Providing a user interface for three-dimensional (3D) modelling, via an apparatus with a touch surface includes displaying a 3D model of a virtual object having an elementary shape. A virtual mesh is displayed over or aside at least a portion of the virtual object. Regions of the virtual mesh are mapped onto regions located on the touch surface. Select of a type and/or a shape of a modification to be performed on the 3D model of the virtual object is detected together with a force applied by the user on a region of the touch surface. A region of the virtual mesh corresponding to the at least one region of the touch surface is determined. The elementary shape of the virtual object is modified corresponding to the region of the virtual mesh, based upon the user's selection. The modified 3D model of the virtual object is displayed.