Resources for making 3d scans of electrically conductive materials? I would like to make a 3d scanner for accurately modeling very small metal parts.

I figured I might be able to take advantage of the fact that metal conducts electricity, and avoid using light. This might be cheaper, easier to make, and wouldn't get thrown off by shiny surfaces. 

Basically, I am imagining an object on a rotating stage, and a movable "feeler" probe. The probe is moved towards the object, and when the probe touches the metal object, a circuit is closed. The distance and angle of the probe and object are then recorded, and used to model a cross section of the object. 

My question is:
Is this technique already being used? If so, where? Is there a name for this technique? What resources should I look at for researching this?
I have heard of similar scanning not using the electrical connecting but using the capacitance of the metal object to detect it. Capacitive Scanning works by detecting a metal object near the prob so the prob doesn't have to touch the object being scanned