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Title
New perspectives to save cultural heritage
Author
Altan, M. Orhan

CIPA 2003 XIX th International Symposium, 30 September - 04 October, 2003, Antalya, Turkey
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Figure 7 - Segmentation of - the “loggetta” of Sansovina. -
Venice - Italy
Figure 8 - solid model of the external walls of the building
4. SOLID MODELLING
4.1 Modelling of the segmented point cloud
After having finished the segmentation stages of the objects,
it is possible to go on to their modelling.
This kind of elaboration should be carried out manually
portion by portion. Many software packages are available on
the market that offer good performances to
model a point cloud.
A specific modelling program was used to prepare the surface
model that is called Cirrus AC and it is made by Menci
software. This programme, which works in AutoCAD, is able
to build surfaces by choosing point cloud portions. These
surfaces are created using the algorithm for the creation of
the meshes.
The thus segmented model was imported into an AutoCAD
graphic environment and a different layer was assigned to
each of the portions of the object obtained by the
segmentation. The modelling of the various aggregations was
obtained by isolating each portion of the point cloud step by
step.
In this way the modelling was particularly simple and quick.
It was in fact possible to model each part of the model one at
a time.
The result of the modelling can be seen in figure 8.
It is possible to automatically export sections or level curves
from the thus obtained solid model.
Another possibility that is offered by modem 3D model
instruments is the possibility of projecting a digital image on
a 3D model thus obtaining a coloured 3D model of the object
and then the orthophoto.
5. FUTURE DEVELOPMENTS
5.1 Future Developments
This article has been written to show some of the first results
of the segmentation that was performed on archaeological
objects surveyed using laser instruments. Particularly simple
instruments have so far been developed by the authors for
segmenting and models that are available on the market were
used. This first approach seems necessary to understand how
to proceed in the research field to segment archaeological
surveys.
In the near future it is intended to optimise the segmentation
techniques, paying particular attention to ground type laser
scanning.
This is an application environment where there is still a lot to
learn because of the recent introduction of sensors that allow
point clouds to be surveyed.