Several times over the years, weve seen 3D technologies applied to help preserve Chinas cultural heritage, from dragons and Buddhist statues to caves and columns. Now, Artec 3D has used its software and two of its handheld 3D scanners to create an extremely detailed 3D model of an architectural landmark at a sacred Buddhist site, documenting the process in a case study.

The front view of the 3D model of the archway

Mount Wutai, also called the Five Terrace Mountain, is one of Chinas Four Sacred Mountains of Buddhism. Home to over 40 temples, the Chinese National Tourism Administration named it a top-tier tourist attraction, UNESCO has acknowledged it as a World Heritage site, and millions of people have visited it every year since the 1st century CE to pay homage. Of all Mount Wutais amazing sites, Longquan Temple stands out due to what the case study refers to as a unique architectural style, largely thanks to famous Chinese artist and stonemason Hu Mingzhu. He proved himself in his mid-20s by designing a sanctuary at Longquan Temple, impressing visitors and fellow artisans with his beautiful stonework, and the next year, he won the bid to build an archway in front of the temple.

Playing with pearls, two dragons will be soaring high in the sky, Hu Mingzhou described the scene that would top his masterpiece.

The artist shaped his initial design for the archway out of yellow wax, and then made a prototype that combined stone carving with traditional Chinese woodwork patterns. It took 50 craftsmen six years but the ornate archway was finally finished in 1930. The pillars all feature artistic dragons, and the arch is on top of a 108-step staircase, this being a sacred Buddhist number. The centerpiece depicts scenes from the life of Buddha.

Ornate carving above the main gate of the archway

Its three gates are formed by four square-shaped piers supported by four columns on the front and four on the back, Artec states in its case study. The vaults of the gates are remarkable for their meticulously carved blossoming peonies, ripe persimmons, traditional Chinese writing brushes, paper fans, treasured books, etc. As well, more than 20 stone-carved lions in different postures are to be found in the middle of the archway.

Thats a lot of detail to scan in a pretty tight space to preserve a cultural work of art, but 3D scanning technology was up to the task. The two main requirements were that each element had to be rendered with absolute accuracy, with no gaps in the 3D model, and that the master has to be able to break down into separate structural parts, so the entirely of the archway can be closely examined.

A figure of a lion poised for attack

This is exactly the kind of project that handheld 3D scanning is meant for, as you can move it around the object to capture every last surface from any angle. Artec 3Ds Gold Partner Beijing Onrol Technology Co., Ltd. was contracted for the archway scanning, and chose to use both the Artec Eva and the Artec Space Spider for the project, as each has different qualities that made them ideal for the job. For instance, the Eva has a higher scanning speed and larger field of view, so it was used to complete the overall scan, while the Space Spider can achieve a higher 3D resolution of up to 0.1 mm, and a higher 3D point accuracy, up to 0.05 mm, and so digitized the archways complex details.

Close-up views of the front part of the 3D model

The team used a secure set of ladders to get to the higher areas of the archway, such as the eves, because the space was too confined for typical scaffolding equipment to be used. Additionally, sunlight seemed like it would be an issue, as it seems brighter, and reflects with a higher intensity, when scanning smooth surfaces at an altitude of 3,000 meters. Some of the scanning planned for cloudless days did have to be completed after sunset, but Artecs Studio software can analyze minor distortions in the scanners rays of structured light once they reach the surface of the object and bounce back. This made it possible to precisely reconstruct the scanned shapes.

Capturing parts of the archway with Artec Eva 3D scanners at night.

It took the team two weeks to collect all 500 GB of raw data, equivalent to 100,000 smartphone images. Because the scans from the Eva and the Space Spider are compatible, they were fused together in the Studio Software, and, when the customer saw the final 3D model a month later, they were purportedly impressed with the high quality.

Thanks to the 3D scanning technology, the entire archway, including the uppermost parts not often seen, has been preserved in a detailed 3D model, and can now be viewed in high resolution by artists, architects, sinology (Chinese studies) experts, and even students.

The first ever 3D model of the Longquan Temple archway in geometry-only model.

(Images provided by Artec 3D unless otherwise noted)

Excerpt from:
Buddhist Temple Archway Preserved in High Detail with Artec 3D Scanning - 3DPrint.com