The following various process methods for tracking objects to the body, including: a step to prepare a three-dimensional model of bodily a process to prepare a three-dimensional model of the subject and bodily the three-dimensional the position of the object in the model, the step of tracking based on the sensor for measuring repeatedly bodily and three-dimensional surface of the subject.以下の諸工程を含む身体に対して対象を追跡するための方法:該身体の三次元モデルを準備する工程;該対象の三次元モデルを準備する工程;および該身体の該三次元モデルにおける該対象の位置を、該身体および該対象の三次元表面を繰返し測定するセンサに基いて追跡する工程。