Written by Doug Moak
When I first read of 3D printing, Discover magazine reported on a “3D fax machine.” A point file was transmitted over phone lines, resulting in a transparent print of a simian skull. The article went on to proclaim that stereolithography would replace the copious backstocks of spare parts in manufacturing facilities, repair shops, and aircraft carriers; I refused to believe that scenario as a possibility. Now that possibility is the new normal, and I was dead wrong.
Stereolithography is primarily manifested in polymer resin excited by a laser, with a hobbyist’s market in desktop rapid prototype machines and websites dedicated to sharing data files that result in robot hands or Baby Groot. The bulk of the individual product are knick-knacks.
3D printing can be used for analytical purposes by virtue of miniaturized models used for study. Of the many things I was not aware of in the field of geospatial analysis is the use of raster data to produce 3D prints of natural features. Aside from nice things to place on the desk or gather dust on a shelf, these products can be used for analysis such as avalanche study, weather modeling, search and rescue, and excursion planning.
There are a couple of different ways- a raster DEM can be converted to a triangulated irregular network (TIN) file, processed through TIN Extrude Between, Decimate TIN Nodes, and Multipatch To Collada tools, then conversion to .STL using a third party Mashlab program, such as this unnamed author. Another way is to feed a DEM into Accutrans 3D, which is a pay-to-use program, explained here.
These processes have been used to produce 3D prints of Mt St. Helens, Yosemite Valley, and an accurate model of Devils Tower-out of mashed potatoes. The possibilities are not limited to exterior natural features. When my friend Clarence was sent through caves at the foot of most of the Cascade’s stratocones with a LiDar package strapped to his back, he produced point clouds that could be processed into accurate cutaway models, enabling close study of cave features by researchers who are nowhere near these caves.
These are just two ways to create tangible representations of spatial data using raster files that are usually readily available online, using processing applications that we are familiar with.