Human Motion Creation through Sketching 2D Trajectories of Joints

基於二維關節軌跡繪製之人體動畫合成法

盧奕丞(I-Chen Lue)

指導教授 ： 楊熙年

國立清華大學/電機資訊學院/資訊工程學系/碩士(2008年)

摘要

在本篇論文中，我們提出了一個以繪製人體末端關節在空間中運動的二維軌跡來產生三維人體動作的方法。在傳統的動畫製作上，美術人員欲繪製較複雜的人體動作時，常會先繪出幾個重要的關節運動的軌跡，再根據這些軌跡去完成整段動作。我們基於此種做法，並將其推展至三維空間的人體動作，藉由繪製腹部、頭部、左右手腕、左右腳跟等六個關節點在空間中運動的軌跡投影至側面的二維曲線，經過反式運動學（Inverse Kinematics）的計算，便可產生三維空間的人體動作。為使關節運動形成的軌跡更為平順，我們採用了B-Spline做為軌跡曲線的表現工具。我們並提出了一個將經過初步反式運動學計算出的動作資料做最佳化的方法，讓最後的成品動作有更佳的品質。

關鍵字

人體動畫 ； 關節軌跡 ； 人體動畫合成

並列摘要

In this thesis, we present a novel three-dimensional human motion synthesis method by sketching two-dimensional trajectories of end joints. According to conventional 2D animation work, before an artist draws a complicated human motion, he usually first sketches trajectories of some important joints and then completes the desired motion based on these trajectories. In this study we extended this approach to three-dimensional human motion synthesis. By sketching the projected trajectories of root, head, left wrist, right wrist, left ankle and right ankle to a side plan, we propose an inverse- kinematics-based algorithm for synthesizing three-dimensional human motions. Moreover, in order to smooth the trajectories of joints, we use b-spline to represent trajectory curves. We also present an optimization method to improve the quality of synthesizes motion. Finally, several examples are given to demonstrate the effectiveness of the proposed method.

並列關鍵字

human motion ； trajectories of joints ； human motion creation

參考文獻

[1]Charles Rose, Bobby Bodenheimer, and Michael F. Cohen, “Verbs and Adverbs: Multidimensional Interpolation using Radial Basis Functions” . In IEEE Journal of Computer Graphics and Applications, 1998.

[2]Jehee Lee and Sung Yong Shin, “A Hierarchical Approach to Interaction Motion Editing for Human-like Figures” . In Computer Graphics(Siggraph’99 Proceedings), page 39-48, 1999.

[3]Zoran Popovi´c and Andrew Witkin, “Physically Based Motion Transformation”, SIGGRAPH 1999 Conference Proceedings.

[6]Vincent Bonnafous, Eric Menou, Jean-Pierre Jessel, and Renfe Caubet. “Cooperative and Concurrent Blending Motion Generators” .In International Conference in Central Europe on Computer Graphics, Visualization and Computer Vision(WSCG’2001), 2001.

[13]Michael Gleicher. “Retargeting Motion to New Characters” .In Computer Graphics (Siggraph ’98 Proceedings), pages 33-42, 1998.