Helge Wrede, Anton R. Wagner, Wojtek Pałubicki, Dominik L. Michels, Sören Pirk
We present a physically based simulation framework for wildland–urban interface (WUI) fires that couples material-aware urban scenes with interactive combustion simulation. Motivated by the dominant WUI exposure pathways of direct flame contact, thermal radiation, and ember transport, our framework combines heterogeneous solid combustion, radiative heat transfer, ember transport, and explicit flame-front propagation. Urban scenes are generated from OpenStreetMap footprints using a procedural pipeline that represents buildings as combustible 3D structures composed of semantic atomic modules with material and fuel annotations. Building on a chemistry-based hybrid Eulerian–Lagrangian fire solver, we model material-dependent heating, conduction, pyrolysis, oxidation, fuel depletion, and ember generation. A hierarchical fuel graph couples semantic scene structure to the solver’s solid fuel grid, enabling subcomponent-level mesh degradation. We demonstrate structure-to-structure ignition, radiative preheating, material-dependent burning, ember-driven spot fires, and validate the method through ablations and comparisons to real-world combustion experiments.