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SIMULATION OF PHYSICAL FORCES FOR WET CLOTHING
OMAR SALIM ABDULLAH
A dissertation submitted in partial fulfilment of the
Requirements for the award of the degree of
Master of Science (Computer Science)
Faculty of Computer Science and Information Systems
Universiti Teknologi Malaysia
APRIL 2013
This dissertation is dedicated to my family especially my father Mr. Salim Abdullah
Ali, my mother and my brother Mr. Qusay Salim Abdullah and all my friends for
their endless support and encouragement.
2
ACKNOWLEDGEMENT
All praise be to Allah and all thanks to him for graces and for giving me the
strength and endurance to complete this research, and then for my parents, my
brothers, sisters and my all friends for helping me.
My high appreciation to my supervisor, Dr. Ahmad Hoirul Basori for
encouragement, guidance, comments and his support which participated actively in
the completion of this work.
Finally, I dedicate the sincere thanks to the staff and lecturers of the faculty of
Computer Science and Information System for their sincere efforts to raise the level
of education.
3
ABSTRACT
One of the mostly researched areas in computer graphic is wet cloth
simulation. Where, there are many factors affecting cloth simulation. Among the
challenges in simulating cloth is taking into consideration all these factors for
example, wetting, internal and external forces. Thus, this study aims to achieve high
realism wet cloth simulation, and take in consideration the forces that may affect the
process of simulation. Mass Spring Model is the technique that proposed to simulate
the wet cloth under the forces of wind and gravity. Initially, to produce the cloth
sheet, a cloth structure is being constructed from a matrix of mass point connected by
springs. Then, external and internal forces were applied on the cloth sheet. The
internal forces represent the tension between the springs in forming the cloth
particles. External forces are represented by wind and gravity. Next, wetting process
is applied on the fabric particles. In wetting process, cloth absorbed a substantial
amount of fluid which will then affect the physical properties and appearance. In the
experiment, the amount of absorbed fluid is calculated using absorption equation,
with increasing values of variable up to saturation level. It was observed that there
are changes on cloth texture as the wetting increased. The color of cloth texture
became darker with increasing wetting value. Highest concentration of texture color
can be observed as the cloth reached the saturation level. Finally, wet cloth is being
compared with dry cloth in terms of color, physical behavior and motion. The cloth
has all the properties of wet cloth like in the real life where, it is appear heavier,
darker color, appearance and physical behavior. Future work for this study suggests
many prospective works especially, simulating the real interaction between the fluid
and the cloth.
4
ABSTRAK
Salah satu bidang yang banyak dikaji dalam grafik komputer adalah simulasi
objek kain. Terdapat pelbagai faktor yang mempengaruhi simulasi kain. Antara
cabaran dalam simulasi kain adalah mengambil kira semua faktor seperti
pembasahan, faktor dalaman dan luaran. Oleh itu, kajian ini mensasarkan untuk
mencapai simulasi kain basah yang berkualiti tinggi, dengan mengambil kira daya-
daya yang mampu mempengaruhi proses simulasi tersebut. Teknik “Mass Spring
Model” dicadangkan untuk simulasi kain basah di bawah pengaruh daya angin dan
graviti. Untuk menghasilkan helaian kain, strukur kain dibina menggunakan matriks
titik-titik yang disambungkan dengan spring. Kemudian, daya dalaman dan daya
luaran dikenakan pada helaian kain tersebut. Daya dalaman mewakili ketegangan di
antara spring yang membentuk partikel kain. Daya luaran diwakili oleh angin dan
graviti. Seterusnya, proses pembasahan dikenakan pada partikel fabrik. Dalam proses
pembasahan, penyerapan cecair pada kain memberi kesan pada ciri-ciri fizikal dan
rupa kain tersebut. Dalam eksperimen yang dijalankan, nilai cecair untuk diserapkan
dikira menggunakan persamaan penyerapan dengan nilai pembolehubah yang
bertambah secara berperingkat sehingga aras tepu. Pemerhatian menunjukkan
terdapat perubahan pada tekstur kain dengan meningkatnya nilai pembasahan. Warna
pada tekstur kain menjadi bertambah gelap dengan peningkatan nilai pembasahan.
Warna paling gelap terlihat apabila kain tersebut mencapai nilai tepu. Akhir sekali,
kain basah tersebut dibandingkan dengan kain kering dari segi warna, ciri fizikal dan
pergerakan. Kain yang terhasil mempunyai ciri-ciri yang sama seperti kain basah
dalam kehidupan seharian dimana beratnya akan bertambah, warna menjadi lebih
gelap dan berbeza dari segi fizikal. Kajian pada masa akan datang dalam bidang ini
adalah lebih luas, terutamanya simulasi antara cecair dan kain.
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TABLE OF CONTENT
CHAPTER TITLE PAGE
DECLARATION
ii
DEDICATION iii
ACKNOWLEDGMENT iv
ABSTRACT v
ABSTRAK vi
TABLE OF CONTENTS vii
LIST OF TABLE x
LIST OF FIGURES xi
1 INTRODUCTION
1.1 Overview 1
1.2 Problem Background 2
1.3 Problem Statement 4
1.4 Aim of Study 4
1.5 Research Objectives 5
1.6 Scope of the Study 5
1.7 Significance of Study 5
1.8 Thesis Organization 6
2 LITERATURE REVIEW
2.1 Introduction 7
2.2 Computer Graphics and Application 7
2.3 Cloth Simulation 8
2.3.1 Cloth Modeling 9
2.4 Cloth Simulation And Modeling Techniques 11
2.4.1 Geometrical Models 11
2.4.2 Physical Models 12
6
2.4.2.1 The Mass-Spring Model 13
2.4.2.2 Particle Based System 17
2.4.2.3 Elastically Deformable
model
18
2.4.3 Hybrid Models 19
2.5 Advance Cloth Simulation 19
2.5.1 Physical Modeling Phase 20
2.5.2 Collision Handling Phase 21
2.6 Interaction of fluid with Textile 23
2.6.1 Under Water Cloth Simulation 25
2.6.2 Wet Cloth Simulation 26
2.7 Discussion 28
3 RESEARCH METHODOLOGY
3.1 Introduction 30
3.2 Research Design Methodology 30
3.3 Generate Mass Spring Model 32
3.4 Cloth Mesh Generation 33
3.5 Cloth Rendering 34
3.6 Water Absorption Calculation 34
3.7 Mass Cloth Calculation (Wind, Gravity) 36
3.8 Loading Wet Cloth Texture 38
3.9 Chapter Summary 39
4 IMPLEMENTATION
4.1 Introduction 40
4.2 Mass Spring Model
42
4.3 Dynamic and Forces
44
4.4 Forces Calculation
45
4.4.1 Internal Forces
45
4.4.2 External Forces
47
4.4.2.1 Gravity Forces
48
7
4.4.2. 2 Wind Forces
49
4.5 Collision Handling 50
4.5.1
Geometric Collision Test
51
4.6 Wet Cloth Finalization
51
4.6.1
Fluid Absorption
52
4.6.2 Texture after Wetting
54
4.7 Wet Cloth Rendering
56
4.8 Testing and Evaluation
56
4.8.1 FPS Evaluation
56
4.8.1.1 Dry Cloth Frames
56
4.8.2.2 Wet Cloth Frames
57
4.8.2 Cloth Behavior Test
62
4.9 Discussion
64
5 CONCLUSION AND FUTURE WORK
5.1 Introduction 65
5.2 Conclusion 66
5.3 Research Contributions 66
5.4 Future Work 67
REFERENCES
68
8
LIST OF TABLES
No.
TITLE
PAGE
4.1 Fabrics parameters of absorption 53
4.2 Masses values for the cloth particles during wetting
Process
53
4.3 Dry cloth’s frames 57
4.4 First wet cloth frames values 59
4.5 Fourth wet cloth frames 60
4.6 Seventh wet cloth frames 61
4.7 Tenth wet cloth frames values 62
9
LIST OF FIGURE
No.
TITLE
PAGE
2.1 Mesh strategy for cloth modeling 10
2.2 Springs types 14
2.3 Mesh grid of masses and springs 15
3.1 Flowchart of the Proposed Method 31
3.2 Types of spring 32
3.3 Mesh between masses and spring 33
3.4 Wet clothes 34
3.5 Cloth mass representations as triangles 36
3.6 Force acting on a triangle 37
3.7 Water influences the fabric drape 38
4.1 Research execution procedures 41
4.2 Clothes ball represented as mass in open GL 42
4.3 Creating clothes particles 43
4.4 Mesh of masses m × n 44
4.5 Spring aspect in the initial positions 46
4.6 Spring aspect after deformation 47
4.7 Gravity actions on each particle 48
4.8 a Cloth with low wind value 50
4.8 b Cloth with medium wind value 50
4.8 c Cloth with high wind value 50
4.9 Cloth in saturation level 54
4.10 Cloth texture in different times of code implementation
reaching to the final color
55
4.11 FPS for dry cloth 57
10
4.12 FPS evaluation after applying first value of wetting
experiment which Equals to 0.093g.
58
4.13 FPS evaluation after applying fourth value of wetting
experiment which Equal to 0.342g
59
4.14 FPS evaluation after applying seventh value of wetting
experiment which equals to 0.591g
60
4.15 FPS evaluation after applying tenth value of wetting
experiment which
61
4.16 Dry cloths in the physical test 63
4.17 Wet cloths in the physical test 64
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CHAPTER 1
INTRODUCTION
1.1 Overview
The computer graphics application has widely used in several fields of our life
such as edutainment, military, entertainment and etc. In the recent years, computer
graphic acquired advance position among the others computer sciences areas. Indeed
it appeared to the computer graphic society at the beginning of computer era in 1954.
First appearance of computer graphic application was in Massachusetts
institute of technology; where Jay Forrester developed the first model by simulate
naval aircraft. Cloth simulation as computer graphic application has strong
relationship with virtual character inside virtual environment. The existing approach
on cloth simulation covers underwater cloth simulation, avatar cloth simulation or
even collision in cloth simulation. The interaction between fluid and cloth in real
world has become a challenge for computer graphics society.
In this thesis, we propose new techniques on wet cloth simulation to simulate
the interaction between cloth and fluid during physical interaction inside virtual
environment. We are focusing our work to study the properties of wet cloth and fluid
that can change the behavior of cloth when they interact with wind or even gravity.
Whereas, the wet cloth is affect the weight and softness of the cloth appearance and
behavior. These changes are very important in representing in realistic simulation.
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Most of the previous studies which used to simulate cloth under fluid influence
focused on immerse the cloth completely under the fluid. In our approach we want to
perceive how to simulate cloth under the impact of the fluid partially such as, cloth
under rainy situation, wind and gravity interaction, etc.
In our work we are going to demonstrate the nature of the wet cloth that will
contribute to several new ideas, such as walking under simulated rain or fall of fluid
on the part of the fabric.
1.2 Problem Background
Cloth is one of the normal human life requirements. To simulate cloth we have
to know what the components which form the fabric are. The components of the
cloth are core element to describe the structure. Cloth simulation under effect of fluid
still needs much attention in particular on how want produce intensive and high
realistic simulation.
Keckeisen et al. ( 2003) described a Virtual Reality application that enables the
user to interactively select garment patterns and place them around a 3D body using
6DOF input devices. Salazar et al. (2010) were suggested several cloth simulation
issues. First of them was reduce the number of iterations required for collision
treatment through AABB hierarchies. As cloth modeling in this form as triangular
meshes composed of particles and springs, this structure of data in hierarchical form
was appointed in arrange to reduce the intersection tests numbers at primitives’
levels. The other issue is quantitative analysis the Computational burden for
application of cloth simulation that employs approach of multi-processor on a multi-
threaded CPU and on an emerging multi-core GPU-CUDA architecture. The
architecture of multi-processor GPU-CUDA enables high-performance since recent
GPU models offer extremely high floating-point arithmetic throughput.
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Huber (2011) presented a way to simulate the cloth and the fluid that also
handles fluid diffusion across absorbent textiles. Based on the cloth simulation
engine, he combined the state of the art- finite element with a smoothed particle
hydrodynamic (SPH) fluid simulation. He explained the possibility interaction
between the fluid and textile. To make model for fluid transformation across wet
cloth, Huber uses Fick's law of translation diffusion.
Fick laws equation used to compute the diffusion states; it's described as very
fast discrete cellular automation. Decaudin et al. (2006) proposed producing virtual
cloth depending completely on geometric method. The resulted fabric consisted of
developed faces sheets that envelop around a mannequin normal method constructing
optically bends. Furthermore, this system supply stitching models, which possible to
use in deformation-free weave designing and for sewing of actual life identical to the
planned clothes.
Mongus et al.( 2011) proposed a road to obtain proper behavior of computer
simulated textiles (e.g. silk, wool, cotton) the physical particularities disfigures when
enabled to hang under its own weight, and is usually measured using a drape meter.
Cloth and fluid simulation represent one of the most important and effective aim in
computer graphic world. Where recent years has a large advance in simulate wet
cloth, however the majority of this studies focused on the underwater cloth
simulation. Chen et al.( 2012) produced one of the most important approaches to
simulate the cloth under wet influence. In this technique they are simulated wet garb
for virtual human with realistic crease and bends. The unique characteristic of this
work is the wrinkle and friction pattern. In our work, we present method to illustrate
the behavior of cloth when it is been under the impact of external effects such as wet,
gravity, and wind.
1.3 Problem Statement
Simulation of wet cloth has long been an objective in computer graphics
areas. How to simulate a soaked garment, especially how to simulate a garment
15
influenced by the forces of wind and gravity. Although latest years significant
researches on wet cloth simulation have be prepared, the earlier work has focused on
underwater cloth such as (Ozgen et al.,2010), saturation models (Huber, 2011) , and
porous flow passing through cloth as in the work of (Lenaerts et al., 2008). Yet the
most familiar scenarios within animation are often simply a wet cloth. Based on the
discussion as stated on problem background, there is an opportunity to enhance the
cloth simulation by adding fluid to the cloth like wet cloth simulation. The main
research question:
(How to create wet cloth simulation based on gravity and wind effects?)
1. Why computer Graphics need wet cloth simulation?
2. What kind of technique that suitable for simulating the influence of fluid to the
cloth
3. How we can calculate physic effect of wind and gravity to the normal and wet
cloth?
1.4 Aim of Study
The aim of this study is to create a new technique for cloth simulation with
the effect of external forces: wind and gravity.
1.5 Research Objective
16
1. To produce a new method for simulating wet cloth with the considering of the
effect of wind and gravity.
2. To develop a prototype for the proposed technique.
1.6 Scope of Study
This research technique is based on mass-spring systems that are still common
for cloth simulation for its ability to reflect the fabrics physical properties and
achieve better representation for cloth behavior. The research will study this behavior
of wet clothes when it exposed to external forces, with taking into consideration the
following conditions:
1. The fluid that use in this research is water
2. The external forces considered are wind and gravity
3. Mass spring model will be used to simulate cloth deformation
3. Textile mass represented as triangles
4. Cotton will be used as the basis for calculating the amount of water absorption
5. Microsoft visual studio version 2006.
1.7 Significant of study
The interaction between fluid and cloth still not explored so well, on the other
hand the effect of wet cloth simulation is needed to simulate realistic physic behavior
on game or 3D movies. Therefore, this research result is believed to bring great
benefit to computer graphics society.
1.8 Thesis organization
17
This thesis is organized into five chapters. Chapter one, presents an
introduction and overview of computer graphics and cloth simulation. It also
includes the objectives and scope of the study. Literature review on cloth modeling
and simulation explained in Chapter two. In Chapter three, the research methodology
including research procedure and design is discussed. Chapter four explain in details
the implementation phases and shows the research results and the evaluation. In
chapter five the conclusion and the future work discussed in details.
82
REFERENCES
Chen, L., Zhao, S., Zhang, L. Z. and Zhang, W. (2011). Analysis and Simulation of
the Shear Deformation for Woven Cloth. Advanced Materials Research, 201-
203, 203.
Chen, Y., Magnenat Thalmann, N. and Foster Allen, B. (2012). Physical simulation
of wet clothing for virtual humans. The Visual Computer, 28(6-8), 765-774.
doi: 10.1007/s00371-012-0687-y
Cloth/ Machinery Coupled System Unified Modeling. Applied Mechanics and
Materials, 37-38, 1-4. doi: 10.4028/www.scientific.net/AMM.37-38.1
Cordier, F. and Magnenat‐Thalmann, N. (2005). A Data‐Driven Approach for
Real‐Time Clothes Simulation†. Proceedings of the 2005 Computer Graphics
Forum, 173-183.
Czilli, G. (2010). Particle-based simulation of deformable bodies.
da Silva, M. G. Cloth Animation with Collision Detection.
ElBadrawy, A. A. and Hemayed, E. E. (2011). Speeding up Cloth Simulation by
Linearizing the Bending Function of the Physical Mass-Spring Model.
Proceedings of the 2011 3D Imaging, Modeling, Processing, Visualization
and Transmission (3DIMPVT), 2011 International Conference on. 16-19
May 2011. 101-107.
ElBadrawy, A. A., Hemayed, E. E. and Fayek, M. B. (2012). Rapid collision
83
detection for deformable objects using inclusion-fields applied to cloth
simulation. Journal of Advanced Research, 3(3), 245-252.
for Fast Cloth Simulation. springer 424–435.
Güdükbay, U., Bayraktar, S., Koca, Ç. and Özgüç, B. (2012). Particle-based
simulation of the interaction between fluid and knitwear. Signal, Image and
Video Processing, 1-8.
Haiyan, Y., Yongxing, W., Shengze, W. and Zhaofeng, G. (2010). A Cloth
Simulation Method for
Hangzhou. (2010). 3D Garment Real-time Simulation in Character Animation
Harada, T., Koshizuka, S. and Kawaguchi, Y. (2007). Real-time fluid simulation
coupled with cloth. Proceedings of the 2007 Theory and Practice of
Computer Graphics,
Helena Wong. (2000). Introduction to Computer Graphics.
Hongyan, L., Yueqi, Z. and Shanyuan, W. (2011). Intersection resolution method for
cloth simulation. Proceedings of the 2011 Electric Information and Control
Engineering (ICEICE), 2011 International Conference on, 491-494.
Huber, M., Pabst, S. and Straßer, W. (2011). Wet Cloth Simulation. Proceedings of
the 2011 Special Interest Group on Computer Graphics and Interactive
Techniques Conference Vancouver, British Columbia, Canada, 92.
Java, W. (2010). Fundamentals of Computer Graphics:
http://math.hws.edu/graphicsnotes.
Jiang, Y. and Wang, R. (2010). Real-time cloth simulation based on improved Verlet
algorithm. Proceedings of the 2010 Computer-Aided Industrial Design &
Conceptual Design (CAIDCD), 2010 IEEE 11th International Conference on,
443-446.
Kieran, E., Harrison, G. and Openshaw, L. Cloth Simulation.
Kwatra, V. Cloth Simulation.
Lee, Y., Yoon, S., Oh, S., Kim, D. and Choi, S. (2010). Multi‐Resolution Cloth
Simulation. Proceedings of the 2010 Computer Graphics Forum, 2225-2232.
Leong, I.-F., Kuo, J.-K. and Fang, J.-J. (2011). A Clothing Simulation System for
Realistic Clothing and Mannequin. Computer-Aided Design & Applications,,
335-344.
Li, B. and Zhao, Z. (2012). Cloth Pattern Simulation Based on a 1/f Noise Method.
Foundations of Intelligent Systems, 463-468.
84
LIU, X. H. and wu, Y. w. (2010). Simulation of cloth multi-drape-pattern
deformation. Paper presented at the 20IO International Conference on
Computer Application and System Modeling (ICCASM 2010).
Mongus, D., Repnik, B., Mernik, M. and Žalik, B. (2012). A hybrid evolutionary
algorithm for tuning a cloth-simulation model. Applied Soft Computing,
12(1), 266-273. doi: 10.1016/j.asoc.2011.08.047
Müller, M., Schirm, S., Teschner, M., Heidelberger, B. and Gross, M. (2004).
Interaction of fluids with deformable solids. Computer Animation and Virtual
Worlds, 15(3‐4), 159-171.
Narain, R., Samii, A. and O’Brien, J. F. (2012). Adaptive Anisotropic Remeshing for
Cloth Simulation. ACM Transactions on Graphics.
Oct. 2010. V3-562-V563-565.
Ozgen, O. and Kallmann, M. (2011). Directional Constraint Enforcement
OZGEN, O., KALLMANN, M., RAMIREZ, L. E. and COIMBRA, C. F. (2010).
Underwater Cloth Simulation with Fractional Derivatives. ACM Transactions
on Graphics, VV.
Provot, X. (1995). Deformation constraints in a mass-spring model to describe rigid
cloth behaviour. Proceedings of the 1995 Graphics interface, 147-147.
Robinson-Mosher, A., Shinar, T., Gretarsson, J., Su, J. and Fedkiw, R. (2008). Two-
way coupling of fluids to rigid and deformablesolids and shells. . ACM
Transactions on Graphics 27, 23, 21–29.
Rudomín, I. and Castillo, J. (2002). Real-time clothing: geometry and physics.
Proceedings of the 2002 WSCG 2002 Conference Program,
Salazar, F. S. R., Machado, B. B., Ocsa, A. and Oliveira, M. C. F. d. (2010). Cloth
simulation using AABB hierarchies and GPU parallelism. IEEE.
Shapri, M. and Saadah, N. (2011). Fixed spherical n points density-based clustering
technique (FixDeC) for cloth simulation. Universiti Teknologi Malaysia,
Faculty of Computer Science and Information System.
Shapri, N. S. M., Bade, A. and Daman, D. (2009). Hierarchy Techniques in Self-
Collision Detection for Cloth Simulation. Paper presented at the International
Conference on Machine Vision.
Shin-Ting, W. and de Monteiro, L. P. (2012). Intuitive Modeling of Folds and
Wrinkles in a Cloth Simulation.
Tank, B. s. T. (2009). Computer Graphics.
85
Thomaszewski, B. and Blochinger, W. (2007). Physically based simulation of cloth
on distributed memory architectures. Parallel Comput., 33(6), 377-390. doi:
10.1016/j.parco.2007.02.008
Volino, P. and Thalmann, N. M. (1997). Developing simulation techniques for an
interactive clothing system. Proceedings of the 1997 Virtual Systems and
MultiMedia, 1997. VSMM '97. Proceedings., International Conference on.
10-12 Sep 1997. 109-118.
Volino, P. and Thalmann, N. M. (2000). Implementing Fast Cloth Simulation with
Collision Response. Paper presented at the Proceedings of the International
Conference on Computer Graphics.
Yan, J., Rui, W. and Zhengdong, L. (2008). A survey of cloth simulation and
applications. Proceedings of the 2008 Computer-Aided Industrial Design and
Conceptual Design, 2008. CAID/CD 2008. 9th International Conference on.
22-25 Nov. 2008. 765-769.
Yang Liu. Advanced Materials Research 108-111, 753-758. doi:
10.4028/www.scientific.net/AMR.108-111.753
Zhao, Y. and Jiang, C. (2008). Online Virtual Fitting Room Based on a Local
Cluster. Paper presented at the Proceedings of the 2008 International
Workshop on Education Technology and Training & 2008 International
Workshop on Geoscience and Remote Sensing - Volume 01.
Zhou, C., Jin, X., Wang, C. C. L. and Feng, J. (2008). Plausible cloth animation
using dynamic bending model. Progress in Natural Science, 18(7), 879-886.
Zhuang Qing, h., Ding, Y. and Gong Guang, h. (2010). A fast Predictive-Corrective
Mass Spring method in cloth simulation. Proceedings of the 2010 Computer
Application and System Modeling (ICCASM), 2010 International Conference
on. 22-24 Oct. 2010. V3-562-V563-565. . from
http://freespace.virgin.net/hugo.elias/models/m_cloth.htm.
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