A Human-Computer Interface that comprises a set of sensors, actuators and computer generated controls is characterised in that the controls are projected in three spatial dimensions by a three dimensional display device and are manipulated by means of an operator interacting with them by movements of the operator's body, these movements being detected using the sensor system, where characteristics of a displayed target volume change according to the movement made, and actuators worn on the body, react according to how the body interacts with the computer generated controls.