A surface digitizing tool has a film of micro-sensor elements, with each micro-sensor element related in a network affected by a shape of the film. The film is flexible to conform to a shape of a selected surface of an object. A processing unit receives signals from the micro-sensor elements of the network. The processing unit has a model generator producing a model of the selected surface of the object from the signals of the network of resistive elements. A positioning frame aligns a position and orientation of a drilling tool with respect to a bone element.