Determining and displaying geometric relationship between objects in a computer-implemented graphics system

Method for the modification of three-dimensional objects via an input device allowing only two-dimensional input. The method comprises creating a three-dimensional object, displaying a three-dimensional representation, activating the three-dimensional object, displaying a representation of a three-dimensional coordinate system, selecting one of the axes of the three-dimensional coordinate system assigned to the object, shifting the origin of the assigned coordinate system within a global three-dimensional coordinate system along a line defined by the orientation of the selected axis of the assigned coordinate system within the global three-dimensional coordinate system, computing the three-dimensional object relative to the global coordinate system after shifting according to the displacement of the origin of the assigned coordinate system, and displaying a representation of the shifted three-dimensional object on the computer screen.