simulating fitting stretch model of three-dimensional apparel surfaces

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Applied Researches in Technics, Technologies and Education Journal of the Faculty of Technics and Technologies, Trakia University https://sites.google.com/a/trakia-uni.bg/artte/

ARTTE Vol. 2, No. 2, 2014 ISSN 1314-8788 (print), ISSN 1314-8796 (online), doi: 10.15547/artte.2014.02.003

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SIMULATING FITTING STRETCH MODEL OF THREE-DIMENSIONAL

APPAREL SURFACES

ElSayed A. ElNashar1, Viktor Kuzmichev2 & N. A. Sakharova2 1Faculty of Specific Education, Kafrelsheikh University, Egypt

El-Geish Street, 33516, Kafrelsheikh City. Egypt cell phone: (+2) (016) 9288940, fax: (+2) (047) 3213751

e-mail: [email protected], [email protected] 2Ivanovo State Polytechnic University, Russia

Abstract: This paper previews a new approach being developed for modeling the dynamic behavior of stretch clothes in apparel surfaces. This work extend the cloth-particle static draping model include dynamics, and extends constrained dynamics simulation techniques to yield performance enhancements. The advantages of this new approach, the new approach includes several steps. First step is set up the 3D garment of woven stretch cloth by using the method developed in this paper, Based on the relationship, the algorithms and generation of rules for transferring style requirements to the parameter values of the garment of woven stretch cloth are developed. As such, the knowledge base can be constructed, and the intelligent design system of the 3D garment style is built, Simulation remains a major challenge, even if applications are numerous, from rapid prototyping to e-commerce. A stable, real-time algorithm for animating stretch cloth apparel surfaces. Keyword: Simulation, Modeling of Apparel Surfaces, Geometric Design.

1. INTRODUCTION The first decade of the 21st century brought about a revolution in anthropometry. For garments the phases of product development and preparation of production require approximately triple the time of the actual garment life span. The development of existing technology made it possible to collect anthropometric data using a non-contact body scanner. In order to compensate for resulting grater efforts in the product preparation and to react more quickly and flexibly to the latest fashion, the technology. Clothing manufacture is extremely labour-intensive. At present, there are various software tools for 2D design, grading, nesting and so on, allowing great saving of time and material; however, each of them covers only a particular step of the garment design process. There is a strong request of integrated systems for the whole process including the possibility for the designer to work directly in a 3D environment. 3D technologies haven't had wide practical application yet, despite the conclusive advantages of virtual design to traditional 2D pattern making. More important reason which limited the distribution of virtual technologies is absent the way how to reproduce the pleated real surfaces of single and multilayered virtual clothes. Nowadays 3D technologies represent the system “body-clothes” in two variants: 1) “skinny” shapes with ideally smooth surfaces located around the human body skirt (based on the Chebishev’s theory). Such method of clothes shaping is used, for example, for underwear design; 2) loose shapes having the air gaps located between the human body and the clothes on the anthropometric levels. By means of the air gaps the single-layer clothes as much as possible may be shaped around the human body. To increase the realness of interaction between the human body and the clothes it’s necessary to use the mathematical description which includes the textile materials

mailto:[email protected]

mailto:[email protected]

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properties. However it is not enough to get the realistic shape of virtual clothes. In our opinion, to improve the 3D clothes virtual design is important to formalize all relationships that consist between the similar parts of three independent objects: (1) the block pattern, (2) the human body, and (3) the clothes shapes made from the patterns and have put on the body. Really practicing designers have such knowledge how to fit the patterns on the body, and the problem is how to formalize it ideas for computer design. New up-to-data information should connect the sizes of the different areas of clothes by equations, for example, on the waist, bust, hip levels, if one of them is changed [7]. The whole garment is constructed from four parts: the collar, the coat, the sleeves and the trousers (or skirt) [9]. A basic technique in any of these areas is the approximation of a desired surface with a given surface such as ancient Egyptian. The systems designed to acquire the motion of points on a flexible-moving surface such as cloth. Historical research has uncovered ancient Egyptian formulae for many conditions of which the aesthetical of stretch fabric, the reduction of stretch wrinkling, and there were in circulation at that time recipes for facilitating hair growth and getting rid of stretch clothes , the dressed of stretch fabric used as the following picture in figure 1.

a b c

Figure 1. Illustration of 3-D energy cloth stretch dress at sculpture:

"a, b, and c" "Egyptian art" [1, 4] The unified stretch theory, adopt unified theory of stretch on the potential of interior fabrics resulting from the stretch raw material and fabric structure "which attract inward", and their relationship to the outside of the energy severity "stretch fabrics" resulting from body size, three-dimensional effect and aesthetical durability. The exiting approaches can generally be classified into three categories: geometric, physical, and hybrid technologies, geometric methods apply geometrical of stretch clothes coefficient (SCC). In this work, stretch clothes coefficient was defined as the ratio of the volume of clothes when it is stretched with the full geometrical volume of the clothes form, expressed as percentage. [9]

100.VWL

VSC SCC

(1)

Where: VSC – Volume of the Stretched Clothes, VWL - Volume Waist length.

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VSC = FUGdC2

4

π (2)

Where: FUC – full length of clothes, 2cdC - chest circumference.

VWL – Volume of Waist Length:

VWL = FUGWd c2

24

π. (3)

Stretch distance coefficient (SDC): When clothes are stretched freely with its only support at bearing area is located between shoulders and chest level for each kind of dresses, the appearance of the clothes depends on numerous factors such as fabric type and construction features. The process of converting the processed image of a dress into a modified form of the polygonal model that is used to calculate stretched distance coefficient. The image after processing the point cloud data of the stretched clothes and mannequin into a polygonal model. Then, the polygonal model is selected and the top surface (waistline) is projected to a common surface. Next, the bottom surface (hemline) is projected to the previously selected common surface. The projections from the waistline and hemline are extended parallel to the dress axis without changing the size or shape of the contour. Then, a portion of extended contour of sliced surface of waistline and hemline is retained deleting all the other portion of the dress. A thin slice of 10 mm in dimension of the extended polygonal model contour was retained for measurement and the same portion in top view. The measurement of the lowest point of a node to the nearest waist line contour (minimum distance, X) and the highest point of a node to the nearest waist line contour (maximum distance, Y).The average values of the maximum distance and minimum distance from all the nodes in the stretched clothes contour were used to calculate stretched distance coefficient. The stretched distance coefficient (SDC) can be defined as the ratio of the average value of maximum node dimension with the average values of minimum node dimensions. [9]

n

i

i ibbo

1

χ SDC (4)

......2VSC2VSC

VSC SDC 34

33

32

31

W

HBb

W

Cb

W

HBb

W

Bbbo (5)

i

n

iibbo

1

/VSC SDC (6)

n

ii

iDbbo1

/ VSC SDC (7)

Where: 0b and ib

are arbitrary constants, n is number of parameters closely related to the stretch coefficient and i represents a mechanical property parameter. Then we can see fitting equation is the stretch distance coefficient as follows:

i

ii

i /n

χVSCVSC SDC Υ100 (8)

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Where: Y = maximum distance of node from the edge of the waistline contour, Where: Y = minimum distance of node from the edge of the waistline contour, n = number of nodes. [9] Stretched distance coefficient, along with number of nodes, provides a distinctive description of the stretched clothes that could be used as the parameter to judge the configuration of the stretched clothes. The results of testing the clothes or apparels for SCC, SDC, n (N) and the discussion involving the selection of three parameters quantifying clothes stretched will be discussed in the results and discussion section. The number of nodes developed due to the draping of circular fabric samples on the pedestal, and the node dimensions, are other parameters generally used to quantify stretched. However, stretched coefficient (SC) remains the most popular and widely used parameter to quantify stretched. A low SC indicates easy deformation of a fabric and a high drape coefficient indicates less deformation. SC was conventionally calculated as:

ASD

AUS VSC FS (9)

FS – factor of stretch. AUS is Area under the stretched sample area of support disk. ASD; is area the specimen area of support disk. The following formula was used to calculate stretch coefficient in the modified digital method:

)...()cm()

1002

Χ

)(cm ASk-)AOS(cm

ASkPP(cm TSPVSC SC(% )

22

2

(10)

TSP; Total selected pixels, PP; pixels per (cm2), AOS; is area of the specimen, ASK; is area the specimen area of support disk. [9] We developed an interactive clothing design system in the vein of Computerized [6]. 3D body models of the human body have recently attracted considerable attention in the clothing industry. For instance, in order to express the curved body surface geometrically, many methods are developed such as cross section model, triangle polygon model, Stretch Theory model, super quadrics, the Delaunay triangulation and meta-balls (Cho et al., 2005) [2] . This paper solves the simulating fitting stretch surface on volume body (of three-dimensional apparel surfaces), using an innovative method. First, we use a triangular mesh to represent a surface. Then a unified stretch theory a based model is established to flatten a 2D surface into a 3D pattern. The accuracy of any local area of the surface can be easily controlled in the process of development. We use an interpolation function to show the unified stretch theory distribution of developed surface. Including the algorithm to reduce error for the resulting developed surface. Our method can efficiently develop a complex trimmed surface, which is usually quite difficult to be developed by earlier methods. 2. IMPLEMENTATION V-Stitcher™ is the most powerful 3D design and visualization software accelerating the entire product development life-cycle; t interfaces seamlessly with AccuMark pattern design, grading and marker making software, enabling a fast and easy transformation of 2D patterns into 3D garments. V-Stitcher is a key component of Gerber’s Product Lifecycle Management (PLM) offering; which significantly reduces product development costs and improves time-to-market through the creation of virtual garment samples. Using 3D simulation to test multiple print variations; allowing you to make important design decisions before a physical sample is produced; saving both time and money. Transform 2D patterns to 3D garments of Patterns developed in AccuMark are used to create the virtual samples in V-Stitcher. Only Gerber

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Technology offers a direct interface between AccuMark and V-Stitcher, and with easy file sharing there is no need for data conversion.

Real-time fit approval sessions can be held online, across the globe. 3D notes, and the ability to save and embed the 3D files allows for maximum flexibility when creating tech packs with WebPDM.

Virtual samples reduce the need to exchange physical samples through the mail, saving time and costs.

3D samples enable faster detection of errors and earlier corrections Eliminates the distance between stakeholders.

Present real life images of collection and color ways in high quality, interactive 3D catalogs, at any point in the pre-production, production or merchandising process.

Virtual Samples can be used for internal design reviews before factory creates first prototype samples

Better introduction of design ideas

Simulate texture, draping and fit of garments by displaying them on a realistic, virtual human body form based on your pattern, fabric and texture data.

Draping simulation is based on advanced mathematical and physical algorithms implemented in real-time.

Utilize the fabric testing kit, allowing the users to test their own fabrics.

Maintain a consistency of fit throughout development process. And using new databases formed after scanning (air gapes values, lengths of cross section’ contours in vertical and horizontal directions, wrinkle depths, etc.) we could calculate the pattern parameters (front, back, sleeve) for the block reconstruction. By this way we could transform the indexes belonging to 3D clothes with non simple shape (such as dress, jackets, trousers, Skirt, etc.) into the indexes of flat 2D pattern [7] ,Which they were put on the standard type of female model[8]. Apparel of woven stretch cloth-based 3D garment modeling there are several techniques to set up the garment of woven stretch cloth, such as Bezier patch, B-stretch theory patch, NURBS patch, etc. The shape of the woven stretch cloth set up by these techniques is suited for interactive modification by designer. However, the aim of our research is to control the shape of the 3D garment of woven stretch cloth automatically; therefore, in this paper the 3D garment of woven stretch cloth is constructed by using the technique of basic concepts surface Patch and the transformation of the shape of the 3D garment of woven stretch cloth can be mastered by controlling the parameters of key form points. This technique, introduced only recently in Computer Graphics, has proven to have very good performance. Baraff and Witkin for instance used implicit integration in the context of cloth animation with great success [3]. 3. MATERIAL AND METHODS Fabrics generally show nonlinear response in bending. Their nonlinear moment-curvature response is often measured by the Kawabata bending test system [5]. One fabric used in this study was a twill-weave, 100-percent cotton fabric. It had the following physical properties: In this software program the bending properties in warp and weft, direction, the tensile properties in warp, weft, 45-degree warp and 135 degree direction and also the weight per unit are considered in the draping module. The scale of the property curves depends on the measurement devices.

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4. RESULT AND DISCUSSION During the developing process, the area of the surface may change. The final relative area difference element method and Patterns developed in AccuMark are used to create the virtual samples in V-Stitcher. Only Gerber Technology offers a direct interface between AccuMark and V-Stitcher, and with easy file sharing there is no need for data conversion. 4.1. 3D Surfaces of Clothes In our opinion the weakest position of modern 3D CAD design is ignorance the clothes patterns influencing for the 3D features. To forecast the patterns indexes. In this direction we did some works which include: A new classifications of 3D clothes shapes based on the usual features of shape (such as closely fitting, loosely fitting, semi closely fitting, etc), on one hand, and the air gapes in system “body - clothes”, on other hand. This classification allows to connect the 3D shape and 2D patterns and to predict the clothes shaping. As example you can see the fragment of such classification that we created for women clothes. 4.2. Measurement Protocol Three trained anthropometrists measured and recorded each dimension three times using a tape measure to the nearest sixteenth of an to minimize error, one anthropometrist measured while the other dimension was deemed as the physical measurement for that dimension. The potential fields for application in particular in mechanical engineering and Pattern construction under consideration of the material behavior, if curved element contours of lightweight textile structures are covered with an undefined shape of the reinforcing textile, the mechanical component properties may deteriorate, the patterns should be developed directly on the object to apply the reinforcing structures to the desired 3D shape according to the required load and thus avoiding rework. Creation the equations for describing the wrinkles that appeared on the shell surface from textile materials. The research is directed on working out of methodology of new design of clothes in system “CAD + 3D body scanner”. Two new databases are put in a basis of this methodology:

the first one includes the schedule of indexes about the patterns (2D), collected from second half ХХ–ХХI;

the second one includes the quantity information about the outline clothes shapes (3D) of the same period, digitized by the body scanner.

(1) The new technology that connecting the flat patterns (front, back, sleeve), on one hand, and the outline shapes of systems “body-clothes”, on other hand, is developed for main kinds of outer clothes (jackets, coats, dresses, trousers, skirt). Curves can be created by the grid method at each block of a semi-fit silhouette and loose-fit silhouette. The grid method is the way to divide the width and height of a block by the number of a row and column and to arrange the curves on the piece. Since flattening is made by using the length of a segment of a triangle, curves were created at each grid diagonally. Using 3D curves, we manufactured 2D triangles we also made grids by connecting two triangles, arranged each grid to keep the length of the outer curve and calculated the surface flattening piece of each block. This surface flattening piece is called an apparel pattern consisting of each silhouette (figure 2).

Then we can see fitting equation is the Chest circumference ( 1 ) of stretch distance coefficient as follows:

BGBG BGE Body1 (11)

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1100

ΔΥ

i

ii

i /n

χVSCVSC CSDC (12)

Where: Y = maximum distance of node from the edge of the waistline contour, Where: Y = minimum distance of node from the edge of the waistline contour, n = number of nodes.

Figure 2. Topological fitting clothes of frame of 3D system

“women body – jacket and skirt” for putting on the surface from textile materials

Then we can see fitting equation is the Bust circumference ( 2 ) of stretch distance coefficient as follows:

FWFW FWE Bod2 (13)

2VSC/VSC100

BSDC

i

ii

in

(14)


Then we can see fitting equation is the Arm circumference ( 3 ) of stretch distance

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coefficient as follows:

ARWARW ARWE Body3 (15)

3VSC/VSC100

ASDC

i

ii

in

(16)

Where: Y = maximum distance of node from the edge of the waistline contour, Where: Y = minimum distance of node from the edge of the waistline contour, n = number of nodes. Then

we can see fitting equation is the Back circumference ( 4 ) of stretch distance coefficient as follows:

BWBW BWE Body4 (17)

4VSC/VSC100

BSDC

i

ii

in

(18)


we can see fitting equation is the waist circumference ( 5 ) of stretch distance coefficient as follows:

WGWG WGE Bod5 (19)

5VSC/VSC100

BSDC

i

ii

in

(20)


we can see fitting equation is the Hip circumference ( 6 ) of stretch distance coefficient as follows:

HGHG HGE Body6 (21)

6VSC/VSC100

HSDC

i

ii

in

(22)

Where: Y = maximum distance of node from the edge of the waistline contour, Where: Y = minimum distance of node from the edge of the waistline contour, n = number of nodes. The fitting form of designing system “body-clothes” from horizontal and vertical cross sections that crossed in more important and informative points. Systems of the equations, uniting both databases and allowing direct of indexes belonging to the clothes outline shape are generated. Relationships for the values of shapes and silhouettes of system "body-

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clothes" under the influence of pattern indexes (eases equal to differences between the pattern sizes and body dimensions, configuration of counter lines, position of darts, etc.) are received. Informative areas of main kinds of clothes and the equations for their changing are defined. Figure 2 shown the theoretical frame of women jacket, for describe fitting clothes. In the table 1 the fragment of new classification connecting 2D pattern and fitting “body- clothes” is resulted. Table 1. Fragment of new classification connecting 2D pattern and fitting “body - clothes” (for women body 164- 88 – 96 and body) Kinds of clothes shape

Pattern eases, cm Fitting clothes on women body , cm, in different sections on the bust/hip/waist levels, degree

Fitting darts of Skirt

ease to half bust

girth

ease to half waist

girth

ease to half hip

girth

front, 0…70

under armhole, 70…120

back, 120…180

front side back

Very closely fitting

1,8…3 2,5…4 2,5…4 0,46 0,34 0,26

0,35 0,64 0,37

0,37 1,26 0,28

0,12 0,20 0,19

0,25 0,44 0,17

0,17 0,62 0,82

Closely fitting 3…5 4…7 4…7

1,75 1,33 2.05

1,55 1,76 0,57

1,08 2,47 0,45

1,02 1,06 1.70

0,85 0,76 0,97

0,18 1,42 0,34

Semi closely fitting

6…10 7…11 7…8 3.04 2,37 3,84

2,84 2,83 0,76

1,68 3,64 0,67

2.04 1,30 2,53

1,04 1,38 0,26

1,28 2,14 0,17

Loosely fitting 10…14 11…14 8…10

4,24 3,36 5,65

5.55 3,94 0,93

2,39 4,86 0,89

3,04 2,26 3,60

3.65 2,74 0,73

2,19 3,26 0,39

(2) Cross sections of system “body – clothes with different outline shapes”. Figure 3 shows the typical cross sections on the bust, waist and hip levels.

а b c

Figure 3. Topological fitting clothes cross sections of red line around the women body -” with different shapes (very closely, closely, semi closely, loosely sections are located in the same

order from the body) on the bust (а), waist (b) and hip (c) levels (3) Cross sections of system “body – clothes with different outline shapes”. Figure 4 shows the typical cross sections on the skirt knee, waist, and hip levels (figure 2).

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a b

Figure 4. Topological fitting clothes cross sections around the women body -” with different shapes (very closely, closely, semi closely, loosely sections are located in the same order from the body) on

the Skirt Knee, waist, and hip levels 4.3. Cloth of Skirt Skirt has its private rule knowledge and processing course. The rule knowledge includes the rules inferring the values of some parameters of the key points from the style description and the cacuprodedure includes the procedure for calculating the values of some parameters of the key points. With the class hierarchy of garment style, the procedure of the illation mechanism is as follows: first, the design interface receives the semantic description of the clothing style, then the illation mechanism searches the corresponding cloth stretch in apparel surfaces of different garment parts, and the 3D clothing style cloth stretch in apparel surfaces is displayed. If the user is not satisfied with the 3D style effect, he can change the 3D shape of the style both by changing the style description and the value of the numeric variables. According to the new style description and the value of the design numeric variables, the illation mechanism will find the definite cacuprocedure and drawing procedure to finish the new 3D style designing. We have simulated a skirt with a shirt but the overlap was very limited as well as collisions. The simulator has been also experimented for men garments; in particular, we modeled a jacket that can be considered one of the most complex garments. Some parts of the jacket are multi-layered, i.e., done by layers of different fabric sewed together. These parts have been modeled changing the forces parameters, always derived from KES measurements performed on multi-layered specimens. The results were encouraging even if simulation times increased rapidly and further improvements are necessary. The most complex part of the body to be covered by garment is usually the bodice, of which the shapes differ from person to person and the surface curvature variations are large. Therefore, the automatic generation of bodice pattern was focused in this study, as it is very difficult to design accurate bodice patterns by flat pattern processes only. Each body scan data is made up of seven segments of skirt, the data of each segment includes two matrixes. One matrix contains the coordinates of the 3D point cloud, another save the coordinate indexes and color values of the triangle patch. In order to ensure that each cross-section of the 3D body data has a same common topological structure, the data of the cross-sections were preprocessed with three methods, including re-sampling, symmetrizing and convex hull calculating. Unified stretch theory technology was adopted to create surface model based on the 3D curve network as theoretical cross sections of system of skirt for “women body - clothes” with different shapes (very closely, closely, semi closely, loosely sections are located in the same order from the

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body) on the waist (а), hip (b) and knee (c) levels. The data preprocessing and surface modeling (Figure 2) can be outlined with the following steps: (1) Sort the data points in order to fit the needs of stretch theory interpolation. (2) Fit horizontal stretch theory curve along the cross-section points, and calculate the center point O of the bounding rectangle of the curve. (3) Re-sample each cross-section at uniform angular centered on point O and re-ordering the sample sequence. (4) Symmetrize the points with y axes as symmetry axis to ensure r1 ¼ r2, in order to get the symmetric skirt model for 3D garment CAD system. (5) Repeat step 1 and step 2 to get new samples and center point of the cross-section again because the center point O is changed after carrying step 3. (6) Calculate the convex hull (Figure 3) of each cross-section points to create a dress-like 3D body model. The convex hull method is used to mimic the physical tape-measurement of the mannequin for the purpose of hip line girth generation, as well as to simplify the body surface complicacy. (7) Build curve network of the skirt according to the point matrix after preprocessed and calculate the control points of mesh, then reconstruct the skirt with the stretch theory surfaces. We may thus first start fitting each row data of the matrix using stretch theory curves Figure 4 and then process each column of the result.

Then we can see fitting equation is the waist circumference ( 5S ) of stretch distance


WGWG WGES Skirt5 (23)

5VSC/VSC100

WSDC

Sn

i

ii

i (24)


Then we can see fitting equation is the Hip circumference ( 6S ) of stretch distance


HGHG HGES Skirt6 (25)

6VSC/VSC100

HSDC

Sn

i

ii

i (26)


Then we can see fitting equation for the knees circumference ( 7S ) of stretch distance


KGKG KGES Skirt7 (27)

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7VSC/VSC100

HSDC

Sn

i

ii

i (28)

Where: Y = maximum distance of node from the edge of the waistline contour, Where: Y = minimum distance of node from the edge of the waistline contour, n = number of nodes. During stretch surface development, overlap may easily occur. In Figure 2 if P1 move to the

right side of edge P2P3 (where v SHOW the moving direction of P1), P1P2P3 overlaps other triangles. Skirt Fitting Function (SFF); to prevent an overlap, a penalty is added to moving masses, of Skirt Fitting methods; we define the stretch Fitting function for mass P as:

)(0

1

1

)(

SFF

jhhFitting

jFittingm

J

jFittingFitting

j

C

jhhC

njhhC (29)

The area density, P here is not the real density of the surface. In most physical-based models, p and C are just scale factors that make the stretch deformation more appropriate C= 0.5 the area density, p and C can also obtained by testing the mechanical stretch

properties, usually we use 01.0t ;

1.....,, 10 npppP ; P, in the initial position, and n is the number of nods.

Where i Stretch Theory, iPand )1( ip

are the coordinates of two endpoint of No. , M and C

is tangent vector of two endpoints of No. jh is the curve shape adjusting coefficient.

Figure 5: fittings to a three skirts (from left; A, B, C) of a surface front of skirt

with six different initial conditions Most of these stretch models are based on the fact that the dominant mode of deformation is shear-rotation of the fiber bundles around their cross-over points. Simple algorithms based on kinematic models do not only predict the final fiber orientation but also are able to translate it into local variations of permeability and can be linked to flow prediction modules in an integrated tool. Although these models work reasonably well with most of the simpler woven structures, it is unlikely that they do so when applied to structures. Figure 3: stretch fitting applied to examples from scientific computing and geometric modeling. Consider the univariate approximation problem with uniform basic concepts B-stretch theory.

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5. FITTING SKIRT SURFACES OF STRETCH CLOTHS From the unified stretch theory, deformation stretch energy distribution topology map darts lines can be defined; many methods can be used to search for acceptable as three divided stretch darts direction. First isolines of stretch energy distribution are obtained. Second, we find the maximum stretch energy point of the surface, in our algorithm the crest line is taken as reference stretch line. After divided some additional can be applied, deformation and stretch divided done repeatedly. The input to the fitting stretch algorithm consists of a subdivision surface with detail coefficients and the target surface which is given as a function mapping for every differs from the identity only in the local area of the skirt stretch surfaces with detail coefficients, the line frame prototype of the skirt can be represented by several Subsections of basic concepts stretch theory curves controlled by key form points. For Example, the waist line is represented by two basic concepts stretch theory curves controlled by three endpoints: center-front point, center-back point, and side seam point. Stretch Theory, the expression can be written as follows:

To describe fitting skirt surfaces of stretch cloths we divided the surface of skirt to three initials pats; The third of front part as form and curve A in figure 6 , the third of Side part as form and curve B in figure 6, the Third of behind part as form and curve C in figure 6. Then we can see fitting equation of The third of front part as form and curve A in figure 6 according

of the waist circumference ( 5 ) and Hip circumference ( 6 ) of stretch distance coefficient as follows:

WGWG WGES Skirt5 (30)

Although a skirt surface of stretch cloths has small deformation due to large tensile modulus, large bending deformation can easily be observed in fabric drape phenomena due to a relatively small out-of-plane bending rigidity. For most particle-based drape simulation algorithm with a rectangular grid structure, A square root filtering function was also used to simulate the non-linear bending behaviour of a fabric through controlling the amount of deformation recovery inverse proportionally to the amount of deformation occurred in a single

Figure 6.: fittings to a three parts (from left; A, B, C) of a surface front of skirt with six different initial conditions

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time step. Our formulation produces very small artificial damping in the out-of-plane direction, which potentially makes the cloth movement look realistic. Skirt surface of stretch cloths has forces stem from deformation: deformations store some potential of stretch energy, Stretch/Shear/Bending, derivative of potential of stretch energy = force, Skirt surface of stretch cloths has the potential of stretch energy functions for each type of deformation is:

Fitting the front part of skirt ( Skirt-FrontFP ) by using the following equation

ii xxxxx

P

xxx

iEEE

P

ASPE

_

stretch of Bendingenergystretch

3_

Skirt-Frontstretch ofShear )5(

FP

(31)

Fitting the front part of skirt ( Skirt-SideFP ) by using the following equation

ii xxxxx

P

xxx

iEEE

P

BSPE

_


3_

Skirt-Sidestretch ofShear )5(

FP

(32)

Fitting the front part of skirt ( Skirt-behindFP ) by using the following equation

ii xxxxx

P

xxx

iEEE

P

CSPE

_


3_

Skirt-behindstretch ofShear )5(

FP

(33)

In additions, Comfort skirt surface of stretch cloths is related to how the clothes feel against the body when the individual is wearing it. Some skirt surface of stretch cloths is not meant to be comfortable while other clothes are focused on this issue. Comfort for most clothes s is related to everyday actions that must be done when wearing skirt surface of stretch cloths such as sitting, bending, walking, and reaching. These actions must be performed in the clothes without straining the clothes and/or seams or feeling compressed or restricted. Thus the shape of the garment patch is decided by basic concepts curves, which are controlled by key from points. A better method may be to specify the guideline as the intersection between two surfaces. For instance, defining the guideline as the intersection between a plane and the given surface may be in most practical cases satisfactory. Another method for specifying the guideline is to define it as a special curve by considering local differential geometry around the starting point of a fit. Such curves may include: 1 – Lines of curvature passing through the starting point, 2 – Geodesics passing through the starting point. It is well known that lines of curvature passing through a point are determined intrinsically and uniquely except at an umbilic point. Moreover, for a non-umbilic point, two lines of curvature are always perpendicular to each other. We may reduce the distortion along the guideline by taking advantage of this feature. On the other hand, if we define the guideline as a geodesic, we may obtain a fit with the smallest amount of woven cloth materials because a geodesic has the shortest length between two points on the surface. 6. CONCLUSION In order to improve the fashion design efficiency and make it possible for the common user to design professionally, we developed researches on fashion intelligent design system. As the process of fashion design is a creative thought process, and the garment is a kind of flexible objects, it is a hard work to express and digitize the knowledge of design. In this paper we constructed the 3D of woven stretch cloth of a garment with basic concepts curves surface

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patches, established the relations between the garment styles and the parameters of 3D garment of woven stretch cloth. By setting up the knowledge base with object-oriented technology and illation mechanism, we accomplished the 3D garment intelligent design. The finite-element approaches show significant promise in the area of fabric motion simulation due to its inherent geniality in dealing with arbitrary shapes, materials, loads, and contact surfaces. Future work must be directed at developing algorithms that promote faster solution times. Current solution times are excessive for use in complex "real-world" garments. 7. REFERENCES [1] Aldred C. (1994). Egyptian art in the days of the pharaohs 3100-32o BC. Published by

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simulating fitting stretch model of three-dimensional apparel surfaces

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