Footprint-based Quadruped Motion Synthesis

Footprints are data structures that specify the positions, orientations, and timing information for the feet of articulated figures. This thesis studies the use of footprints to generate animations of legged animals. After introducing several met hods to generate footprints, we develop an algorithm t hat synt hesizes realistic motions of animals from footprints only. Our method employs a hybrid physically-based/kinematic approach. We first perform a trajectory optimization on an underlying approximation of the animal, in order to determine its overall motion. Soft physical and kinematic constraints employed in the optimization functional ensure that the trajectory's motion is both physically plausible and visually pleasing. By utilizing the optimized trajectory information, the footprint positions, and a variety of animation techniques, we reconstruct the motion of the animal. Our results show that various motions can be synthesized with this approach, including walking, galloping, jumping, pushups, and skating motions. Finallÿ, we summarize our contributions and discuss future directions. I would like to thank my supervisor, Michiel van de Panne, for his excellent supervision and guidance. He developed the underlying concepts on which this work was based, and inspired my creativity with his great brain storming sessions. Thanks, Michiel! Eugene Fiume, who enthusiastically read over my thesis, helped me look at my work from a different perspective, and gave me some ideas to speed up my animation routines. My friend and fellow Mater's student, Ivan Neulander, for allowing me to use his paintstroke rendering system to display my animated creature in ail its hairy glory. The paintstroke primitive in that system made it easy for me to generate images, and the A-buffer implementation in the renderer kept the images crisp and anti-aliased. My friends at DGP and DCS. You have al1 made my experience as a graduate student unforget t able. Thanks for distracting me from the pressures of research. Finaliy, 1 would like to thank my parents, George and Freda, and my brother, Jim. Without their encouragement and support, 1 would not have gotten as far as 1 have in my education and persona1 development. 1 want them to know that 1 appreciate al1 they have ever done for me.