In recent years, 3D modeling has become easier than it ever has been before. In the past, we had to use an expensive 3D scanner, though these still have their uses. Now, however, anybody with a smartphone can make a reasonable 3D model using a program called 123D Catch. With a little more time and financial investment, we can make a model that is accurate enough to draw data from (https://sketchfab.com/models/22623871f783442a8f1779f5e52841fe).
This magical process is called “photogrammetry.” Essentially, this uses a collection of photographs from a variety of angles to create a three dimensional model of an object. What has really changed in recent years is the ease of use. Even with the professional version of Agisoft PhotoScan (a more robust, paid version of 123D Catch) the process of going from photos to a three dimensional model takes only a few steps.
There are a few limitations to this technique, however. Tall objects (such as buildings) are difficult to fully cover due to their height and size (without some creativity or a drone anyways) and the program has difficulty dealing with patterns such as plaid or other subjects that are not distinct enough, like grass. The biggest restriction is in the program’s inability to deal with movement, so live subjects are nearly impossible to record without a large and expensive rig of cameras to take all the pictures in a single instant. Fortunately, most of our subjects in archaeology are not very lively, so this is a fairly minor restriction.
The uses for such a program in archaeology are incredibly exciting, especially for underwater archaeology. Due to limitations on dives caused by weather and human endurance, it can easily take a decade to fully map a complex shipwreck. However, with five days of photographing and a few hours of processing time archaeologists can now have a highly detailed and accurate three dimensional map (https://sketchfab.com/models/6d22d91ea0f24967831e395f321477d0 https://sketchfab.com/models/3b40e2c6d8ce40a19e07f43a5ee5a2f1).
Preservation is another excellent use for photogrammetry. If an historic building is about to be demolished, a day or two photographing every possible inch inside and out can result in detailed models for the building. Alternatively, if the current political climate (hypothetically) expanded from the removal of a statue in D.C. (link) to the removal of other Civil War monuments, we have a method of preserving these monuments in a more detailed form than photographs (https://sketchfab.com/models/f9901b07e8e44207a51fc7df6d622702).
While the effect this method will have on archaeological research is impressive, imagining how it will contribute to public outreach is what I find particularly exciting. So often a site or artifact cannot be used in public outreach beyond a photograph and our enthusiastic descriptions. Three dimensional models (like this one) does more than allow someone to see it from all sides, it adds depth and texture to the image, immediately making it feel more real. Alternatively, digital site tours (https://www.youtube.com/watch?v=fcQfzuQXcq8) become relatively simple to make, and accessible to anyone in the world. If we pair these models with 3D printers, then there is almost no limit to what we could do.
A special thanks to Kotaro Yamafune for getting everybody I know excited about the potential uses for photogrammetry in archaeology.