n ( i), n (i + 1), n (i + 2), nn (i), nn (i + 1), nn (i + 2): normal n ^* , n (i) ^* : pseudo-normal P, P0 to P8, P ( i-1), P (i), P (i + 1), P (i + 2): sample points P ⁺ , P ⁻ on the first reference line: reference points PP (i), PP (i + 1), PP (i + 2) : Proximity points Q, Q0 to Q8, Q (i), Q (i + 1), Q (i + 2): representative points QQ (i), QQ (i + 1), QQ (i + 2) constituting the second reference line: proximity Point r: Circle radius r (θ): Length corresponding to angle θ in rθ polar coordinate system S: Reference line of graph (surface position of object)
S1 to S17: Steps s, s1, and si of the flowchart: distances T (i), T (i + 1), and T (i + 2) from the starting point P0: tangent vectors TT (i), TT (i + 1), and TT (i + 2) : Projection vector V: Projection direction vector V ⁺ , V ⁻ : Vector used for normal determination Vsum: Sum vector x of vectors V ⁺ , V ⁻ , y: Each coordinate axis δ of two-dimensional orthogonal coordinate system: Distance to the proximity point λ: Length of one pitch of seam θ, θ ⁺ , θ ⁻ : Angle

Claims (15)

A device for creating three-dimensional shape data including a seam for an object having a seam on the surface,
Basic shape data input means for inputting three-dimensional shape data of an object that does not include seam information as basic shape data;
First reference line defining means for defining a first reference line indicating a direction on the object surface of the seam on the surface of the object indicated by the basic shape data based on an instruction from the operator;
Thread section parameter definition means for defining a thread section parameter indicating the section shape of the thread constituting the seam and its size based on an instruction from the operator;
Based on an instruction from the operator, a sewing process parameter indicating the shape of the ups and downs of the object surface of the seam for one pitch is defined using a periodic function having a period λ corresponding to the length of one pitch of the seam. Sewing process parameter definition means,
For a plurality of sample points P on the first reference line, a pseudo normal n ^* of the first reference line at the position of the sample point P is obtained, and the sample is on the pseudo normal n ^*. The second representative point Q is obtained by obtaining a representative point Q at a position separated from the point P by a predetermined distance determined by the periodic function, and indicating a direction in a three-dimensional space of a seam that causes ups and downs with respect to the object surface by the set of representative points Q A second reference line creating means for creating a reference line of
Thread shape data creating means for creating three-dimensional shape data of a thread constituting a seam based on the second reference line and the thread section parameter;
By combining the three-dimensional shape data of the thread with the basic shape data, combined shape data creating means for creating combined shape data that is the three-dimensional shape data of the object including stitch information;
An apparatus for creating three-dimensional shape data of an object having a seam on a surface. The creation device according to claim 1,
The second reference line creation means is
A sample point determination unit for determining a sample point P for which the pseudo normal n ^* is to be obtained;
A first reference point P ⁺ located in a first direction from the sample point P along the first reference line; and a first reference point P ⁺ from the sample point P along the first reference line. A reference point determination unit that determines a second reference point P ^{− at} a position separated in a second direction opposite to
A first vector V ⁺ having a predetermined length directed from the sample point P toward the first reference point P ⁺ and a predetermined length directed from the sample point P toward the second reference point P ^−. A vector determining unit for obtaining a second vector V ^{− of}
A sum vector determining unit for obtaining a sum vector Vsum of the first vector V ⁺ and the second vector V ⁻ ;
A normal determining unit that determines the direction opposite to the sum vector Vsum as the direction of the pseudo normal n ^* ;
A representative point determination unit for obtaining a representative point Q based on the sample point P;
An apparatus for creating three-dimensional shape data of an object having a seam on a surface, characterized by comprising: The creation device according to claim 2,
The first reference line defining means defines the first reference line by a permutation of a plurality of discretely located sample points P;
When the reference point determination unit obtains the pseudo normal n (i) ^* for the i-th sample point P (i), the (i + a) -th sample point P (i + a) is used as the first reference point P. ⁺ a, and the (i-b) -th sampling point P (i-b) a second reference point P ^- and,
A vector determining unit determines a predetermined unit length in advance, and a unit vector having the unit length in the direction from the sample point P (i) to the sample point P (i + a) is set as the first vector V ^+. and set, from the sample point P (i) a unit vector having a direction the unit length direction toward the sample point P (i-b) a second vector V ^- seams on the surface, characterized in that to determine the A device for creating three-dimensional shape data of an object having In the production apparatus in any one of Claims 1-3,
A first reference line defining means, based on an instruction from an operator, in a three-dimensional space in which an object indicated by basic shape data is defined, a reference line made of a straight line or a curve, and a projection direction indicating a predetermined projection direction A projection image formed on the surface of the object indicated by the basic shape data when the reference line is projected in the projection direction indicated by the projection direction vector. An apparatus for creating three-dimensional shape data of an object having a seam on a surface, which is defined as a reference line. In the preparation apparatus in any one of Claims 1-4,
The sewing process parameter defining means has a function of defining a sewing process parameter using a length λ of one pitch of the stitches and a periodic function h (s) having a period λ,
A sample in which the second reference line creation means is on the first reference line, and the distance along the first reference line from the predetermined start point P0 defined on the first reference line is at the position s. With respect to the point P, a pseudo normal n ^* at the position of the sample point P is obtained, and a representative point Q which is on the pseudo normal n ^* and is separated from the sample point P by a distance h (s) is obtained. A device for creating three-dimensional shape data of an object having a seam on the surface, which has a function of creating a second reference line by a set of representative points Q. The creation device according to claim 5,
The sewing process parameter defining means has a length function λ represented by a length λ corresponding to one pitch of a stitch and h (s) = Asin ^γ (2πs / λ) (where A and γ are predetermined constants). s) and defining a sewing process parameter, the apparatus for generating three-dimensional shape data of an object having a seam on a surface. In the preparation apparatus in any one of Claims 1-4,
The undulation table in which the sewing process parameter defining means shows a combination of the length λ for one pitch of the seam, a plurality of discrete values s within a range of 0 to λ, and a predetermined value h (s) corresponding to each discrete value. And define sewing process parameters using
The second reference line creating means is on the first reference line, and the distance along the first reference line from the predetermined start point P0 defined on the first reference line is a position (kλ + s) ( However, a pseudo normal n ^* is obtained for each sample point P at k = 0, 1, 2,..., Is on this pseudo normal n ^* , and is separated from the sample point P by a distance h (s). An apparatus for creating three-dimensional shape data of an object having a seam on a surface, wherein a representative point Q at a position is obtained and a second reference line is created by a set of representative points Q. The creation device according to claim 7,
The second reference line creating means interpolates the discrete information based on the undulation table and creates the second reference line using the information after the interpolation process, and has a seam on the surface. A device for creating three-dimensional shape data of an object. In the production apparatus in any one of Claims 1-8,
The thread shape data creation means defines placement representative points at predetermined intervals on the second reference line, and the two-dimensional cross-sectional figure of the yarn indicated by the thread cross-section parameter at each placement representative point position, at the placement representative point. A stitch is formed on the surface, characterized in that processing is performed in a direction orthogonal to the tangent vector of the second reference line, and three-dimensional shape data of the thread is created using the arranged two-dimensional sectional figure A device for creating three-dimensional shape data of an object having   A program for causing a computer to function as the creation device according to claim 1. A method of creating three-dimensional shape data including a seam for an object having a seam on a surface,
A basic shape data input step in which three-dimensional shape data of an object not including stitch information is input as basic shape data to storage means in the computer;
The computer defines a first reference line indicating the direction on the object surface of the seam on the surface of the object indicated by the basic shape data based on an instruction from the operator, and stores the first reference line in the storage means. 1 baseline definition stage,
A computer defines a thread cross-sectional parameter indicating a cross-sectional shape and a size of a thread constituting the seam based on an operator's instruction, and stores the thread cross-sectional parameter in a storage unit;
The computer uses a periodic function having a period λ corresponding to the length of one pitch of the seam based on an instruction from the operator, and shows a sewing processing parameter indicating the shape of the ups and downs of the object surface of the stitch of one pitch. And a sewing process parameter definition stage for storing this in the storage means,
The computer obtains the pseudo normal n ^* of the first reference line at the position of the sample point P for each of the plurality of sample points P on the first reference line, and is on the pseudo normal n ^* . Then, a representative point Q located at a predetermined distance determined by the periodic function from the sample point P is obtained, and the direction in the three-dimensional space of the seam that causes ups and downs with respect to the object surface is determined by the set of representative points Q. Creating a second reference line to be shown and storing it in the storage means;
A computer that creates three-dimensional shape data of a thread constituting a seam based on the second reference line and the thread section parameter, and stores the data in a storage means;
A computer creates composite shape data, which is three-dimensional shape data of an object including stitch information, by combining the basic shape data with the three-dimensional shape data of the thread, and stores this in storage means Shape data creation stage,
A method for creating three-dimensional shape data of an object having a seam on a surface, characterized by comprising: The creation method according to claim 11,
The process of obtaining the pseudo normal n ^* for the sample point P at the second reference line creation stage is as follows:
A first reference point P ⁺ located in a first direction from the sample point P along the first reference line; and a first reference point P ⁺ from the sample point P along the first reference line. Defining a second reference point P ^{− at} a position separated in a second direction opposite to
A first vector V ⁺ having a predetermined length directed from the sample point P toward the first reference point P ⁺ and a predetermined length directed from the sample point P toward the second reference point P ^−. Obtaining a second vector V ^{− of} :
Obtaining a sum vector Vsum of the first vector V ⁺ and the second vector V ⁻ ;
Obtaining a pseudo-normal n ^* oriented in the opposite direction to the sum vector Vsum;
A method for creating three-dimensional shape data of an object having a seam on a surface, characterized by comprising: The creation method according to claim 12,
In the first reference line definition stage, a permutation of a plurality of discretely located sample points P is determined, and the first reference line is defined by sequentially connecting the plurality of sample points P.
When the second reference line creation means obtains the pseudo normal n (i) ^* for the i-th sample point P (i), the (i + a) -th sample point P (i + a) a reference point P ^+, the (i-b) -th sampling point P (i-b) a second reference point P ^- from a, keep predetermined predetermined unit length, the sample point P (i) A unit vector that faces in the direction toward the sample point P (i + a) and has the unit length is defined as a first vector V ^+, and the direction from the sample point P (i) toward the sample point P (ib). A method for creating three-dimensional shape data of an object having a seam on a surface, wherein the unit vector having the unit length is defined as a second vector V-. A method for pseudo-determining a normal n for the surface of the object at a position of a predetermined sample point defined on the surface of the object based on the three-dimensional shape data of the object,
A step in which the three-dimensional shape data of the object is input as basic shape data to storage means in the computer;
The computer defining the position of the sample point P of interest;
A computer defining a reference line through the sample point P on the surface of the object;
A first reference point P ⁺ located in a first direction from the sample point P along the reference line, and a first direction from the sample point P along the reference line; a step of determining a, ^- a second reference point P on the spaced apart position in a second direction opposite
A computer directs a first vector V ⁺ having a predetermined length from the sample point P toward the first reference point P ⁺ and a direction from the sample point P toward the second reference point P ^−. Determining a second vector V ⁻ having a predetermined length,
Computer, wherein the first vector V ⁺ and the second vector V ^- and determining a sum vector Vsum of
A computer determining a vector oriented in a direction opposite to the sum vector Vsum as a pseudo normal n ^* for the object surface at the position of the sample point P;
A method for determining a normal on a surface of a three-dimensional object. A method for pseudo-determining a normal n for the surface of the object at a position of a predetermined sample point defined on the surface of the object based on the three-dimensional shape data of the object,
A step in which the three-dimensional shape data of the object is input as basic shape data to storage means in the computer;
A computer defining a permutation of a plurality of sample points discretely located on the surface of the object;
A computer determining an i-th sample point P (i) of the plurality of sample points as a sample point for which a normal is to be obtained;
Recognizing the (i + a) th sample point P (i + a) and the (i−b) th sample point P (ib) based on the permutation;
A computer sets a predetermined unit length in advance, and sets a unit vector having the unit length in the direction from the sample point P (i) to the sample point P (i + a) as the first vector V ^+. , a unit vector having a direction the unit length direction toward the sample point P (i-b) from the sample point P (i) the second vector V ^- and the step of determining,
Computer, wherein the first vector V ⁺ and the second vector V ^- and determining a sum vector Vsum of
A computer determining a vector oriented in a direction opposite to the sum vector Vsum as a pseudo normal n (i) ^* for the object surface at the position of the sample point P (i);
A method for determining a normal on a surface of a three-dimensional object.