Documentation of the Baroque Theatre at the Cesky Krumiov Castle
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In the Baroque theatre in Cesky Krumiov castle various methods of data acquisition were applied up to now. The kinds of the meth
ods differed according a character of a documented part of the theatre. Photogrammetrical and surveying methods were used.
The digital non-metric camera was used in various ways - simple photo-documentation, taking images for visualization, data for pho
togrammetrical processing. The photogrammetric evaluation of the data was done by way of two digital methods - rectification,
stereorestitution. The first type of the result was planar. Applied technology, a vectorization above a raster data with consecutive
placement into the space via identical points, was convenient for this application. This technology is the ideal tool of documentation
mainly for planar parts (e.g. wall painting, drawings etc.). The testing of the digital stereorestitution on one of the stereo-pairs was
not so successful. The main problem we found was that the digital non-metric camera has a known problem with precise calibration
(interior orientation). This necessarily requires a lot of control points and values, which have to be determined within the area of
documentation. The time required is much longer which negates one of the main advantages of photogrammetry. The application of
digital non-metric cameras is convenient for documentation where a high degree of precision is not required. The precision attained
in this particular case was not acceptable.
The data acquired by surveying methods had to be complemented by additional data (measurement of dimension etc.) because of
creation of the complete model.
The processing of the data sets into photo-realistic models was done by MicroStation software. The wire models of the documented
parts of the theatre were acquired firstly. The processing has been done by editing of input data - editing of space position of some
points (a threshold was assigned by expected precision), elimination of some data etc. The design as one of the methods of a creation
of the model was used mainly in the case of processing of the data acquired by the surveying methods. During the creation of the
models, great emphasis was placed on the logical classification of entities into particular levels. This request was very important to
avoid any big changes of each simple model in the consecutive creation of complete three-dimensional model of the entire theatre.
During the next phase, the surfaces were defined and filled with colours or textures. The textures of materials were acquired by digi
tal camera and the images were subsequently adjusted in a graphical editor. The diversity of textures had a big influence on the
credibility of visualization. MicroStation system has a number of tools for visualization. The results of this visualization are very de
pendent on the choices and use of light sources. This means that illumination is of primary importance in the general impression of
visualization. The next phase of the documentation will be focused on this topic - localisation and determination of kinds of light
sources also. The best results of visualization were obtained by Phong method of rendering. Some simple animations of the models -
flights through the area - were created as the last step of workflow. The number of available techniques of animations was a little bit
narrow, but the results of animations are in a good quality and usability for presentation purposes is very good.
Tab. 1 : Stages of the project
Year
Part
Method
Model
V
a
Notice
1996
Scene - Baroque hall
Analogue phot.
w
1997
Part of auditorium
Analogue phot.
w
unused
1997
Scene - Forest
Analogue phot.
w
1998
Lower part of machinery I
Resection phot.
p-r
X
1998
Lower part of machinery II
Surveying
p-r
X
1999
Auditorium - left part
Digital photogrammetry
w
unused
1999
Auditorium - right part
Digital photogrammetry
w
unused
2000
Auditorium
Semi-analytical phot.
p-r
X
2000
Stage
Surveying
p-r
X
X
2001
Upper part of machinery I
Surveying
p-r
X
X
2001
Upper part of machinery II
Surveying
p-r
X
X
v - visualization, a - animation; Models: w - wire, p-r - photo-realistic
Methods Analogue photogrammetry - analogue stereoplotter Technocart with registration
Semi-analytical photogrammetry - stereoplotter Topocart with AutoCAD system
Resection photogrammetry - RolleiMetric CD IV software
Digital photogrammetry - stereorestitution - DWS - VSD software
- single image - TopoL software
Surveying - total station (Topcon, Leica)
5. CONCLUSION
The various modem methods of collecting three-dimensional data were used in this particular build,ng. These data were acquired in
fully digital form Photo-realistic models were then created using different tools for editttton Presentation of these data sets was
done using various techniques of visualization and animation. The main purpose of this part of the project - verification of applicabil
ity of the new technologies in acquisition, processing and visualization of the three-dimensional data was achieved.