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Motion capture (Mo-cap for short) is the process of recording the movement of objects or people. It is used in military, entertainment, sports, medical applications, and for validation of computer vision〔David Noonan, Peter Mountney, Daniel Elson, Ara Darzi and Guang-Zhong Yang. A Stereoscopic Fibroscope for Camera Motion and 3D Depth Recovery During Minimally Invasive Surgery. In proc ICRA 2009 , pp. 4463-4468. In motion capture sessions, movements of one or more actors are sampled many times per second. Whereas early techniques used images from multiple cameras to calculate 3D positions, often the purpose of motion capture is to record only the movements of the actor, not his or her visual appearance. This ''animation data'' is mapped to a 3D model so that the model performs the same actions as the actor. This process may be contrasted to the older technique of rotoscope, such as the Ralph Bakshi 1978 ''The Lord of the Rings'' and 1981 ''American Pop'' animated films where the motion of an actor was filmed, then the film used as a guide for the frame-by-frame motion of a hand-drawn animated character. Camera movements can also be motion captured so that a virtual camera in the scene will pan, tilt, or dolly around the stage driven by a camera operator while the actor is performing, and the motion capture system can capture the camera and props as well as the actor's performance. This allows the computer-generated characters, images and sets to have the same perspective as the video images from the camera. A computer processes the data and displays the movements of the actor, providing the desired camera positions in terms of objects in the set. Retroactively obtaining camera movement data from the captured footage is known as ''match moving'' or ''camera tracking''. ==Advantages== Motion capture offers several advantages over traditional computer animation of a 3D model: * More rapid, even real time results can be obtained. In entertainment applications this can reduce the costs of keyframe-based animation. The Hand Over technique is an example of this. * The amount of work does not vary with the complexity or length of the performance to the same degree as when using traditional techniques. This allows many tests to be done with different styles or deliveries, giving a different personality only limited by the talent of the actor. * Complex movement and realistic physical interactions such as secondary motions, weight and exchange of forces can be easily recreated in a physically accurate manner. * The amount of animation data that can be produced within a given time is extremely large when compared to traditional animation techniques. This contributes to both cost effectiveness and meeting production deadlines. *Potential for free software and third party solutions reducing its costs. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Motion capture」の詳細全文を読む スポンサード リンク
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