Sungmin Kim

SEOUL NATIONAL UNIVERSITY

Fashion Technology6. 3D Garment CAD-2

Garment Design

• Body modeling• 3D draping simulation

Pattern Design

• 2D Parametric design• 3D pattern design

Fabric Design

• Weave CAD• 2.5D Mapping

Flat Sketch

• Scalable vector graphics• Feature-based design

Design Process

Overview

2

DesignProcess

Surface Peeling

Parametric Body Surface Model Parametrically Deformable Body Surface Model

Cross Section Initial Solid Model Refined Model Parametric Surface

3

Surface Peeling

Parametric Body Surface Model Cylindrical Approximation of Body Parts

4

Deformable Body Model

Parametric Surface

Surface Peeling

Parametric Body Surface Model Intuitive Definition of Pattern Outline using Landmarks

5

Surface Peeling

Parametric Body Surface Model Garment Surface Generation

Formation of mesh structure on the parametric surface model

6

Surface Peeling

Parametric Body Surface Model 2D Projection Method

Basic method

– Project 3D elements one by one

– May result in irregular darts

Automatic dart location

– According to Gaussian curvature

– Curvature evaluation is difficult for polyhedral surface

7

Surface Peeling

Parametric Body Surface Model 2D Projection with Predefined Darts

MassCenter

ProjectionCenter

Surface NormalDirection

C

P

V

Target Plane

8

Initial projection with distortion

Surface Peeling

Parametric Body Surface Model Physics based projection

9

Stretch tolerance along UV axis

U=5%, V=0% U=5%, V=5%

Surface Peeling

Body Surface Analysis Automatic Landmark Location

10

Landmark location on 3D scan data

Trimmed Data

Surface Peeling

Body Surface Analysis Isoparametric 2D-3D Mapping

FrontBack

11

3D Mesh Structure Corresponding 2D Grid 2D-3D Analogy

Surface Peeling

Body Surface Analysis

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Garment Modeling

Modeling of Ideal Garment

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Fit zone

Fashion zone

Garment Modeling

Modeling of Ideal Garment Preparation of Fit Zone

From body scan data

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Body Scan Data Mesh Generation usingDigitized Points

Zebra Striping for Verification

Garment Modeling

Modeling of Ideal Garment Preparation of Fit Zone

Convert into deformable parametric surface

15

Bodice

Slacks

Skirt

Garment Modeling

Modeling of Ideal Garment Formation of Fashion Zone

Parametric representation of fashion features

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Garment Modeling

Modeling of Ideal Garment Examples of Synthesized Garments

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Garment Modeling

Modeling of Ideal Garment Definition of Darts

Horizontal and vertical darts can be defined along structural mesh

Multiple darts can be placed on a pattern guided by curvature map

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Garment Modeling

Modeling of Ideal Garment Flat Pattern Development

User defined darts or automatic dart generation

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User-defined dartsAutomatic Darts

3D Textile Design

Technical Textile Interior Design

Automotive

Aircraft

Watercraft

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3D Textile Design

Technical Textile

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3D Textile Design

Technical Textile Intuitive Design

Optimum Marking

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Drape Simulation

Interdisciplinary Nature of Drape Simulation

AnthropometryAnthropometry

GarmentEngineering

GarmentEngineering

TextileEngineering

TextileEngineering

Electro-opticsElectro-optics

ComputerScience

ComputerScience

ElectronicsElectronics

DrapeSimulation

DrapeSimulation

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Drape Simulation

FEM (Finite Element Method) Based Approach Principles

Approximation of the region of interest and subdivision into a number of meshes

Good for small deformation problem

24

Drape Simulation

Particle System Approach Principles

Fabric is divided into small elements with concentrated mass

Interconnected spring system

25

Drape Simulation

Particle System Approach Principles

Numerical integration based on particle-spring system

26

Particle System

2

2

dt

xdmmaF

dt

dx

P

C

dt

dxg

dt

xd

mass

damping

2

2

Gravitational Contribution

0

02

2

l

ll

P

CPQ

dt

xd

mass

tensile

Tensile Contribution

1

221

210

2

1,

2

1

,,

l

l

P

COQv

P

COPv

OQlOPlPOQPOQ

mass

bending

mass

bending

Bending & Shearing Contribution

CollisionDetection and

Resolution

Drape Simulation

Mesh Generation Triangular Mesh

Subdivision of arbitrary domain into triangular elements

Basic technology for drape simulation

– Darts and internal openings must be considered

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Drape Simulation

Mesh Generation Automatic Mesh Generation

Node connection approach

– Node generation

» Cavendish’s method (1974)

» Shimada’s method (1992)

– Element generation

» Delaunay triangulation (1981)

» Lee’s method (1983)

28

Drape Simulation

Mesh Generation Automatic Mesh Generation

Grid-based approach

– Rectangular grid and triangles

– Quadtree representation

29

Drape Simulation

Mesh Generation Automatic Mesh Generation

Geometry decomposition approach

– Generates triangular or quadrilateral elements in two dimensions

» Recursion based iterative approach

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Drape Simulation

Collision Handling Collision Detection and Resolution

The rate-determining step in fabric drape simulation

Fabric-external body, fabric-fabric collision

Robust collision detection and response is very important

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Drape Simulation

Spatial Arrangement of Patterns Initial condition for physical simulation

Using bounding volume defined in body model generation process

32

Drape Simulation

Texture Mapping Swatch vs Full-Garment Texture

Versatility vs Reality

33

Drape Simulation

Simulation Results

34

Drape Simulation

Simulation of Detailed Features Rendered Images

35

Drape Simulation

Fitting Evaluation Visualization of Physical Properties

Distribution of strain, pressure, clearance, etc.

36

Drape Simulation

Commercial Systems

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OptiTex

Clo3D

Drape Simulation

Commercial Systems

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Tuka 3D by TukaTech

AccuMark 3D by Gerber

Drape Simulation

Applications

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Magic Mirror

Fashion Kiosk

Drape Simulation

Applications

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Online Dressing Room

Drape Simulation

Applications Virtual Draping Pattern Making

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Drape Simulation

Challenges Technical

Implementation of actual fabric physics in real time

Robust multi-layer garment modeling

Interactive fabric manipulation

Educational

Conventional fashion design curriculum is unsuitable for CAD

Insufficient investment and lack of standardized systems

Industrial

Employers want to introduce 3-D systems to prepare for the future

Employees are generally reluctant to new methods

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