During the brief reign of the Northern Qi Dynasty (AD 550-577), part of the chaotic period of the Southern-Northern Dynasties (AD 420-589) that saw Buddhism gain increasing popularity, China's rulers carved elaborate cave temples into the mountains of what is now the limestone Xiangtangshan, or "Mountains of Echoing Halls", in southern Hebei province.
Meant to depict paradise, the caves were decorated with detailed images of Buddha and other spiritual figures. Many were looted and spirited out of China in the early 20th century, and are now housed in Western institutions.
A new exhibit at New York University attempts a virtual reunification of those objects, using 3-D technology to identify and re-create the items in their ancient setting.
"It's a beautiful marriage between traditional iconographic studies, stylistic presentations of art and 21st-century digital technology," says Jennifer Chi, exhibitions director at NYU's Institute for the Study of the Ancient World.
Echoes of the Past: The Buddhist Cave Temples of Xiangtangshan, on display until Jan 6, 2013, presents a dozen sculptures on loan from the Metropolitan Museum of Art, the Royal Ontario Museum in Toronto, Britain's Victoria and Albert Museum and other institutions.
The figures include a 1-meter-tall Buddha head dating to AD 550-559, a free-standing figure of a seated Buddha, several bodhisattvas and pratyekabuddhas (solitary Buddhas), and a number of deities.
Especially compelling is the show's 3-D reconstruction of the interior of one of the seven caves of Xiangtangshan, from which the bulk of treasures on display were excavated.
Visitors stand between three screens, onto which digitized scans of the temple caves are projected, layered with those of the sculptures. The result allows viewers a chance to experience the space as it existed hundreds of years ago.
"It's one of the most innovative and unique displays I've ever seen," says Chi, who is also chief curator of the Xiangtangshan show. "The digital cave features a combination of digital imagery, contemporary photos, archival photographs, and then these 3-D scans.
"I've never seen an exhibition that's attempted to do anything at such detailed manner."
The collection was previously shown at the San Diego Museum of Art and the Smithsonian Institution's Arthur M. Sackler Gallery in Washington, among others.
Katherine Tsiang, associate director of the Center for the Art of East Asia at the University of Chicago, led the team that initiated the project. Between 2005 and 2008, she and her associates visited museums around the world, using 3-D laser-scanning to document sculptures known to have been taken from the caves at Xiangtangshan.
"Our work is quite new," Tsiang says. "It is groundbreaking because of the use of 3-D models that can be viewed on the computer to find the original locations of the pieces by matching the traces from the caves with the cuttings on the sculptures. It was very exciting."
The research team worked closely with a group of Peking University's scholars, who used the same technology to scan the interiors of the caves. The results were then stitched together and merged with the scans of the sculptures, to create 3-D models, Tsiang says.
"The exhibition demonstrates what 21st-century techniques and a modern mentality can do to recontextualize sculpture," Chi says.
"These sculptures have always been recognized as extraordinarily beautiful emblems of early iconic Buddhist style, and have always carried historical cachet."
But the original setting, she says, can teach patrons "a lot more about the meaning and historical context of the sculptures".
For example, by reconstructing the caves in their original configurations, researchers were able to posit that the 16-seated Buddhas likely represented northern princes, she says.
There were a number of surprises, Tsiang says. Several pieces surfaced unexpectedly. The head of New York City's Morgan Library and Museum visited the exhibition when it came to the University of Chicago, and recognized a piece from an archival photo.
That sculpture, a Buddha head, had been in the Morgan's reading room since the 1950s, Tsiang says. Another had been stored in a Columbia University library basement for decades. A researcher recognized it while working on the collection.
The exhibition will likely travel to China in some form, Tsiang says. But some Western institutions would be hesitant to allow any of the sculptures to cross back into China, she says.
"There is a sensitive aspect to it, because these pieces were removed in the last century, during a period of political disorder," Tsiang says. "There was very little control or supervision of sites during that time of great political upheaval. Today, something like that would never happen because the caves are protected."
The issue of art repatriation has become acute given Turkey's recent call for New York's Met and London's Victoria and Albert Museum to return pieces that may have been looted.
"We want people to understand the consequences of looting and collecting art. Buddhist sculptures were originally meant for worship, but in the West during the early part of the 20th century, they were bought as art. As a result, many of the sculptures were destroyed or damaged," Tsiang concludes.