COMPUTER GRAPHICS Edited by Nobuhiko Mukai Computer Graphics Edited by Nobuhiko Mukai Published by InTech Janeza Trdine 9, 51000 Rijeka, Croatia Copyright © 2012 InTech All chapters are Open Access distributed under the Creative Commons Attribution 3.0 license, which allows users to download, copy and build upon published articles even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. After this work has been published by InTech, authors have the right to republish it, in whole or part, in any publication of which they are the author, and to make other personal use of the work. Any republication, referencing or personal use of the work must explicitly identify the original source. As for readers, this license allows users to download, copy and build upon published chapters even for commercial purposes, as long as the author and publisher are properly credited, which ensures maximum dissemination and a wider impact of our publications. Notice Statements and opinions expressed in the chapters are these of the individual contributors and not necessarily those of the editors or publisher. No responsibility is accepted for the accuracy of information contained in the published chapters. The publisher assumes no responsibility for any damage or injury to persons or property arising out of the use of any materials, instructions, methods or ideas contained in the book. Publishing Process Manager Dragana Manestar Technical Editor Teodora Smiljanic Cover Designer InTech Design Team First published March, 2012 Printed in Croatia A free online edition of this book is available at www.intechopen.com Additional hard copies can be obtained from orders@intechopen.com Computer Graphics, Edited by Nobuhiko Mukai p. cm. ISBN 978-953-51-0455-1 Contents Preface IX Chapter 1 Approach to Representation of Type-2 Fuzzy Sets Using Computational Methods of Computer Graphics 1 Long Thanh Ngo and Long The Pham Chapter 2 Self-Organizing Deformable Model: A Method for Projecting a 3D Object Mesh Model onto a Target Surface 19 Ken’ichi Morooka and Hiroshi Nagahashi Chapter 3 Bounding Volume Hierarchies for Collision Detection 39 Hamzah Asyrani Sulaiman and Abdullah Bade Chapter 4 Modeling and Visualization of the Surface Resulting from the Milling Process 55 Tobias Surmann Chapter 5 A Border-Stable Approach to NURBS Surface Rendering for Ray Tracing 71 Aleksands Sisojevs and Aleksandrs Glazs Chapter 6 Design and Implementation of Interactive Flow Visualization Techniques 87 Tony McLoughlin and Robert S. Laramee Chapter 7 Simulations with Particle Method 111 Nobuhiko Mukai Chapter 8 Fast Local Tone Mapping, Summed-Area Tables and Mesopic Vision Simulation 129 Marcos Slomp, Michihiro Mikamo and Kazufumi Kaneda Chapter 9 Volume Ray Casting in WebGL 157 John Congote, Luis Kabongo, Aitor Moreno, Alvaro Segura, Andoni Beristain, Jorge Posada and Oscar Ruiz VI Contents Chapter 10 Motion and Motion Blur Through Green’s Matrices 179 Perfilino E. Ferreira Júnior and José R. A. Torreão Chapter 11 Maxine: Embodied Conversational Agents for Multimodal Emotional Communication 195 Sandra Baldassarri and Eva Cerezo Chapter 12 To See the Unseen – Computer Graphics in Visualisation and Reconstruction of Archaeological and Historical Textiles 213 Maria Cybulska Chapter 13 Developing an Interactive Knowledge-Based Learning Framework with Support of Computer Graphics and Web-Based Technologies for Enhancing Individuals’ Cognition, Scientific, Learning Performance and Digital Literacy Competences 229 Jorge Ferreira Franco and Roseli de Deus Lopes Preface It is said that computer graphics has begun when Dr. Sutherland invented sketch pad system in 1963. Computer graphics has been developed with the help of computer power, and therefore the history of computer graphics is strongly connected to the history of computers. The first general-purpose electronic computer was ENIAC (Electronic Numerical Integrator and Computer), developed at the University of Pennsylvania in 1946. In past computer was expensive, large and slow; now it has become inexpensive, small and fast so many people are using computers all over the world. With the development of computers, computer graphics technology has also developed. During 1960s, the main topics of computer graphics were how to draw lines and surfaces, as well as how to remove the hidden lines and surfaces. In 1970s, modeling techniques of smoothed curve was one of the main themes, in addition to rendering surfaces with color gradation. After 1980s, standard libraries of computer graphics have been established at ISO (International Organization for Standardization). In addition, de facto standard has become open from several companies, and many useful tools of computer graphics have been developed. As mentioned above, computer graphics has been developed with the development of computer, with modeling and rendering as the two main technologies. If one of them has not improved, we would not be able to create very beautiful and realistic images with computer graphics. In addition, a generation of real images is based on physical simulation. People can create real images by performing physical simulation with natural law. The most difficult task is how to generate the appropriate model that obeys the natural law of the target, and also how to render the object that is generated with the appropriate model. This book covers the most advanced technologies for modeling and rendering of computer graphics. For modeling technology, there are some articles in various fields such as mathematical and surface based modeling. On the other hand, there are varieties of articles for rendering technologies with simulations such as fluid and lighting tone. In addition, this book includes some visualization techniques and applications for motion blur, virtual agents and historical textiles. I hope his book will provide useful insights for many researchers in computer graphics. Nobuhiko Mukai Computer Science, Knowledge Engineering, Tokyo City University, Japan [...]... computational geometry algorithms on TIN The result is shown and corroborated for robustness of the approach, rendering type-2 fuzzy sets in 3-D environment using OpenSceneGraph SDK 2 2 Computer Graphics Computer Graphics The chapter is organized as follows: II presents TIN and geometric computation; III introduces type-2 fuzzy sets; IV presents approximate representation of type-2 fuzzy sets; V is... the opposite diagonal of Q (edge f lip) does not increase Approach to Representation Approach to Representation of Type-2 Fuzzy Sets using Computational Methods of Computer Graphics of Type-2 Fuzzy Sets Using Computational Methods of Computer Graphics 3 3 the minimum of the six internal angles of the resulting triangulation of Q τ is a Delaunay triangulation if and only if every edge of τ is locally optimal... similar to the condition of being Delaunay, but only the two triangles that contain e are considered For instance, Figure 4 demonstrates two different ways to triangulate a subset of 4 4 Computer Graphics Computer Graphics Fig 3 (a) A planar straight line graph (b) Delaunay triangulation of the vertices of the PSLG (c)Constrained Delaunay triangulation of the PSLG Fig 4 Two triangulations of a vertex... Half-edges are directed and the two edges of a pair have Approach to Representation Approach to Representation of Type-2 Fuzzy Sets using Computational Methods of Computer Graphics of Type-2 Fuzzy Sets Using Computational Methods of Computer Graphics 5 5 opposite directions Data structure of each vertex v in TIN contains a clockwise ordered list of half edges gone out from v Each half edge h = (eV, lF... Then set endpoint of respective inverse half edges is v0 3 Delete half edges from position i − 1 to i + 1 of v1 and their inverse half edges 4 Delete vertex v1 and its related data 6 6 Computer Graphics Computer Graphics Fig 6 Edge collapse Flip operation mentioned above is shown in Figure 7 The algorithm is applied to the edge which does not satisfy the empty circle property of Delaunay triangulation... the integral sign denotes the collection of all points Approach to Representation Approach to Representation of Type-2 Fuzzy Sets using Computational Methods of Computer Graphics of Type-2 Fuzzy Sets Using Computational Methods of Computer Graphics 7 7 x ∈ U with associated membership function μ F ( x ) When U is discrete, F is re-written as F = ∑U μ F ( x )/x, in which the summation sign denotes the... uzzy set, denoted A, is characterized by a type-2 membership function μ A ( x, u) where x ∈ X and u ∈ Jx ⊆ [0, 1], i.e., ˜ ˜ A = {(( x, u), μ A ( x, u))|∀ x ∈ X, ∀u ∈ Jx ⊆ [0, 1]} ˜ (9) 8 8 Computer Graphics Computer Graphics or ˜ A= x∈X u ∈ Jx μ A ( x, u))/( x, u), Jx ⊆ [0, 1] ˜ (10) in which 0 ≤ μ A ( x, u) ≤ 1 ˜ At each value of x, say x = x , the 2D plane whose axes are u and μ A ( x , u) is called... A are two type-1 membership function and bounds of FOU Approach to Representation Approach to Representation of Type-2 Fuzzy Sets using Computational Methods of Computer Graphics of Type-2 Fuzzy Sets Using Computational Methods of Computer Graphics 9 9 4 Approximate representation of type-2 fuzzy sets Extending the concept of interval type-2 sets of upper MF and lower MF, we define a membership grade... exists a type-2 fuzzy set with membership grade is a TIN TA , ˜ ˜ ˜ ˜ ˜ denoted A T , so that A T is -approximation set of A, i.e, μ A ( x, u) − μ AT ( x, u) < , ∀( x, u) ∈ D ˜ ˜ (21) 10 10 Computer Graphics Computer Graphics ˜ Proof If A has membership grade consisting a set of patches of continuous linear surfaces (example of its membership grades are made by only using triangular and trapezoid ˜ membership... M TINs ST1 , ST2 , , STM and S∗ into only one TIN ST T Approach to Representation Approach to Representation of Type-2 Fuzzy Sets using Computational Methods of Computer Graphics of Type-2 Fuzzy Sets Using Computational Methods of Computer Graphics 11 11 Definition 4.4 A base-line of a TIN representing a type-2 fuzzy set is a polyline vi (i = 1, , N ) satisfying vi u = 0 and vi vi+1 is a edge of triangle . that computer graphics has begun when Dr. Sutherland invented sketch pad system in 1963. Computer graphics has been developed with the help of computer power, and therefore the history of computer. past computer was expensive, large and slow; now it has become inexpensive, small and fast so many people are using computers all over the world. With the development of computers, computer graphics. companies, and many useful tools of computer graphics have been developed. As mentioned above, computer graphics has been developed with the development of computer, with modeling and rendering