The Identifiability of Osteological Traits on 3D Models of Human Skeletal Remains

Abstract: Previous studies have entertained the prospect of having 3D models substitute for their dry bone originals in osteological analysis. The objective of this study was to contribute to qualifying to what extent this may be possible given current technology. To this purpose, rather than choosing just a quantitative and purely technical method for evaluating models, as has been the norm in previous studies, a qualitative method was also applied where the visual identifiability of the traits was taken as the standard. A cranium and a metatarsal bone were chosen as case studies, and three types of models were created of each specimen – a scan-based model, an image-based model and a model combining geometry from scans with textures from photos. The relative identifiability of the traits on the different models was graded and compared, and the factors that contributed to the results discussed. The study found that while 3D models may hold some advantages over photo documentation as substitutes to originals in osteological analysis, primarily due to preserving much of the originals’ geometry, the technology also suffers some disadvantages, notably that the textures’ image quality often fall short of photos, especially when superimposed on distorted geometry generated from scans. It can also prove difficult to create models capable of representing all parts of their originals equally well without making the models excessively heavy. Furthermore, the study showed that some morphological traits were more difficult to digitize and thus less identifiable on 3D models than others, and that qualitatively evaluating 3D models is a complex and challenging task. These results challenge assertions about the capabilities of 3D models in previous studies, and suggests that establishing a common standard for evaluating digital models, such as the identifiability of osteological traits introduced here, is a desirable development in digital osteology.