Collaborative defect annotation on 3D seamless open-source framework

Abstract. Geomatics has become a critical tool for efficiently documenting the built environment, using photogrammetry, LiDAR and laser scanning to produce highly accurate 3D surveys. UAV photogrammetry enables non-intrusive documentation of heritage sites, while laser-based methods increase efficiency with millimetre accuracy. The integration of these technologies provides decision-makers with essential data for planning and conservation. However, the complexity of heritage documentation requires modular solutions capable of managing different data formats, spatial and temporal changes, while ensuring data quality and interoperability. Despite the availability of digital tools for heritage documentation, no single system seamlessly integrates all the required functionalities. Existing approaches often face challenges related to data redundancy, proprietary software limitations, and technical expertise requirements. Open-source solutions offer a viable alternative, providing low-cost, customisable tools for the presentation of thematic, 2D and 3D information. This work presents a workflow for integrating 3D survey products into a shared web-based digital platform designed to support collaborative defect mapping of built environments. The proposed framework, characterized by its open source and adaptable nature, aims to bridge the gap between research and practical applications, facilitating its adoption in diverse built heritage contexts while promoting sustainable data management practices.