The web and its recent advancements represent a great opportunity to build universal, rich, multi-user and immersive Web3D/WebXR applications targeting Cultural Heritage field—including 3D presenters, inspection tools, applied VR games, collaborative teaching tools and much more. Such opportunity although, introduces additional challenges besides common issues and limitations typically encountered in this context. The “ideal” Web3D application should be able to reach every device, automatically adapting its interface, rendering and interaction models—resulting in a single, liquid product that can be consumed on mobile devices, PCs, Museum kiosks and immersive AR/VR devices, without any installation required for final users. The open-source ATON framework is the result of research and development activities carried out during the last 5 years through national and international projects: it is designed around modern and robust web standards, open specifications and large open-source ecosystems. This paper describes the framework architecture and its components, assessed and validated through different case studies. ATON offers institutions, researchers, professionals a scalable, flexible and modular solution to craft and deploy liquid web-applications, providing novel and advanced features targeting Cultural Heritage field in terms of 3D presentation, annotation, immersive interaction and real-time collaboration.

This article is framed into the theoretical and methodological background of virtual archaeology. The advantages of virtual archaeology and its weak points have long been discussed in academia, formulating theoretical foundations and principles to be followed in order to guarantee scientific results, where data are traceable, transparent and verifiable. Gathering the inheritance of the last 30 years of debates and research, this work proposes implementing these principles through the formulation of a methodological approach, to virtual reconstruction of archaeological contexts, consisting of an application protocol articulated in five steps. In particular, the proposed methodology is grounded in the Extended Matrix (EM), a formal language and tools entirely developed and tested by the Virtual Heritage lab of the CNR ISPC. The EM takes its cue from the Matrix of Harris and adapts its system to the specific needs arising in the fields of virtual reconstruction and scientific visualisation. This protocol, which ranges from fieldwork to the publication of scientific data, has been tested and systematised in over ten years of activity on various complex and significant archaeological contexts. In the article, each methodological step is supported by case studies described in detail and accompanied by a graphic apparatus that clearly illustrates the results obtained. These case studies led to the definition of version 1.2 of the EM as described in the methods section.

Over the last few decades, there has been a growing interest in the fusion of the humanities and the hard sciences. The continuous experimentation and contamination between these two disciplines has led to the emergence of new horizons of research and open to perspectives and issues previously unthinkable. Finally, it has started the development of specific technologies for the cultural domain. Among these technologies, virtual archaeology, which we could define as the set of processes of acquisition, analysis and interpretation aimed at visualizing and simulating the past using 3D digital technologies and a theoretical and multidisciplinary scientific approach, has now reached its maturity. In this contribution the potentials in using 3D modelling as a tool of investigation and visualization for a deeper understanding of archaeological sites is presented. The discussion is supported by the case study of the roman villa of Aiano, built at the beginning of the 4th century A.D. and characterized by monumental architecture and decorations.

Today, Web3D technologies and the rise of new standards, combined with faster browsers and better hardware integration, allow the creation of engaging and interactive web applications that target the field of cultural heritage. Functional, accessible, and expressive approaches to discovering the past starting from the present (or vice-versa) are generally a strong requirement. Cultural heritage artifacts, decorated walls, etc. can be considered as palimpsests with a stratification of different actions over time (modifications, restorations, or even reconstruction of the original artifact). The details of such an articulated cultural record can be difficult to distinguish and communicate visually, while entire archaeological sites often exhibit profound changes in terms of shape and function due to human activities over time. The web offers an incredible opportunity to present and communicate enriched 3D content using common web browsers, although it raises additional challenges. We present an interactive 4D technique called “Temporal Lensing”, which is suitable for online multi-temporal virtual environments and offers an expressive, accessible, and effective way to locally peek into the past (or into the future) by targeting interactive Web3D applications, including those leveraging recent standards, such as WebXR (immersive VR on the web). This technique extends previous approaches and presents different contributions, including (1) a volumetric, temporal, and interactive lens approach; (2) complete decoupling of the involved 3D representations from the runtime perspective; (3) a wide range applications in terms of size (from small artifacts to entire archaeological sites); (4) cross-device scalability of the interaction model (mobile devices, multi-touch screens, kiosks, and immersive VR); and (5) simplicity of use. We implemented and developed the described technique on top of an open-source framework for interactive 3D presentation of CH content on the web. We show and discuss applications and results related to three case studies, as well as integrations of the temporal lensing with different input interfaces for dynamically interacting with its parameters. We also assessed the technique within a public event where a remote web application was deployed on tablets and smartphones, without any installation required by visitors. We discuss the implications of temporal lensing, its scalability from small to large virtual contexts, and its versatility for a wide range of interactive 3D applications.