The STAR Geometry is implented in geant 3, which provides the geometry description to STAR's Monte Carlo application, starsim.   The geant3 model is implemented using the Advanced Geometry Interface for GSTAR language.  AGI provides a flexible and robust framework in which detector geometries can be quickly implemented.  STAR is currently migrating from the AGI language to a related framework called AgML.  AgML stands for "Another Geometry Modelling Language."  It is based on XML, and is the preferred language in which new geomtries should be implemented.   AgML provides backwards compatability with the AGI language, in order to continue supporting the starsim application as we transition to a new STAR virtual Monte Carlo application. 

the new FTS geomoetry is writen in StarVMC/Geometry/FtsdGeo
the geometry name is FtsdGeo.xml
Language for FTS geometry are AgML.  

Description can be find in this linL:
http://www.star.bnl.gov/~jwebb/AgML_doc/AgML.html

In this geometry file, you will also need to declare what kind of information will store.
currently, follow information are in record.
++++++
x , y, z        -- the local coordinates w/in the detector volume
ptot            -- the total momentum of the track  
cx, cy, cz    -- the cosines of the angles of the track
sleng          -- the pathlength of the track through the volume in the current tracking step
tof              -- the time of flight of the track to the current point
step            -- the stepsize of the track in the current tracking step
eloss           -- the energy lost by the track in the current tracking step

After you have finish the geomerty
you need cons twice. you can do it as follow:
cons +StarVMC/Geometry
cons

This will take a while to compile, during which time you can get a cup of coffee, or do your laundry, etc...

Actually, you also need pa