About a year ago I volunteered at the Cambridge Archaeological Unit for three weeks, during which I had some time to carry out some experiments with Photogrammetry with the help of some of the people there. One of the projects I carried out involved using the photograph archive they had to create 3D models with 123D Catch, to see if it was possible to create models from photographs not taken with this purpose in mind.
Looking through the archive one site in particular caught my eye, as the photographs perfect for this use: Must Farm, Cambridgeshire. The site itself is extremely interesting, and has won a Site of the Year award for the level of preservation. It is mostly a Bronze Age site, and throughout the years it was excavated it revealed a series of intact wooden boats, as well as a living structure which had collapsed into the river, waterlogging the timber frames and all that was within, including weirs and pots with food residue. For more information visit the official website http://www.mustfarm.com/.
The photographs I found were from the 2006 excavation, and they consisted of series of shots from similar angles of same objects. The number of images per feature was around 8, depending on what it was. The most common things photographed were waterlogged wood beams, pottery spreads, sections and weirs.
Generally, the number of images and the fact they were all taken from a very similar angle would mean making a model is impossible. But through different test I have found that there is an exception to this rule when the object is particularly flat. If you are photographing a wall, there is no need to go round it to create a model, all you need is to take the images from the front and then change the angle slightly. The idea is also at the root of Stereophotography, in which two images at slightly different angles give the illusion to our eyes that they are in 3D. Similarly modern 3D films use a similar idea, with incredible results.
Running the images through 123D Catch provided the proof of this theory, as in out of 40 or so potential models, around 70% were extremely good. The models had all the detail of a 3d model made with intentional photographs. Some details could have been a bit better, like some models of timber sticking out of the ground, for which only the front is available as would be expected, and the side of protruding objects which are blurry, but overall the results are amazing for what they are.
Most of the models are now available at http://robbarratt.sketchfab.me/folders/must-farm
If we consider the amount of archaeological photographs that are taken at every site, surely amongst them there is enough to create at least some fantastic models.