The ATLAS detector is described in terms of a small but extensible set of geometrical primitives. Upon the layer of raw geometrical and material information, we layer subsystem specific information, for example the location and number of ion implant boundaries in silicon detectors, wires in tracking detectors, and projective towers in calorimeters.
Several libraries are available for this task. They are collectively called as GeoModel:
| Package Name | Description | Dependencies |
| GeoModelKernel | Geometrical Primitives | CLHEP
|
| GeoModelSvc | Interface to Athena | GeoModelKernel + Gaudi & Storegate
|
| GeoModelExamples | Example code: "Toy" detector managers, factories, and detector elements (forward and central scrutinizers). | GeoModelSvc + Identifier
|
| GeoModelGraphics | An athena package for browsing the geometry. | External graphics libraries, especially Open Inventor, Athena, RAL, and the other GeoModel Packages. |
For subystems people the following links will be useful: