  Citation: Carre, A.L.; Dubois, A.; Partarakis, N.; Zabulis, X.; Patsiouras, N.; Mantinaki, E.; Zidianakis, E.; Cadi, N.; Baka, E.; Thalmann, N.M.; et al. Mixed-Reality Demonstration and Training of Glassblowing. Heritage 2022, 5, 103–128. https://doi.org/10.3390/ heritage5010006 Academic Editor: Christos Fidas Received: 10 December 2021 Accepted: 24 December 2021 Published: 2 January 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 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/). heritage Article Mixed-Reality Demonstration and Training of Glassblowing Anne Laure Carre 1 , Arnaud Dubois 1 , Nikolaos Partarakis 2, * , Xenophon Zabulis 2 , Nikolaos Patsiouras 2 , Elina Mantinaki 2 , Emmanouil Zidianakis 2 , Nedjma Cadi 3 , Evangelia Baka 3 , Nadia Magnenat Thalmann 3 , Dimitrios Makrygiannis 4 , Alina Glushkova 4 and Sotirios Manitsaris 4 1 Histoire des Technosciences en Société, Conservatoire National des Arts et Métiers (HT2S-CNAM), 75003 Paris, France; anne-laure.carre@lecnam.net (A.L.C.); arnaud64.dubois@gmail.com (A.D.) 2 Institute of Computer Science, Foundation for Research and Technology (ICS-FORTH), N. Plastira 100, Vassilika Vouton, GR-70013 Heraklion, Greece; zabulis@ics.forth.gr (X.Z.); patsiouras@ics.forth.gr (N.P.); mantinaki@ics.forth.gr (E.M.); zidian@ics.forth.gr (E.Z.) 3 MIRALab, Centre Universitaire Informatique (CUI), University of Geneva Battelle, Building A, 3rd Floor 7, Route de Drize, CH-1227 Carouge, Switzerland; cadi@miralab.ch (N.C.); ebaka@miralab.ch (E.B.); thalmann@miralab.ch (N.M.T.) 4 Centre for Robotics, MINES ParisTech, PSL Universite Paris, 75006 Paris, France; dimitris.makrygiannis@mines-paristech.fr (D.M.); alina.glushkova@mines-paristech.fr (A.G.); sotiris.manitsaris@mines-paristech.fr (S.M.) * Correspondence: partarak@ics.forth.gr; Tel.: +30-2810-391754 Abstract: Traditional crafts exhibit tangible and intangible dimensions. Intangible dimensions include the practitioner’s gestural know-how in craft practice and have received smaller attention than tangible dimensions in digitization projects. This work presents the process of representation and presentation of the glasswork and is exemplified in the re-creation of a historical object. Following an articulated pipeline approach for data collection, annotation, the crafting process is represented visually and semantically in a way that can be meaningfully presented and utilized in craft training and preservation. The outcomes of the proposed approach were used to implement a Mixed Reality installation. The installation targets craft presentation through an exploration of the workspace, as well as craft training through an interactive experience where users re-enact gestures of a glass master holding a tool and receiving audiovisual feedback on the accuracy of their performance. Preliminary evaluation results show high acceptance of the installation and increased user interest. Keywords: traditional crafts; traditional craft digitization; process representation; vocational training; virtual humans; semantic web; knowledge representation; mixed reality 1. Introduction Traditional crafts (TCs) are a Cultural Heritage (CH) and exhibit tangible and intan- gible dimensions. Tangible dimensions regard craft articles and products, materials and tools, as well as natural resources, built workshops, and workplaces. The tangible aspect of TCs is evident in their practice, where materials are transformed with the use of tools, but also skill and knowledge. According to UNESCO, crafts are probably the most tangible of intangible heritage [1]. Comparatively to other forms of Intangible Cultural Heritage (ICH), TCs have received smaller attention by digitization projects [2]. Intangible dimensions regard technical knowledge as well as the socio-historic content of the communities and regions in which they are, or were, practiced. In this work, our effort is to represent these dimensions for the TC instance of glassworking, using an articulated approach to the digitization, representation, and preservation of TCs. Glasswork is a TC that combines hand and body gestures and a thorough under- standing of the material. Glasswork is a challenging craft because, during production, the material changes states from liquid to solid. Such transitions pose requirements in terms of material handling. In this work, we are challenging the technical means for capturing and Heritage 2022, 5, 103–128. https://doi.org/10.3390/heritage5010006 https://www.mdpi.com/journal/heritage