Self-collision avoidance through keyframe interpolation and optimization-based posture prediction

ii To my grandmother, Margaret Degenhardt, who encouraged her children to attend an institution of higher learning, thereby instilling a desire for knowledge within her family for generations to come iii ACKNOWLEDGMENTS First, I would like to thank my advisor, Professor Karim Abdel-Malek, for providing me with great opportunities in such an interesting field. I would like to thank Kimberly Farrell for her guidance and significant contributions to the implementation of this work. Further thanks to my family, co-workers, and friends, for their support and encouragement. A special thanks to Chloe Metzger, for her help with editing and invaluable moral support. Lastly, I would like to thank the members of my thesis Guadalupe Canahuate, for their time and feedback. iv ABSTRACT Simulating realistic human behavior on a virtual avatar presents a difficult task. Because the simulated environment does not adhere to the same scientific principles that we do in the existent world, the avatar becomes capable of achieving infeasible postures. In an attempt to obtain realistic human simulation, real world constraints are imposed onto the non-sentient being. One such constraint, and the topic of this thesis, is self-collision avoidance. For the purposes of this topic, a posture will be defined solely as a collection of angles formed by each joint on the avatar. The goal of self-collision avoidance is to eliminate the formation of any posture where multiple body parts are attempting to occupy the exact same space. My work necessitates an extension of this definition to also include collision avoidance with objects attached to the body, such as a backpack or armor. In order to prevent these collisions from occurring, I have implemented an effort-based approach for correcting afflicted postures. This technique specifically pertains to postures that are sequenced together with the objective of animating the avatar. As such, the animation's coherence and defining characteristics must be preserved. My approach to this problem is unique in that it strategically blends the concept of keyframe interpolation with an optimization-based strategy for posture prediction. Although there has been considerable work done with methods for keyframe interpolation, there has been minimal progress towards integrating a realistic collision response strategy. Additionally, I will test this optimization-based approach through the use of a complex kinematic human model and investigate the use of the results as input to an existing dynamic motion prediction system. v PUBLIC ABSTRACT The research presented in this thesis provides a …