CIPA 2003 XIX th International Symposium, 30 September - 04 October, 2003, Antalya, Turkey 
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4. ARCHITECTURAL HERITAGE DATA 
COLLECTION FOR VIRTUALISATION 
Appropriate and accurate methodology for collecting data 
required for virtual heritage is an important issue. The realism 
of the virtual reconstruction greatly relies on the quality of the 
data collected. Therefore, a detailed database covering 
numerous subjects have to be formed in order to recreate an 
historical building together with virtual humans and activities 
realised within this building in virtual environment [7]. On the 
other hand, the extent of the scope and the details are directly 
related to the building function and the aimed precision. In this 
section the methodology developed for creating the database for 
acoustical and visual virtualisation of CAHRISMA Project 
buildings will be presented and exemplified. 
4.1 Methodology of Data Collection 
Detailed data on the acoustical and visual properties of the 
ancient spaces are required for the virtualisation. Different types 
of data, grouped as architectural, functional, acoustical and 
visual, have to be gathered in order to create the basic database 
for the virtual conservation and restoration of the buildings. 
Basic steps of the data collection are designed as follows: 
Architectural data 
Three basic investigations are required in order to obtain a 
complete architectural data: 
- Structural and architectural specifications of the 
buildings 
- Visual properties of interiors and exteriors 
- Furnishing 
Data related with functional activities 
Activities related to the building function have also to be 
determined in order to realise the visualisation. People’s 
clothing should be considered according to the era that the 
visualisation would be realised. 
Acoustical data 
Acoustic properties of 
- Rooms 
- Materials used in indoors 
- Activities (speech/ music) 
should be determined. 
Lighting and colour data 
For the lighting and colour properties, determination of 
- Indoor’s lighting syste ms 
- Natural and artificial illuminances 
- External daylight illumination levels 
- Ancient luminary properties 
- Indoor material light reflectance and colours 
should be realised. 
Steps of the mentioned methodology will be exemplified in the 
following sections, based on the Project. 
4.2 Collection of the Architectural Data 
While trying to recreate historical edifices in virtual 
environment, it is important to expose the ancient and the recent 
situations of these buildings. For the buildings investigated in 
the CAHRISMA Project, it has been detected that some 
modifications were occurred due to different reasons such as 
renovations, restorations and functional changes through the 
time. Therefore the period that will be presented in the 
virtualisation has to be determined. 16 th Century has been 
chosen for the virtual restitution of Sinan’s mosques because 
this was the era they have been built. Almost no great changes 
have been occurred in the religious rituals and the objects used 
on Islamic prayer throughout the time. At 1054 Roman Church 
and Byzantine Patriarch excommunicated each other causing 
their definite separation on the liturgical initial, spaces and use 
of objects, so the 1 l lh Century has been accepted as the era for 
virtual restitution of the selected Byzantine churches [8]. 
In order to expose the structural and architectural specifications 
of the buildings; 
-Plans and sections were collected. 
-Modifications occurred in time were determined. 
-Collected data were compared with the recent 
situation by checking measures in situ where necessary. 
In Figure 1, an example showing the alterations in one of the 
edifices- St. Sophie (Haghia Sophia) Church- is shown [9]. For 
the visual properties of the interiors, drawings and photos were 
examined. Furnishing of the ancient and the recent situation was 
also determined. The data collected under this topic is used as 
the database of the visual and acoustical virtual reconstruction 
of the buildings. 
4.3 Collection and Presentation of the Acoustical Data 
As mentioned in Section 2, acoustical data covers rooms, 
materials used in indoors and activities. Room acoustical 
properties can be determined by measurements and/or 
calculations [1, 3, 4]. In the CAHRISMA Project both have 
been realised and crosschecked to show the accuracy of the 
findings. Measurements were realised by three teams (UNIFE, 
DTU and YTU) according to ISO standards and calculations 
were done by using Odeon and other softwares [2, 4, 8, 10]. 
Each space has been elaborated carefully in-situ and surfaces 
having different materials in terms of acoustics are identified. 
These are shown on coloured drawings (plans and sections) and 
used to estimate the sound absorption properties of the indoor 
surface materials. An example is given in Figure 2 [1, 11]. 
Sound absorption coefficients of the materials such as carpets, 
tiles and stones are measured in laboratory. The alterations 
occurred in time are determined from the available literature in 
order to use in the virtual restitutions. 
According to the activities realised in the buildings, acoustical 
activities such as speech and music have to be determined. In 
the CAHRISMA Project, sounds related to religious activities 
such as sermons and prayers are specified and recordings in situ 
during ceremonies as well as recordings in anechoic chambers 
are realised. 
-Findings of these works were used in the auralisations created 
for the virtual environment. 
4.4 Collection and Presentation of the Lighting and Colour 
Data 
In order to create a realistic virtual environment, lighting 
systems and colour of the materials should be determined 
precisely. Natural and artificial lighting systems of the 
CAHRISMA Project’s edifices were examined in situ (YTU).