Virtual object manipulation using dynamically selected constraints with real-time collision detection

A method is proposed to help a user manipulate an object in a virtual environment. The method does not give special properties to the object in advance, and does not use special hardware. Instead, it uses only visual constraints among object features that are dynamically selected while the user manipulates the object. It uses face-to-face, edge-to-face, and vertex-to-face constraints; therefore, it provides a natural and intuitive environment for virtual object manipulation that replicates the task in a real environment. The constraint is transferred with a smooth motion. Experimental results show the effectiveness of this method in providing the user with a natural impression of motion in a virtual environment equipped with 3-D/6-D input devices and a conventional graphic workstation to finish all procedures within the cycle time of the human perceptual processor for objects with complicated shapes.