Adaptive regional segmentation and fitting-based building LOD reconstruction method

Reconstructing accurate urban building models remains challenging due to large-scale variability and complex topology. We introduce a practical multi-step framework that reconstructs a single building from a dense triangle mesh by explicitly exploiting its block-wise composition. The pipeline first partitions the mesh into spatially coherent regions, then extracts height-aware contours and classifies geometry into facades, roofs, and appurtenances. For each part, we perform contour-guided vectorized modeling with profile fitting and consistency constraints, producing watertight, semantically structured models at Level-of-Detail (LOD) 2.3. An interactive refinement module further supports user adjustments to resolve rare failure cases and enforce design regularity. The proposed decomposition and layered fitting yield compact outputs while preserving salient geometry, and make the reconstruction robust across scales and moderate noise. We also analyze modeling assumptions and implementation details to ensure reproducibility. Overall, this work offers a component-aware, engineering-ready solution for converting unstructured meshes into structured building models that are amenable to downstream urban modeling and visualization. buildingreconstruction; block-wisesegmentation; contour-guidedvectorization; LOD;interactiverefinement; watertight modeling