| 摘要 |
TWO-DIMENSIONAL EMULATION OF THREE-DIMENSIONAL TRACKBALL A technique using a 2-dimensional input controller such as a mouse, a 2-D trackball, a joystick, a touch screen, a touch tablet or a digitizer for rotating an object displayed by a computer controlled video display system in 3-dimensional representation. A user visible reference circle is provided, and a pointer associated with the 2-D input controller is moved by the user relative to the reference circle in a control movement mode. Movement of the pointer within the reference circle produces rotation of the displayed object about arbitrary axes in 3-dimensional space, while movement of the pointer on or outside the reference circle produces rotation about a 3-dimensional axis that is oriented toward the viewer. |
