GEOMODELATOR-GUI: A web-based graphical user interface for 3D geological modelling

Geological modelling workflows often rely on command-line tools requiring programming expertise, limiting accessibility for domain scientists. This paper introduces GEOMODELATOR-GUI, a novel web-based graphical user interface for the open-source 3D geological modelling software GEOMODELATOR. The GUI abstracts complex configuration and execution processes into an intuitive, step-wise wizard interface, enabling geoscientists to generate structural geological models without coding, and thereby turning available field data into practical insights in a straightforward process. Built using Streamlit for the client and Flask for the server, the application implements a session-based architecture where model configurations are transmitted via JSON. The core innovation lies in its hybrid local-storage approach: large geological structural datasets and model outputs (ParaView VTK and VTS, numpy npz) are managed via a shared directory to circumvent network transfer limitations, while configuration logic remains server-mediated. The system performs model pre-configuration including grid alignment and data transformation, partitioning using cubic interpolation and priority-based sequential assignment of fault/strata relationships, and post-processing by inverse transformation and output generation. Validation using synthetic and real-world datasets demonstrates successful generation of complex faulted and stratified geological models. GEOMODELATOR-GUI significantly lowers the barrier to entry for geological modelling, enhances reproducibility through session management, and provides interactive 3D visualisation via PyVista. The fully open-source Python implementation of the GUI supports efficient 3D model development for numerical simulations within short time frames.