By Julian Smith
In May, a film production company and deep-sea mapping company announced that they had completed the first full-scale scan of the wreck of the Titanic. The 3D digital model of the wreck was created by combining more than 715,000 sonar images with 4K video footage shot by submersibles in more than 200 hours of surveys. It shows the entire ship in astonishing detail, down to individual rivets, as well as the 3-mile-long debris field that surrounds it. Engineers and historians can now use the data to study how the ship broke apart and sank, without having to take a risky submersible dive in person.
The Titanic may be in a class by itself, but there are countless archaeological sites and artifacts that can and have benefited from the research and attention brought by 3D mapping. The technology is revitalizing the field of archaeology by bringing detailed copies of sites and artifacts into the digital world and, through 3D printing, back into the real world. As scanning and printing devices become cheaper, smaller, and more powerful, researchers are putting them to more and more creative — and practical — uses.
3D mapping involves scanning an object from all sides (or as many angles as possible, when only part is visible) with a digital scanning device, ranging from satellite-based LiDAR to the latest iPhone, and recording the data as a cloud of points in 3D space. This point cloud can be converted into a “mesh,” a huge number of tiny triangles connected edge to edge that represents the surface of an irregular shape. Researchers can rotate the shape in digital space, zoom in and out, and sometimes even see certain features that would have been difficult or impossible to see in person. A 3D printer builds up a replica of the shape by laying down many thin layers of plastic.
Archaeologists, educators, and museums use 3D models to analyze, measure, and reconstruct fragile or inaccessible artifacts in ways they never could in the real world, without having to touch them. They can share models easily, and use them as teaching aids and tools for public outreach.