A hand-free solution for the interaction in an immersive virtual environment: the case of the agora of Segesta

The paper illustrates the project of an interdisciplinary team composed of archaeologists and researchers of the Scuola Normale Superiore and the University of Pisa. The synergy between these Centres has recently allowed for a more articulated 3D simulation of the agora of Segesta. Here, the archaeological excavations have brought to light the remains of a huge public building (stoa) of the Late-Hellenistic Period. Computer graphics and image-based modeling have been used to monitor, document and record the different phases of the excavation activity (layers, findings, wall structures) and to create a 3D model of the whole site. In order to increase as much as possible the level of interaction, all the models can be managed by an application specially designed for an immersive virtual environment (CAVE-like system). By using hands tracking sensor (Leap) in a non-standard way, the application allows for a completely hand-free interaction with the simulation of the agora of Segesta and the different phases of the fieldwork activities. More specifically, the operator can use simple hand gestures to activate a natural interface, scroll and visualize the perfectly overlapped models of the archaeological layers, pop up the models of single meaningful objects discovered during the excavation, and obtain all the relative metadata (stored in a dedicated server) which are visualizable on external devices (e.g. tablets or monitors) without further wearable devices. All these functions are contextualized within the whole simulation of the agora, so that it is possible to verify old interpretations and enhance new ones in real-time, simulating within the CAVE the whole archaeological investigation, going over the different phases of the excavation in a more rapid way, getting information which could have been ignored during the fieldwork, and verifying, even ex-post, issues not correctly documented during the fieldwork. The opportunity to physically interact with the 3D model of the agora increases drastically the level of affordance between operator and 3D simulation, and to verify with a completely new approach, issues which can be hardly investigated by using traditional 2D documentation.