1. A method of volume visualisation comprising: providing of volumetric data, the volumetric data having first voxels belonging to a reference surface, entering a user selected distance by means of user interface means comprising a wheel mouse, an amount of rotation of the wheel of the wheel mouse being indicative of the user selected distance, determining of second voxels of the volumetric data having the user selected distance from the reference surface, visualising of the second voxels.