The Digital Mogao Caves

Mogao Caves: A new era of Dunhuang ushering in. The total digitalization of the frescos in the Mogao Grottoes will not only help protect the caves but also be of great service to academia with its systematic collection of data and materials.

Mogao Caves

Roundup by Confucius Institute Reporter,
Tu Yuanyuan.

One day at noon in August 2014, a couple of sophisticated cameras were working quietly in the Mogao Caves at Dunhuang. A camera crew was shooting one of the medium-sized Buddha shrines. In the damp and dark cave, it was difficult to recognize the patterns on the shrine with the naked eye. What they were doing was taking the latest images for a huge project — the Digital MogaoCaves.

Meanwhile, in the tourist information center 15 kilometers away from the Mogao Caves, with a click of the mouse, a huge statute of Sakyamuni unfolded slowly on a bright spherical screen of 18 meters in diameter, and details of “Flying Apsaras”—the ceiling frescos ten meters high above the ground— were also in full view. The audience was amazed and couldn’t contain their excitement. From 1st August this year, tourists visiting the Mogao Caves will experience the Digital Dunhuang first in the Digital Exhibition Centre before they visit the real Caves. With the help of digital technology, visitors will be able to see the minute details of cave architecture and frescos so as to have a comprehensive understanding of the Mogao Caves as well as the historical and cultural background of Dunhuang art.

Technology is always there to meet a demand and the Digital Mogao Caves came about from the need to preserve these cultural relics.

The aging caves

To many art lovers around the world, their knowledge of Dunhuang starts with the Mogao Caves . Buttressed against the Mingsha Hill, the Mogao Caves face the Sanwei Mountains, with the Daquan Valley in its fore. The construction of this “Oriental Art Treasury” started in AD 366 and went on until 1368. Incorporating the architectural styles, frescos and painted sculptures of different ages, the Mogao Caves contained the largest collection of Buddhist art treasures in the world. Studies show that the earliest caves of the Mogao Caves were made for Buddhists to sit and meditate. Dunhuang was a strategic town on the Eurasian Silk Road. In AD 366 when northern China was in a time of conflict during the period of the Sixteen States, people suffered because of the wars and thirsted for peace. Buddhism, which had spread to China through the Silk Road and brought them spiritual belief and consolation, started to prosper.

Fan Jinshi is the Director of the Dunhuang Research Academy. On the desk in her office are two photos of the same fresco in a cave taken in 1908 and 1998 respectively. It can be clearly seen that a good half metre of the frescos at the bottom is missing in the more recent photo.

The construction of this “Oriental Art Treasury” started in AD 366 and went on until 1368. Incorporating the architectural styles, frescos and painted sculptures of different ages, the Mogao Caves contained the largest collection of Buddhist art treasures in the world.

The Mogao Caves, located at the junction of the Sanwei Mountains and the Mingsha Hill. Erosion by wind and sand has always been the caves’ No. 1 enemy. According to statistics provided by the local meteorological bureau, strong winds and sand storms occur in 48% and 47.5% of the year respectively. Small sand particles undetectable to the naked eye easily get into the caves with the help of strong winds and abrade the relics day after day and year after year. Furthermore, the accumulation of sand inside the caves leads to poor evaporation and water-logging. Stagnant water in the rainy season can permeate into the caves and cause direct damage to the frescos and statues. Nature works silently but it leaves behind powerful reminders of its ruthlessness.

Mogao Caves
The exterior of the dome theater featuring the Digital Mogao Caves.

Mogao Caves

Apart from natural factors, the increasing number of visitors, especially after the Caves became one of the UNESCO World Heritage Sites, poses another threat. The average number of visits exceeds 6,000 per day and over 700,000 per year, which is twice as many as the Mogao Caves can reasonably accommodate. Every 10 minutes of stay by every 15 visitors in a cave will cause the inside temperature to rise by 5℃ . The carbon dioxide they exhale together with the moisture causes irreparable damage to the frescos.

Since it opened to the public at the end of the 1970s, the Mogao Caves has received over 6 million visits from more than 80 countries and regions. While Dunhuang is becoming a popular tourist attraction, the dilemma between heritage preservation and commercial development is getting increasingly apparent. The Mogao Caves “is currently heading for destruction at a pace that is 100 times faster than in ancient times!” With a total of 735 caves, 492 groups of frescos and more than 2,400 painted statues covering 45,000 square metres, how can we bear to see them disappearing in front of our eyes? Ms. Fan and her team have been haunted by this issue: How do we find a balance between preservation and development? How can we ensure the Mogao Caves’ permanent survival?

After many years of work, the idea of digital Mogao Caves is becoming a reality step by step.

Mogao Caves

The digital age

The Mogao Caves only became what it is after centuries of existence, and similarly, the Digital Mogao Caves is not a project that can be completed overnight.

Fan Jinshi became involved in this project in as early as the 1990s. The Digital Mogao Caves is an essential component of the Preservation and Development of the Dunhuang Mogao Caves Project. “This is the largest, most extensive and comprehensive preservation project in the history of the Mogao Caves; this is also the component most accessible for ordinary visitors to experience at first hand,” said Ms. Fan.

With the help of advanced technology, the Digital Mogao Caves establishes classified digital archives of the caves and frescos, collects and stores digital samples of the cultural relics at Dunhuang. The details that cannot be viewed in the caves due to limited time and access can be seen in full splendour by accessing a digital terminal and browsing the panoramic simulations.

“The Digital Mogao Caves can never be made by simply using computers and cameras,” said Wu Jian, Director of the Digital Centre of Dunhuang Research Academy. There are not only professional photographers taking photos inside the caves, but also experts in charge of checking the photos outside the caves. A great many sophisticated technologies, such as intelligent image collection, high-resolution image integration and 3-D positioning and measuring, are required here. A lot of work has to be completed by research institutions working together at home and abroad. Compared with the traditional repairing method based on manual repainting, the IT-based approach is significantly faster, but it is still a daunting task to make a high-quality virtual image of a cave. “It takes five people nearly half a year to take over 4,000 pictures to complete the digitalization of a 40-square-metre cave.”.

“This is the largest, most extensive and comprehensive preservation project in the history of the Mogao Caves”
Fan Jinshi
Director of Dunhuang RA

Since 2006, the digitalization of 90 caves has been completed. At present, the speed of digitalization is 20 caves per year. Cultural relic experts and technicians are attempting to digitalize the Dunhuang scrolls and Buddhist scriptures scattered around the world and to integrate them with Dunhuang’s frescos and caves so as to create a Digital Dunhuang in the true sense of the phrase.

Rebirth of a masterpiece

The Digital Mogao Caves has created a completely new experience. With the opening of the Exhibition Centre, a visit of the Mogao Caves now consists of both the virtual and physical caves. The length of the whole visit has increased from 120 to 180 minutes, while the time spent in the actual caves has been reduced to 75 minutes, which in turn will greatly reduce the damage caused by visitors. In the past, it was hard for visitors to see details of the frescos inside the Mogao Caves unless the tour guide illuminated them with a flashlight. Today, when you are appreciating Dunhuang frescos and painted statues in an immersive 3D virtual environment, the constraints are gone and even the minutest details are clearly visible. According to the Dunhuang Research Academy, 97.3% of visitors are satisfied with the newly-opened Mogao Caves Digital Exhibition Centre, and 67% of them find the virtual experience as “terrific”.

Since 2006, the digitalization of 90 caves has been completed. At present, the speed of digitalization is 20 caves per year.

The Digital Mogao Caves is a continuing project. On a central monitor at the Mogao Surveillance Centre, real time information, such as relative humidity and carbon dioxide concentration, is constantly being updated. If any of these indices exceeds their preset limit, the warning light will turn red and the staff will take immediate action. This monitoring system has been highly praised by the UNESCO experts inspecting the site. At present, it has been installed in every cave that is open to visitors. In the near future, it will be installed in all caves.

The total digitalization of the frescos in the Mogao Caves will not only help protect the caves but also be of great service to academia with its systematic collection of data and materials. Enabling more people to enjoy the cultural heritage and  reserving these cultural relics for the future are what the technology is all about. The digitalization of this cultural heritage is calling on experts from all over the world to create a new Silk Road. Over 50,000 pieces of cultural relics unearthed along the Silk Road are scattered in various places around the world. Thanks to modern technology and international cooperation, scholars can have free access to information about them through the internet. Once digitalized, these virtual works of art will be easier to study than their physical counterparts.

In our race against time to save the disappearing cultural relics, we can’t afford to stop for a rest.


ic_ENG_34

Published in Confucius Institute Magazine
Number 34. Volume V. September 2014.

Comments

You may also like

By 

Email Newsletter

Pin It on Pinterest

Share This