Computer graphics and three-dimensional modelling techniques extend the abilities of archaeologists in the visual reconstruction of ancient sites, and monuments, reproduced with high level of realism. Modern computational systems allow the implementation of virtual hybrid scenarios tailored to human cognitive capacities. Although Virtual Archaeology is not a novelty in the panorama of the archaeological methods, no agreement there is among the scholars on the minimal parameters necessary to rebuild an ancient context, nor any requirement is needed to guarantee the accuracy and the effectiveness of the reconstruction; the strength of a model is based mainly on the capacity of the archaeologist to control the final result in terms of interpretation and hypothesis. From this point of view archaeologists need to participate in large teams including different experts in order to adopt a multidisciplinary approach to data processing, visualization and validation.

The paper aims at exploring how the archaeologists in a computational laboratory perform their work. The case-study selected is the recent virtual reconstruction of the so-called Basilica in Herculaneum, a monument - 250 years after its discovery - still largely unexplained. Although still completely buried by the volcanic lava save for part of its entrance porch, this huge building was extensively explored by tunnels and looted by its early excavators. Different scholars based their reconstructions mainly on the basis of two plans, drawn in ‘700, and few notes taken by the archaeologists during the exploration. The 3D model, carried out by integrating cad modelling with close-range photogrammetry techniques, aims at highlighting some controversial parts of the reconstructions. Metadata associated to the digital replica describe the physical object and register all phases from data-acquisition to data-visualization in order to allow the validation of the model and the use on re-use of the digital resource.