Handling GDML files

Handling of GDML files is performed via the GaussinoGeometry() configurable.

GDML import

If you wish to import the logical volumes from the GDML file you have to provide all the necessary options in the ImportGDML property of GaussinoGeometry. All the imported volumes will be embedded in a G4Assembly that can be translated and rotated with respect to the existing world. For example:

from GaudiKernel.SystemOfUnits import m, deg
from Gaussino.Geometry import GaussinoGeometry
GaussinoGeometry().ImportGDML = [
    {
        "GDMLFileName": "path_to_your_gdml_file_1.gdml",
        "GDMLTranslationX": 10. * mm,
        "GDMLRotationX": 45. * deg,
    },
    {
        "GDMLFileName": "path_to_your_gdml_file_2.gdml",
    },
]

It will import the volumes from the two files: path_to_your_gdml_file_1.gdml and path_to_your_gdml_file_2.gdml. Volumes from the first files will be embedded in a rotated and translated assembly.

Attention

GDML importing feature is not a geometry service on its own. If you are not using DD4hepCnvSvc or any other geometry service that creates the world volume, then you can use the ExternalDetector package. Options below will create an empty world volume, in which you will have your volumes imported from a GDML file:

from Configurables import (
    GaussinoGeometry,
    ExternalDetectorEmbedder,
)

emb_name = "Embedder_1"
GaussinoGeometry().ExternalDetectorEmbedder = emb_name
external = ExternalDetectorEmbedder(emb_name)

# plain/testing geometry service
external.World = {
    "WorldMaterial": "OuterSpace",
    "Type": "ExternalWorldCreator",
}

from ExternalDetector.Materials import OUTER_SPACE
# material needed for the external world
external.Materials = {
    "OuterSpace": OUTER_SPACE,
}

Making the imported volumes sensitive

The sensitive detector classes have to be added manually to the imported sensitive volumes. Below you will find an example of how to add a generic MCCollectorSensDet factory to an imported volume ImportedLVol:

GaussinoGeometry().SensDetMap = {
    "MCCollectorSensDet/ImportedSDet": ["ImportedLVol"],
}

# and if you wish to change the default properties of the factory

from Configurables import MCCollectorSensDet
MCCollectorSensDet(
    "GiGaMT.DetConst.CubeToImportSDet",
    PrintStats=True,
)

GDML export

If you wish to export the whole world to aGDML file you have to provide all the necessary options in the ExportGDML property of GaussinoGeometry. For example:

GaussinoGeometry().ExportGDML = {
    "GDMLFileName": "export.gdml",
    # G4 will crash if the file with same name already exists
    "GDMLFileNameOverwrite": True,
    # name of the volume name that will be the root in the gdml file
    # leave empty for the default world volume
    "GDMLRootVolumeName": "",
    # add unique references to the names
    "GDMLAddReferences": True,
    # export auxiliary information
    "GDMLExportEnergyCuts": True,
    "GDMLExportSD": True,
}

GDML exporting of a parallel world

Parallel worlds follow the same configuration as in the mass geometry case, but it has to be provided in the properties of you parallel world. For example:

ParallelGeometry().ParallelWorlds = {
    'ParallelWorld1': {
        'ExternalDetectorEmbedder': 'ParallelEmbedder',
        'ExportGDML': {
            'GDMLFileName': 'ParallelWorld1.gdml',
            'GDMLFileNameOverwrite': True,
            'GDMLExportSD': True,
            'GDMLExportEnergyCuts': True,
        },
    },
}