Old exhibits archived in 2-&-3D


Two and three-dimensional documentation was being conducted last week at Pipestone National Monument’s Visitor Center in preparation for the new exhibits and changes to some of the building’s historic features.

The two dimensions were being rendered through black and white photographs, the three dimensions with laser scanning technology. Both were documenting what it all looks like today prior to dismantling the space.

The Monument’s current exhibits, installed in 1958 in the main gallery at the Visitor Center, are scheduled for removal and replacement with exhibits that have been six years in the making. The new exhibits will be installed by year’s end.

Austin Butterfield, GIS specialist with the Midwest Archeological Center, was about half a week into the two-week scanning project last Wednesday that involved the operation of a Trimble TX8 3D laser scanner. The equipment sits atop a tripod, spinning and rotating to create a “point cloud” of the interior structure by shooting out millions of laser points. Software then reads the data to create an accurate, 3D representation.

The scans of the 1,400-square-foot space can be exported to AutoCAD to make measured drawings or as a video file that will allow viewers to walk through the space digitally. The Monument will use the scans most immediately on a monitor at the Visitor Center while the new exhibits are being installed.

“Mainly, we’re trying to give people who come to see the museum exhibit and are wondering what we’re doing and why we’re doing it, a chance to see where we started while the museum is closed off, particularly the main gallery,”  said Anne Dowd, Ph.D, the Monument’s interdisciplinary cultural resources program manager. “And then secondarily to have this record so if somebody wants to learn about this Mission 66 Visitor Center Museum exhibit, they can reference it and study it and compare it to other examples around the country.”

Meanwhile, out in the hallway, Daniel Pratt, a freelance photographer/archaeologist, was working with equipment that’s been around since the 19th century capturing images that will be submitted to both the Library of Congress and the Minnesota State Historic Preservation Office. He uses photographic standards he helped develop for the Minnesota Historical Property Record.

“So you’re always balancing as much information as you can pack into the shot, also portraying the property as people see it,” Pratt said. “It’s delicate.”

Both the photography and the laser scanners are used to record significant historical places and landmarks the way they were before changes were made, Dowd said. Sometimes, those changes are dramatic, like demolishing a building. Sometimes, those changes are conservative, like the hallway space that Pratt was photographing last Wednesday.

“We’re making a few changes but we’re keeping the layout, we’re keeping the floors, which are original, we’re keeping the beams, the windows will stay the same,” Dowd said. “But there are some minor changes, particularly where new exhibits will attach to the walls.”

Once the documentation is complete, Dowd will begin removing objects from the cases.

“I do that by hand,” Dowd said. “I’ll be going case-by-case around the room. That will take several weeks. Then we’re going to modify the interior in preparation for the new exhibit. All-in-all, we’re hoping to be finished in 2019.”

 

Daniel Pratt, photographer/archaeologist, uses this camera to document for state and federal agencies what the Monument Visitor Center looks like today. He describes his camera as “actually very simple, with a film sheet in the back and a lens up front and nothing but empty space in between” and with “an underwhelming shutter sound.” He was using a 65 mm wide angle lens, and 4 x 5 inch film to accommodate the tightness of the hallway and to create greater detail and resolution. D.A. Fitzgerald

 

 

 

 

 

 

 

 

 

The output screen above shows the unedited, 3D image of the main gallery at Pipestone National Monument that was created through the collection of some 2 billion data points — four complete scans, collecting 550,000,000 points per scan. Little white ceramic spheres, or ‘targets,’ were placed around the room to tie all the scans together. On the screen is the raw data, or the ‘point cloud,’ that software has read from the data to render the three-dimensional space. Laser technology similar to this was used in 2010 to document Notre Dame Cathedral in France. The output from those scans may aid the rebuilding of that structure by offering accurate renderings of the construction as it was. D.A. Fitzgerald