An open 3D scene-description framework, originally built for film production, increasingly used to bring BIM models into real-time visualization and simulation pipelines like NVIDIA Omniverse. USD's ability to layer and merge huge scenes from multiple sources non-destructively is what makes it attractive for AEC beyond film - a Revit model can be converted to USD and combined with other data sources in a shared real-time environment without flattening everything into one fixed file the way older exchange formats do.