1 Interactive Editing of Human Locomotion on an Arbitrary Motion Path Yejin Kim and Myunggyu Kim Electronics and Telecommunications Research Institute 218 Gajeong-ro, Yuseong-gu, Daejeon, 305-700, Republic of Korea yejink@etri.re.kr, mgkim@etri.re.kr ABSTRACT This paper introduces an interactive editing system for a human locomotion which considers quantitative and qualitative aspects of motion and suggests two editing processes to generate a convincing output animation. Based on a minimal set of sample locomotion clips containing only straight motion paths, an animator controls a character's motion path and stylistic posture changes during the editing processes. During quantitative editing, our system generates a locomotion sequence following a curved motion path specified by an animator. Key-times of foot strikes are detected automatically for each sample in order to specify motion cycles which are appended and interpolated for a continuous and smooth output sequence. Additionally, the system provides a timing interface in order to specify temporal points of transition from one sample to another. In addition, qualitative editing is supported by incorporating a procedural system which provides a set of controllable parameters to facilitate posture editing. Initiated with a sample clip, this process produces motion that differs stylistically from any in the sample set, yet preserves the high quality of data- driven motion. A post-processing step enforces foot constraints, and modifies the character's posture to account for important physical forces acting on the body while navigating a curved path. As shown in the experimental results, our system provides intuitive interfaces for editing motion capture clips and generates realistic locomotion at interactive speed. KEYWORDS Character Animation, Locomotion, Interactive Editing, Motion Cycle, Motion Capture. 1 INTRODUCTION The recent popularity of motion capture technology [1] makes it possible to produce realistic animation for human locomotion, embedding all important stylistic features as well as the physical essence captured live from a performer's locomotion. Nevertheless, it is difficult to reuse a recorded locomotion clip for editing since such data is specialized to a particular gait and condition at the time of capture. Moreover, the nature of the locomotion's continuity and physical constraints preserved in motion capture data can be easily disrupted if one edits the high degrees of freedom (DOFs) in an articulated model without a careful selection of editing techniques. Therefore, an effective editing tool should provide not only for a variety of different styles, but also maintain the original details and high quality of locomotion in the output, considering both time and space constraints. The various motion properties can be divided into two main categories at play during the editing process: quantitative and qualitative. For animation of human locomotion, the quantitative aspects consist of easily measured, meaningful numeric descriptors of the locomotion. For instance, speed and orientation are two common parameters that can be measured and manipulated to direct the character's current position to a desired point in the virtual environment [2, 3, 4]. On the other hand, the qualitative aspects represent the abstract description of locomotion that is difficult to quantify and can be perceived most accurately only by human observation. In fact, there is no ISBN: 978-1-941968-02-4 ©2014 SDIWC Proceedings of the International Conference on Computer Graphics, Multimedia and Image Processing, Kuala Lumpur, Malaysia, 2014