The first experience has been made on the choir stalls of S. 
Nicoló's Church apse, that date back to 1750. They have been 
realised by Nicola Bagnasco from Palermo entirely from walnut 
wood, with sculptures in the back' s panels. 
At the present time, these choir stalls are studied by a doctoral 
thesis entitled “Gli arredi lignei delle chiese monasteriali e 
basilicali dell’arcidiocesi metropolita di Catania”. 
  
Fig. 4 - Choir stalls of S. Nicoló's Church apse. 
= xi pn 
  
ses 
Panton BRIE 
ÜBER GER 
sd 
  
Fig. 5 - LPM-SCAN's on-line visualization. 
several 
methodologies and technologies for architectural surveying, in 
order to find out those that are the most suitable to represent 
This research's aim is the experimentation of 
choir stalls. This is an object typology that, because of its 
  
They represent scenes which refer to the Old and the New Testament 
and moreover episodes taken from Saint Benedetto's, Saint Placido's, 
Saint Mauro's, Saint Niccoló's and Saint Giorgio Magnum's lives. 
     
  
dimensional and formal characteristics, can be considered 
intermediate between sculpture and architecture . 
In an hour work we have surveyed about 481600 points, in an 
unique scansion: scanner has been placed at a distance of about 
6 m from the object and we have set up an angular stepwidth of 
10 Mgon, so that we have obtained a step of 1.0 cm. This is a 
good result for a detailed scale (1:20, 1:10),too. This scale is 
necessary to draw this kind of architectural objects. 
Point clouds have been converted before in DXF and after in 
DWG format. So we have been able to create a 3D model, using 
Cirrus’s software, provided by Menci Software. It administrates 
vectors data, by employing algorithms to display and edit point 
clouds. It permits to create bodies and solid models and to make 
smoothing and data decimating operations; it automatically 
extracts sections and contour lines. 
In a second moment we scanned the altars of S. Nicoló's 
Church that constitute the only element interrupting the 
monastic simplicity of the church's interior. They are of 
considerable dimensions (about 15 m high), particularly the two 
altars set inthe transept's wings (about 20 m) that belong to the 
neo-classical style. They have been realised in polychrome 
marbles and exhibit good workmanship paintings. 
These elements cannot be easily defined either typically 
architectural or sculptural because of their remarkable 
proportions and the richness of their decorative motif. 
In particular, we thought to survey them by a 3D scansion in 
order to make the decorative elements readable in the clearest 
and most complete way. As a matter of fact, the spatial 
configuration of the altars, which is mainly a curved one, makes 
extremely difficult both its surveying through traditional or 
photogrammetric techniques and its representation. 
  
Fig. 6 — One of the altars of S. Nicoló's Church. 
We performed various scansions with different settings. Scanner 
has been placed at a distance of about 11-16 m from the object; 
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