Notes on the three dimensional photogrammetric model of second cervical vertebra of Individual Sk-04 (Winterbourne Kingston, Dorset).
By Heather Tamminen 

Contact details: Heather Tamminen, Department of Archaeology, Anthropology and Forensic Science, Bournemouth University, Poole, BH12 5BB. Email: tamminen@bournemouth.ac.uk

A two-stage approach was taken to creating the digital model of the vertebra using close-range photogrammetry (Agisoft Metashape 1.6.1). This involved, two levels of photogrammetry being used: one digitising the entire CV2 and the other digitising just the suspected cutmark. This was done to create a highly-detailed model of the cutmark that could be integrated into the overall model of the vertebra, resulting in one model at two scales. 
The image capture was performed with a Nikon D810 camera with an AF-S Micro NIKKOR 60mm f/2.8G ED lens. Both of these are full-frame or “FX”. An ISO of 100 and an aperture of 25 were used for both sets of images and the CV2 was photographed using a shutter speed of 4s, whereas 2s was used for the cutmark. A total of 17 images were used for the cutmark model and 82 images were used for the full CV2 model (41 for each view, inferior and superior). The distance from the camera to the bone was approx. 0.2m and 0.8-1m for the cutmark and entire CV2, respectively.
The two models were aligned separately, 3D control was added to each, and the dense point clouds were created. The overall vertebra model was processed in two parts (inferior and superior) before merging. After that, the cutmark point cloud was then trimmed before being “patched” into the vertebra model point cloud using additional manually placed markers and the Merge Chunk function. A mesh was created and subsequently textured with masked versions of the original images to create the photorealistic model.

References
Tamminen, H 2022. The Digital Dead: Virtual Modelling of Human Remains using Photogrammetry for Presentation and Preservation by Record. PhD Thesis, Faculty of Science and Technology, Bournemouth University.

Tamminen, H, Smith, M, Welham, K and Ford, A 2023. ‘3D printed control for commercial off-the-shelf (COTS) close-range photogrammetric reconstruction’, Digital Applications in Archaeology and Cultural Heritage 30, 1-12.