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dense grid would not result in any improvement. 
The quality and the processing speed of all following steps of 
treatment of the measured points are strongly dependent on the 
software used for this purpose. MENSI provides the 3Dipsos 
software which is designed primarily for engineering projects 
with the extraction of CAD-features from the point cloud. The 
treatment of irregularly shaped surfaces including triangulation 
and model generation is possible but is not always very 
effective. 
The single scans are registered into a common coordinate 
system using red spheres placed around the sculpture. The 
center of each single sphere is modeled in the software and the 
points of the scans are transformed using these positions of the 
spheres as common tie points. At least three spheres are needed 
for every observing point. The accuracy of these 
transformations is limited to the accuracy of the positioning of 
the points and thus, especially in close range applications, often 
not sufficient, therefore. The point clouds of the single scans 
were registered more accurately using the point clouds 
themselves for the calculation of the transformation parameters, 
as provided by the 3Dipsos software. The result of this 
registration process was an oriented point cloud of the statue. 
Because of the overlapping scans of parts of the surface, the 
density of the points had to be reduced using a spatial sampling 
resulting in a point spacing of 1mm. The resulting model 
consists of about 1.000.000 points on the surface of the statue 
(fig 2, 3). The following steps are the elimination of wrong 
points, e.g. occurring at edges, and the smoothing of the point 
cloud. 
3Dipsos provides two different approaches for the triangulation 
of the point clouds. Firstly, a true 3D triangulation which 
requires a regularly spaced point cloud. The second method uses 
projection surfaces like planes, cylinders or spheres, and 
performs a 2.5 D triangulation on this reference surface. This 
can be useful for building the mesh, e.g. for a part of an arm, but 
on the other hand leads to single mesh arrangements that must 
be stitched together to achieve a complete model of the statue. 
The time needed for the generation of the complete model was a 
multiple as compared to the time needed for scanning. Reasons 
for this are firstly the poor calibration of the scanner which led 
to a higher noise in the recorded points and secondly the 
software that provides only basic support for the generation of 
triangulated surface models and thus is not optimal for this task. 
The noise in the data itself also led to a higher effort in time for 
the model generation, as a higher effort is necessary in the 
preliminary treatment of the point cloud (cleaning, filtering) 
prior to the modeling of the surface. 
PHOTOGRAMMETRY 
The parts of the statue containing seams between the copper 
sheets and rivets were recorded with stereo models using an 
analogue middle format camera Rollei 6008 metric. 
For the orientation process of the single stereo models, point 
markers were stuck onto the statue. 16 convergent images were 
taken in addition to the stereo images. The distances between 
selected marked points were measured directly to introduce a 
scale into the following calculations. 
After measuring the image coordinates of all marked points in 
all images, a bundle adjustment was calculated to determine the 
3D position of the marked points . The coordinates of the points 
could be determined with an accuracy of about 0.3 mm. 
The features on the statue were plotted using an analytical 
plotter Zeiss P3 with MicroStation® as connected CAD-system. 
The features to be plotted were attributed very simply using 
different layers for rivets, rivet holes, the contours of missing 
Ki 
parts of the statue, the construction holding up the statue and 
other details like the remains of the crown or the loincloth. The 
final 3D vector data set can be viewed and plotted in various 
projections showing the metric correct position of these features 
in the plots (fig 4). 
VISUALIZATION 
For all further visualization tasks, 3D Studio Max®, a 3D 
visualization and animation software, was used. The data 
transfer was realized using Wavefront OBJ and AutoDesk DXF 
formats.