Detector Definition

Geant4 provides 3 ways for its users to define their own detector models:

• C++: the hardest to use and master, yet described in detail in Geant4 User Guide for Application Developers, and demonstrated in most Geant4 official examples.
• Text with simple syntax: the easiest to use and surprisingly versatile, but only briefly mentioned in Geant4 User Guide for Application Developers with an outdated manual.
• GDML: XML files for exchange of geometry data between programs, such as CAD, Geant4 and ROOT. It is optional and NOT enabled by default in a Geant4 installation.

Every detector defined using C++ demands the creation of a new Geant4 applicaiton. Detectors defined using simple text can be all used by the same Geant4 application that accepts detector definitions in simple text (for example, MinGLE or GEARS). A lot of redundant work can be avoided this way.