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The ancient city of Ayutthaya - explorations in virtual reality
and multi media
Cliff Ogleby
Department of Geomatics
The University of Melbourne
Victoria, 3010, Australia
E-Mail:
c.ogleby@eng.unimelb.edu.au
Abstract
The University of Melbourne, in conjunction with Chulalongkorn University in Bangkok, has been developing a virtual reality reconstruction of the Ancient Thai City of Ayutthaya circa 1600AD.
The visualisation is based on photogrammetry, architectural history and analogy, archaeology and site surveys. Many of the missing significant buildings have been reconstructed, and a 3d VR model of the palace precinct has been produced. The visualisation also uses live actors and video production to bring the model to life. The virtual reality model has also been compiled into a bi-lingual CD-ROM for distribution to secondary schools in the Bangkok district.
This paper will detail the photogrammetric modelling process, and illustrate how the addition of live actors can give life to an otherwise sterile virtual reality model.
Introduction
Ayutthaya is presently a modern city of around 60,000 population, some 80km from Bangkok in Thailand. Part of it is a UNESCO World Heritage Site, as it was the capital of the Kingdom of Siam for around 400 years up until 1767CE, and contains ruins of many of the religious structures from this and previous periods. In its day Ayutthaya (there are many variations in the spelling of this word like Ayuthaya, Ayodhaya and Iudea for example) was reported to be one of the most spectacular cities anywhere in the known world. Today it is a collection of monuments and precincts surrounded by the bustle of a modern regional city in Thailand.
The University of Melbourne in Australia, and Chulalongkorn University in Thailand are conducting a joint research project to re-create the greatness of Ayutthaya in the form of a photo-realistic, three-dimensional virtual world heritage model. In order to achieve this, photogrammetric records of the remaining monuments have been combined with early written records of the city and the assistance and expertise of the Royal Thai Government Fine Arts Department. The basis for the creation of the CAD models is, in many cases however, the photogrammetric record which will be described later. The models resulting from the research has formed the basis of a series of 'visualisations' and animations of the city, which are under continual development and enhancement.
A Glossary of Thai architectural terms is available at the end of the paper.
The Ancient city of Ayuthaya
Ayutthaya was a well established town before it became the capital of Siam, following the fall of the previous 'capital' at Sukhothai. It was supposedly founded by a Prince of Ut'ong (U-Thong) in the year 1350 or 1351. Or, more to the point: ... So he had his troops cross over and establish themselves on Dong Sano Island.... In 712, a Year of the Tiger, second of the decade, on Friday, the sixth day of the waxing moon of the fifth month, at three nalika and nine bat after the break of dawn, the Capital City of Ayutthaya was first established [i.e., Friday March 4th 1351, shortly after nine o'clock in the morning] (Wyatt 1984, translation from Cushman). It is named after Ayodhaya, the home of Rama in the Ramayana epic, which means 'unassailable' in Sanskrit. It is set on an island situated at the confluence of three rivers; the Chao Phrya (also known as the Menam, which flows south to the sea via Bangkok), the Lopburi and the Pasak.
Ayutthaya became one of the wealthiest and greatest cities in Asia, and attracted the interest and awe of visitors. In the 16th Century, travellers from elsewhere in Asia and Europe were arriving in Thailand, for trade in both goods and Christianity. Visitors, traders and missionaries from Portugal arrived around 1511, from Japan around 1690, from Holland around 1605, England around 1612, Denmark around 1621 and France in 1662. Many of these foreign missions were allowed to settle effectively as 'embassies' and it is from many of these travellers that the historical details of Ayutthaya can be discovered (for example Tachard, 1688, in Smithies 1995).
The city is associated with a high time in Thai history, with the borders of Siam extending into Burma, Cambodia and Malaysia. It was also a period of many wars, and Ayutthaya was severely damaged on several occasions. In time, the large canons of the Burmese Army once again helped to conquer the Kingdom of Ayutthaya, and on January the 7th 1767 CE the resultant fire consumed much of the inner city, destroying some 10,000 houses. Ayutthaya did not rise again, and eventually the capital of Siam moved to Bangkok leaving a ruined and plundered landscape. As a result, all that really remains of the greatness of historical Ayutthaya are the chedi, prang and defaced statues of the temples; all of the timber buildings, the palaces and the houses from the period are gone. The city of Ayutthaya was synonymous with Siam the Kingdom in the 18th Century. After the 2nd World War, on May 11 1949, Siam was renamed Prathet Thai, or Thailand as it is known to the world today.
Data Acquisition
A variety of data sources have been used in the virtual reality reconstruction of Ayutthaya. Many of the significant chedi, prangs and statues were documented using photogrammetry, giving a good geometric basis for the modelling process. Numbered targets were temporarily fixed to the monuments and coordinated using radiation surveying. Features on the monuments were also used as control points, coordinates for these points were derived from reflector-less EDM measurements. The approach taken was the more traditional stereo-photogrammetric technique, with stereo-pairs being acquired from baselines, but also augmented with convergent photography for control densification. The stereo-pairs were then measured using an Intergraph ImageStation photogrammetric system.
In addition GPS measurements were made to a series of ground control pints in anticipation of small format aerial photography (Fraser, C. S. et al, 1995) being acquired, however the discovery of recent digital base maps meant that this was not eventually necessary. This provided the three dimensional location of the structures, as well as terrain information.
This provided information on dimensions, there was the need to obtain information on many other aspects of Ancient Ayutthaya.
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