heritage Article Smart Architectural and Urban Heritage: An Applied Reflection Stefano Brusaporci and Pamela Maiezza *   Citation: Brusaporci, S.; Maiezza, P. Smart Architectural and Urban Heritage: An Applied Reflection. Heritage 2021, 4, 2044–2053. https:// doi.org/10.3390/heritage4030116 Academic Editors: David Batchelor, Marc Aurel Schnabel and Michael Dudding Received: 26 July 2021 Accepted: 27 August 2021 Published: 30 August 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). Department of Civil, Construction-Architectural and Environmental Engineering, University of L’Aquila, Via Giovanni Gronchi 18, 67100 L’Aquila, Italy; stefano.brusaporci@univaq.it * Correspondence: pamela.maiezza@univaq.it Abstract: The aim of this paper is to present the use of 3D models and augmented reality (AR) to study and communicate architectural and urban values and, therefore, favor the development of dedicated forms of “smart heritage”. The study rises from a reflection on the concept of “heritage”, as defined in the international documents, intended as an evolving idea that puts together tangible and intangible aspects. Moreover, digital technologies favor “phygital” applications where the digital dimension support the traditional ones. In this way, AR allows the superimposition of multimedia information to heritage, respecting the historical matter of the artefacts, and supporting a “smart heritage” application. In particular, mobile AR, with real-time and ubiquitous visualizations, offers the opportunity to show past urban and architectural configurations to investigate and describe the transformations that have led to the current configuration, and consequently highlighting the present historical and architectural values of the buildings. Two case studies are presented: the square of St. Basilio Monastery, with its historical transformations, and the Basilica of Collemaggio, a pivotal building in the rites of “Perdonanza Celestiniana”. Keywords: architectural and urban heritage; 3D modeling; digital heritage; augmented reality 1. Introduction The concept of “heritage” has developed over time; on the one hand, making the differ- ence between tangible and intangible more and more blurred, on the other, by highlighting the importance of the active role of people [1–4]. In this context, the digital technologies have become increasingly important, first of all because they are an integral part of everyday life, and second, because they offer new ways of viewing information: in particular, the different forms of mixed reality [5] allow the superimposition of information of different nature on architectural heritage without interfering with its materiality, i.e., by acting only in the dimension of the visual [6]. This application to cultural heritage can favor the development of new forms of smart heritage. In particular, in 1999, virtual heritage was defined as “the utilization of technology for interpretation, conservation and preservation of Natural, Cultural and World Heritage” [7]. Unlike this definition, Digital Heritage, as described in its Charter [8], has a tendency to assume an independent connotation and value from the “real” dimension, but the digital objects begin to have a new meaning of “real”. Nevertheless, in digital heritage from real content, conceptually, this digital sphere has to be related with the physical content from which it derives: “in this kind of digital heritage, there is not visualization without a prior reality and, in a philological study of a digital model, we cannot forget its real reference from whom it is born. Therefore, the issues related to data and information grow to include the relationship with history and materiality” [9]. The concepts of “virtual heritage” and of “digital heritage” are well known and discussed by scholars from different fields [10]. Currently, digital heritage involves not only the intangible sphere, but also the tangible one, according to the lines of the so-called “phygital” heritage [11]. In this way, augmented reality or extended reality could be intended as methodologies for advanced information visualization, and therefore useful tools for advanced ways of communication. Heritage 2021, 4, 2044–2053. https://doi.org/10.3390/heritage4030116 https://www.mdpi.com/journal/heritage