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R&D Project Report

3DCG reconstitution and virtual reality of UNESCO
world heritage in danger: the Citadel of Bam
Kinji ONO1 , Elham ANDAROODI2 , Alireza EINIFAR3 , Nobuaki ABE4 , Mohammad Reza MATINI5 , Olivier BOUET6 , Frank CHOPIN7 , Takashi KAWAI8 , Asanobu
KITAMOTO9 , Asaka ITO10 , Eskandar MOKHTARI11 , Saeed EINIFAR12 , Seyyed
Mohammad BEHESHTI13 , and Chahryar ADLE14
1,2,5,9National Institute of Informatics, 3 University of Tehran, 4,8 Waseda University,
L’ecole Nationale Superieure d’Architecture Paris Val de Seine (ENSAPVS), Virtual Space of Conception in Architecture and Urbanism (EVCAU), 11,13 Iranian Cultural
Heritage and Tourism Organization, 12 Raazaahang Architectural Firm, 10 Ergovisions,14
Centre Nationale de Recherche Scientifique
6,7

ABSTRACTThis paper provides a report of a research project on virtual revival of the Citadel of Bam,a UNESCO world heritage site in danger that was destroyed in an earthquake in 2003. The
simulation of damaged buildings that lies along the primary axes of the citadel and 3-D reconstitution using state-of-the-art 3DCG tools are presented. The key approach to 3-D modelingof the destroyed buildings is complementary usage of heterogeneous data such as 2-D maps,
photos, cartography maps, and sketches in collaboration between different teams. As thebasic 2-D maps had error, analytic and comparative research is conducted on diverse data
resources to create a knowledge-base for the 3DCG restoration of the site. The process ofmodeling is completed with regard to the complicated and curved mud brick buildings withtraditional architectural details. For this purpose proper functions of the tools is selected
and in some cases different tools are used. The modeling is done by linking the component
with their semantic by a metadata-based layer naming process. The tasks of evaluating thehistorical, architectural, and technical details of the 3-D buildings are done in parallel withthe modeling by a team of CG and architecture experts in order to increase the precision of
the 3DCG reconstitution so that it can be used as a reference for the physical restoration. The
first trial version of virtual reality demonstration of the main axes of the Citadel of Bam is
described. The paper concludes with proposals to enhance the process of simulation and also
to open the restricted views of the virtual reconstitution on Internet.
KEYWORDS
3DCG, virtual reconstitution, Citadel of Bam, 3-D modeling, heterogeneous data, semantic layer
management, modeling technical evaluation, virtual reality demonstration

Received August 10, 2007; Revised November 27, 2007; Accepted January 8,
2008.
1)
ono@nii.ac.jp, 2) elham@nii.ac.jp, 3) aeinifar@ut.ac.ir,
4)
zen@toki.waseda.jp, 5) matini@nii.ac.jp,
6)olivier.bouet@paris-valdeseine.archi.fr, 7) lfchopin@club-internet.fr,
8)
MXE03620@nifty.com, 9) kitamoto@nii.ac.jp,
10)asaka ito@ergovisions.com, 11) eskandarmokhtari@yahoo.com,

12)

info@razahang.com, 14) cadle1944@yahoo.com

DOI: 10.2201/NiiPi.2008.5.10

c2008
National Instiute of Informatics

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Progress in Informatics, No. 5, pp.99–136, (2008)1• A virtual reality of the citadel can be viewed anddemonstrated remotely.

Introduction

The historical city of Bam is situated along the Silk
Road more than 1200 kilometers south of Tehran, andit once flourished for its production of silk and cotton.
The city is well known by its qanat water management
system1) , mud brick citadel, and date palm trees. An
earthquake measuring 6.3 on the Richter scale occurredat Friday 26 December 2003 and destroyed many of its
quarters. The historical Citadel of Bam (Arg-e-Bam)
was destroyed, and many lives were lost. Restoration
and reconstruction of the citadel, which is now classed
as a world heritage site in danger2) , will be a great challenge and many organizations and individuals are attempting to find adequate solutions3) .
As part of the Digital Silk Roads project a threedimensional reconstitution and virtual reality of the
Citadel of Bam was proposed. Revival of this heritage in the virtual world seems essential because of
the complexity of physical reconstruction. Any physical restoration might face limitations of technique, material, manpower, budget, and even access to the site4) .
Our 3-D reconstitution and virtual reality demonstration are parts of the virtual revival of the Citadel ofBam. Our research activity was motivated upon the following reasons:• A virtual reconstitution is faster and less expensive
than a physical one.

After the disaster, we started to make a 3-D simulationof the destroyed buildings inside the citadel by usingstate-of-the-art computer graphics tools and prepare a
virtual reality demonstration of the digitally reconstituted buildings.
1.1 First phase of research
The Citadel of Bam covers a huge area and has several complexes. To start 3-D modeling, we had to selecta number of target cases. We referred to the site planand specified two important axes, north-south and eastwest. The north-south axis runs from the main entrance
gate and ascends to the governor’s section and highest
point of the citadel. Major public buildings are locatedalong this axis. The east-west axis runs from the bazaar
and passes through the religious and educational buildings and noble houses before reaching the ancient eastgate. We selected these two axes for the first phase of
3-D modeling.
1.2 Summary of the research process
The steps of the project are outlined in Fig. 1 and aresummarized as follows:• Collect data including photos, maps, videos anddocuments related to Bam from diverse and sparseresources.

• A revival in the virtual world may be the only solution for those spaces which are very difficult or
impossible to reconstruct.

• Conduct analytic and comparative research on thisheterogeneous data, as well as categorization andannotation to complete the basic resources formodeling.

• A systematic knowledge base can be provided of
raw documents such as photos, maps, movies,
texts, etc., to build three-dimensional models andidentify the shortcomings of data and documentation of the site.

• Develop a three-dimensional simulation of buildings inside the citadel by complementary application of diverse data resources by using state-ofthe-art 3-D modeling techniques and tools.

• The 3-D models would be important references forphysical reconstruction.

• Add semantic information to the 3-D models
through a systematic modeling process.

1)

A qanat is a water management system used to provide a reliable supply of water to human settlements or for irrigation in hot arid and semiarid climates. The technology is known to have developed in ancient Persia, and then spread to other cultures, especially along the Silk Road (fromhttp://en.wikipedia.org/wiki/Qanat [7 Jan, 2008]). The geographical locationof Bam city has helped to sustain its advanced qanat system for thousands ofyears (possibly since the Achaemenian dynasty in 500 B.C.).
2)
http://whc.unesco.org/en/list/1208 [7 Jan, 2008].
3)
The rehabilitation of the citadel has been a topic of intensive discussion.
In particular, on 17-21 April 2004, an international workshop took place in
Bam. Some 52 senior representatives and experts from different organizations
and universities around the world shared experiences and lessons taken fromthe earthquake and proposed a list of recommendations that was publishedas the Bam declaration (from www.international.icomos.org/xian2005/Bamdeclaration.pdf [7 Jan, 2008]).
4)
The upper part of the citadel presents a complex problem regarding debris
removal and stabilization; it is a critical situation hampering access and field
operations.

• Devise a virtual reality demonstration of the simulated spaces by importing a VRML5) file of the 3D models into VR tools and set up a virtual walkthrough of the digitally restored buildings.
This paper is a report on the current state of the project.
A brief history of the citadel and its situation after the
5)

VRML stands for Virtual Reality Modeling Language or Virtual Reality
Markup Language. It is a text file format in which vertices and edges for a
3D polygon can be specified along with the surface color, image-mapped textures, shininess, transparency, and so on. (from http://encyclopedia.thefreedictionary.com/VRML [7 Jan, 2008]).

3DCG reconstitution and virtual reality of UNESCO world heritage in danger: the Citadel of Bam

Fig. 1 Process of virtual reconstitution of the Citadel of Bam.

earthquake is explained in section 2. The process of 3D modeling is described in section 3. Semantic annotation of the data and the provision of technical guidelines are covered in sections 4 and 5. Sections 6, 7, and8 describe the first phase of 3-D modeling of the major
case studies inside the citadel. Technical evaluation andmodification of the 3-D models are discussed in section
9. The virtual reality demonstration of the simulatedbuildings is introduced in section 10. The paper concludes with future perspectives in section 11.

2

Historical and architectural background

Old Bam was one of five areas of the state of Pars.
Its strategic location along roads connecting the Silkroads from Afghanistan and India to the centre to Ray(present-day Tehran) and toward the east to Merv andtoward the west to Istanbul made it an important historical and commercial location in the south-eastern Persia from about 120 B.C. (Fig. 2). Caravans that passed
through Bam carried spice and silk and cotton clothes.
The travelogues of people who visited Bam between
the 9th to 11th centuries mentioned the extremely finecotton and silk cloth that used to be produced there andexported to the major cities along the Silk Road [1]–[3].
The historical Citadel of Bam covers approximately
200000 m2 . It is one of the biggest mud brick defensive
complexes in the world and has had around 20 centuriesof habitation, making it one of the most ancient earthen
structures (Fig. 3). Its strategic location on top of a hill
about 50 meters above the surrounding terrain gave it animportant defensive function and made it easy to fortify.
The citadel is a typical desert city divided into eightresidential districts and a governor’s section. The city
is surrounded by a defensive wall more than 1500 meters long and 5 to 6 meters in height and is protectedby 38 watch towers and a moat all around it. The
main gate controlled the comings and goings of inhabitants and travellers. Right past the gate, there is alinear bazaar passing through the residential districts.
Around 20 building types existed before the quake ascomplete examples of a typical Middle Eastern desert
city made from layers of mud. The residential district includes mosque, bazaar, tekkiyeh (religious plazaor theatre), caravanserai, school, bath, zoorkhaneh (aplace for playing traditional sports) and houses of noblemen. The governor’s section consists of defensive
complexes such as stable, barracks, mill, and commander’s house. The governor’s quarters consists of thegovernor’s house, bath, watch tower, and the Chaharfasl(Four Season) reception room at the top of the citadel.
Variety of function of buildings inside the citadel madeit as a precious example for desert city typology along
the Silk Road.
Although there are different hypotheses as to thefounding date of this citadel, i.e., some time during
the Achaemenian and Partian dynasties (550 B.C.–224
A.D), most of the buildings that existed before theearthquake seemed to belong to the Teimorid to Qajar period (1381–1921). [1]–[3] Table 1 lists a historicalchronology of the citadel and shows photos of remains
corresponding to the respective historical periods.
Some huge mud brick structures like the Great
Iwan6) of the Jamee mosque might date from the
Samanid dynasty and Seljuk dynasty (819–1186).
Travelogues from these periods mention the Citadel of
Bam and this mosque in their records (e.g., Ibne-Haugal(943–977) [4]. The Citadel of Bam was evacuated dur6)
Large vaulted halls having one side open to a court; prevalent inParthian, Sassanian, and Islamic architecture: http://www.getty.edu/vow/
AATFullDisplay?find=iwan&logic=AND&note=&english=N&prev page=1&
subjectid=300075830 [7 Jan, 2008].

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Table 1 Chronology of the Citadel of Bam and comparative analysis of remains from different centuries.

date
550
B.C.–
224 A.D

Location of remains

Sample of remains

The remains consist of large mud bricks that formed arches
or walls at the top of a cliff. Their original function is unclear. Was it a citadel or was it a temple?
Mud-brick arch discovered after quake.
819–
1186
A.D.

The remains consist of the old gate or parts of walls in thegovernor’s district, especially around the mosque. The site
is cited in famous travelogues to be a huge citadel. However, it seems to be the noblemen district of a bigger citadel.
It is known that the region flourished with the productionof silk and cotton cloth.

Main mud-brick iwan of the mosque (photo credit:
ICHTO).

1381–
1921
A.D.

Constructions belonging to different periods. Over thecourse of centuries of economic stagnancy in the region,
people’s dwellings moved closer to the center and the older
citadel shrank to its current size.

The governor’s district and eight other residential districtsin the Citadel of Bam with different types of public buildings, including a mosque, school, bath, bazaar, sports hall,and religious theater

3DCG reconstitution and virtual reality of UNESCO world heritage in danger: the Citadel of Bam

Fig. 2 Strategic location of Bam along the Silk and Spice Roads.

Fig. 3 The Citadel of Bam: a view from the first city wall
toward the bazaar, governor’s district, and main tower.

Fig. 4 The Citadel of Bam: the same view as Fig. 3 after
the earthquake in December 2003.

ing the Qajar Period7) .
The material used to build the citadel is sticky mud
containing a very resistant type of clay for building
good-quality sun dried brick [1]. The region is very dry
and there are only a few rainy days during the year; thishad helped the mud brick constructions to last a longtime.
Following the destruction caused by the earthquake,
UNESCO added “Bam and its Cultural Landscape” toits World Heritage in Danger list in 2004 (UNESCOWorld Heritage Centre8) ). Although the earthquake, as
can be seen from Fig. 4, almost completely destroyed
the site, it led to new archaeological discoveries. It was

7)
For further information about the history Citadel of Bam, please referto the complete list of references from the ICHTO Documentation Center:
http://www.ichodoc.ir/argebam/bookname.htm [7 Jan, 2008].

8)

http://whc.unesco.org/en/list/1208 [7 Jan, 2008]

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Before the earthquake, the citadel has been restored
several times. The last restoration started around 35
years ago and continued until 2003. Many parts of thecitadel (like the bazaar) were reconstructed during therestoration period. The situation of the citadel just before the earthquake was a reference for our 3-D reconstitution.

3 3DCG of Citadel of Bam

Fig. 5 Mosque after the earthquake.

Fig. 6 Barrack after the earthquake.

as if the destruction had peeled back layers of newer
mud brick to reveal ancient ones underneath. Very old
mud brick constructions were revealed in the upper partof the citadel, and their huge size was reminiscent ofancient mud brick sites such as ancient Tchogha Zanbil9) [1] (see Table 1).
The earthquake also offered an opportunity to study
the architectural styles of mud brick structures. Parts ofthe citadel, e.g., the stables and barrack (Fig. 6), were
not as seriously damaged as the rest, and the earthquake revealed the construction of vaults and the roofthat had been hidden in the finished buildings. Learning
the manner in which such structures withstand an earthquake and discovering why some parts remained standing while other parts were demolished can give us important information about how such structures weather
natural disasters.
9)

Tchogha Zanbil is a UNESCO world heritage site containing the ruins of
the holy city of the Kingdom of Elam, surrounded by three huge concentric
walls. Founded c. 1250 B.C., the city remained unfinished after it was invaded
by Ashurbanipal, as shown by the thousands of unused bricks left at the site:
http://whc.unesco.org/pg.cfm?cid=31&id site=113 [7 Jan, 2008]).

3.1 Review of the state of the art
There are several examples of 3-D modeling of acultural heritage or of damaged sites by using photogrammetry, photo modeling, and other 3-D modeling techniques. An example of a virtual heritage is thereconstitution of the Bamian Great Buddha that was
generated with VirtuoZo digital photogrammetric systems [5]. Another example is the virtual reconstitutionof the Great Buddha in Japan, which uses geometricmodeling (scanning, merging, and alignment of the target object) and photometric and environmental modeling for rendering and demonstration [6].
Regarding virtual representations of individual buildings, the Parthenon virtual reality [7] was modeled using laser scanning and photogrammetry. Another example is the virtual reality of the city of Pompei [8]wherein 3-D models of the target buildings were created from available documents.
In contrast to the cases described above, our target buildings had mostly been destroyed. Furthermore, 3-D simulation was necessary for the interior
as well as the exterior spaces of buildings that weremade from mud brick and had unusual curves, arches,and other complicated shapes. Moreover, the site ishuge (about 200,000 m2 ) and comprises several districts. There are few detailed images of the buildings that are good enough for reconstitution by photogrammetry technique [9], [10]. Therefore, we chosethe method of 3-D modeling from 2-D maps and othercomplementary resources.
3.2 Process of 3-D modeling
Modeling of a building involves making the geometry of the building components in three dimensions
Rby using 3-D modeling software such as AutoCAD10)R
11)
and MAX[11], [12]. The basic data corresponds
R
10)
AutoCAD
is a suite of Computer Aided Design (CAD) software products for 2- and 3-Dimensional design and drafting, developedand sold by Autodesk, Inc. (from http://usa.autodesk.com/adsk/servlet/index?siteID=123112&id=2704278 [7 Jan, 2008].
R
11)
3D Studio Max (sometimes called MAXor just MAX) is a 3-Dimensional
vector graphics and animation program, written by Autodesk Media & Entertainment (formerly known as Discreet and Kinetix). It was developed
as a successor to 3D Studio for DOS, but for the Win32 platform. Kinetix
was later merged with Autodesk’s latest acquisition, Discreet Logic. (fromhttp://usa.autodesk.com/adsk/servlet/index?id=5659302&siteID=123112 [73DCG reconstitution and virtual reality of UNESCO world heritage in danger: the Citadel of Bam

to the dimensions of the building. If the basic data is
accurate, the model will accurately simulate the realbuilding. If it has error, the modeling process will facecomplexity in order to solve the errors by using otherdata such as photos.
The demolition of the site, lack of precise 2-D maps
and lack of photos before the earthquake has made theprocess of 3-D modeling of this project a rigorous research activity by collaboration of experts of history or
architecture and computer graphics who supervised the3-D modelers. The research activity that supported themodeling task has ensured the precise virtual reconstitution of the damaged heritage on the contrary of errorsof 2-D maps and lack of photos. The modeling of firstphase of the project proceeded as follows.
Provision of primary data
The basic data consisted of 2-D maps, photos,
movies or textual explanations, aerial photos, cartography maps, oral explanations and other pieces of information related to Bam found in different references(see section 4).
Development of 3-D modeling guidelines
Guidelines for drawing and developing the 3-D models were created so that different modelers could coordinate their work, to provide coherent output and reduce the errors in the final model.
3-D modeling
The development of the 3-D models from the different case studies was collaboration between researchersand 3-D modelers. The first step was to superimpose 2D maps on the 3-D cartography data (IFCA project) tocompensate for the errors in the maps. Photos, movies
and sketches were used to modify the model, especiallythe elevations and interiors. The team exploited stateof-the-art modeling tools, but as a unified 3DCG tool
for simulation of architectural buildings could not befound, the team had to use different tools simultaneously.
The three groups of modelers had to conduct tasks
jointly in different stages of this project (see sections
6, 7 and 8). It is important to notice their different approaches even though they used the same tools.
3-D model technical quality and correctness control
This task was part of the comparative study of 3D models and heterogeneous data sources, and it increased the precision and correctness of the final 3-D
models by identifying the architectural, historical or
technical modeling errors. Because of the various reJan, 2008].

sources and errors of the 2-D maps, this process was
essential to ensure the precision and quality of the models and to notify the modelers of their errors.
Management and coordination of different teams
The first phase of the virtual reconstitution involved
groups from the National Institute of Informatics (NII)and Waseda University in Japan and the Iranian Cultural Heritage and Tourism Organization (ICHTO).
The first 3-D reconstitution of the main entrance andbazaar began in October, 2004 by team of Universityof Waseda. The University of Tehran joined the projectin September 2005 and conducted a survey of buildings
the site for 3-D modeling of five case studies. Espace
Virtuel de Conception Architecturale et Urbaine (EVCAU), a laboratory of the Ecole Nationale Supérieured’Architecture de Paris-Val de Seine (ENSA PVS) in
France, joined the project in October 2006; they helped
to improve the modeling skills of the group by simulating two case studies, the caravanserai and school inside
the citadel.
The experience of managing modeling groups withdifferent attitudes and capabilities provided important
insights into how to produce a coherent output fromsuch a large undertaking.
In the following of the paper each process is discussed in detail.

4 Analytic management of heterogenious data for 3-D modeling
The case studies selected for modeling had varying
degrees of damage, from totally destroyed (as in thecase of the mosque, Fig. 5) to less than half demolished(as in the case of the barracks, Fig. 6). Experts believedthat the construction of mosque on older layers of habitation and on non-resistant soil and the construction of
the barracks on a strong foundation rock were the reasons for their respective weakness and strength in theearthquake. In all cases, though, the amount of damage
was considerable.
The inadequacies of the 2-D maps made collecting
other information and annotating the data essential, thedocuments we worked with were resources with missing data. The images had only limited views of thecomplicated mud brick structures. This entailed a vast
investigation to find pieces of information because the
Citadel of Bam had not been completely documented
before the quake. For this task, we had to be like architectural detectives on a quest to discover the ambiguous
shapes of buildings that had disappeared.
Data resources
The basic data was acquired from the following
sources and were implemented complementary for 3-D

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Fig. 7 Research process of data analysis and 3-D model evaluation.

modeling (Fig. 7):• Iranian Cultural Heritage Organization (Bam recovery project office, Documentation Centre,etc.), for maps, photos, texts, movies, etc.,• National Cartography Centre (of Iran), for aerial
photos,• IFCA (Irano-French Cartography Agreement) andCentre National de la Recherche Scientifique(CNRS), for a three-dimensional cartography map
in the form of a DWG12) file,13)

4.1 Collected data and their role in modeling
Various data were used for developing the 3-D model
as listed below.
Maps
There were maps and 2-D drawings of buildings
from horizontal (plan) and vertical (façade, sections)plans from a survey done before the earthquake. These
data were as follows:• Underground floor plans• Ground floor plans• First floor plans• Open source data from the Internet, for images14) ,and the website of the DSR project, for a collection of images of the Citadel of Bam,15)• Site plan
• Facades• Survey of information in the form of photos andmaps showing details and perspectives of the site
after the earthquake• Verbal explanation made by experts who had
worked at the site before the earthquake.16)
R Computer
A file extension that indicates a drawing from the AutoCAD
aided Design tool.
13)
A project of Dr. Adle.
14)
Here is a list of web pages for this purpose (last viewed on 1 November2007): http://www.chnphoto.ir/
http://www.ichodoc.ir/argeBam/
http://www.cais-soas.com/CAIS/virtual museum/parthian/Sites/Bam.htm
http://www.gimizu.de/orient/2001/kerman/Bam.html#0911 d17
http://www.mcah.columbia.edu/Bam/main.htm
http://www.Bam-iran.com/Bam City/index.htm
15)
http://dsr.nii.ac.jp/Bam/collection/
16)
Dr. Hossein Tayari (head of the Bam restoration project from 1995 to 2003),
Ms. Mahshid Jafarizadeh (Expert on the Bam restoration project).
12)• Sections• Perspectives
The surveys had been done by the experts of the Bam
restoration project before the earthquake, and they wereof 23 buildings inside the citadel17) . Normally, a complete survey of a building includes different levels (from17)

The buildings are as follows:
Arg-e Bam (citadel) general map, main gate (south gate), governor’s postal
office, tea shop, west house of Saabaat, the religious theater (tekkiyeh), stable &water storage, barracks, small house (west of the caravanserai), a house besidea passageway, Jaam’e mosque, governor’s house, commander’s mansion, Four
Season building (Emarat Chahar Fassl), a house on the west side of the baazar,
second gate (governor’s district), complex governor’s house, bazaar (inside thecitadel), caravanserai (behind stable), school and school and houses of Mirza
Naeem, and houses and complex of Mir.

3DCG reconstitution and virtual reality of UNESCO world heritage in danger: the Citadel of Bam

Fig. 8 Analysis of map of the main entrance and errors in coincidence between plans of different levels.

underground floors to the roof), complete sections, theoutside and inside elevations (including the elevationsof each space and each room), and details with all dimensions, and the scales range from 1:100 to even 1:1.
However, due to limited sources for the survey and thecomplexity and huge scale of the site, our research had
to deal with several shortcomings of these maps as follows:• There are dimensional incompatibilities between
the plans of different levels (Fig. 8 shows the caseof the main gate (entrance)) and between plan andsection.
• Elevation and sections are not provided for all facades of the building.
• There are errors in coincidence of the ground floor
plan of the building and the roof plan derived fromthe 3-D cartography data (Fig. 9).
To cope with these shortcomings, we complemented themap data with the data listed below.
3-D Cartography Map18)
Cartography is defined as the study and making ofmaps from spatial information19) . The 3-D cartography
map that we used as the reference was reconstituted
from aerial photos of the Citadel of Bam from 1994.
These photogrammetric materials were made available
under the Irano-French 3-D Cartographic Agreement
18)
19)This section is co authored by Dr. Chahryar Adle.
http://www.gtasa.asn.au/glossary/gloss c.htm [7 Jan, 2008].

on Bam (IFCA) and the Iranian National Cartographic
Centre (NCC). The reconstitution provided by the 3-D
cartography map is precise in relative value (comparison of the XYZ coordinate value of one element in thesystem with the XYZ coordinate value of another element in the system) to within 5 cm and in absoluteterms within about a decimetre (for instance, regarding
the XYZ of a point perhaps less than 10 cm in X, lessthan 20 cm in Y and less than 20 cm in Z). If any architectural or natural element is clicked on in the 3-D
cartography map, the XYZ values in the UTM20) system are revealed. The cartography map is developed byR
R
Micro Station
tool21) and imported as an AutoCAD
file with a DWG extension. Because of this, the colors of the layers of each set of lines have changed andbecome similar, and this complicates the layer management process. The map is a ‘wire frame’ 3-D model
consisting of lines, not surfaces or solid volumes.
The cartography map was used as a reference forchecking the correctness of plans surveyed before theearthquake (Fig. 9) and for the development of a 3-D
model for free-hand constructed mud brick walls or
vaulted roofs. Fig. 10 shows an example of the Great
Iwan of the grand mosque. To develop such a model
adjustment of lines of the map is necessary. In somecases like the tower of the main gate (see Fig. 11), the20)

Universal Transverse Mercator, a special grid map adopted by the National
Imagery and Mapping Agency (NIMA). This grid is arranged so that the earth isdivided into 60 north-south zones (each is a strip 6 degrees wide in longitude).
These zones are numbered consecutively beginning with Zone 1 between 180
and 174 degrees west longitude.
www.seilerinst.com/gps/gpsterms.asp [7 Jan, 2008].
21)
http://www.bentley.com/en-US/Products/MicroStation/ [7 Jan, 2008].

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Progress in Informatics, No. 5, pp.99–136, (2008)• The map is drawn by hand and its lines need to be
adjusted before they can be used for 3-D modeling.
• Although the shapes viewed from the top (roofplan), especially of the domes and vaults are precise, there is a serious lack of detail on the facades(vertical views).
• The errors in XYZ coordinates cause ambiguities
in delicate forms requiring a precision of 30 centimetres or better.
Fig. 9 Comparison of cartography map (white lines, IFCA
project) and plan (red lines).

Fig. 10 Using 3-D cartography map (IFCA project) for development of the 3-D model of irregular and curved mudbrick surfaces in the case study of the ancient iwan of themosque.

PhotosThe 2-D and 3-D cartography maps were used tomodel the walls and vaulted roofs. But these data
sources didn’t contain enough information for determining the frontage and elevations of the interior
spaces. Hence, photos of the Citadel of Bam became
the major complementary resource for the 3-D modeling.
We posted a call in three languages for contributions
on the DSR website22) . We requested photos of thecitadel, especially ones taken before the earthquake. As
a result of this call, we collected more than 200 photos
from website visitors of five nationalities (Fig. 12).
This photo collection has helped us to disambiguate
the shapes of the facades, details, ornaments, and interiors. We also had access to or compiled photo databases
from the following sources:• Photos taken by individuals and sent to us by othermeans beside the DSR website,• Photos taken by ICHTO during the restoration
process,• Photos taken at special events and ceremonies.
The collected photographs are of 37spots23) around thecitadel and were taken before the earthquake. Unfortunately, the photos still had a number of problems:• Low resolution,
22)

Fig. 11 Using cartography map (IFCA project) to modify
the 3-D model of the tower of the citadel’s main gate.

cartography map can resolve the problems stemmingfrom dimension errors (including height errors). Sometimes, models long and narrow spaces like the bazaar
can be adjusted by using the cartography map.
Although the 3-D wire frame model of the cartography map is the most reliable reference for checking the
3-D models, it has the following shortcomings:

http://dsr.nii.ac.jp/bam/index.html.ja [7 Jan 2008]. The website was createdby collaboration of Assoc. Prof. Dr. Asanobou Kitamoto and Dr. Elham
Andaroodi.
23)
General view, entry gate [main gate], southern wall, east of entry gate [eastof the main gate], eastern wall, north-eastern wall, north-eastern wall behind
the governor’s mansion, external part of the north-eastern wall, northern wall,
western wall, southern wall west of entry gate, bazaar, tekkiyeh, grand mosque,Mirza Naim school, Mirza Naim private residence, main caravanserai and Mirhouse, gymnasium (Zoorkhaneh), Al Rasoul mosque, baths, Jewish passageway, house located at the west side of the Jewish Passageway, small caravanserai, old wall, Konari neighborhood, stable, second entry gate, second wall,
Kot E Kerm gate, third wall, barracks, commander’s mansion, governor’s mansion and watch tower, Four Seasons building (Emarat Chahar Fassl), governor’sbath house and well, and tower.

3DCG reconstitution and virtual reality of UNESCO world heritage in danger: the Citadel of Bam

Fig. 12 Photo collection sent by contributor in response to open call for materials on the DSR website.

• Too many photos from popular views (such as
Fig. 2) and very few images of private buildings
or residential districts,• Lack of images of interior spaces,• From 1971 to 1993: the citadel was partially restored. (It was registered as the 154th nationalmonument of Iran in 1966 and has been protectedby the National Cultural Heritage Organization
since 1971.)• No data related to settings of the cameras and no
photos from calibrated cameras.

• From 1993 to 2003: the citadel underwent massive
reconstruction as one of five big ICHTO projects.

The demolished state of the buildings has made the process of photo archiving more complicated. Some information still exists and photos can still be taken of the remains that have been excavated. To complete the photocollection, we surveyed the site and photographed thetwo main axes after debris had been removed.

• 2003 and 2004: the citadel was destroyed in an
earthquake and was covered by debris.

Aerial Photos
Aerial photographs of the Citadel of Bam taken on
seven different years (the first dating from 50 years
ago24) ) and with a scale more than 1:2000 were provided by the National Cartography Centre and Digital
Globe25) . These photos revealed the changing situationof the citadel during the last 50 years. In fact, we recognized three different periods as follows:• After 2004: debris removal started and somebuildings were excavated.
Aerial photos were complementary data for making the
3-D models. Although their scale is too small for them
to be used to make a precise map, they were used whenno other reference was available. Some of these photos
are not perfectly vertical; hence, the facades, especiallythe east and north sides, are visible. In some cases likethe west façade of the Mirza Naim School, no map or
photo was available and aerial photos had to be used as
the main reference for 3-D modeling.

• Before 1971: the citadel was abandoned and suffered damage from nearby human habitation.

Movie, texts, and sketches
Other references for completing the 3-D models weremovies taken by professionals26) or by amateurs ofThese years are 1335, 1343, 1356, 1360, 1373, 1375, and 1382 of the Persian
calendar (2008 is 1386–1387 of the Persian calendar)25)
http://www.digitalglobe.com/ [7 Jan, 2008].

26)
The Bam citadel directed by M. Zahedian, Bam, the eastern gate of Irandirected by H. Emami, Bam, sustainable heritage, ICHTO, Bam in the Silk
Roads series by NHK.

24)

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Fig. 13 Snapshot of the movie (credit by ICHTO) of interior of Four Seasons building.

4.2 Data categorization, semantic annotation and provision for 3-D modeling
Most of the data listed above didn’t have categorization or metadata. We made categorized them according to data type (maps, photos, etc.) and data location(names of buildings such as gate, and bazaar). Later, areference guide map for the photos was drawn up27) .
For each building, the target image from aerial photos was extracted from among more than 40 importantmonuments within the 200000 m2 of the site. Furthermore, the movies were reviewed and the snapshots related to target buildings for 3-D modeling were annotated and specified. A metadata list of architectural
maps was created and locations lacking facades andother details were specified on a guide map. Moreover,a 3-D cartography map of each building was extracted
and saved in a separate DWG file.
Each team of 3-D developers were provided witha classified database of heterogeneous information
related to the target building and their annotations(Fig. 15).

5 Systematic and semantic 3-D modelingFig. 14 3-D model of interior of Four Seasons building
modeled from movie.

spaces for which no photos or maps were available(Fig. 13 and 14 shows images from a movie of the interior of the Four Seasons building and the 3-D model).
Among the movie data was a movie of NHK’s Silk
Road series made in 1981 showing helicopter aerial
shots. This was an especially valuable reference formodeling the upper part of the citadel.
Texts were used for disambiguating the changes inshapes during the restoration periods, discovering thehistory of the citadel and the buildings inside it, anddescribing the spaces. The textual references included
annual reports on the restorations, unpublished papers
about history and architecture, papers submitted to thefirst and second congress of history of Iran and Citadel
of Bam (1374–78), and the Bam region report [1]–[3].
Oral survey of explanation of experts who worked
at the citadel before the earthquake was done when noother information could be found. The sketches basedon these explanations were drawn. Sometimes thesesketches were made by comparing the target space witha similar style of architecture or construction.

For modeling selected cases of the main two axes ofthe site, despite having state-of-the-art 3-D modelingtools, we had to choose the most suitable techniques
for the shapes of mud brick buildings from among avast number of options and functions. The modelingR
was done with the 3ds MAX
tool. Although thistool is good for modeling animations and games28) ,it posed complexity for modeling components withcurved shapes and vaults. The key approach was to select the most suitable function among the large optionsof the tool.
Because comprehensive software for modeling architectural buildings could not be found, different tools
were used together to overcome the shortcomings ofeach one. Modeling buildings is better done by drawRing precise lines. Auto CADtool provides betterRfunctions for drawing lines than MAX. Therefore,
in some cases, the basic lines of walls and arches wereR
drawn as DWG files and then imported to MAX
tocomplete the model.
The 3-D model of the Citadel of Bam has extremelycomplicated semantic information for each of its elements. First there are building types; then data re27)

The map was provided by Ms. Maryam Nezari, formerly of the Bam recovery project, and Ms. Mahshid Jafarizadeh of the Bam recovery project.
R
28)
Autodesk 3ds Max
3D modeling, animation, and rendering software helps design visualization professionals, game developers, and visual effects artists maximize their productivity by streamlining the process of working with complex scenes. http://usa.autodesk.com/adsk/servlet/index?id=5659302&siteID=123112 [7 Jan, 2008].

3DCG reconstitution and virtual reality of UNESCO world heritage in danger: the Citadel of Bam

Fig. 15 Annotated primary data using different resources for 3-D modelers.

sources with different levels of accuracy and quality.
Different groups were involved in developing the 3D models of the different buildings. All these factors
made the systematic and semantic modeling essential.

5.1 Layer management of the 3-D models
To create semantic annotations of components, to coordinate and manage the process of drawing 3-D models between various teams, to avoid errors when merging the different models into a unified one and to control the correctness and quality of the modeling of different groups, the research team defined a systematic
layer naming for the components of the 3-D model andcreated technical drawing guidelines for the 3-D model
developers.
Layer management is the process of naming andmaking different categories of layers for the 3-D models according to their characteristics in the target building. The name of a layer corresponds to the semantic
categories of the 3-D model. The layer names were kept
short and written in such a way that different developers could easily recognize, define, and modify them;
therefore instead of a word, a single letter indicated thespecific subject in the layer. In some cases, these letters were different from international standard abbreviations. The reason was to make the names and usage

shorter and more practical.29)
5.2 Layer naming and related semantics
The chosen 3-D modeling tool does not support thedesign of an advanced schema with a hierarchy ofclasses, attributes of classes, and instances (like ontology schemas). Hence, we devised a simple methodology similar to linguistic morphology30) by defining
affixes to name different layers as a single string.
PrefixPrefix indicates the most general information about alayer. In our case study, the prefix refers to the type ofbuilding (Table 2).
Infix
Infix specifies the data type. The 3-D model is basedon the basic data resources such as architectural maps
(plan, façade, sections). 3-D laser scans, 3-D carto29)
For more specific information please refer to these references: Architectural
Graphic Standards, 1912, 1951, and 1956; Time Saver Standards, 1966; Skidmore, Owings and Merrill Drafting Standards, 1986; Holabird & Root DraftingStandards, 1987; Nagle Hartray & Associates Standards, 1989; Murphy/Jahn
Office Reference Manual, 1973; Braun/Skiba Standards Manual, 1990; Recommended Standards on Production Procedures (the so-called ”POP Manual”),
Northern California Chapter AIA, 1980; Graphic Communication in Architecture, William J. O’Connell, 1972; Interior Graphic and Design Standards, S.C.
Reznikoff, 1986.
30)
http://en.wikipedia.org/wiki/Morphology (linguistics) [7 Jan, 2008].

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Table 2 Layer management abbreviations for development of 3-D models.
Type of
Layer
Name
PrefixAbbreviation

Infix

Suffix

r
l
f
w
d
t
o
g
Suffix+i
Suffix+e

Full Name

Description

name“Vague”

name of building identifying its function
The building doesn’t have a name, there is a lack of data on the building,or the building is small or less important (the 3-D model is conceptual).
The component is part of a circulation element like a street.
topography of groundgreen spaces and natural scenerycity or defensive walls
imprecise maps (mostly surveyed before quake)precise maps (mostly surveyed before quake and corrected after)
photossketches by skilled experts
maps of similar style of construction or shapelaser scan
3-D cartography maps

circulation
topography
landscape
wall
1
2
3
4
5
6
7
roof
wall
floor
window
door
topography
ornament, decoration
green spaceinterior component
exterior component

topography inside the area of the building
little gardens in the interior spaces of houses
component below the ceiling of a closed spacegraphic maps, and similar data are also basic resources.
Photos, movies, and sketches are complementary resources. In some cases in which the building was destroyed, the sketches created by experts who remember
its spaces are also used as reference maps.
The infix specifies the accuracy of the corresponding
part of the 3-D model according to the basic maps. If
the reference maps are inaccurate and the modeling isdone based on the photos, then the 3-D model is not a 1
to 1 precise map. The list of infixes is given in Table 2.

can be accessed by the function ‘layer’ from the main
toolbar. Each layer has some attributes such as colour.
The models were developed in the first phase of research by using the layer management method. It provides the modelers and users with the following opportunities:

SuffixThe suffix specifies a building component or architectural element. Moreover, it specifies the location of
the component in the building as an interior or exterior
part. The suffixes mentioned here are simply defined asa single alphabet abbreviation of the component name
(Table 2).

• It is possible to make one or more layers transparent (by changing the ‘opacity’ of the component inRthe ‘material editor’ function of MAX) and seethe rears of the target component, and thereby tocheck the correctness of the drawing.

5.3 Application and constraints
R
The layer manager in MAXis a powerful tool fororganizing and managing objects in complex scenes. It• The quality control team can turn the layers off oron and analyse the components of the 3-D model
without having to deal with complicated technicalmodeling details.

• It shows how the metadata corresponds to eachcomponent (type of building, type of data, type ofarchitectural element, etc.)• Each layer can have a different colour; it is easy to3DCG reconstitution and virtual reality of UNESCO world heritage in danger: the Citadel of Bam

recognize when the components of the 3-D modelinterfere with each other.
• The user can search inside the 3-D models to retrieve specific components according to the layer
management metadata.
• All the models are merged into a basic 3-D model
without errors that can arise from files with similarnames.
Fig. 16–21 show how this layer management is used
to structure the model of the “Four Seasons” building.

The space was once used as a reception room for distinguished guests and was located at the highest pointof the citadel.
One constraint of using the layer-based 3-D model
arises from the minds of the modelers. Normally inRMAX
modelers build models with objects and groupof objects. Layer management and layer-based 3-DRmodeling are originally based on AutoCAD
, anotherR
product of AutoDesk . Although the modelers haddifficulty in shifting from object-based to layer-basedmodeling, layer-based modeling provided a more systematic 3-D model and an opportunity to give semantic information to each component. Over the course oftime, the modelers were able to adapt themselves andtheir results to the layer management techniques dis-Fig. 19 Interior roof component and layer name “fourseason-2-ri”.
Fig. 16 View from the Four Seasons building of the other3-D models of the Citadel of Bam developed in the firstphase of research.

Fig. 20 Exterior roof component and layer name “fourseason-3-re”.

Fig. 17 Floor component and layer name “four season-2-f”.

Fig. 18 Wall component and layer name “four season-2-l”.

Fig. 21 Complete 3-D model of Four Seasons building
and associated attributes.

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cussed above.

6

3-D modeling of entrance (main gate),
bazaar, and Four Seasons building

The modeling of entrance (main gate), bazaar andFour Season building was done by the University of
Waseda team31) . The entrance (main gate) of the citadel
was the first case selected for modeling. Here, we givea sequential description of the modeling tasks. Notethat the reference of the 3-D reconstitution is the shapeof the entrance just before the quake. This is different
from the original shape before the restoration process.
6.1 Process of modeling
The entrance was modeled with a specific method as
it was connected to the rampart in an irregular architectural shape. Here, we explain the modeling processR
and the functions of MAXthat we used for this pur32)
pose .
To make the walls, we traced the lusterware image
Rin the plan with Adobe Illustrator
, then imported theRlines and Bezier curves to MAX to convert each intoa spline object. After the conversion, we applied the‘Loft Modifier’ together with the height extracted fromthe elevation data to make the wall. Modeling the entrance itself required us to reproduce the curved shapeon three axes. For this, we traced three plans at different
heights, imported them, converted them into spline objects, and arranged these objects according to the converted plan of the heights extracted from the elevation
data. In addition, the top of each object was related bya ‘Crossing Session Modifier’ to make wire fame, anda surface was made for the wire frame. We transformed
the wire frame by using free form deformation (FFD)
while referring to the original photograph to complete
the curved wall. For the battlement of the entrance wall,
we traced the elevation to get the spline shapes andpushed it out to make the bare-bones model; finally wetransformed the bare-bones model by using FFD along
the wall (Fig. 22 and 23).
For architectural elements like doors and windows,
we made the entrance part with a door-object making
tool. During the modeling, we referred to the photographs to decide the number of glass windows, thewidth, etc., of the window frame. We referred to thelatest photos of the entrance taken just before the earthquake.
Modeling the Four Seasons building involved mak31)

This part introduces the models which are developed under supervision of
Associate Prof. Dr. Takashi Kawai., Mr. Nobuaki Abe (for the main gate
(entrance) and Four Seasons building and Ms. Asaka Ito and Mr. Ha Young
Yoon (master’s degree student of Waseda University) for the bazaar.
R
32)
The functions of MAXare cited inside quotation marks, e.g., ‘Polygon
Edit Modifier’.

Fig. 22 Modeling of battlement before transformation using FFD.

Fig. 23 Modeling of battlement after transformation using
FFD.

ing less complex shapes but more decorations. We
started making the roof of the dome by referring to its
shape in section or elevation. First, we displayed thelusterware section image of the elevation with AdobeR
Illustrator
, and traced it with Bezier curves. The
R
curves were imported to MAX, and after rotation
around a central axis were converted into the face ofthe dome by using ‘Lathe Modifier’. In the final step,
we performed transformations by comparing the modelwith the original photograph (Fig. 24).
To make the chalk-band decoration (ornament), we
used an edge made by using Boolean or Shape Merge.
First, we selected the edge with the chalk band, andthen cloned the spline to be extruded after applying
the ‘Extrude Modifier’ to get the depth; we applied itwith necessary thickness by using the ‘Shell Modifier’
to complete the model.

3DCG reconstitution and virtual reality of UNESCO world heritage in danger: the Citadel of Bam

Fig. 24 Roof surface of the dome of the Four Seasons building.

Figs. 25 and 26 Reference photograph used for camera matching (left, photo credit: ICHTO), and image rendered from thesame aspect as the reference photograph (right).

Camera matching technique
The use of photographs taken before the earthquake
has played an important role in this project. In particular, rendering of the CG model from the same aspect asthese photograph materials has made it much easier tomake comparative study of the CG model and the photograph material (e.g., compare Figs. 25 and 26). To
do so, we used the ‘Camera Match’ utility. To findthe common characteristics of the photos and model,
the camera setting was calculated for when the specific photograph was taken. After that, we reproduced
the same camera setting in a specific scene of the CG
model. This enabled us to render from the same aspect
as the original photograph (Fig. 27).
6.2 Process of adjustment
The camera match technique has a number of difficulties; its accuracy is especially a problem. However, comparing the ruins before the earthquake withCG restoration model at the same angle was an effective
way of modeling and correcting decorative parts likesmall holes in walls and the precise shapes of arches.
The shapes of model elements such as arches werecorrected after receiving the expert evaluation (section8) (Figs. 28-30). As can be seen in the figures shapeof the arch was modified according the photo and theguidelines provided by the evaluators so that it properly
replicated the original one.
Since the CG model was based on an unreliable plan,
we collated it with cartography data and corrected it
when necessary. After allocating ‘Polygon Edit Modifier’, we stretched and corrected the model by using‘soft selection’. Before making the corrections, we
compared the 3-D cartography data with aerial shots
taken from the building in a movie that was made before the earthquake (Figs. 31 and 32).

7 3-D modeling of mosque, Sistanihouse, Tekkiyeh, barracks, and stable
The University of Tehran team developed detailed 3D model of five cases among the important buildings33) .
33)
This part introduced the 3-D models developed under the supervision of
Associate Professor Dr. Alireza Einifar and M. Arch. Mr. Said Einifar and the
Raazahaang company’s team of 3-D developers, Mr. Human Kian-Ersi, Mr.
Pouya Khosro Jerdi, and Mr. Morteza Hengofti in modeling the tekkiyeh, Sis-

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R
Fig. 27 Snapshot of “Camera Match” utility inside MAX.

Figs. 28, 29 and 30 Example of arch shape modeled from elevation data (left), original photograph (middle, photo credit:
ICHTO), and transformed arch shape based on the photograph (right).

The Mosque was the main prayer place in the citadel
and one of its most ancient buildings. Sistani house wasa precious house of a noble inhabitant and had been themain office of ICHTO in Bam before the earthquake.
The Tekkiyeh was a religious and ceremonial place fortani house, mosque, barracks, and stable.

mourning, the performance of rituals, and the holdingof historical-religious events. The barracks housed thearmy and governor’s soldiers; the stable kept army andgovernment horses. All these places were of architectural excellence and key places in the citadel.

3DCG reconstitution and virtual reality of UNESCO world heritage in danger: the Citadel of Bam

Figs. 31 and 32 Modification of the 3-D model of Four Seasons building (in grey) by referring to 3-D cartography map (redlines). Before adjustment (left) and after adjustment (right).

7.1 Process of modelingTo draw the 3-D model of the five case studies,the first step was to modify the basic maps in theR
AutoCAD
software. The modified maps were imported from DWG or DXF34) to MAX, and the geometry, layers and spline rendering parameters of the imported file were then adjusted. In the primary models,
the data were used to draw the solid volumes of external
spaces.
The next step involved drawing the internal and external spaces by referring to the technical drawings andlayer management guidelines (see section 4). In thisstep, the 3-D cartography map (see section 3) was used
to draw the external roof layer35) .
Buildings were primarily modeled without ornaments. Each building component like a floor, roof, wall,etc., was similarly modeled in 3-D, in separate layers
and with specific borders. This was a difficult task as
the software did not provide good options to define precise borders of architectural elements. We tried to reduce the intersection of volumes and make the borderof each element explicit.
Each floor was drawn in a separate layer as an independent volume. Walls and pillars were excluded
from these surfaces. Based on technical guidelines, elements such as stairs which arose from the floor wereconsidered to be part of the floor layer. Ceilings androofs were defined as internal and external roofs, respectively. They were drawn as separate surfaces indifferent layers. ‘Mesh’ was adapted for drawing ceiling surfaces with regular shapes. Some irregular roof
surfaces were created by ‘poly modeling’.
The modeling of the ceilings was a challenge because of the serious lack of 2-D maps. The models wereR
Drawing Interchange Format, or Drawing Exchange Format of AutoCAD
files.
35)
The roof of the tekkiyeh was an exception. The reason was lack of information on the cartography map. In this case, aerial photos taken after the
restoration process were used.

34)

Fig. 33 3-D model snapshot of Sistani house, from themain yard toward the wind catcher tower after rendering.

based on pre-earthquake sections, very limited numbersof photos, and a technical analysis of the construction
methods. Sometimes, the arched shape of the ceiling
was reflected in the facades and could be modeled fromthem. In most cases, the structure of the vault and ceiling influenced the 3-D cartography map of the roof.
Therefore, the ceiling was controlled by the roof surface that was modeled according to the 3-D cartography map. One problem was the incompatibility of theinternal and external surfaces of the roof in some places
that were drawn using two different sources. The 3-D
cartography map was used as the reference for modifications to minimize the errors in the thickness between
roofs and ceilings (Fig. 35).
Modeling the facades was easier because we had access to better photos and maps. But in most cases,
the arches were not correctly drawn in the 2-D maps.
Therefore, the geometrical methods for drawing different arches provided by the team of evaluators of NII
were important guides for modeling facades. Snapshots
taken from the model of Sistani house and model of the

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stable are shown in Fig. 33 and 34.
The 3-D cartography map was used to smooth theappearance of the external roof surfaces. The mesh of
the external surfaces of the roof had to be reduced forthe files of the 3-D model to be able to be imported to
the VR environments without error. In this case, the‘optimize’ function was used to reduce the number ofmeshes and polygons.

Fig. 34 3-D model view of the stable after trial renderingand texture mapping.

Fig. 35 Inner and outer arches and vaults of roof of thestable model.

7.2 Process of modification
The 3-D modeling of mud brick buildings with traditional arches, vaults, and details was a new experience
for the team. Each 3-D model was corrected (and insome cases remodelled) in three major stages according
to the evaluation report of errors provided by the teamof supervisors (see section 9). For example, Fig. 36, 37,
and 38 present these three stages for the model of themain iwan of the mosque. The details and shapes wereenhanced in the photos. The modelers gained valuablelessons for modeling similar buildings.
Drawing of ornamentations
Ornamentations were categorized into four types.
The most common ornamentations were chalk bands.
These were in fact an aspect of a construction technique for controlling the borders of geometrical volumes between chalk and mud-straw covering and werelead frames for constructing the arches. The chalkbands were added to the models as a general group ofornamentations. These ornamentations were drawn as
separate volumes using the ‘mesh modeling’ function
and were adjusted to the main volume of the building.
These ornaments were fixed in the right place by using
the ‘locking’ function. The general ornamentations also
included ornaments on the external walls of the stable.

Fig. 36 Preliminary model of mosque, ancient iwan (Feb. 2006).

3DCG reconstitution and virtual reality of UNESCO world heritage in danger: the Citadel of Bam

Fig. 37 Corrected model of mosque, ancient iwan after some modifications (Feb. 2007).

Fig. 38 Final model of mosque, ancient iwan after correction and modification (Oct. 2007).

They were drawn by 3-D modeling instead of mapping(Fig. 42).
In addition to these general ornamentations, there
were three specific groups that needed combinationsof different MAX functions to draw. These groups
included the ‘muqarnas’36) of one of the mosque’s‘mehrabs’37) , mud brick details on the stable towers,
36)

Use for the network of small, repeated cellular forms resembling bottomless
niches and sometimes corbelled and structural, more often suspended and decorative, which form the undersurfaces of vaults and domes common in Islamicarchitecture. (fromhttp://www.getty.edu/research/conducting research/vocabularies/aat/ [7 Jan,2008].
37)
Mehrab is an arch recess in a mosque indicating the direction of the Qebleh
and where the ‘Emam-e Jama’at’ stands. Qebleh is direction toward whichprayers are rendered and Emam-e Jama’at is a person who, in a congregational
prayer, stands in front of the congregation and is followed by it in the ritual(Haji-Qassemi, 1998).

and the chalk decorations and fire places of rooms on
the first floor of the stable. Modeling of these ornamentations required various techniques, such as 3-D drawing of volumes and mapping of two-dimensional patterns.
• Muqarnas
There are muqarnas ornaments in the two ‘mehrabs’of the mosque and in one of the fire places on thefirst floor of the stable. The largest and complicatedone in terms of geometry was the main mehrab of themosque. Muqarnas ornaments are complicated geometrical forms, and are defined as a ‘type of roofing harmoniously combining concave elements of equal
size’ [13]. The rational way of modeling the muqarnas
is to find and draw it from precise two-dimensional ge-

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Fig. 41 3-D model of the mud brick work decorations of
the tower of the stable.

Figs. 39 and 40 Photo of muqarnas of the mosque and its
Rgeometry generated using AutoCAD
software.

ometrical plans and its elevation. The pictures of themuqarnas were thus analysed and compared with othersources on the geometry and categorization of muqarnas (for instance, Lorzadeh, cited in Raees-zadeh andMofid [14]), and muqarnas maps of three levels weredrawn (Figs. 39 and 40). The 3-D model was drawn by
finding the heights of these detail from pre-earthquake
photos. We used the ‘NURBS38) modeling’ function.
One important point here is that there are differences
between the pre-earthquake data and the drawn model.
These differences arose from the restorations conductedin different times, which have caused errors in geometry. Further work would entail modification of themuqarnas volumes based on the pre-earthquake photos
and its real appearance.
• Mud brick decorations of stable tower
The stable building had two towers in the south-west
and south-east corners. Both towers had mud brickornaments. These ornaments were restored with clay
and straw covers. Before the earthquake, part of the
mud brick ornaments of the south-east tower had been
uncovered, whereas the ornaments of the south-west
tower had been completely covered by mud and straw.
Photos from before the earthquake were used as basic
information for drawing the ornaments.
In addition to the ornamentations, there were holes in
the walls of the towers that had to be represented in the38)

Non-Uniform Rational B-Spline.

models. The holes’ two-dimensional pattern was drawnRand edited in Adobe Illustrator
, and then the pattern
was matched with the surfaces of the towers. The third
step used ‘displacement’ function of MAX to change
the pattern into a 3-D model, and the model was editedby ‘poly’ modeling. The fourth step was to smooththe covered and uncovered ornamentations by using the‘subdivision surface’ in the ‘editable poly’ function of
MAX (Fig. 41). Although, this drawing provided a precise model of the towers, the file was quite large. The
whole stable model would become very large if thesefiles were added to it. The problem was thus how to
reduce the number of meshes, while maintaining themodel’s quality.
• Chalk decorations of room on first floor of stable
The house of the ‘Mir-Akhor’ (the stable keeper) is
located on the north-west side of the first floor. It contains three rooms, and each room has a decorated fireplace (Fig. 42). The main challenge for modeling thishouse was the need for a combination of 3-D modelingand mapping. The main volume of the fireplaces wasmade by 3D modeling. Two-dimensional patterns wereR
drawn from photos by using Adobe Illustrator
. Thesewere mapped and adjusted to the 3-D model (Fig. 43).
In addition, there were small muqarnas on the top of thefireplace in the middle room. The muqarnas drawings
were based on information extracted from photos by using the camera matching technique (Fig. 44). The modeling team checked resulting models against the fieldsurvey data.

3DCG reconstitution and virtual reality of UNESCO world heritage in danger: the Citadel of Bam

Fig. 42 3-D model of chalk-band decorations on first floorof the stable (after rendering).

Fig. 43 3-D model of chalk-band decorations, different
methods of mapping with photo (left, middle) and 3-D modeling (right).

8

3-D modeling of caravanserai (small)and school (Mirzanaim)

8.1 Survey data
3-D models of the school and caravanserai weremade by the EVCAU team39) . The basic documents,
including the maps and a few sections of bitmap type(scanned images), and documents from before therestoration process were incomplete. As the models
must show the buildings after they had been restored,
the lack of data was a serious problem.
A few low-resolution aerial photographs offered few
details and were from three different periods: before
restoration, after restoration, and after the earthquake.
Unfortunately no photographs showing details of theinteriors of these buildings were available. The 3-D cartography in DWG format showed the contour lines on
39)

This part introduced the 3-D models which are developed under the supervision of Associate Professor Dr. Olivier Bouet and M. Arch. Frank Chopinheaded by Mr. Andr Del and the EVCAU students for modeling small caravanserai and school of Mirza Naim by Ms. Vida Gholipour, Mr. Benoit Guillou, Ms. Sahar Ghaderi and Mr. Majid Bequali.

Fig. 44 3-D model of muqarnas with chalk-band decorations on the first floor of the stable.

Fig. 45 Preliminary 3-D model of school of Mirza Naim.

the domed roofs of the buildings.
The imprecise documents were used in preliminarymodeling that experimented with a variety of modelingmethods (for instance, ‘Patch modeling’ or using ‘space
warps’ for the roofs), as shown in Fig. 45 and 46 thatwould allow for future refinements. The preliminarymodels had to fit the 3-D cartography map as shownin Fig. 46. We explored various methods of modeling(Patch, use of the surface tools, NURBS, for editing
curves and surfaces, spline extrusion, mesh, polygons,
displacement mapping). However, because the basic
data had such low precision and resolution, a new physical survey of the site had to be done to get enough data.
SurveyA survey of the citadel of Bam was conducted during
a workshop in January 2007. This survey, which initially was intended as a guide to completing the modeling, motivated us to modify the content in a fundamental way. After the survey, we found the following
shortcomings:
For the Mirza Naim school:

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Fig. 46 First trial of comparative 3-D modeling of small caravanserai.

Fig. 47 Data survey of caravanserai and metadata management of the surveyed information.

• Differences in ground levels.
• Differences between the original plans and the surveys.
• Few systematic and regular categorizations of
niches and details. Each room had to be treatedindependently.
• Difficulty in distinguishing the borders of thebuilding from nearby buildings (The school of
Mirza Naim is surrounded by three adjacenthouses).
• Missing parts for which the only available documents were sketches based on recollections of ex-

perts who remembered the building.
For the Small Caravanserai:• Missing parts for which the only available documents were sketches based on recollections of experts who remembered the building.
• Changes made to the building and deformations
due to the earthquake.
• Lack of constructive systems of typologies forvaults and arches.
• Lack of regularity of niches and details. Eachroom was treated independently.

3DCG reconstitution and virtual reality of UNESCO world heritage in danger: the Citadel of Bam

Photographs of every part of these buildings, theirinteriors and external frontages, and details were systematically collected and indexed in a database.
Sketches and surveys were added to the database.
3-D cartographic data were also collected with a 3D measuring system (Total Trimble Station 3600) as
a complement to the 3-D cartography from the IFCA
project. The measuring points were remarkable spots,
and they were used as control elements of the model.
Metadata management of surveyed information
The whole data set became the subject of a systematic nomenclature; each room has a name, a level number (ground floor, first floor, etc.) and a number order
beginning with the rooms facing north. Each part was
described using photographs, sketches and computerdrawings in DWG and DXF formats. The vaults wereclassified by their method of construction (barrel vault,
cloister vault, etc.), and the niches were also classified.
The various materials were also classified (Fig. 47).
This information was important for precisely generating data to reflect the changes in the geometry of thebuildings that occurred over time and from deformations of the ground. They were not used as basic data,
but as supplementary data for checking and modifying
other recorded data as shown in Fig. 48.
8.2 Process of 3-D modelingApproaches
Different techniques can be applied to develop 3D model surfaces (Fig. 49), and the modeling teams
took two approaches. The first was a mixed modelingR
R
that started on AutoCAD
and continued on MAX;R

the other was done entirely with MAX . There areRrisks to modeling entirely in MAX. All the resources
are used, but more particularly editing polygon andmeshes.

Two aspects and emerging them
Here we introduce 2 aspects of modeling which canbe emerged for the case of this research. The strategic
aspect is the choice of the assembly of various building elements. It is important to determine the fragmentthat needs to be assembled given the constraints on thevarious objects which compose them, their partitions or
their connections as referred to in the guidelines (seesection 4).
The technical aspects of modeling (that requires
knowledge to make rigorous and precise model) can becontinued until the individual handling of a great number of vertexes.
With a view to future model development, the dependence techniques that can be used for relational modeling would seem judicious. However these techniques
suppose to have complete knowledge of the compo-

Fig. 48 First trial of 3-D modeling the small caravanseraiand dependence reference of corresponding points.

Fig. 49 Different methods of surface modeling (mesh, Poly, Patch, NURBS).

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nents of the model.
Patch modeling
Patch modeling and surface tools control curved andsurfaces by using a minimum of points; the disadvantage is the lack of precise details; the drawings are more
approximate than ones drawn geometrically, in particular, with respect to tangents. The patch technique is
not suited to the varying level of detail in the survey
on the two buildings. Moreover, as the complexity ofthe model increases, the modifications prove to be delicate and the dependences make the task difficult. Worsestill, precision is lost when patches are converted into
meshes and details are lost during optimization of themesh after conversion (Fig. 50) [15].
NURBS modeling
The concept of dependence is inherent in NURBS.
NURBS modeling seems to be more practical for deducing from the curves and existing surfaces and forkeeping between them a link of dependence. However
it is necessary to pass by splines for a correct geometrical construction for example when drawing arches.
Splines can be converted into NURBS with good precision, but the need for rebuilding the NURBS curves tocontrol the number of points slows down the modelingprocess. Moreover the topology of the mesh does nothave the desired regularity when returning to the meshmodel (Fig. 51) [16].

Poly modeling
Although modeling by polygon and the editing themesh with all the editing tools is an artisan-like approach, it is nevertheless effective. Poly modeling allows a case-by-case approach, and each room of thebuildings is different in its own way in order to answer all the surveyed geometries. However, the functionalities of these tools are not always compatible with
the need for managing dependences. Each modification
implies a new realization of the model (Fig. 52). This

Fig. 50 Example of patch model of vault of a room in caravanserai 3-D model.

Fig. 51 Example of NURBS model of interior of vault of a room in caravanserai 3-D model.

3DCG reconstitution and virtual reality of UNESCO world heritage in danger: the Citadel of Bam

Fig. 52 Example of poly model (NURBS transform of polygons) of interior of vault of a room in caravanserai 3-D
model.

Fig. 54 Example of mesh model of a vault in caravanserai
3-D model.

ing process induced errors because the modelers were
CG experts and not architects or historians. Therefore,
the research team supported and supervised their output40) . To assure the 3-D models’ technical quality andtheir similarity to the real building, we undertook analytic and comparative research to establish a quality
control process for the 3-D models and promptly reported errors to the modelers.
9.1 Modifications
The research involved architects who were experts
on historical architecture and 3DCG experts. We evaluated the 3-D models against the available data resources(described in section 3) and told the team of developers
about the errors. The errors reported were categorized
as follows (see also Table 3).

Fig. 53 Example of mesh model of interior of vault of aroom in caravanserai 3-D model.

Errors of architectural details and traditional methods• Dimension errors in the superimposition of themodels and 2-D maps (plans, facades, photos)• Adjustment errors in the superimposition of themodels on the 3-D cartography map

kind of modeling is like Japanese origami, which involves meticulousness and attention to details.
Fig. 53 shows a mesh modeling of a cloister vault (amesh is simply a collection of vertices that define a 3-D
object [17]), and Fig. 54 shows one for a ribbed vault.

9• Errors in architectural details that were revealed
after comparing the models with photos taken before or after the earthquake. These included errors
in the type of arch, drawings of vaults, missing details or elements such as windows or light holes,
lintels, step, walls, and floors, errors in drawing

Technical evaluation and supervisionof modifications

The different teams developed 3-D models by using heterogeneous data such as maps, photos, and 3-D
cartography map. The teams needed to take an analytic, comparative and semantic approach. The model-

40)

Technical control of 3-D models is done by Mr. Mohammad Reza Matini,
Doctorate of Engineering and Dr. Elham Andaroodi, who evaluated the technical quality and architectural details of the 3-D models.

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the brick parapets and decorations such as chalkbands, etc.
Layer naming and semantic errors• Errors in naming layers according to layer management guidelines, errors in prefix, infix, or suffixof the name string• Errors in grouping components under a layer, suchas grouping the top of a wall under the layer ofroofs, etc.
Technical 3D modeling errors• Errors in modeling showing for example, seams
on what should appear to be solid pieces of wall,interference of different faces or solids, errors indrawing meshes especially of the interior vaults,
and errors in Boolean functions for making volume sections, error of border between different architectural elements in the model.
After analysing the coincidence between 3-D models
and the data resources on each building, the evaluators
sent the developers modification reports indicating theerrors in each part of the model and supervised the corrections. The developers are currently in the process ofcorrecting and adjusting the 3-D models of first phaseof Bam VR project.
This process involves step-by-step comparative 3-Dmodeling, and it requires precision and patience fromeveryone involved. Lack of primary references has
made this process time consuming and complicated.
The fact that the real heritage is seriously damaged
added urgency to our task. Our 3-D model might be
the only reference for a heritage may completely disappear from the real world. As an example the 3-D modelof Sistani house was requested by a team of restorers
in Bam as a reference for physical reconstruction41) so
precision of 3-D model was essential.
A comparison of the initial 3-D models and the final ones reveals considerable improvement in both themodels and the modelers’ skills.

10Construction
space42)ofvirtualOmegaSpace is also space construction software. It enables real-time rendering in a PC environment and it
can be used in various fields. Moreover, it can be extended to a cyberspace type of system on a network
whereby two or more users can use a single VR simultaneously. Thus, the VR space can be shared andcooperative work can be done in it. The process of
preparing the VR of the simulations is shown in Fig. 55
the VR demonstration enables users to interact with thecomputer simulated spaces and walk virtually inside thebuildings displayed on screen.
10.1 VR preparation process
Before importing the 3-D models to the VR tool, it
was necessary to combine all the 3-D models into a unified environment. The basic map to superimpose the 3D model was 3-D cartography map imported to the tooland fitted to a black-and-white aerial photo taken after
the earthquake. The 3-D models were attached to theirpositions by using the geographical features (longitude
and latitude) of the 3-D cartography map of each building. The whole file was then exported to OmegaSpace.
The layer management insured the least error during theprocess of merging the models.
The model was output in VRML form with coordinate information and read into OmegaSpace. The
model could be lit arbitrarily, and two or more cameras were set up in each building. The walk-throughcould be done by switching cameras with a joystick.
Moreover, we added a collision detection mechanism
to prevent the operator from walking through walls andother objects in the model [18]. Images from the firsttrial VR demo of the citadel’s main axes are shown in
Fig. 56 and 57.
10.2 VR demonstration
OmegaSpace provides a viewing and interactive environment for 3-D and VR modeling. Nevertheless thecomplete application and virtual demonstration needspecific demonstration technology. Three state-of-theart technologies that can be used for this purpose are:• Cave: A virtual theater that includes a surroundscreen, surround-sound, projection-based virtual
reality (VR) system44) .

reality

The VR space of the completed 3DCG model is intended to be a basis for future restoration work. The
OmegaSpace VR presentation software developed by
Solidray Co., Ltd43) was used to build the VR space.
41)
A Dresden University team experienced in the restoration of traditional mud
brick structures who is in charge of reconstruction of Sistani house under supervision of Prof. Wolfram Jäger and Dipl.-Ing. Christian. Fuchs.
42)
This section is coauthored the same as section 6.
43)
http://www.solidray.co.jp/ [7 Jan, 2008].

• Responsive Workbench: a 3D interactive workspace. Computer-generated stereoscopic images
are projected onto a horizontal tabletop display
surface via a projector-and-mirrors system, andthey are viewed through shutter glasses to generate
the 3D effect45) .
44)
45)

http://www.evl.uic.edu/pape/CAVE/oldCAVE/CAVE.html
http://graphics.stanford.edu/projects/RWB/

3DCG reconstitution and virtual reality of UNESCO world heritage in danger: the Citadel of Bam

Table 3 Evaluation of 3D models and proposed modification.

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Fig. 55 VR workflow using OmegaSpace tool.

Fig. 57 First trial of VR demo of the Citadel of Bam.

Fig. 56 Snapshot of VR scene from the top of citadel looking toward the city.

scopic and autostereoscopic VR displays.
• 3D displays: any display device capable of conveying three-dimensional images to the viewer.
Visbox or VisDuo 46) displays, planar SD
stereo/3D monitors47) and head mounted displays(HMD) such as 3DVisor48) are examples of stereo46)
http://www.visbox.com/stereo.html?gclid=CKGz1OmCx40CFRYYAod62oOGQ
47)
http://www.sharpertechnology.com/planar.html/
48)
http://www.3dvisor.com/

Each of these devices is defined inside the VR viewing and interactive freeware and can be used to create
three dimensional images. The virtual reality demonstration of the VR theater in the Forbidden city of China
is an example of an innovative application for revivaland representation of a cultural heritage49) . We are
currently testing the system that would be best for the
Citadel of Bam VR demonstration.
49)

http://www.barco.com/entertainment/en/references/references.asp?ref=2536

3DCG reconstitution and virtual reality of UNESCO world heritage in danger: the Citadel of Bam

11Conclusion and future perspectives

This paper described collaborative research on developing a three-dimensional reconstitution and virtual
reality of Bam and its cultural landscape, a UNESCO
world heritage in danger. This research is now in theprocess of final modifications to the 3-D simulationof major buildings along the two main axes destroyedin the earthquake of 2003. These models were madeas precisely as possible by using heterogeneous data
(Fig. 56).
11.1 Demonstrations
The preliminary VR demonstration was presented
in a workshop that was held at the Citadel of Bam
in September 2006. The open house of NII in June2007 also had a virtual tour inside the digitally restored
citadel.
A virtual demonstration was broadcasted by NHK
in its ‘SOS from World Heritage’ program in May
200650) . In this program, the NHK Virtual Studio System [19] provided the virtual walk-through of the narrator inside the 3D simulation of the entrance and bazaar.
The two models were separately loaded onto the virtual system in four sections to optimize the number ofpolygons as follows:
Entrance model (outside): 25517
Entrance model (inside): 20535
Bazaar model (inside): 11206
Bazaar model (aerial shot): 15992
Each of the sections became the background with asimple texture mapping, as shown in Fig. 58 and 59. As
the narrator walked through, she explained the virtual
restoration of the entrance and bazaar.
The latest demonstration of this project was provided by NHK at the anniversary of the earthquake in26th December 200751) . It was a short report in thenews “good morning Japan” about latest achievementof modeling the 2 primary axes with walk through inside the 3-D model of Four Season building and the Sistani house.
The project was also introduced at, the Nihon Keizai
Shimbun cultural section on December 21st 200452)
and Mainichi Weekly on September 15th 200753) .

50)

The program producers were:
Mr. Atsunori Kawamura - Executive Producer, Mr. Junichi Okamura - Executive Producer, Mr. Satoru Nagai - Senior Producer, Mr. Ryoichi Ogane Program Director/Producer.
51)
Produced by Mr. Taro Mitamura, Science Reporter of the International Department of NHK.
52)
Written by Mr. Masahiro Tamura, staff writer, cultural news department,
editorial bureau, Nikkei shimbun.
53)
Written by Ms. Akiko Ogawa from Mainichi Weekly, the Mainichi Newspapers.

11.2 Main achievements
The main achievements of our research till now are
as follows:• The CG simulation was done by simultaneously
exploiting different data resources: 2-D maps,
photos, cartography maps, movie, sketches of experts, etc. were used together to complete themodel.
• The research to determine the original shapes ofdestroyed buildings aided the 3-D modeling teamin increasing the model’s precision.
• 3-D modelers, architects, historians, and CG experts worked closely together to create the output.
• Application of layer management added semantic(type of building, type of resource, type of component) to 3-D models.
• Remodeling and technical evaluations enhanced
the technical quality of the output to be used as
accurate digital documentation even for physicalrestoration.
• Scientific exchange between students, researchers,
and professors from different nationalities enhanced their level of knowledge of CG modelingand historical architecture. This research provided
them with knowledge and experience they can use
for 3-D documentation of similar architectural heritages made from mud.
• The task of managing a large modeling process illustrated differences in the modelers’ approaches
toward 3DCG.
• The VR demonstration revived buildings of the
Citadel of Bam which are now impossible to visit
in the real world.
11.3 Future tasks
We will complete the 3-D modeling, and will provide rendering and texturing of the buildings to giverealistic views. and will devise a semantic VR demonstration with accompanied metadata such as textual orvisual annotations. Moreover, a survey on the site todetermine the next case studies for modeling will benecessary. The potential survey locations are shown in
Fig. 60.
The following tasks are involved in the second stage ofmodeling:• Model case studies of important buildings including the governor’s house, commander’s house, the

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Fig. 58 Entrance (main gate) of the citadel and virtual narrator, photo courtesy of NHK.

Fig. 59 Virtual walk inside bazaar, photo courtesy of NHK.

second, third, fourth and ancient gates, the surrounding and defensive walls, and slopes and othertopography (as specified in Fig. 60).

• Prepare a new VR demonstration• Develop a multilingual and metadata-basedknowledge model proper for annotation of the
3-D building models

11.4 Proposal for future modeling process• Do analytic and comparative research on the vague
parts of the Citadel of Bam, the ordinary people’s
residences, and make a simple simulation of these
districts (red parts of Fig. 60).
• Properly render and texture the developed 3-DmodelsAs a solution to increase the technical quality andcorrectness of the 3-D models, to reduce the numberof errors in 3-D models, and to make the process ofmodeling faster and avoid remodeling, we propose thata semantic wire-frame 3-D simulation complementary
exploiting heterogonous data resources be used by the
3-D model developers as their main reference. The research plan is illustrated in Fig. 61.

3DCG reconstitution and virtual reality of UNESCO world heritage in danger: the Citadel of Bam

Fig. 60 Proposal for future 3-D modeling on the site plan.

11.5 Proposal for open access to Internet data
Currently, a report on the VR of the Citadel of Bam
is accessible at the DSR project website of NII54) . The
following is proposed for the future demonstration of
the 3-D model and the virtual reality demonstration aspart of the Digital Silk Roads [20].
• Interactive map and photos from the 3-D models• MPEG format walk-through of the 3-D models• QuickTime virtual reality demo of the 3-D models
Furthermore, an ontology knowledge model will be
developed to provide a Topic Map application on theInternet and link different types of resources and the 3D models with its metadata and related topics such as
typology.
This work is a practical contribution related to thesubjects of digital archives and 3DCG on solving the
problems affecting the revival of a real-world heritage
damaged in a natural disaster.

Acknowledgements
The authors would like to express their sincere gratitude to Prof. Masao Sakauchi (Director General of NII)
54)

http://dsr.nii.ac.jp/bam/virtual/Bam-VR-report-V3.pdf [7 Jan 2008].

and Prof. Yohichi Tohkura (Deputy Director Generalof NII) for supporting Bam 3DCG Virtual reconstitution project. In addition, we greatly appreciate thecooperation and support of the Iranian Cultural Heritage and Tourism Organization (ICHTO), Dr. Hossein
Tayyari (previous head of the Bam restoration project),
Dr. Mahmoud Nejati (Deputy of Research & TechnicalConsultant, Recovery Project of Bam’s Cultural Heritage), Ms. Mahshid Jafarizadeh (expert of Recovery
Project of Bam’s Cultural Heritage), Ms. Mahsa Momenzadeh (Recovery Project of Bam’s Cultural Heritage), Mr. Akbar Taghizadeh (head of the Pardisan
project), and Ms. Fariba Farzam (head of ICHTO Documentation Centre). We would like to appreciate too
Ms. Fatemeh Farahani (head of cultural sector of the
Iranian National Commission of UNESCO) for her support.
We also appreciate former Director General of NII
Prof. Yasuharu Suematsu, Prof. Emeritus Takeo Yamamoto and members of the Digital Silk Road project,
Prof. Yoshiyori Urano (GITI, Waseda University), Assoc. Prof. Fredric Andres (NII), Prof. Pierre Lebigre(EVCAU), and Prof. André Del (EVCAU).
We would like to thank other contributors who provided us with photos, movies and documents related

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Fig. 61 Process of analytic and comparative research on available data resources for development of a line-based 3-Dmodel as a wire-frame-map basic modeling resource.

to Bam especially Mr. Ryoichi Ogane (NHK) and Ms.
Atsuko Tai (NHK) and Ms. Chihiro Ohkubo. Special
thanks to team of modelers Mr. Human Kian-Ersi, Mr.
Pouya Khosro Jerdi, and Mr. Morteza Hengofti, Mr. Ha
Young Yoon, Ms. Vida Gholipour Mr. Benoit Guillou,
Ms. Sahar Ghaderi and Mr. Majid Bequali.
This work is partially supported by Grants-in-Aid for
Scientific Research (Category A: Principal Investigator
Kinji Ono) by JSPS.

Organization, 1997, pp.11–21. (in Persian)[4] A. Ibn e Haugal, Surat-ol-Arz, Translated by J. Sho’aar,
1345, Tehran. (in Persian)[5] A. Gruen, F. Remondino, and L. Zhang, “Image-based
Reconstruction and Modeling of the Great Buddha
Statue in Bamiyan, Afghanistan, International Archivesof the Photogrammetry,” Remote Sensing and Spatial
Information Sciences, Vol.XXXIV-5/W10.

[1] M. Mehriar, “the history of Citadel of Bam”, Publishedreport of archaeological studies (in Persian), Bam recovery office, Iranian Cultural Heritage and Tourism Organization, 2004.

[6] D. Miyazaki, T. Ooishian, T. Nishikawa, R. Sagawa,K. Nishino, T. Tomomatsu, Y. Takase, and K. Ikeuchi,“The Great Buddha Project: Modeling Cultural Heritage Through Observation,” Proc. 6th Int. Conf. Virtual Systems and MultiMedia (VSMM 2000), Dec. 2000,
pp.138–145, 2000.

[2] A. Karimi, The architecture of Citadel of Bam and the
Silk industry, Proc. the second congress of the historyof Iranian architecture and urbanism, Iranian Cultural
Heritage Organization, 2001, pp. 233, 267. (in Persian)[7] J. Stumpfel, C. Tchou, and N. Yun et al. “Digital Reunification of the Parthenon and its Sculptures,” 4th International Symposium on Virtual Reality, Archaeology
and Intelligent Cultural Heritage, 2003.

[3] H. Tayyari, “The report of the results of the projectof Citadel of Bam from 1372 (1993) till 1374 (1995),”
Proc, the congress of the history of Iranian architecture
and urbanism, Fifth Volume, Iranian Cultural Heritage[8] J. Jacobson and J. Vadnal, “The Virtual Pompeii
Project,” Proceedings of World Conference on ELearning in Corporate, Government, Healthcare, andHigher Education, 2005.

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Kinji ONO
Kinji ONO is a professor emeritus
and special appointment professor for
Digital Silk Road project at National
Institute of Informatics (NII) and visiting professor of Waseda University.
He received his B.S. in physics fromthe University of Tokyo, M.Sc in electrical engineering from Stanford University, and Dr. of engineeringfrom the University of Tokyo. After serving as director of the Research Laboratories of KDD, he became
professor and director of R&D at NACSIS in 1993. After NACSIS was reorganized into NII in April 2000, he
served as professor and executive director for research
until March 2004. His research interests cover computer communications, network architecture and protocol, distributed multimedia, digital archives of cultural
heritage. He served as vice chairman of TSAG of ITU,
program chairman of ICCC ’99, chairman of Information Access of CULCON, co-executive director for the
Digital Silk Roads Initiative Framework (DSRIF) of
UNESCO, and chairman of the Tokyo and Nara Symposium of Digital Silk Roads. He received the Purple
Ribbon Medal in 2002. He is a Life Fellow of the IEEEand a Fellow of the IEICE and IPSJ.

Elham ANDAROODI
Elham ANDAROODI is a postdoctoral researcher of the Digital Silk
Road project of the National Instituteof Informatics (NII). She earned hermaster’s degree in architectural engineering from the University of Tehran
in 2001 and got her Ph.D. from NII and the Graduate
University for Advanced Studies in 2006. She has been
an expert of the Iranian Cultural Heritage Organizationand had renovated Ameri-Arsham historical houses in
Bam (Iran) from 2001 to 2002.
Her research interest is knowledge management for
cultural heritages, the classification of architectural edifices, their spatial analysis and 3-D simulation. She hasreceived award of cultural research of the year 2001,
from the Ministry of Culture and Islamic Guidance, andthe Young Khwarazmi award of the year 2002, from the
Ministry of Science, Research and Technology for her
research on caravanserais of the Silk Roads in Iran.

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Alireza EINIFAR
Alireza EINIFAR is an associate professor of architecture in the Facultyof Architecture, University College
of Fine Arts, University of Tehran.
He received a master’s degree inarchitecture from the University of
Tehran and a Ph.D. in the same field from the University of New South Wales, Sydney, Australia. After serving as head of the School of Architecture, University of
Tehran from 1997 to 2000, he was Director of Postgraduate Studies at the Faculty of Fine Arts from 2000 to
2005. After an administrative change of faculties to the
University College at the University of Tehran, he now
serves as vice chancellor for Planning and Development
at the University College of Fine Arts. His major areaof research is the history and theory of architecture, andhis special interests are cultural landscape and environmental studies.

Mohammad Reza MATINI
Mohammad Reza MATINI received
his master’s degree in architectural
engineering from the Faculty of Fine
Arts, University of Tehran, in 1998.
He worked for five years in architecture offices as designer in Tehran and
Mashhad and was a lecturer of architecture at Azad
University of Mashhad from 1998 to 2003. He received
his doctor of engineering degree from the Faculty ofArchitecture, University of Stuttgart in 2007.
His major interest is the development process of architectural designs based on geometrical patterns andimplementation of computer aided design as a tool tofacilitate the formation process. He used this method totransform natural principles into convertible structuresin architecture in his doctoral thesis. He is currently a
post-doctoral researcher at National Institute of Informatics.

Nobuaki ABE
Nobuaki ABE is currently enrolled
in the doctoral program at the Graduate School of Global Information
and Telecommunication Studies at
Waseda University. He received his
B.A. degree in arts in performance,and M.S. degree in global information and telecommunication from Waseda University, in 2004 and 2006, respectively. His research interests include 3-D CG, digital archives, and virtual reality.

Olivier BOUET
Olivier BOUET is an associate
professor at the Ecole Nationale
Supérieure d’Architecture de Paris
Val de Seine (ENSAPVS). He received B.S. and M.S. in physics fromthe University of Paris XI and his Dr.
of optics and image processing from the University ofParis VI. He has worked on medical image processingin the GAIB laboratory (University of Paris VI) and onarcheological restitution and virtual reality at the Espace Virtuel pour la Conception Architecturale et Urbaine lab (EVCAU).

Frank CHOPIN
Frank CHOPIN is DPLG architect,lecturer and researcher of the Espace Virtuel pour la Conception Architecturale et Urbaine (EVCAU), alaboratory of the Ecole Nationale
Supérieure d’Architecture de Paris
Val de Seine (ENSAPVS). He made research on picture
synthesis in the research structures (Ecole des Minesde Saint-Etienne) before the software became commercial. During the 1990s, he worked for Ikone Infographie Corporation, one of the pioneers of picture synthesis for architectural offices. He is responsible forcourses on computer graphics at architecture schools
since 1991.

3DCG reconstitution and virtual reality of UNESCO world heritage in danger: the Citadel of Bam

Takashi KAWAI
Takashi KAWAI graduated from the
School of Human Sciences, Waseda
University in 1993. He received his
B.A., M.A., and Ph.D. degrees in human sciences from Waseda University in 1993, 1995, and 1998, respectively.
He became a research associate at the School of Human Sciences, Waseda University in 1998 and an assistant professor at the Global Information and Telecommunication Institute, Waseda University in 2000. He
has been an associate professor at the Graduate Schoolof Global Information and Telecommunication Studies,
Waseda University since 2002.
His recent research interests are the application andevaluation of advanced media technologies from theviewpoint of human factors.

Asanobu KITAMOTO
Asanobu KITAMOTO is an associate professor of the Digital Content
and Media Sciences Research Division, National Institute of Informatics(NII). He received his B.S., M.S. and
Ph.D. in electronic engineering fromthe University of Tokyo. He joined NACSIS in 1997
as a research associate and has been an associate professor at NII since 2004. His research focuses on theapplication of data-centric approaches to various academic domains, including earth science (e.g., meteorological databases) and humanities (e.g., cultural digitalarchives).

Asaka ITO
Asaka ITO graduated from the
School of Human Sciences, Waseda
University in 1997. She received her
B.A. degree in human sciences fromWaseda University in 1997.
After working on the space designof office spaces as an interior coordinator, she started
creating 3D images and editing movies on architecture and medicine. She started her own company,
Ergovisions, in 2005.

Eskandar MOKHTARI
Eskandar MOKHTARI is graduatedfrom Tehran University with a degree
in archaeology and art history anddid his postgraduate studies at Pardis University on the restoration ofmonuments and historical fabrics. He
holds a Ph.D. in art research from Azad University. His
research and maintenance projects have included over
170 historic properties in Saveh, Tehran, and Bam. Hisstudies have ranged from rudiments of Islamic architecture in Iranian penmanship in the field of contemporary
architecture to pedagogy at universities and higher education institutions in the fields of architecture, preservation, and restoration of historical edifices.
From 1994 to 2004, he was deputy-president of the
Department of Preservation and Rehabilitation of Historical Monuments of the Tehran Cultural Heritage Organization. Following the Bam earthquake in 2003, hebecame director of Recovery Project of Bam’s Cultural
Heritage.

Saeed EINIFAR
Saeed EINIFAR is a professionalarchitect and director manager ofRazahang Architectural Consultantsin Tehran, Iran. He received his M.
Arch degree from the University of
Tehran in 1981. He is a specialist incomputer graphics and an experienced photographer.
He served as lecturer in photography from 1984 to 1989
in the Faculty of Fine Arts, University of Tehran. During last two decades, his professional activity has concentrated on architectural design and practice. Oneof his major designed and constructed buildings is the
Ministry of Energy Headquarters in Tehran (completed
in 2005).

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Seyyed Mohammad BEHESHTI
Seyyed Mohammad BEHESHTI was
deputy minister and head of the
Iranian Cultural Heritage Organization(ICHO) from 1997 to 2005. He
was head of the Farabi Film Foundation in Iran in the 1990s. He is currently head of the Architecture and Urban Planning Department of the Iranian Academy of the Arts and headof the Electronic Encyclopedia of Iranian Architectural
History. He is member of the supervisors of 3DCG virtual reconstitution of UNESCO world heritage in danger, Bam and its Cultural Landscape. He received his
master’s degree on architectural engineering from the
University of Shahid Beheshti in Tehran.

Chahryar ADLE
Chahryar ADLE is currently research
director at the French National Centre for Scientific Research (CNRS).
He studied oriental archaeology andthe arts of Islam at the Ecole du Louvre (Louvre Museum, Paris), and presented his memoir to the Fourth Section of the Ecole
Pratique des Hautes Etudes (EPHE, Sorbonne, Paris).
He obtained his Ph. D. from the University Sorbonne
Nouvelle in Paris in 1976. Doctor Adle is a memberof the editorial board of the Studia Iranica and leadsarchaeological investigations in Iran and the IranoAfghan Border. He is the president of the International Scientific Committee for the Publication of theHistory of Civilizations of Central Asia (published by
UNESCO). He has been awarded the CNRS Bronze
Medal for Research (France, 1985) for his archaeological discoveries in Bastam and UNESCO’s Aristotle Silver Medal (1996) and Avicenna’s Medal for his
contributions on the subject of Central Asian civilizations. After the earthquake which devastated the regionof Bam (Iran) on 26 December 2003, he took chargeof the Franco-Iranian project on investigating and 3D
mapping of the archaeological remains in that area.