Purdue University Purdue e-Pubs Department of Computer Graphics Technology Department of Computer Graphics Technology Degree Theses 4-12-2012 Sketching 3D Animation Innfarn Yoo [email protected] Follow this and additional works at: http://docs.lib.purdue.edu/cgttheses Part of the Other Computer Engineering Commons Yoo, Innfarn, "Sketching 3D Animation" (2012). Department of Computer Graphics Technology Degree Theses. Paper 25. http://docs.lib.purdue.edu/cgttheses/25 This document has been made available through Purdue e-Pubs, a service of the Purdue University Libraries. Please contact [email protected] for additional information. Graduate School ETD Form 9 (Revised 12/07) PURDUE UNIVERSITY GRADUATE SCHOOL Thesis/Dissertation Acceptance This is to certify that the thesis/dissertation prepared By Innfarn Yoo Entitled Sketching 3D Animation Master of Science For the degree of Is approved by the final examining committee: Bedrich Benes Chair Nicoletta Adamo-Villani Raymond P. Hassan To the best of my knowledge and as understood by the student in the Research Integrity and Copyright Disclaimer (Graduate School Form 20), this thesis/dissertation adheres to the provisions of Purdue University’s “Policy on Integrity in Research” and the use of copyrighted material. Approved by Major Professor(s): ____________________________________Bedrich Benes ____________________________________ Approved by: Bedrich Benes 04/12/2012 Head of the Graduate Program Date Graduate School Form 20 (Revised 9/10) PURDUE UNIVERSITY GRADUATE SCHOOL Research Integrity and Copyright Disclaimer Title of Thesis/Dissertation: Sketching 3D Animation For the degree of MasterChoose ofyour Science degree I certify that in the preparation of this thesis, I have observed the provisions of Purdue University Executive Memorandum No. C-22, September 6, 1991, Policy on Integrity in Research.* Further, I certify that this work is free of plagiarism and all materials appearing in this thesis/dissertation have been properly quoted and attributed. I certify that all copyrighted material incorporated into this thesis/dissertation is in compliance with the United States’ copyright law and that I have received written permission from the copyright owners for my use of their work, which is beyond the scope of the law. I agree to indemnify and save harmless Purdue University from any and all claims that may be asserted or that may arise from any copyright violation. Innfarn Yoo ______________________________________ Printed Name and Signature of Candidate 04/12/2012 ______________________________________ Date (month/day/year) *Located at http://www.purdue.edu/policies/pages/teach_res_outreach/c_22.html SKETCHING 3D ANIMATION A Thesis Submitted to the Faculty of Purdue University by Innfarn Yoo In Partial Fulfillment of the Requirements for the Degree of Master of Science May 2012 Purdue University West Lafayette, Indiana ii ACKNOWLEDGMENTS I would like to express my appreciation for Prof. Bedˇrich Beneˇs,my advisor. He inspired me to start this project, suggested many ideas and algorithms, and gave our research team invaluable insights during the whole process. Juraj Vanek initiated this project with me and developed several parts of the system, especially the beautiful pose matching. Also, we shared and discussed many ideas and motivated each other. Prof. Nicoletta Adamo-Villani provided hand-made animations, sketches, and several solutions as a professional animator. Prof. Raymond P Hassan gave me advice, which helped me improve this project. Esteban Garcia taught me professional sketchers' behaviors, and important conditions for sketches. Michel Abdul Massih Said made grammatical corrections to this thesis and suggested improvements. John Yamich also helped me with the grammatical structure of the text. Lastly, Carnegie Mellon University shared the huge motion capture database that we used in this project. iii TABLE OF CONTENTS Page LIST OF TABLES :::::::::::::::::::::::::::::::: v LIST OF FIGURES ::::::::::::::::::::::::::::::: vi ABSTRACT ::::::::::::::::::::::::::::::::::: vii CHAPTER 1. INTRODUCTION :::::::::::::::::::::::: 1 1.1 Scope :::::::::::::::::::::::::::::::::: 3 1.2 Significance ::::::::::::::::::::::::::::::: 5 1.3 Research Questions ::::::::::::::::::::::::::: 5 1.4 Assumptions ::::::::::::::::::::::::::::::: 5 1.5 Limitations ::::::::::::::::::::::::::::::: 6 1.6 Delimitations :::::::::::::::::::::::::::::: 6 1.7 Definitions :::::::::::::::::::::::::::::::: 6 1.8 Acronyms :::::::::::::::::::::::::::::::: 8 1.9 Summary :::::::::::::::::::::::::::::::: 8 CHAPTER 2. REVIEW OF RELEVANT LITERATURE :::::::::: 9 2.1 Sketch-Based Modeling ::::::::::::::::::::::::: 9 2.2 Sketch-Based Animation :::::::::::::::::::::::: 10 2.3 Sketch-Based Mesh Modeling and Their Animation ::::::::: 14 2.4 Motion Retargeting ::::::::::::::::::::::::::: 15 2.5 Summary :::::::::::::::::::::::::::::::: 16 CHAPTER 3. METHOD :::::::::::::::::::::::::::: 17 3.1 Overview ::::::::::::::::::::::::::::::::: 18 3.2 Motion Databases and Pre-processing ::::::::::::::::: 19 3.2.1 Motion Sequence Database ::::::::::::::::::: 20 3.2.2 Motion Snapshot Database ::::::::::::::::::: 20 3.3 Stroke-Based Skeleton Extraction ::::::::::::::::::: 22 3.4 Matching :::::::::::::::::::::::::::::::: 24 3.4.1 Pose Matching ::::::::::::::::::::::::: 24 3.4.2 Curve Matching ::::::::::::::::::::::::: 25 3.4.2.1 Comparing Joint Trajectory ::::::::::::: 26 3.4.2.2 Comparing Joint Rotation :::::::::::::: 27 3.4.3 Matching Result Calculation :::::::::::::::::: 27 3.5 Animation Merging ::::::::::::::::::::::::::: 28 3.6 Graphical User Interfaces :::::::::::::::::::::::: 29 iv Page 3.7 Summary :::::::::::::::::::::::::::::::: 30 CHAPTER 4. IMPLEMENTATION :::::::::::::::::::::: 31 4.1 Pre-processing :::::::::::::::::::::::::::::: 31 4.2 System and Algorithms ::::::::::::::::::::::::: 33 4.3 Summary :::::::::::::::::::::::::::::::: 35 CHAPTER 5. RESULTS :::::::::::::::::::::::::::: 36 5.1 Comparison of Discrete-time and Angle-difference Resampling ::: 36 5.2 Pose Matching Results ::::::::::::::::::::::::: 37 5.3 Curve Matching Results :::::::::::::::::::::::: 39 5.4 Summary :::::::::::::::::::::::::::::::: 40 CHAPTER 6. CONCLUSION :::::::::::::::::::::::::: 42 6.1 Summary and Conclusion ::::::::::::::::::::::: 42 6.2 Future Work ::::::::::::::::::::::::::::::: 42 LIST OF REFERENCES :::::::::::::::::::::::::::: 44 v LIST OF TABLES Table Page 4.1 Joint Constants ::::::::::::::::::::::::::::::: 33 5.1 Similarity of Snapshot Database Resampling Methods :::::::::: 36 5.2 Pose Matching Performance :::::::::::::::::::::::: 40 vi LIST OF FIGURES Figure Page 3.1 The overview of processes ::::::::::::::::::::::::: 18 3.2 Standard skeleton structure :::::::::::::::::::::::: 19 3.3 Examples of four skeleton types. More than 40 different types of skeletons exist in the actual database. :::::::::::::::::::::::: 20 3.4 Examples of the snapshot database. :::::::::::::::::::: 21 3.5 Comparisons between the discrete-time resampling and angular-difference resampling. ::::::::::::::::::::::::::::::::: 22 3.6 Examples of the stroke-based skeleton extraction method. ::::::: 23 3.7 First three iterations of adaptive pose matching. ::::::::::::: 24 3.8 Packing bits ::::::::::::::::::::::::::::::::: 26 3.9 Combining two or more pose matching results :::::::::::::: 27 3.10 Transition and interpolation region :::::::::::::::::::: 28 3.11 Graphical user interfaces. ::::::::::::::::::::::::: 29 5.1 Pose matching test. (a) shows 1 - 5 % random jittering, and (b) describes 1 - 5 % jittering with 7.5 % hands and toes jittering. :::::::::: 37 5.2 Skeleton extraction results; the left column represents the original strokes, the middle column depicts the extracted skeletons, and the last column shows the found motion sequence. ::::::::::::::::::::: 38 5.3 Skeleton strokes and snapshot matching result. :::::::::::::: 39 5.4 The comparisons of pose matching and combined curve matching. First and second column represent original sketch and pose matching results. And third and fourth column describe the joint trajectory and combined curve matching results. ::::::::::::::::::::::::::: 40 5.5 Characteristics of curve matching algorithm: (a) shows similar curve com- parisons, (b) depicts partial curve comparisons, (c) represents scale-insensitive curve comparison, and (d) shows different curve comparisons. ::::: 41 vii ABSTRACT Yoo, Innfarn M.S., Purdue University, May 2012. Sketching 3D Animation . Major Professor: Bedˇrich Beneˇs. This thesis presents a method for creating natural 3D animation based on sketches. Our method provides novice and professional sketchers an easy, fast, and intuitive way to create three dimensional animations by drawing sketches, enhanced by strokes, and joint trajectory or rotation curves. It also allows searching massive databases of 3D animation as an application for motion capture system and major animation software. We extract 2D skeletons from strokes and find similar motion sequences by comparing all the important pre-generated key poses in database. To give the system more hints, users can draw joint trajectory and rotations curves that are similar to traditional motion sketches. The curves will be compared with the motion sequences that are found. The system supports graphical interfaces that are able to select the motion sequence candidates, to allow for changes in the range of the motion sequence, and to merge the final animation. The proposed system gives a solution for creating natural 3D motions from simple 2D sketches. 1 CHAPTER 1.