Three-Dimensional Scanning Techniques Applied to 3D Modeling of Pottery Finds

At the beginning of 2001, during restoration works at the Santa Maria del Carmine monastery in Siena, we came upon 360 complete pottery pieces, placed over a 14th century brick vault. The excavation has been conducted by archaeologists of the Medieval Archaeology Area of the University's Archaeology and Art History Department (http://medievalarchaeology.unisi.it), supported by the digital recording systems adopted at the LIAAM (Laboratory of Information Technology Applied to Medieval Archaeology).
The VIVID 900 3D scanner of Minolta has been experimented for the first time on the pottery finds mentioned above; the scanning technique consists in acquisition through a laser beam (stripe light) and conversion into 3D surface (including a bitmap texture) by a CCD system. A Pentium 4 PC (1,6 Ghz, 1 Gb RAM, GeoForce2 graphic card) represented the hardware environment.
Our aim has been to create 3D models of a typological sample relating to the ceramic finds of the monastery; for a first rendering of every model we used QuickTime QTVR object technology, allowing user interaction in the final product. This choice has been determined mainly by three factors:
- the native (.vvd) format is not readable by widespread 3D and multimedia applications;
- pottery pieces present often differences in colours/treatments between external and internal surfaces;
- it is almost always impossible to completely acquire internal surfaces of closed forms (jugs, amphoras, etc.);
The complete acquisition, modeling and rendering process can be resumed in four steps:
1. scanning of the pottery piece (using 3D scanner and native software called Poygon Editing Tool);
2. import into a 3D modelling software (Form-Z), reconstruction of missing internal surfaces and export to an animation and rendering software (Electric Image)
3. surface texture adjustment using a bitmap graphics application (Photoshop)
4. texture mapping and movie rendering.