Preah vihear project: obtaining 3D point-cloud data and its application to spatial distribution analysis of Khmer temples

Preah Vihear Temple, a Hindu temple located on the border between Cambodia and Thailand, is under the need of digitization mainly because of two reasons: possible destruction of the temple, and its unique characteristics. While most of the archaeological sites from the Angkor Dynasty, such as Angkor Wat Temple and Bayon Temple, are oriented in the east-west direction, Preah Vihear Temple is one of the few archaeological sites to be oriented in the north-south direction. The first half of this paper reports the digitization project of Preah Vihear Temple. While it is possible to acquire 3D digital data of tangible cultural heritage by using existing methods, the size and location of the temple, which resides near a cliff, inhibits us from directly applying existing methods. This causes the need to design methods that are applicable for these environments. For the first time in the world, we have succeeded in acquiring 3D digital data of the entire Preah Vihear Temple, by specially designing both hardware and software that is suitable for our task. We report details of our method and present visualizations of the obtained 3D point-cloud data. The second half of this paper provides an example of an application of this 3D point-cloud data. As an example, we determine the direction of the central axis of Preah Vihear Temple using the obtained 3D point-cloud data. We also provide a hypothesis for an interpretation of the direction of the central axis by examining a Khmer legend, using the results obtained from the 3D point-cloud data.