An haptic interface including a knob manipulated by a user, a rotation shaft with a longitudinal axis to which the knob is fixed in rotation, an interaction element with a magneto-rheological fluid in rotation with the shaft, the fluid, a system for generating a magnetic field in the fluid, and a control unit capable of generating orders to the system for generating the magnetic field to modify the magnetic field. The system includes a coil type mechanism generating a variable magnetic field, and a permanent magnet type mechanism generating a permanent magnetic field.