In this paper we present our experience in using Virtual Reality Technologies to accurately reconstruct and further explore ancient and historic city buildings. Virtual reality techniques provide a powerful set of tools to explore and access the history of a city. In order to explore, visualize and hear such history, we divided the process in three phases: historical data gathering and analysis; 3D reconstruction and modeling; interactive immersive visualization, auralization and display. The set of guidelines devised helped to put into practice the extensible tools available in VR but not always easy to put together by inexperienced users. These guidelines also helped the smoothness of our work and helped avoiding problems in the subsequent phases. Most importantly, the X3D standard provided an environment capable of helping the design and validation process as well as the visualization phase. To finalize, we present the results achieved and further analyze the extensibility of the framework. Although VR tools and techniques are widely available at present, there is still a gap between using the tools and really taking advantage of VR in historic architectural reconstruction so that users might immerse themselves into this world and thus be able to consider various scenarios and possibilities that might lead to new insightful inspiration. This is an ongoing process that we think will increase and help current architectural development.

This paper introduces the Laboratory of Technologies for Interaction(LaTIn) and briefly describes its current main projects. The mainfocus of LaTInhas been developing new ways of human-machineinteraction using computer vision techniques. The projects arecathegorized according to the distance between the human user and themachine being operated. For close distances, appropriate forinteraction with desktop computers for example, we have developed eye-gazebased interfaces. We have also built hand and body gestures interfacesappropriate for kiosks and virtual reality settings and, for largedistances, we have developed novel multiple people tracking techniquesthat have been used for surveillance and monitoring applications.