PHYSDEFECT: A PHYSICS-BASED BENCHMARK FOR 3D ANOMALY DETECTION

3D anomaly detection is central to industrial inspection, yet progress is constrained by scarce real defects and confidentiality restrictions. Existing synthesis pipelines often apply analytic displacements directly to point clouds. While they can create plausible local anomalies, they struggle to represent global shape deviations, material-dependent responses, and the scanning process used in practice. We introduce , a physics-based benchmark for 3D anomaly detection. Its synthesizer organizes seventeen mechanisms into material deformation, removal, and addition, modeling elastoplastic response, transport-driven interface recession, and continuous deposition and growth. Geometry and material state pass between successive events. A triangulation-based simulated scanner explicitly models occlusion, artifacts, and measurement noise, producing incomplete observations. Across 100 industrial geometries, contains 3,213 anomalous and 2,000 normal instances and evaluates eight established methods plus a geometric baseline. Their localization performance is substantially below published results on other benchmarks, while changes in scanning conditions affect methods in both directions. The benchmark and its components are open source to support research on physical defect synthesis, scan simulation, and transfer to real settings.