Systematizing Virtual Reconstructionof Lost or Never Built Architectures

European Architectural Cultural Heritage is immense. Yet part of this Heritage is invisible: churches, synagogues, mosques that have either been destroyed or never been built. Now the digital world offers the possibility to bring these artefacts to a new life, through 3D reconstruction. This way of studying and representing the past has become increasingly important in the academic world and the domain of digital entertainment. These applications make use of the so-called ‘virtual 3D reconstructions’, which are 3D models based on figurative/textual sources or ruins of artefacts that no longer exist or have never been built.This paper aims to present ‘CoVHer’ (Computer-based Visualisation of Architectural Cultural Heritage), an Erasmus Plus Project that deals with this vast theme and involves five universities and two private companies from five European countries (Italy, Spain, Portugal, Poland and Germany). The main objective of CoVHer is to define applicable/practice guidelines and operational methodologies aimed at the study, implementation, visualization and critical evaluation of the 3D models. Some of the ongoing theoretical studies developed in the project will be presented. In particular, this paper will focus on the systematization of the reconstruction process. It defines and classifies different aspects of 3D digital modelling; and other aspects concerning visualization in the field of architectural hypothetical reconstruction.