Import a stp or GDML into root as a TGeoVolume

[lgolino]

Hi all, so I have a project with root sims. I am creating a bunch of tubes, and boxes and simulating various things.

I want to add a very unique piece to the simulations. I have the piece as a step file, and I have also been able to convert it into a GDML but how do I then import as a TGeoVolume to be placed in root?

Cheers

---

Please read tips for efficient and successful posting and posting code

ROOT Version: Not Provided
Platform: Not Provided
Compiler: Not Provided

---

[agheata]

Hi, in the main gdml file you have to embed the child volume definition within the parent volume definition:

    <volume name="parent">
      <materialref ref="Air"/>
      <solidref ref="parent_box"/>
      <physvol name="child_1" copynumber="1">
        <file name="child_definition.gdml" volname="child"/>
        <positionref ref="child_pos"/>
      </physvol>
    </volume>

See the example in the attached tarball. Note however that if your “piece” is a tessellated volume, the navigation functionality for it (that you may need in your sims) is NOT implemented.
teddy.tgz (77.1 KB)

[lgolino]

Hi, thanks for the response but which is the “main” gdml? I have 0 GDML files in my repo currently. I would like to add one.

Unfortunately could not get the tarball to run:

root [0] TGeoManager::Import("teddy.gdml");
Info in <TGeoManager::Import>: Reading geometry from file: teddy.gdml
Info in <TGeoManager::TGeoManager>: Geometry GDMLImport, Geometry imported from GDML created
Fatal in <TGDMLParse::Tessellated>: Vertex pos_2 not defined
aborting
#0  0x00007f7622909c3a in __GI___wait4 (pid=19486, stat_loc=stat_loc
entry=0x7fff0c9e4a68, options=options
entry=0, usage=usage
entry=0x0) at ../sysdeps/unix/sysv/linux/wait4.c:27
#1  0x00007f7622909bfb in __GI___waitpid (pid=<optimized out>, stat_loc=stat_loc
entry=0x7fff0c9e4a68, options=options
entry=0) at waitpid.c:38
#2  0x00007f7622878f67 in do_system (line=<optimized out>) at ../sysdeps/posix/system.c:172
#3  0x00007f7622f260be in TUnixSystem::StackTrace() () from /home/lgolino/packages/root/install/lib/libCore.so
#4  0x00007f7622def2da in DefaultErrorHandler(int, bool, char const*, char const*) () from /home/lgolino/packages/root/install/lib/libCore.so
#5  0x00007f7622eb0598 in ErrorHandler () from /home/lgolino/packages/root/install/lib/libCore.so
#6  0x00007f7622e0290d in TObject::Fatal(char const*, char const*, ...) const () from /home/lgolino/packages/root/install/lib/libCore.so
#7  0x00007f760e467ac9 in TGDMLParse::Tessellated(TXMLEngine*, void*, void*) () from /home/lgolino/packages/root/install/lib/libGdml.so
#8  0x00007f760e4821b6 in TGDMLParse::ParseGDML(TXMLEngine*, void*) () from /home/lgolino/packages/root/install/lib/libGdml.so
#9  0x00007f760e481d1a in TGDMLParse::ParseGDML(TXMLEngine*, void*) () from /home/lgolino/packages/root/install/lib/libGdml.so
#10 0x00007f760e481d1a in TGDMLParse::ParseGDML(TXMLEngine*, void*) () from /home/lgolino/packages/root/install/lib/libGdml.so
#11 0x00007f760e484462 in TGDMLParse::VolProcess(TXMLEngine*, void*) () from /home/lgolino/packages/root/install/lib/libGdml.so
#12 0x00007f760e481f81 in TGDMLParse::ParseGDML(TXMLEngine*, void*) () from /home/lgolino/packages/root/install/lib/libGdml.so
#13 0x00007f760e481d1a in TGDMLParse::ParseGDML(TXMLEngine*, void*) () from /home/lgolino/packages/root/install/lib/libGdml.so
#14 0x00007f760e481d1a in TGDMLParse::ParseGDML(TXMLEngine*, void*) () from /home/lgolino/packages/root/install/lib/libGdml.so
#15 0x00007f760e4823a0 in TGDMLParse::GDMLReadFile(char const*) () from /home/lgolino/packages/root/install/lib/libGdml.so
#16 0x00007f761caf0034 in ?? ()
#17 0x0000000000000000 in ?? ()

Using ROOT 6.26/06, is this an issue with my build?

Cheers

[agheata]

Hi, 6.26/06 should do, the error you get is weird, why it only complains about pos_2 and not about pos_0 or pos_1? Anyway, I figured you want to integrate this special tesselated volume imported from step in your geometry, and this is a way to do it: say you have a previous geometry, where this volume is missing and you have a gdml file coming from a step conversion (looking more or less like the teddy_volume.gdml). In a first step add this volume as a box in your geometry, and export the geometry using:

gGeoManager->Export("geom.gdml");

Then either manually replace the box volume with the definition in the geom.gdml file, or use the trick above to add the volume from a file. Finally, read the new geometry and optionally export it as a root file using:

TGeoManager::Import("geom_with_volume.gdml");
gGeoManager->Export("geom_with_volume.root");