Research On Technology Of Motion Editing And Motion Synthesis

Benefited from the rapid development of information technology, 3D animation is recently becoming a new type of medium after sound, image, video and 3D model. As a main part of 3D animation, character animation plays an important role in movie production and computer games. The appearance of motion capture made character animation more active, and made up the deficiency of traditional key-frame animation. So from the point of view of applications, it is necessary to research on motion capture data in order to produce novel character animations.From the point of view of theory, motion capture data is a new type of information carrier, so it is necessary to research on data capturing, processing, analysis, storing, browsing and transferring. In addition, motion capture data records the motion of a real character, so it is natural that traditional animation techniques such as key-frame, dynamics, kinematics, space-time constraints, and dynamical simulation are closely relative to the processing and analysis of motion capture data. Motion capture data can be thought as time series, signals, patterns, and curves in form, so time series analysis, signal processing, pattern recognition and curve editing techniques can play a great role on motion capture data. The above characteristics determine that the research on motion capture data is a field of multiple subjects.Motion editing and motion synthesis discussed in this thesis are techniques that research how to produce new motion from current available motions. Specifically, we make the following contributions:(1) Motion path editing with multiple level B-Spline.(2) An algorithm is designed to extract key-frame from motion capture data. It is beneficial to motion data compression and browsing, and make a bridge between motion capture and key-frame animation.(3) 3D reconstruction of a character using shape from silhouette technique. From the reconstructed character, skinning is done to make a believable animated character.(4) A motion editing prototype system called Eidolon is developed. In this prototype system, many character animation and motion editing algorithms are implemented.After introducing some backgrounds and the state of art of motion editing and motion synthesis, we introduce some basic operations of motion editing and show implementation results in Eidolon. Chapter 3 describes inverse kinematics, and two real time algorithms: CCD and Jacobian Transpose are discussed in detail. In chapter 4, we introduce the principle of multiple level B-Spline, and motion path editing is achieved with such spline. An algorithm to extract key-frame from motion capture data is introduced in chapter 5. In chapter 6, Shape from Silhouette, a technique from computer vision is used to construct virtual character, and we show you the result of motion retargeting onto the reconstructed model. In chapter 7, we discuss some materials about the design and implementation of our motion editing system-Eidolon. Finally, we conclude this thesis and discuss some directions for future work.