Palaeolithic archaeology and 3D visualisation technology: Recent developments

This paper presents computer-aided lithic analysis conducted in the context of an interdisciplinary research framework combining computer science and archaeology – the Partnership for Research in Stereo Modeling (PRISM), at Arizona State University. Pilot projects conducted as part of PRISM serve to find real-world applications to the tridimensional visualization technology developed as part of the project. Here, we focus on one of these projects which aims at automating the lithic refitting process. The artefacts used in this study are refitted Ahmarian cores collected at Wadi Hasa Locality 623X (Lindly et al. 2000) and curated at Arizona State University. Using previously refitted material allows us to know exactly which pieces refit to which, thereby giving us an external way of testing the results of the refitting software. As well, it provides an estimate of the time involved in doing the refit manually and, by extension, a baseline for how rapid the automatic program would have to be in order to usefully substitute manual efforts. 3D models of those artefacts were created by scanning each piece using a Cyberware M15 Laser Digitizer (Figure 1). This generates a cloud of points, each of which is defined by x, y, z coordinates. The points are then topologically connected together through the process of triangulation, which results in a " mesh-frame " from which a smooth surface is extrapolated; this system of surface generation is common in computer imaging. The scanned lithics are then imported into Raindrop Geomagic 4.0 to