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3-D imaging technology helps bring the past to life

by Mami Maruko

Staff Writer

Imagine standing in the middle of Angkor Thom in Cambodia, located next to Angkor Wat, the largest religious monument in the world, and seeing the ancient capital come to life in its entirety in front of you in three dimensions — the way it looked back in the 12th century.

This is exactly what University of Tokyo professor Katsushi Ikeuchi is attempting to do at his laboratory at the university’s Institute of Industrial Science.

His research, with that of others at the nation’s top university, known as Todai for short, is gradually being introduced abroad by foreign media through its Todai Research project, initiated in 2011 by the university’s public relations office.

The project introduces cutting-edge, innovative research coming out of Todai’s various science laboratories.

“This is positive PR. Todai’s public relations hasn’t been doing this kind of PR actively until now. We thought that we should be introducing Todai more to the outside world,” said Euan McKay, project researcher at the public relations office.

In a field generally referred to as cyberarchaeology, Ikeuchi not only digitizes data, but also thinks of ways to use it.

Ikeuchi gives two reasons for the necessity of digitizing World Heritage sites and cultural assets.

First, he says, the sites and assets are so valuable that they are worth preserving, and second, data must be collected in case they are lost.

Ikeuchi gave as examples the destruction of the Buddha at Bamiyan in Afghanistan in 2001 and the loss of Buddhas at various temples in Tohoku due to the March 11 earthquake and tsunami of 2011.

For their first project, Ikeuchi and his team collected data of the Great Buddha in Kamakura, Kanagawa Prefecture, and modeled its entire shape and color.

They went on to create in 3-D a section of the Imperial capital city of Asuka (593-710) in Nara Prefecture.

After creating the digital data, they organized a bus tour to take visitors to see Asuka in mixed reality — the rice paddies of today overlaid with 3-D computer-generated models of ancient Asuka structures — that could be seen at different angles through special cameras mounted on the bus.

Visitors could even see the historical scene of the assassination of a seventh-century statesman, dramatized by Ikeuchi’s students, by wearing head-mounted displays (special goggles).

In the last decade, the project team has worked at the huge Bayon temple complex in the center of Angkor Thom. It covers an area of 160 meters by 140 meters, and stands 45 meters at its highest point.

Ikeuchi said the team used different kinds of sensors depending on the locations and distances to scan and gather data for constructing a 3-D model.

For example, an aerial laser scanner was used to scan the entire surface of the complex.

The scanner makes use of a GPS unit attached to a large helium balloon.

A sensor equipped with a mirror was used to scan the reliefs from the ground level.

To generate a 3-D model, data are acquired by scanning a shape from different angles. Once gathered it is integrated using computer software developed by associate professor Takeshi Oishi from the laboratory.

Using mixed reality, which merges virtual and real-world objects, Ikeuchi and his research staff reconstruct and preserve architectural structures from the past.

Ikeuchi says that after the March 11 Tohoku earthquake and tsunami, his laboratory also got involved in a project to make a 3-D representation of the former Town Hall in Otsuchi in Iwate Prefecture — an area hard hit by the tsunami.

“This is what we’ve been engaged in as part of disaster mitigation efforts,” said Ikeuchi, adding that they plan to create a virtual monument where the actual Town Hall existed that people can see with 3-D goggles.

“Until now, these kinds of visual images were shown at theaters unrelated to the actual spot.

But if one sees it at the actual place wearing a pair of 3-D goggles, one should be able to see it in relation to the actual images one remembers,” said Ikeuchi.

Ikeuchi stressed that showing the buildings in 3-D has special value, especially for the younger generations.

“If elementary school children visit historical remains like Asuka, and are told that an Imperial palace once existed on the spot, they won’t be touched at all. They would only see the place as lumps of stones or something,” Ikeuchi explained.

“On the contrary, if they see the real buildings in 3-D format, they can actually ‘experience’ history,” he said.