Virtual humans in cultural heritage ICT applications: A review

Virtual Reality (VR) is becoming an increasingly important tool for the research, the communication and the popularization of cultural heritage. A great deal of 3D interactive reconstructions of artefacts, monuments and entire sites have been realized which meet the consent of both specialist and public at large. However, until a few years ago most of these reconstructions were basically static and often missing an important factor: human presence. Thanks to the advancements in the technology, in latest years Virtual Humans (VHs) have started being used in a variety of cultural-related VR applications. From simple 2D characters to complex 3D avatars, technology continues to evolve and so is the adoption of virtual assistants in digital heritage. The acceptance of such tools deserves a greater attention from the scientific community. When designing such applications, researchers need to take into consideration not only motivations and constraints, but also the type of virtual human fitting in the scenario. In this paper we aim at providing a state-of-the-art on this subject, focusing specifically on the cultural heritage area, underlining the technological challenges and also analyzing the effects of avatar interaction on user engagement, sense of immersion and learning effectiveness. This review also presents the usage of VHs from user's perspective and from the design point of view. We finally discuss the strengths and weaknesses of current approaches and point out unsolved issues, identifying a set of recommendations and good practices to follow when designing VR-based cultural heritage applications including VHs.