本論文實現即時性人體動作捕捉系統中之人機互動介面與其基於物理模擬的虛擬實境應用。使用者在配戴動作捕捉感測裝置後，人機介面中的虛擬人物即可顯示出使用者當前的姿態，而此人機介面也具有虛擬實境的功能，使用者能以肢體操控虛擬人物並與虛擬實境中的物體互動，也可模擬人體在虛擬實境中受力的反應。人機介面是以電腦繪圖程式介面OpenGL為基礎，描繪虛擬人物的外型及虛擬實境中的場景與物體。虛擬人物的骨架則是使用樹狀的資料結構建立而成，並使用前序搜尋演算法依序繪出骨架姿態並以OpenGL顯示於螢幕中。虛擬實境是以剛體運動學與碰撞偵測等物理學為基礎模擬真實世界的情境。本論文將虛擬人物骨架簡化成由多個剛體所組成，以拘束力演算法模擬關節轉動的方式連接不同剛體，使虛擬人物的骨架模型不會因受力後而散開。當虛擬人物與虛擬實境中的物體發生碰撞時，虛擬人物會模擬碰撞時所發生的物理反應。當碰撞發生後，虛擬人物會繼續依照當前使用者輸入的姿態即時更新當前的動作，讓使用者可繼續地操控虛擬人物。結合虛擬實境的動作捕捉系統可令使用者以生動且饒富趣味的方式體驗虛擬世界的情境。

This thesis presents a real-time human–computer virtual reality interface (HCVRI) for a wearable human motion capture system. By wearing the human motion capture system, a virtual character can mirror the user’s body movement. In addition, the HCVRI has a physics-based virtual reality function. A user can control the virtual character with his motion and interact with objects in the virtual reality. The virtual reality can also simulate the collision between objects and a user. The HCVRI is developed by application programming interface (API) – OpenGL, which is used for drawing the outline of the virtual character and the scene in virtual reality. The virtual character’s skeleton is designed by a tree-model data structure, and a preorder traversal algorithm is used to search a tree and draw the node’s posture in order, and then the result is presented on the screen by OpenGL. The virtual reality simulates the real world phenomenon by using physical simulation including rigid body dynamics and collision detection. In the virtual reality, the virtual character’s skeleton is represented by a composition of rigid bodies. The joint simulation between different rigid bodies is developed by a constraint force algorithm which can bind the skeleton when the virtual character experiences a force on itself in the virtual reality. When a collision is happened, the virtual character will simulate a really physical reflection. After the collision, the virtual character can still trace the user’s motion so that the user can continue to use his motion to control the virtual character. With the human motion capture system and the HCVRI, users can experience the virtual world circumstances with interest and vividness.

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