利用圓錐曲線理論發展網路虛擬環境下低成本並易於操作之人機介面

Using Conics Theory to Develop a Low-cost, Easy-to-operate Man Machine Interface for Web-based Virtual Environment

韋立明(Li-Ming Wei)

指導教授 ： 孫天龍

元智大學/工程學院/工業工程與管理學系/碩士(2001年)

摘要

為了更方便的建構包含人物之虛擬環境，一低成本並易於操作之動作擷取方法在先前的研究中被提出（張朝順, 1999）。先前的研究方法主要基於圓錐曲線理論的一重要特性：空間中一已知半徑之平面圓的3D旋轉與位移資訊可由其2D的橢圓投影來獲得。
本研究主要著重於強化先前系統中不足。第一，我們利用Java Media Framework（JMF）將攝影機與本動作追蹤系統作一整合。第二，（張朝順, 1999）的研究中對於相互覆蓋與不完整之投影橢圓無法很有效的從中正確的辨別橢圓邊緣點。本研究中我們建立了四個限制條件，以在連續的影像中正確的粹取出橢圓邊緣點。第三，利用正向運動學原理並配合Quaternion Transform來自動的設置3D虛擬人物模型的動作。最後我們並討論在影像經數位化後發生誤差的情形下本系統的準確性。

關鍵字

動作擷取 ； 圓錐曲線理論 ； 虛擬人物 ； 虛擬環境

並列摘要

To facilitate the development of a human-popularized environment, a low-cost, easy-to-operate motion capture method has been developed in a previous work (Chang, 1999). This method is based on an important property of conics theory: the 3D rotation and translation of a planar circle with known radius could be derived from its 2D elliptic projection.
This work focus on the improvement of several drawbacks suffered by previous system. First, we employ the Java Media Framework (JMF) to integrate the video camera with our motion tracking system. Secondly, (Chang, 1999)’s approach has problems identifying boundary pixels when ellipse are broken or overlapping with each other. In this work, we develop four constraints to correctly extract boundary pixels of ellipses in consecutive images. Thirdly, a forward kinematics approach, together with the quaternion transform technique, is used to automatically specify the pose of the 3D computer graphic model of a virtual human. Finally, we discuss the accuracy evaluation of our motion tracking system under digitalization error.

並列關鍵字

motion capture ； conics theory ； virtual human ； virtual environment

參考文獻

張朝舜，『以單台攝影機配合圓錐曲線理論發展網路3D場景中人物動作擷取技術』，私立元智大學，碩士論文，民國88年6月（1999）。

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