Harvard Graduate School of Design academics use Leica Geosystems’ compact imaging laser scanner to map indigenous cave structures for the very first time.
Nearly 1,000 years ago, the Pueblo people settled in an area of New Mexico near the flowing banks of the Rio Grande. There, they found soft volcanic tuff perfect for carving out homes, storehouses, and communal spaces in large villages that spanned miles. These carved architectural structures, or “cavate dwellings” were cool in the summer and warmed by easterly light in the winter — a type of natural, sustainable architecture.
Those features piqued the interest of Jialei Tang and Gracie Meek, two graduate students at the Harvard Graduate School of Design. Meek, because of her specialization in landscape architecture, and Tang, because of her focus on urban planning.
“A longstanding curiosity of mine is the relation of things. I wanted to dissect the different considerations that people or stakeholders hold and the construction of our built environment to infer cultural and socioeconomic structures from the resulting aesthetic, functionality, and use,” Tang explained. “And urban planning is a synthesis of everything because what you review is how things are built, how things are executed, and then also how they're preserved.”
But to really dig into what makes these structures unique, they needed to create digital twins of the cavate dwellings, which would complement their photography, drawings, and other study materials. For that, they reached out to Leica Geosystems to get their hands on the Leica BLK360.
“I always knew there was a project in Bandelier,” Meek said. “I wanted to draw it, scan it, model it.”
For Tang, laser scanning the site was also part of the philosophical conversation around preservation.
“With Bandelier National Monument, we wanted to explore what gives it value today and why we devote resources to uphold it,” she told Leica Geosystems. “And then, why do we test out new technologies, like laser scanning, and how does that contribute to larger cultural conservation efforts and its future?”
“Because something virtual is, in a way, immortal. Whereas materials break down,” she added.
In the desert with the BLK360 — and the tourists
Meek and Tang cleared their project with National Park Rangers who safe keep the park, but they weren’t given unfettered private access to the cavate spaces. They would still have to contend with the regular flow of tourists who come to explore these indigenous artifacts.
“There were a lot of people walking by, so our scans included caterpillar-like figures [from peoples’ movements],” Meek said. “But most visitors, including the rangers, were intrigued by the project.”
“It was also surprising in how many people we ran into were acquainted with the idea of laser scanning and the conversations that sparked,” Tang said. “And then we'd say, ‘Oh, this is the Leica Geosystems version, and we could do this on an app,’ and they were amazed at how handy this was.”
The tandem started out scanning the Long House, an 800-foot-long serpentine run of cliff dwellings up to four stories tall. It took them around three days to scan the complete structure, with setups every 10 to 15 feet, and the dodging of the occasional thunderstorm.
“We weren't expecting issues with thunderstorms because it wasn’t monsoon season yet,” Meek explained. “So we had to be ready to go up to the threshold of the clouds and then take a gamble.”
But that bet paid off — much to their delight — and that of the park rangers.
“Every day after scanning or during lunch, we'd go back and show the rangers what we had done on the app, and they were so keen to see it,” Meek said.
Capturing the Main Pueblo Cliff Dwellings
After scanning the Long House, Tang and Meek went to scan the Main Pueblo Cliff Dwellings, a more complicated project with some daunting nooks and crannies.
“The Main Pueblo Cliff Dwellings was a lot more complex to maneuver with stairs and rock spires throughout,” Meek said.
That meant getting creative with scan setups – and working on their sprints.
“There were interior caves we crawled into, so we had to set the tripod inside at its lowest level. It was nice the tripod collapsed so short because the caves are only about three or five feet tall,” she explained. “So we'd put the phone underneath the tripod, hit the scan button, run outside, and sit on an exterior ladder while we waited for the scans to finish.”
“It was an adventure!” Tang said.
The team said that Leica Cyclone FIELD 360 app was an indispensable part of the laser scanning experience.
“The field app was straightforward to learn and very user-friendly,” Meek said. “The point clouds registered to each other like magnets — each new scan automatically snapped to the previous one. We loved how incredibly easy and seamless the data collection process was by such a precise instrument.”
A multi-media exploration
But laser scanning is only one important part of the researchers’ project. To truly capture the scope of the site, they viewed it from all angles, including a variety of traditional media.
“We took a lot of photos, everything from Polaroids to experimental 35mm film and panoramas to digital and thermal imaging,” Tang explained. “The results were fun to look at when we could compare film to a laser scan to a digital photo. We were able to capture some of the different sensibilities of the space.”
They also said they were surprised by the unique perspectives on the geological and architectural forms that the laser scans were able to provide, aided by uploading to Reality Cloud Studio, powered by HxDR, and creating some virtual tours.
“Being able to see the backside of the cliff surface and the “shells” of the caves was compelling because, for the first time, we could experience the cliff’s negative space,” Meek said. “The scanner allows you to access a new interpretation of the ruin system.”
“We filmed a tour in Reality Cloud Studio through one of the caves, and it’s challenging to experience the cave system in one smooth movement because you’re climbing over boulders and crouching under low ceilings,” she said. “The holistic flythrough allows you to see the space differently and a lot more clearly.”
As for what’s next, Tang and Meek are working on exhibition proposals to Harvard and Cornell for a multimedia gallery showing in the fall of 2023 that would represent an exploration of the cavate structures and what they learned from the project, including a hands-on demonstration of the point cloud, and 3D printed models of the area generated from the meshes they obtained from their scans and processed in Leica Cyclone 3DR.
Those printed models got the staff of the National Park Service intrigued too.
“When we were talking to the rangers at Bandelier, they asked us to make one for them for their Visitor Center, because it provides a novel and comprehensive perspective of the entire cliff dwelling system for the visitors to interact with,” Meek said. “We're really excited about that.”