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University Microfilms International A Bell & Howell Information Company 300 North Zeeb Road, Ann Arbor, Ml 48106-1346 USA 313/761-4700 800/521-0600 Order Number 8913622 A physically-based simulation approach to three-dimensional computer animation Caldwell, Craig Bemreuter, Ph.D. The Ohio State University,1989 UMI 300 N. Zeeb Rd. Ann Arbor, MI 48106 A PHYSICALLY-BASED SIMULATION APPROACH TO THREE-DIMENSIONAL COMPUTER ANIMATION DISSERTATION Presented in Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the Graduate School of the Ohio State University By Craig Bernreuter Caldwell, B.A., M.F.A. ***** The Ohio State University 1989 Dissertation Committee: Approved by Thomas E. Linehan "7 Charles A. Csuri Advisor Richard E . Parent Department of Art Education ACKNOWLEDGEMENTS I would like to express my sincere appreciation to Dr. Thomas E. Linehan for his guidance and insight throughout the research. I am indebted to him for his patience and encourage­ ment throughout this process. I am also deeply grateful to the the other members of my committee, Professors Charles A. Csuri and Rick E. Parent, for their invaluable suggestions and com­ ments . None of this would be possible without the dedication and perseverence of Charles A. Csuri in starting and developing this graduate specialization with the considerable efforts of Thomas E. Linehan. Without both of them The Advanced Computing Center for the Arts & Design would not exist. Gratitude is expressed to all the special people that have made up the Advanced Computing Center for the Arts & Design Team. I acknowledge the considerable assistance provided by John Chadwick, Dave Haumann, Ruedy Leeman, Michael Girard, Brian Guenter, Ron Piotrowski, and Mark Jansen. To my wife, Amy, I have no sufficient way of thanking her for her unshakable faith in me and her willingness to endure with me the vicissitudes of my endeavors. To my children, Ryan and Joanna, I can only hope that now I can make up for the years of growing up they did while I was away, and thank them for their understanding of why I had to do it. ii VITA October 6, 1950...... Born - Chicago, Illinois 1972..................... B.A., Florida Southern College, Lakeland, Florida 1974 ......... ............ M.F.A., University of Florida, Gainesville, Florida 1974-1976................ Instructor, Columbus College of Art and Design, Columbus, Ohio 1976- Present............ Associate Professor, School of Art and Design, Northern Arizona University, Flagstaff, Arizona PUBLICATIONS Caldwell, C. (1989). "Looking In". In G. de Valois (Producer/Director), Computer Dreams. [Video Tape]. Hollywood, CA: Digital Visions. Caldwell, C. (1989). "Looking In". In M. Kusahara (Producer/Director), COMPUTER GRAPHICS ANTHOLOGY. [Lazer Disk] Tokyo: AMAYAKAN. Caldwell, C. (1988) . "Collaboration," ACM SIGGRAPH '88 Tu­ torial Notes, Educators Workshop. Caldwell, C. (1988) . "Interaction Between Computer Science and Art in Computer Graphics," National Computer Graphic Association '88 Conference Proceedings, Volume III. pp. 653-663. Caldwell, C. (1987). "Overlapping Images and Ideas," IEEE Computer Graphics and Applications, l_f (8) , pp. 3-6. Caldwell, C. (1987). Edited by B. E. Brown in "SIGGRAPH '87 Technical Slide Set," Computer Graphics, 21, (5), p. 289. iii Caldwell, C. (1987). Edited by J. P. Culver and B. E. Brown in "SIGGRAPH ' 87 Art Show Slide Set," Computer Graphics, 21, (5), p. 290. Caldwell, C. (1987). Visual Works, PIXEL, 56, (5), pp. 38-39. Caldwell, C. (1987). Electronic Musician maga­ zine. May 1987, Vol. 3, No. 5. Caldwell, C. (1987). Cover of PIXEL magazine. (Japanese Computer Graphics Magazine) April 1987, No. 55. Caldwell, C. (1985). Computer Graphic Concepts and Tech­ niques for Artists and Designers. National Computer Graphic Association '85 Conference Proceedings, Volume I, pp. 393-413. Wagner, P. and Caldwell, C. (1984). Digital Portfolio (Visual Work by Caldwell) Computer Graphics World, 7, (9), 62-63. Caldwell, C. (1984). First Annual Computer Art Competi­ tion, Popular Computing magazine. September, 1984. (Work selected for reproduction in Special Graphics issue) p. 27. FIELDS OF STUDY Major Field: Computer Graphics and Animation (Department of Art Education) Studies in Computer Graphics and Animation. Professors Thomas E. Linehan, Charles Csuri, J. Christian Wedge. TABLE OF CONTENTS ACKNOWLEDGEMENTS...................................... ii VITA.................................................. iii LIST OF FIGURES....................................... viii CHAPTER I. INTRODUCTION.................................... 1 1.1 Importance of Simulation as Animation 2 1.2 Purpose of Study.......................... 4 1.3 Overview of Study................. 7 II. METHODOLOGY..................................... 10 2.1 Inception of the Problem................. 12 2.2 Statement of the Problem................. 13 2.3 Criteria for Assessing the Model......... 14 2.3.1 Fidelity...................... 15 2.3.2 Utility............................. 15 2.4 Delimitation.............................. 16 2.5 Basic Assumptions......................... 17 2.6 Definitions............................... 18 III. REVIEW OF LITERATURE - ART, ANIMATION, AND SIMULATION........................ 23 3.1 Traditional Art Media.................... 24 3.2 Beginnings of animation............ 28 3.3 Animation - Early aesthetic directions.... 30 3.4 Media Artifacts......................... 34 3.4.1 Media Transformations.............. 35 3.5 Mimetic Tradition in Art................. 37 3.6 Animation - Timing........................ 39 3.6.1 Principles of Animation............ 41 3.7 Rotoscoping..................... 48 3.8 Animation - Computer...................... 53 3.8.1 Computer Motion - Applications 56 3.8.2 Computer Animation - 2D beginnings.. 57 3.8.3 Computer Animation - System Hierarchy Levels................ 58 3.8.3.1 Guiding Level.............. 59 v 3.8.3.2 Procedural Level........... 64 3.8.3.3 Task or Goal-Directed Level................. 66 3.8.3.4 Synergic Control........... 68 3.8.4 Computer Animation - Production Process.............. 70 3.9 Simulation................................ 72 3.9.1 Simulation Applications............ 73 3.9.2 Simulation Methods.......... 74 3. 9.2.1 Robust...................... 75 3.9.2.2 Stochastic.................. 76 3. 9.2.2.1 Ad-Hoc.............. 76 3.9.2.3 Deterministic versus Non-Deterministic Simulations.. 78 3.9.3 Simulation as Animation. 79 3.10 Physics - Mechanics...................... 82 3.10.1 Laws of Motion........... 83 3.10.2 Kinematics......................... 83 3.10.2.1 Forward Kinematics....... 85 3.10.2.2 Inverse Kinematics..... 86 3.10.3 Dynamics ..................... 88 3.10.3.1 Forward Dynamics......... 89 3.10.3.2 Inverse Dynamics......... 89 3.10.3.3 Dynamic Analysis......... 90 3.11 Simulation of Aesthetic Criteria.,....... 91 3.11.1 Story Simulation................... 95 IV. REVIEW OF INTERDISCIPLINARY FACTORS AND SYSTEMS........................... 110 4.1 Abstractions............................. 113 4.2 Behavior - Physical....................... 116 4.2.1 Behavior of Flexible Surfaces....... 117 4.2.1.1 Flexible Objects - Constrained Surfaces...... 117 4.2.1.2 Flexible Surface - Facial Animation.......... 122 4.2.1.3 Deformation................. 126 4.2.2 Articulated Structures............. 128 4.2.2.1 Figurative Motion.......... 128 4.2.2.2 Generative Modeling........ 137 4.2.2.3 Constraints................. 140 4.2.3 Particle Systems................... 144 4.3 Behavior - Environmental.................. 146 4.3.1 Object Oriented Programming....... 147 4.3.2 Self-Scripting..................... 149 4.3.2.1 Behavior Simulation - Flocking Behavior......... 150 4.4 Simulation/Animation Hybrid................ 152 V. THE MODEL....................................... 162 vi 5.1 Geometric Primitives...................... 165 5.2 Mechanical Attributes..................... 167 5.3 Functional Procedures................... 172 5.4 Behavioral