g2root (1) - Linux Manuals

g2root: convert GEANT geometry files to ROOT files


g2root - convert GEANT geometry files to ROOT files


g2rootd [-f map_name] geant_name macro_name


You can convert a GEANT (see http://geant.cern.ch/ fore more on GEANT) geometry to ROOT geometry with the following steps
Run the interactive version of GEANT and produce a Zebra RZ file detector.geom, by typing the command:

Geant > rz/file 21 detector.geom on

Run the g2root program to convert the Zebra RZ file into a ROOT macro detector.C:

g2root detector.geom detector.C

Run the following ROOT session;

root [1] .x detector.C
root [2] detector.Draw()
root [3] c1.x3d()   // (this invokes the 3-d Root viewer)
root [4] TFile f("detector.root","NEW") //open a new root file
root [5] detector.Write() //Write the geometry structure
root [6] f.Write()

Note that the TNode structure currently in ROOT was not designed as a replacement for a true geometry package. The idea was mainly to draw simple geometries in event display programs. We are currently investigating several alternatives for a true & efficient geometry package supporting;

a disk data base with storage of multiple geometry versions
an interactive editor and viewer
with 3-d views
but also 2-d cut views
with interfaces to existing or future MC such as GEANT3 or GEANT4

A second program called gh2root (see http://root.cern.ch/root/gh2root.html) generates automatically C++ code corresponding to the GEANT3 Zebra structures JSET, JVERTX, JKINE, JHITS and JDIGI.


The ROOT team (see web page above):
Rene Brun and Fons Rademakers


This library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version.

This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License along with this library; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA


This manual page was written by Christian Holm Christensen <cholm [at] nbi.dk>, for the Debian GNU/Linux system (but may be used by others).


root(1), h2root(1),
The ROOT Users Guide
available from the main ROOT website: