Recent Developments and Upgrades to the Geant4 Geometry Modeller

The Geometry modeller is a key component of the Geant4 toolkit [1,2]. It has been designed to exploit at the best the features provided by the Geant4 simulation toolkit, allowing the description of the geometrical structure of complex detectors in a natural way, ranging from a few up to hundreds of thousands volumes of the LHC experiments, as well as human phantoms for medical applications or devices and spacecrafts for simulations in the space environment. The established advanced techniques for optimizing tracking in the geometrical model have been recently enhanced and are currently under evolution to address additional use-cases. New geometrical shapes increased the rich set of primitives available, and new tools help users in the process of debugging the geometrical setup. The major concepts of the Geant4 geometry modeller are reviewed, focussing on recent features introduced in the last releases of the Geant4 toolkit.