Thanks a lot everybody for all your answers and suggestions!
I thought that maybe I could make some use of microsoft kinect or imilar device to make the 3d map of the object (since getting the data rom simple photos looks incredibly cpu intensive) using some open ource elaboration program like PCL ( http://pointclouds.org/ )

Still I'll be extremely interested if anybody could link me some info bout 3d objects handling in ruby or would simply have some insight to hare on the argument.

Many thanks,
Nicolò