Re: About VGM dependent code

 Hi Hengtong,

 See my answers below in your text.

On Fri, 24 Feb 2006, Ding Hengtong wrote:

> Hi,
>
> I'm new to vmc root, and when I install Geant4_VMC,according
> to your webpage http://root.cern.ch/root/vmc/VirtualMC.html
> I set USE_VGM to be 1 to build VGM dependent code.

  If you set USE_VGM you have to install the VGM package   first. The source is available at:
  http://ivana.home.cern.ch/ivana/VGM.html

  Note that this web page is linked directly from   the VMC web page, section "Install geant4_vmc"   You will find there also the installation instructions.

> But there are
> errors during the compilation. And For the pre-requirmentes
> my geant3 and geant4.8.0(patch01) are all built OK.
> Part of error information is showed below:
>
> geometry/src/TG4DetConstruction.cxx
> In file included from geometry/include/TG4DetConstruction.h:18,
> from geometry/src/TG4DetConstruction.cxx:10:
> geometry/include/TG4XmlVGMMessenger.h:14:30: XmlVGM/VExporter.h: No such
> file or directory
> geometry/include/TG4XmlVGMMessenger.h:15:38: Geant4GM/volumes/Factory.h:
> No such file or directory
>
> I aslo tried tagged version 1.8 and development version, and they both
> really don't have XmlVGM/VExporter.h and Geant4GM/volumes/Factory.h.

  These errors should disappear once you have istalled VGM   and set path to its installation.    

>
> When I don't need VGM dependt code,I set USE_VGM to 0 or just
> do nothing about this variable and then codes built OK.

>
> Finally my question is will the "VGM depent code"'s absence affect the
> future simulaion and where I can get the offical source including
> "XmlVGM/VExporter.h" and "Geant4GM/volumes/Factory.h"

  You need to build VGM dependent code in case   you define your geometry directly via TGeo   (root geometry modeller).  

  Best regards,

  Ivana

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