Page History

The LCDD geometry needs to be dumped to plain GDML to be loaded by ROOT.

Before using ROOT, the environment needs to be setupCreate the script GDMLROOT.py containing the following and put it in $ROOTSYS/gdml.

import sys
import xml.sax
import ROOT
import ROOTBinding
import GDMLContentHandler

ROOT.gSystem.Load("libGeom")

gdmlhandler = GDMLContentHandler.GDMLContentHandler(ROOTBinding.ROOTBinding())

filename = 'test.gdml'
if sys.argv.__len__() > 1:
    filename = sys.argv[1]

xml.sax.parse(filename, gdmlhandler)
geomgr = ROOT.gGeoManager

geomgr.SetTopVolume(gdmlhandler.WorldVolume())
geomgr.CloseGeometry()

geomgr.DefaultColors()

geomgr.SetExplodedView(1)
geomgr.SetBombFactors(5.0,5.0,5.0,5.0)

gdmlhandler.WorldVolume().Draw("ogl")

This command will load a geometry from that directory.

...

export ROOTSYS=/my/root/dir
cd $ROOTSYS
. $ROOTSYS/bin/thisroot.sh

Assuming that there is a file called test.gdml in the current directory, a script similar to the following will load a plain GDML file into ROOT.

TGeoManager::Import("test.gdml");
gGeoManager->GetTopVolume()->Draw("ogl");

This command should display the ROOT OpenGL viewer with the geometry from the test.gdml file.

One can customize this by displaying only a particular volume, specified by name, using the following command:

gGeoManager->GetVolume("VolumeName")->Draw("ogl");

Note that in the gdml file the volume name has a hexadecimal number appended to it. This should be disregarded when specifying the volume name.

...