Report from Dagstuhl Seminar 21471 Geometric Modeling: Interoperability and New Challenges Edited by Falai Chen 1 , Tor Dokken 2 , and Géraldine Morin 3 1 University of Science & Technology of China – Anhui, CN, chenfl@ustc.edu.cn 2 SINTEF – Oslo, NO, tor.dokken@sintef.no 3 IRIT – University of Toulouse, FR, geraldine.morin@irit.fr Abstract This report documents the program and the outcomes of Dagstuhl Seminar 21471 ŞGeometric Modeling: Interoperability and New ChallengesŤ. This seminar was initially planned on May 2021, and was delayed due to the pandemic. The seminar took place as a hybrid version with on site and remote participants. It provided a great opportunity for exchanges which, as pointed out by participants, were very appreciated in this period where international scientiĄc interactions have been diminished. This report summarizes the seminar communications, Ąrst by providing the abstracts of the talks which present recent results in geometric modeling. Moreover, the scientiĄc exchanges during the seminar provided a great basis for scientiĄc discussions that resulted to the included Ąve reports which highlight the new and future challenges in Geometric Modeling. Seminar November 21Ű26, 2021 Ű http://www.dagstuhl.de/21471 2012 ACM Subject Classification Mathematics of computing → Mathematical software; Comput- ing methodologies → ArtiĄcial intelligence; Computing methodologies → Computer graphics; Applied computing → Physical sciences and engineering; Mathematics of computing → Numerical analysis Keywords and phrases Additive Manufacturing; Computer Graphics; Design Optimization; Geometric Modeling; Geometry; Geometry Processing; Isogeometric Analysis; Shape Design; Computer-Aided Design Digital Object Identifier 10.4230/DagRep.11.10.111 Edited in cooperation with Konstantinos Gavriil 1 Executive Summary Falai Chen (Univiversity of Science & Technology of China – Anhui, CN) Tor Dokken (SINTEF – Oslo, NO) Géraldine Morin (IRIT – University of Toulouse, FR) License Creative Commons BY 4.0 International license © Falai Chen, Tor Dokken, Géraldine Morin The Dagstuhl seminar, initially planned in May 2020, took place as a hybrid conference in November 2021. Eighteen participants were on site, and thirty three participated remotely out of which Ąve from East Asia and twelve from America. Due to the pandemic, getting together for a conference has been an important event, and an outstanding exchange time between researchers (compared to a two years pandemic context where interaction has greatly been reduced). In particular, having a signiĄcant part of the participants on site has been a real asset compared to the full online conferences. Note also that this has been particularly true for young researchers that are in the process of developing networks and developing collaborations. Except where otherwise noted, content of this report is licensed under a Creative Commons BY 4.0 International license Geometric Modeling: Interoperability and New Challenges, Dagstuhl Reports, Vol. 11, Issue 10, pp. 111–150 Editors: Falai Chen, Tor Dokken, and Géraldine Morin Dagstuhl Reports Schloss Dagstuhl – Leibniz-Zentrum für Informatik, Dagstuhl Publishing, Germany