a gesture refers to a motion of an appendage making contact with the touch screen in other words a gesture corresponds to a motion sequence which begins when the user makes contact with the touch screen by means of an appendage and which ends when he lifts the said appendage in the following description one or several fingers are used as an appendage however it will be apparent to one of ordinary skill in the art that the present invention may be practiced by using other kind of appendages fig1 a 1e illustrate gestures which can be used for interacting with a modelled object displayed by a touch screen device fig1 a represents a pinch and stretch action allowing for example to zoom in or out fig1 b represents a slide gesture with two fingers allowing for example to translate a modeled object fig1 c represents a slide gesture with one finger allowing for example a translation in depth of a modeled object fig1 d represents a gesture allowing rotating a displayed modeled object for that purpose two fingers are placed on the modeled object and the hand is then turned fig1 e represents a gesture allowing copying a modeled object to drag a duplicated version towards a target location and to drop it there for that purpose the touch screen device is adapted so that it implements the method according to the invention fig2 is a flow diagram illustrating a method for copying a modeled object displayed on.