3D acquisition and modeling of a large plaster of ancient Rome

This paper describes 3D acquisition and modeling of the “Plastico di Roma antica”, a large plaster-of-Paris model of imperial Rome (16x17 meters) created in the last century. Its overall size demands an acquisition approach typical of large structures, but it also is characterized by extremely tiny details typical of small objects: houses are a few centimeters high; their doors, windows, etc. are smaller than 1 centimeter. The approach followed for solving this “contradiction”, generating a huge but precise 3D model by using a special metrology Laser Radar, is described. The procedures for reorienting the huge point clouds obtained after each acquisition step (50-60 millions of points each) in a single reference system thanks to the measurement of fixed redundant references, are reported. A proper splitting of the data set in 2x2 meters sub-areas for allowing data merge and mesh editing is finally shown.