g2rootold1

Usage

Overview

You can convert a GEANT (see http://wwwinfo.cern.ch/asd/geant/index.html fore more on GEANT) geometry to ROOT geometry with the following steps

1

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

2

Run the g2rootold program to convert the Zebra RZ file into a ROOT macro detector.C:

g2rootold detector.geom detector.C

3

Run the following ROOT session;

root [1] .x detector.C
root [2] detector.Draw()
root [3] c1.x3d()   // (this invokes the 3-d Root viewver)
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

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an interactive editor and viewer

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with 3-d views

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but also 2-d cut views

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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.

Original authors

The ROOT team (see web page above):