C1PA 2003 XIX 1 ' 1 international Symposium, 30 September - 04 October, 2003, Antalya, Turkey 
260 
The calculated contours can be interpolated in order to achieve 
smooth closed curves. This is possible due to the direct transfer 
of these data sets to two and half axes milling machines. 
On the basis of these contours the triangulation and 
reconstruction process (loannides) can begin. The triangulation 
and reconstruction can be achieved using the Voronoi and 
Delonoy methods in 2D form at the beginning and later in 3D 
form (Delaunauy B. and G.F. Voronoi). 
The calculated contours procedure will be the volume oriented 
model as well as the tetraeder form. Furthermore in specific 
cases, free form surfaces can be calculated and presented in 
standard data interchange formats. 
Figure 3. Half of the model as a Freeform data structure 
Figure 4. The triangulated structure of a part of the object 
3.4 The Reconstruction Process and Generation of 
Surfaces 
The accurate digitization of sculptured surfaces can result in a 
very high amount of data, possibly even in the order of Giga 
Bytes of computer memory (Levoy 2000). The computation 
performance of existing CAD/CAM-systems is insufficient for 
the processing of this data. 
A data reduction is required to solve this problem. A data 
reduction of more than 80% can be achieved depending on the 
complexity of the work piece by computing spline -curves and 
-surfaces using the following algorithms: 
bicubic Bezier, 
polynomial representation (Coons), 
. - B-Spline, 
Non Uniform Rational B-Splines, (NURBS) repre 
sentation. 
These computer internal representations of the digitized object 
are obtained by the Advanced Surface Modeling Software 
Package (ASMOS) developed at the University of Stuttgart and 
the Higher Technical Institute in Nicosia, Cyprus. 
Figure 5. The shaded and freeform structure of the object joined 
together. 
The output of ASMOS can be processed by all 2D / 3D-oriented 
CAD/CAM-systems. For the data transfer within CAD -systems 
the following interfaces are available: 
• IGES, 
• VDAFS and 
• STEP. 
4. VISUALIZATION AND ANIMATION 
4.1 Visualization Introduction 
Archaeologists try to document their findings in the best way 
possible. They use varying techniques, from aerial photographs, 
Photogrammetry, GPS, to simple hand surveys. They log their 
findings with precision and try to reconstruct very accurately 
what was there thousands of years ago. Visualizations of their 
hypothesis of how things were help them verify and easily 
communicate to other researchers the reconstruction they have 
put together. There are many different visualization methods