Sungmin Kim

SEOUL NATIONAL UNIVERSITY

Fashion Technology4. Digital Body Modeling

Garment Design

• Body modeling• 3D draping simulation

Pattern Design

• 2D Parametric design• 3D pattern design

Fabric Design

• Weave CAD• 2.5D Mapping

Concept Design

• Scalable vector graphics• Feature-based design

Design Process

Overview

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DesignProcess

Introduction

Digital Body Data Definition

3D body shapes scanned by 3D scanners and anthropometric data measured from them

Acquisition Method

3D Scanning

– Full body scanning in seconds

– Repeated analysis can be performed on stored data

– 3D observation of specific body parts

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Introduction

Three-Dimensional Scanners Acquisition of point cloud data

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Introduction

Three-Dimensional Scanning Intellifit Scanner

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Introduction

Photogrammetry Type Principles

Instant capture using numerous high-resolution cameras

High quality textured 3D model without any blind spot

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Introduction Digital Body in Garment Industry Development of Customized Dummy

Customized dummies for various customer groups

– Reconstruction of body shape using only 2D measurement is difficult

– Generation of dummy with appropriate amount ease is difficult

Easy anthropometric measurement

– Cross sectional shape in every direction

– Surface curvature, volume, etc.

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Introduction

Digital Body in Garment Industry 3D Pattern Design

Development of individually fit garment patterns

Elimination of trial-and-error based grading process

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Cross Section

Structural Model

Parametric Surface

Introduction

Digital Body in Garment Industry Virtual Fitting Room

Digital fashion

– Construction of personalized models

– Fitting of various fashion items online on own body model

Reduction of impulsive and mistake buying

– Observation from various angles

– Mix and match of colors and items is available online

Save time and money

– A lot of clothes can be tried in minutes

Retailers' profits

– Brand advertising, increased sales and new customers

– Increase customer loyalty for the website

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Introduction

Digital Body in Garment Industry Implementation of Customized Production

Necessity

– One of the most important features of QR (Quick Response) system

– Consumers can pick a product and try it on online

Current status

– Asahi and Toray partially implemented the system

– Technical cooperation of Lectra FitNet (CAD / CAM) and Techmath Vitus scanner

In the near future...

– The production of custom fit garment based on 3D measurement data will be generalized

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Measurement

Scanning Posture

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UprightStanding

ModifiedStanding

ModifiedSitting

BasicStanding

Measurement

Automatic Landmark Detection Should include...

Reference points for manual measurement process

3D feature points for anthropometric measurement

Points required for reconstructing the silhouette of body shape

Points required for the development of automatic measurement algorithm

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Measurement

Automatic Landmark Detection

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Measurement

Specifications of Some Commercial 3D Scanner

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Scanner Manufacturer Light Source Scanning Time (Sec)

Scanning Range(WDH, cm) Analysis S/W

WB4 Cyberware(USA)

Laser 17 120x120x200 Digisize

Bodyline Scanner Hamamatsu(Japan)

(PDS) Position Detection Sensor

16 50x90x200 Bodyline Manager

Vitus Pro/Smart Vitronics(Germany)

Laser 8~20 100x100x210 ScanWorx

Voxelan Hamano(Japan)

Laser 5 50x85x200 Voxelan

Danae-S NEC(Japan)

White Light 1.9 60x100x190 Slimform

2T4 TC2

(USA)White Light 10 110x100x200 Body Scanning

Cartesia 3D Space Vision(Japan)

Laser 2 65x65x200Under

Development

Measurement

Current Status of 3D Anthropometry Projects Domestic Status

The first nationwide 3D scanning project was made in 2003

– The fourth in the world (after the US, Japan, UK)

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No. Year Subjects' Age No. of Subjects Measurement Items Institute

1 1979 0-45 18,013 117 KIST

2 1986 0-51 21,648 80 KRISS

3 1992 6-50 8,886 84 KRISS

4 1997 0-70 13,062 120 KRISS

5 2003-2004 0-90 21,000Static 119

Dynamic 353D 205

ESK/KSCT/KRISS

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2010 7-69 14,016 Static 139 Kangnam Univ.

2010 20-39 848

3Di-Fashion Center

SNUDSC

2011 7-13 1,238

2012 40-69 1,228

Measurement

Current Status of 3D Anthropometry Projects International Status

International competition is intensifying for obtaining body shape and body size data

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CAESAR Size UK Size USA Size Japan

Year 1998-2000 2001-2002 2002-2003 2004-2006

Institute USA, Netherlands, Italy 3DEC Center TC2 HQL

Subject No. 7,400 11,000 12,000 6,742

Subject Age 18~65 16~ Adult 7~90

Method 3D ScanningDirect measurement

3D Scanning3D Scanning

Direct Scanning3D Scanning

(Whole, Foot, Hand)

Posture Whole body 3 Whole body 2 Standing Whole body 3

Modeling Method

Human Body Modeling3D Body Model

High qualityDynamic DrapeSimulation andAnimation

Static Drape Simulation

Animation

Dynamic Drape Simulation

Movable Fixed

Surface ModelAnatomicallyBased

Fixed ShapeDeformable

Static DrapeSimulation

Anthropometry

Technology

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Modeling Method

Human Body Modeling Fixed Shape Model

Raw 3D scanned data

– Simple triangular mesh structure

Used for accurate anthropometry

Lacks in meta information for other applications

Deformable Model

Can be deformed to various sizes and shapes

Cannot reflect every detail in the body

Rich in meta information

– Landmarks

– Baselines for garment design

– Body surface equation

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Modeling Method

Deformable Model Anatomically Based Model

Skeleton-muscle-skin structure

Accurate expression of realistic deformation

Used for high-quality animation

Too complex to be practical

Volumetric deformation

FacialAnimation

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Modeling Method

Deformable Model Geometrically Based Model

Cross-sectionbased

Template-basedMeta-ballbased

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Modeling Method

Metaball Based Modeling Principles

Definition of a imaginary ball with certain amount of energy

Energy level decreases along the distance

An implicit surface can be defined at the threshold energy level

Smooth and complex surface can be defined using multiple metaballs

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Distance

Energy

Threshold forSurface

Modeling Method

Metaball Based Modeling Metaball Fitting

Distribute multiple metaballs within the body scan data

Determine the initial energy of each metaball to fit the point cloud data

Considerable amount of calculation is needed

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Fit metaballs to body cross section

Collision resolution

Modeling Method

Metaball Based Modeling Advantages

Smooth surface

Easy deformation by relocating the position and/or reassigning the energy level

Easy determination of inside-outside check for collision detection in garment simulation

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Metaball Polygonal mesh

Deformation

Modeling Method

Template Based Modeling Method

Formation of a body template with meta information for anthropometric analysis

Fit the template to 3D body scan data

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Modeling Method Template Based Modeling Advantages

Perfect mesh structures on joint areas (armpit, crotch, etc.)

Well structured surface for easy shape analysis

Disadvantages

Cannot reflect the possible asymmetry in scan data

Applications

Development of standard body models or garment design dummies

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Template

Modeling Method

Cross Section Based Modeling Method

Extracts the cross-sectional shape of key sections

Connects the key sections to form a structured mesh

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Cross Sections Structured Mesh Parametric Surface Model

Modeling Method

Cross Section Based Modeling Advantages

Relatively easy 3D model generation

Complex shape can be made by increasing the number of key sections

Easy to construct a parametric surface model

Disadvantage

Difficult to model the joint areas on the body (armpit, crotch, etc.)

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u

v

Parametric Surface

Functionality

Customization Customized Body Model Generation

By adding the details to the 3D modeled body

– Head, hand, foot, and texture maps

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BodyTextureImage

UnderwearTextureImage

Functionality

Customization Customized Body Model Generation

Face, hair style, skin tone, underwear

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Functionality

Customization Customized Body Model Generation

Shoes and stockings

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Functionality

Size Variation Free Form Deformation (FFD)

Deformation of complex shape using a few control points

User for the deformation of soft matter

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FFD LatticeFFD Lattice

Lattice DeformationLattice Deformation

Functionality

Size Variation Definition of FFD lattice

Form an FFD lattice around the body

Include every section for size variation

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Functionality

Size Variation Definition of Lattice Deformation Operators

Establishing the relationship between the amount of lattice point movement and shape

Body size can be changed by inputting target sizes

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Functionality

Posture Variation Definition of Skeletal Structure

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Joints

BonesWeightDistribution

Functionality

Posture Variation Angular deformation

Rotate a bone about a joint

Connected bones are also rotated

Skin points bound to those bones are also rotated to deform the posture

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Functionality

Posture Variation Motion by multiple key posture sequences

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Functionality

Posture Variation More Natural Motion

Using the motion capture system

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Functionality

Posture Variation Research Topic

Unrealistic deformation around joint regions

Skeleton-Muscle-Skin model is required for realistic deformation

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Functionality

Measurement Predefined items

Landmarks

Girth/Length

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Convex hull generation for simulating tape measurementConvex hull generation for simulating tape measurement

Functionality

Collision Volume Definition and Role

A low resolution 3D model tightly enclosing the body model

Reduces the amount of polygon-polygon collision to speed up the drape simulation

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Functionality

Bounding Surface Definition and Role

A convex developable surface defined around each body part

Serves as the basis for arranging the garment patterns around body appropriately

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