INFORMATION TO USERS This manuscript has been reproduced from the microfilm master. UMI films the text directly firom the original or copy submitted. Thus, some thesis and dissertation copies are in typewriter fiice, while others may be fi*om any type of computer printer. The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleedthrough, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send UMI a complete manuscript and there are missing pages, these will be noted. Also, if unauthorized copyright material had to be removed, a note will indicate the deletion. Oversize materials (e.g., nuq)s, drawings, charts) are reproduced by sectioning the original, beginning at the upper 1^-hand comer and continuing fi’om left to right in equal sections with small overlaps. Each original is also photographed in one exposure and is included in reduced form at the back of the book. Photographs included in the original manuscript have been reproduced xerographically in this copy. Higher quality 6” x 9” black and white photographic prints are available for any photographs or illustrations appearing in this copy fi>r an additional charge. Contact UMI directly to order. UMI A Bell & Howell Infimnation Company 300 North Zeeb Road, Ann Arbor MI 48106-1346 USA 313/761-4700 800/521-0600 Encapsulated Models: Procedural Representations for 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 Stephen Forrest May, B.S., M.S. ***** The Ohio State University 1998 Dissertation Committee: Approved by Prof. Wayne E. Carlson, Adviser Prof. Richard E. Parent Adviser Prof. Neelam Soundarajan Department of Computer and Prof. Charles A. Csuri Information Science UMI Number: 9822347 UMI Microfonn 9822347 Copyright 1998, by UMI Company. All rights reserved. This microform edition is protected against unauthorized copying under Title 17, United States Code. UMI 300 North Zeeb Road Ann Arbor, MI 48103 © Copyright by Stephen Forrest May 1998 ABSTRACT This research defines the term “encapsulated model” or “emodel.” An encapsulated model is an animated object containing an integrated set of dynamic attributes — e.g., shape, motion, materials (surface properties), light sources, cameras, user interfaces, sound — represented by a procedural data format (i.e., a program written in a procedural anima­ tion language). A set of properties that characterizes encapsulated models is presented. From these properties, a set of requirements for an appropriate procedural animation language is de­ rived. Chief among these requirements is the requirement for mechanisms that permit interactive manipulation of the procedural specification of an emodel. To satisfy this re­ quirement, a new programming language mechanism called “articulation functions” (or “afuncs”) is proposed. To demonstrate the practical application of the concepts in this research, a prototype procedural animation language, called AL, was developed. The AL language incorporates the best features of previous animation languages and includes several new features in­ cluding the articulation function mechanism. The AL software environment includes an AL language interpreter and graphical user interface tools for interactive manipulation of encapsulated models via articulation functions. 11 The results of this research are given in the form of working examples of encapsulated models that can be manipulated in real-time using current workstation technology. These examples demonstrate that articulation functions are a more powerful and general mech­ anism for interactive animation and manipulation than previously developed mechanisms. Further, these examples illustrate the benefits of encapsulated models over existing, static data formats. In particular, emodels are shown as an enabling technology for the (possibly commercial) exchange of models that are parameterized (i.e., reusable), have high-level interactive controls, and have self-contained, integrated components such as animation and modeling. These traits potentially lead to reduced costs in the production of photorealistic computer animation. m To my loving and devoted wife Gwen and my supportive and inspiring parents. Bob and Mary. IV ACKNOWLEDGMENTS This dissertation was possible only through the support and inspiration of many family members, friends, and colleagues. I owe a great deal to so many. These acknowledgment cannot fully express my indebtedness. I would like to thank my adviser Wayne for supporting this research and for being such a great role model — both as a scholar and as a person. I would like to thank Chuck Csuri. It is because I read an article about Chuck and Ohio State in 1984 that I decided that computer graphics was my calling and that Ohio State was where I had to go. Over the years. Chuck has become a very good friend and mentor and has taught me many things including a deep insight into the relationship between science and art. I am in debt to Flip Phillips, Tom Linehan, and the others at CGRG who encouraged me to come to Ohio State. Flip named the “AL” language and inspired me to work in this area after his return to Ohio State from Fixar. Without his insights, this work would not have been possible. I am thankful to Don Stredney who, when I was a very poor grad student, offered me a research assistantship to do “medical brain imaging” which not only allowed me to eat but also introduced me to the ACCAD environment. I would like to thank the other members of my committee — Neelam and Rick. Neelam has been a great adviser and has advised me since I was an undergraduate which makes it at least 10 years. Rick and a number of long since departed graduate students, including Con O’Connell, Hal McMillan, and Mike Fortin, inspired me to continue my graduate work and become a Ph.D. student and taught me how to conduct scholarly activities while playing pool. I would like to thank all of the staff at ACCAD and the CIS department including Aline, Barb, Bob, Chad, Chris, Deanna, Dennis, Donna, Elaine, Elizabeth, Phil, Marty, Midori, Ruedy, Tom, Viki, and especially the three amigos, Pete, Steve and Matt. I would like to thank the graduate students at CIS and ACCAD ^— I learned something from each one of them and many were my students too — Agata, Alison, Andrew S., An­ drew B., Beth, Bill, Brad, Bren, Carol, Cemil, Chitra, Dan, David E., Dave M., Dave R., Derek, Ed, Erika, Ferdi, Gigi, Hae-jeon, Heath, Henry, Janet, Jean, Jim, Joe, John, Karan, Kevin G., Kevin R., Kevin S., Kirk, Lawson, Leslie, Mark, Marla, Meg, Melissa, Miho, Moon, Moose, Muqueem, Nathan, Nathania, Neal, Pete, Paul, Paolo, Raghu, Reddy, Rina, Rhonda, Roberta, Saty, Scott K., Scott G., Sara, Terry, Tim, Todd, Tonya, Torsten, Traci, Yina, and Zil. In particular, I want to thank Lawson Wade for implementing the “alarm clock” emodel and Melissa Kupper for working with me on the “chandelier” emodel. 1 would also like to recognize my dear friend and colleague, Ferdi Scheepers. Ferdi was always there for me as a sounding board for new ideas, to help work out math equations, to implement software, and to coauthor papers. Finally, 1 would like to thank my wife Gwen, my family, and our friends for their unwavering support. In the end, I did it for them. VI VITA February 15, 1968 ..............................................Bom - Sarasota, Florida 1990 ................................................................... B.S. Computer and Information Science The Ohio State University Columbus, Ohio 1991-1992 ...........................................................Graduate Research Associate, ACCAD The Ohio State University Columbus, Ohio 1992 ................................................................... M.S. Computer and Information Science The Ohio State University Columbus, Ohio 1992-present .......................................................Graphics Research Specialist, ACCAD The Ohio State University Columbus, Ohio PUBLICATIONS Ferdi Scheepers, Richard E. Parent, Wayne E. Carlson, and Stephen F. May. Anatomy- based modeling of the human musculature. In Turner Whitted, editor, SIGGRAPH 97 Conference Proceedings, Annual Conference Series. ACM SIGGRAPH, Addison Wesley Publishing Company, August 1997. David Y. Y. Yun, Hong-Mei Chen Garcia, Seong K. Mun, James E. Rogers, Walid Thome, Wayne E. Carlson, Stephen F. May, and Roni Yagel. Three dimensional volume visual­ ization in remote radiation treatment planning. In IS&T/SPIE Symposium on Electronic Imaging Science & Technology Proceedings, volume 2656, January 1996. vu Alan Paeth, Ferdi Scheepers, and Stephen R May. A survey of extended graphics libraries. In Alan Paeth, editor, Graphics Gems V. AP Professional, 1995. Wayne E. Carlson, Roni Yagel, Stephen F. May, Stephen Spencer, Donald L. Stredney, and Charles Bender. Remote diagnosis using volume visualization of satellite transmitted medical data. Ohio Journal Of Science, May 1994. Scott E. Lukas, M. Sholar, Donald L. Stredney, Michael W. Torello, Stephen F. May, and Ferdi Scheepers. Apparent source of EEG sleep spindles and K-Complexes: Correlations with anatomical sites identified using magnetic resonance imaging. In Sleep Research Society, American Sleep Disorders Association APSS 8th Annual Meeting, June 1994. Scott E. Lukas, M. Sholar, Donald L. Stredney,