More Caves From China’s Yungang Grottoes are Reproduced Thanks to 3D Printing

Archaeology labs, museums, and cultural heritage institutions around the world have been using 3D printing technology to fabricate countless objects and provide access to cultural heritage. Thanks to additive manufacturing, experiencing artwork, buildings, artifacts and other pieces of a country’s history has become easier, not only because people can get closer to traditional heritage without damaging the real objects, but because their reconstruction can enhance research, documentation, and preservation. The Yungang Grottoes Research Institute in the city of Datong, in the Shanxi province of China, has been using 3D printing technology for over five years to replicate some of the famous caves from the 1,500-year-old Yungang Grottoes, a UNESCO World Heritage Site.

The Institute has recently announced the full-size reproduction of one of the caves in the Yungang Grottoes, which is expected to debut soon in one of the museums of the Zhejiang province. According to the official state-run Chinese press agency, Xinhua News, the replicated grotto is based on the original Cave Number 12, also known as the ‘Cave of Music’, and consists of more than 1,300 printed modules. Standing at nine meters tall, 12 meters wide and 14 meters long, the replica is the latest integration of technology and heritage protection.

“The replica of the grotto is made of light materials and can be dismantled and pieced together like building blocks. In the future, we can display it worldwide to help more people learn about the Chinese culture,” revealed Ning Bo, director of the Digitalization Office of the Yungang Grottoes Research Institute.

With 252 caves and more than 51,000 statues within a carved area of 18,000 square meters, the Yungang Grottoes represent the outstanding achievement of Buddhist cave art in China in the fifth and sixth centuries. Built under Imperial instructions, they are known to have a far-reaching impact on Buddhist cave art in China and East Asia and receive thousands of tourists every year.

The original Cave of Music’s intricate designs displays row upon row of carved musical instruments, statues, and references to the Buddhist faith. The sandstone of the cave is bathed in hues of red and yellow that make each piece of carving stand out from the rest as it reveals the painting style and musical instruments of the Northern Wei Dynasty, as well as the court orchestra and social music system of the time. Its elaborateness makes the cave very difficult to replicate. In fact, Bo said that it took around three years to complete the project, which includes data collection and processing, 3D printing of modules, and coloring.

Cave Number 12 (Credit: China Discovery)

For the past six decades, the special organization Yungang Grottoes Research Academy was established to carry out protection, monitoring, and regular daily maintenance as part of conservation intervention to counter some major threats to the site, including water seepage, rain erosion, weathering, and loose rocks. According to Lu Jiwen, deputy head of the institute, they have made efforts to curb environmental pollution in the surrounding areas, reinforce loose rocks around the caves and restore the murals and statues to make the ancient grottoes regain their past glory.

In fact, researchers started exploring the digitalization of the Yungang Grottoes in 2003, trying to permanently preserve its valuable cultural relics and historical documents through digital technologies. In 2017, thanks to 3D printing technology, they were able to make a reproduction of Yungang Grottoes Cave Number Three, which was displayed in the eastern coastal city of Qingdao. And in 2018 residents of the capital city of Beijing were able to take a closer look at the 1:1 replica of the ancient relics of Cave Number 18, considered to be one of the most exquisite caves due to the large Buddhist sculptures that are carved in full detail. In this case, it took the team two years to complete the replica and they utilized more than 20 3D printers for the job.

“The Yungang Grottoes attract a large number of visitors from Qingdao annually. Most of them decide to visit the grottoes after seeing the replicas,” said Bo last year after the unveiling of the previous caves.

Yungang Grottoes (Credit: McKay Savage)

In recent years, China has been promoting digital technologies. From laser scanning to 3D modeling and photogrammetry in order to conserve cultural heritage sites, especially ancient architectures such as the ones in the Yungang Grottoes.

Zhang Zhuo, head of the Yungang Grottoes Research Institute, said that the digital platform that integrates protection, research, management, and display allows people to learn about the current condition of the grottoes and to promptly grasp the morphological changes of the cultural relics in years to come. Further explaining that if the grottoes are damaged due to natural disasters or human factors, it will be possible to carry out repairs with high precision.

High-technology methods have been used to contribute to preserving the treasured relics. Actually, Yungang Grottoes is not the only pioneer in the application of digital technologies in cultural heritage preservation and display in China. For the display and preservation of a 1,600-year-old UNESCO world heritage site known as the Dunhuang Mogao Grottoes, in China’s Gansu province, experts turned to immersion display, precious reproduction, and virtual interaction. Furthermore, digital technologies have also been adopted in creating a three-dimensional digital archive and a monitoring system for the caves.

“After years of effort, the Yungang Grottoes are in good shape and with the help of digital technologies, we have shifted our focus from rescue conservation to preventive and research-oriented protection,” indicated Jiwen.

As the replica of Cave Number 12 prepares to go on display in Zhejiang, more than 20 relics workers are simultaneously treating the cracks and other erosions of the original cave, expecting that the combined efforts will help preserve the site for posterity. This is yet another effort by a country to enhance its historical and architectonical heritage using 3D printing, like others before them, including Syria, South Korea, India, and many conflict zones throughout the Middle East and Africa that struggle to save their landmarks, China is attempting to conserve the past for future generations.