Preface: 3D GeoInfo 2021

Abstract. 3D GeoInfo 2021, the 16th GeoInfo conference, is an annual ISPRS workshop offering a forum for leading international decision makers and prominent voices in the field of 3D Geoinformation across the academic, commercial, and public sectors. The 2021 workshop is organized in conjunction with the 7th International FIG workshop on 3D Cadastres. The 2021 event was held virtually. Topics included:

• 3D data creation and acquisition
• 3D data processing and analysis
• 3D data management - data quality, metadata, provenance and trust
• Data integration, information fusion, multi-modal data analysis
• 3D visualization, including gamification, virtual reality, augmented reality
• 3D and Artificial Intelligence/Machine Learning
• 3D and Big Data, parallel computing, cloud computing
• 3D city modeling, underground infrastructure modeling, topography, and bathymetry modeling
• Building Information Modeling, Digital Twins, Smart Cities, Smart Infrastructure
• Usability and Human-Computer interaction in 3D GIS
• 3D GIS, spatial analysis and other applications (such as 3D cadastral systems, land administration, utilities, asset management, infrastructure, navigation, urban planning, geology, archaeology, marine systems, simulations, autonomous vehicles, facilities management, energy modeling, disaster and risk management, pandemic monitoring)

The 3D GeoInfo 2021 tracks received 73 manuscripts including 30 full papers and 43 extended abstracts. The manuscripts were reviewed with a double-blind review process by members of the organizing and scientific committee and external reviewers. Ultimately 24 papers were accepted for the ISPRS Annals and 24 papers for the ISPRS Archives. We thank all of the authors and reviewers for their contributions.

We look forward to the 3D GeoInfo 2021 virtual oral presentations and the opportunity to exchange ideas within our workshop and with the presenters and visitors of the 7th International FIG workshop on 3D Cadastres.