Detector geometry information

Files
file	ChannelMapAlg.h
	Interface to algorithm class for a specific detector channel mapping.
file	AuxDetGeo.h
	Encapsulate the geometry of an auxiliary detector.
file	AuxDetGeometryCore.h
	Access the description of auxiliary detector geometry.
file	GeoObjectSorter.h
	Interface to algorithm class for sorting geo::XXXGeo objects.
file	AuxDetSensitiveGeo.h
	Encapsulate the geometry of the sensitive portion of an auxiliary detector.
file	BoxBoundedGeo.h
	Provides a base class aware of world box coordinates.
file	ChannelMapAlg.h
	Interface to algorithm class for a specific detector channel mapping.
file	CryostatGeo.h
	Encapsulate the construction of a single cyostat.
file	Decomposer.h
	Classes to project and compose a vector on a plane.
file	DriftPartitions.h
	Data structures and algorithms to partition a cryostat volume.
file	geo_vectors_fhicl.h
	Helpers for reading vectors from FHiCL files.
file	geo_vectors_utils.h
	Utilities to extend the interface of geometry vectors.
file	geo_vectors_utils_TVector.h
	Specializations of geo_vectors_utils.h for ROOT old vector types.
file	GeometryCore.h
	Access the description of detector geometry.
file	GeometryData.h
	Simple data structure holding the data of the geometry.
file	GeometryDataContainers.h
	Containers to hold one datum per TPC or plane.
file	GeometryIDmapper.h
	Mapping between geometry/readout ID and flat index.
file	GeoObjectSorter.h
	Interface to algorithm class for sorting geo::XXXGeo objects.
file	GeoObjectSorterStandard.h
	Interface to algorithm class for standard sorting of geo::XXXGeo objects.
file	GeoVectorLocalTransformation.cxx
	Specialization of local-to-world transformations for ROOT GenVector.
file	GeoVectorLocalTransformation.h
	Specialization of local-to-world transformations for ROOT GenVector.
file	LocalTransformation.h
	Class containing local-to-world transformations.
file	OpDetGeo.h
	Encapsulate the geometry of an optical detector.
file	PlaneGeo.h
	Encapsulate the construction of a single detector plane.
file	ReadoutDataContainers.h
	Containers to hold one datum per TPC set or readout plane.
file	ReadoutIDmapper.h
	Mapping between geometry/readout ID and flat index.
file	SimpleGeo.h
	Some simple functions to represent geometry entities.
file	StandaloneGeometrySetup.h
	Utilities for one-line geometry initialization.
file	TPCGeo.h
	Encapsulate the construction of a single detector plane.
file	TransformationMatrix.h
	Selection of the type of transformation matrix used in geometry.
file	WireGeo.h
	Encapsulate the geometry of a wire.
file	geo_optical_vectors.h
	Definitions of vector data types for optical detectors.
file	geo_types.cxx
	Definition of data types for geometry description (implementation).
file	geo_types.h
	Definition of data types for geometry description.
file	geo_vectors.h
	Definitions of geometry vector data types.

Namespaces
	geo::vect
	Utilities to manipulate geometry vectors.The utilities include generic vector interface facilities allowing to use different vector types via templates.
	geo::vect::extra
	Convenience utilities not directly related to vectors.
	lar::util::simple_geo
	Simple class definitions for geometry concepts.
	geo
	Namespace collecting geometry-related classes utilities.

Classes
class	geo::AuxDetChannelMapAlg
class	geo::AuxDetGeo
struct	geo::AuxDetGeometryData_t
class	geo::AuxDetGeometryCore
	Description of geometry of one set of auxiliary detectors. More...
class	geo::AuxDetGeoObjectSorter
class	geo::AuxDetSensitiveGeo
class	geo::BoxBoundedGeo
	A base class aware of world box coordinatesAn object describing a simple shape can inherit from this one to gain access to a common boundary checking interface. More...
class	geo::ChannelMapAlg
	Interface for a class providing readout channel mapping to geometry. More...
class	geo::CryostatGeo
	Geometry information for a single cryostat. More...
class	geo::DriftPartitions
	Set of drift volumes. More...
class	geo::GeometryCore
	Description of geometry of one entire detector. More...
class	geo::GeoObjectSorter
class	geo::GeoObjectSorterStandard
class	geo::LocalTransformation< StoredMatrix >
	Class to transform between world and local coordinates. More...
class	geo::OpDetGeo
class	geo::PlaneGeo
	Geometry information for a single wire plane.The plane is represented in the geometry by a solid which contains wires. Currently, only box solids are well supported. The box which is representation of the plane has some thickness, and it should not be assumed that the wires are in the median section of it, that is, the center of the box may not lie on the plane defined by the wires. More...
class	geo::TPCGeo
	Geometry information for a single TPC. More...
class	geo::WireGeo
	Geometry description of a TPC wireThe wire is a single straight segment on a wire plane. Different wires may be connected to the same readout channel. That is of no relevance for the geometry description. More...
std::unique_ptr< geo::GeometryCore >	lar::standalone::SetupGeometryWithChannelMapping (fhicl::ParameterSet const &pset, std::unique_ptr< geo::ChannelMapAlg > channelMap)
	Initializes a LArSoft geometry object. More...
template<typename ChannelMapClass , typename... Args>
std::unique_ptr< geo::GeometryCore >	lar::standalone::SetupGeometry (fhicl::ParameterSet const &pset, Args &&...args)
	Initializes a LArSoft geometry object. More...

Detailed Description

See also

geo::GeometryCore

The description of the detector as seen by LArSoft is accessed via LArSoft "geometry system".

A high level explanation of the geometry description is present in the official LArSoft collaboration web site, at the bottom of which further sources are detailed.

The geometry system revolves around the geo::GeometryCore service provider, which is the hub to access all the geometry information. The information accessible via this interface include:

• geometric description of the TPC components (wires, cryostats...)
• geometric description of the optical detectors
• geometric description of the "auxiliary" detectors (i.e. every detector which is not the two above)
• a ROOT representation of the detector geometry
• relation between readout channels and physical components (especially TPC readout channels vs. wires)
• tools to navigate this information
• ... and a load more stuff.

The service provider can be obtained including larcore/Geometry/Geometry.h header and calling:

auto const& geom = *(lar::providerFrom<geo::Geometry>());

Function Documentation

template<typename ChannelMapClass , typename... Args>

std::unique_ptr< geo::GeometryCore > lar::standalone::SetupGeometry	(	fhicl::ParameterSet const &	pset,
		Args &&...	args
	)

Initializes a LArSoft geometry object.

Template Parameters

ChannelMapClass	type of geo::ChannelMapAlg to be used
Args	(optional) arguments for the construction of channel mapping

Parameters

pset	complete set of parameters for geometry configuration
args	arguments to the channel mapping object constructor

Returns

the geometry object, fully initialized

This function creates, sets up and returns a geometry object using the specified channel mapping. This is a simplified version of SetupGeometryWithChannelMapping(), that can be used if no special treatment is needed for the channel mapping after construction and before it is made to interact with the geometry.

// read FHiCL configuration from a configuration file:
fhicl::ParameterSet pset;
cet::filepath_lookup_after1 policy("FHICL_FILE_PATH");
pset = fhicl::_ParameterSet::make(configPath, policy);

// set up message facility
mf::StartMessageFacility
  (pset.get<fhicl::ParameterSet>("services.message"));

// geometry setup
std::unique_ptr<geo::GeometryCore> geom
  = SetupGeometry<geo::StandardChannelMapAlg>(pset);

Note that this function constructs the channel mapping object using a constructor with arguments a parameter set and in addition, optionally, any other argument specified in args.

Definition at line 141 of file StandaloneGeometrySetup.h.

References fhicl::ParameterSet::get(), and lar::standalone::SetupGeometryWithChannelMapping().

Referenced by testing::GeometryTesterEnvironment< ConfigurationClass >::RegisterGeometry(), and testing::GeometryTesterEnvironment< ConfigurationClass >::Setup().

{
  auto const SortingParameters = pset.get<fhicl::ParameterSet>("SortingParameters", {});
  auto channelMap =
    std::make_unique<ChannelMapClass>(SortingParameters, std::forward<Args>(args)...);
  return SetupGeometryWithChannelMapping(pset, move(channelMap));
} // lar::standalone::SetupGeometry()

std::unique_ptr< geo::GeometryCore > lar::standalone::SetupGeometryWithChannelMapping	(	fhicl::ParameterSet const &	pset,
		std::unique_ptr< geo::ChannelMapAlg >	channelMap
	)

Initializes a LArSoft geometry object.

Parameters

pset	parameters for geometry configuration
channelMap	channel mapping object to be used, already constructed

Returns

the geometry object, fully initialized

See also

SetupGeometry()

This function creates, sets up and returns a geometry object using the specified channel mapping.

// create a channel mapping algorithm
std::make_unique<geo::StandardChannelMapAlg> channelMap
  (pset.get<fhicl::ParameterSet>("SortingParameters"));

std::unique_ptr<geo::GeometryCore> geom
  = SetupGeometryWithChannelMapping(pset, channelMap);

If no set up is required for channel mapping after construction, the use of SetupGeometry() is preferred over this function.

Configuration parameters

It is expected that a standard geo::Geometry service configuration will correctly set up the geometry.

In addition to the parameters documented in geo::GeometryCore, the following parameters are supported:

• RelativePath (string, default: no path): this path is prepended to the geometry file names before searching from them; the path string does not affect the file name
• GDML (string, mandatory): path of the GDML file to be served to GEANT4 * for detector simulation. The full file is composed out of the optional relative path specified by RelativePath path and the base name specified in GDML parameter; this path is searched for in the directories configured in the FW_SEARCH_PATH environment variable;
• ROOT (string, mandatory): currently overridden by GDML parameter, whose value is used instead; this path is assembled in the same way as the one for GDML parameter, except that no alternative (wireless) geometry is used even if DisableWiresInG4 is specified (see below); this file is used to load the geometry used in the internal simulation and reconstruction, basically everywhere except for the GEANT4 simulation
• DisableWiresInG4 (boolean, default: false): if true, GEANT4 is loaded with an alternative geometry from a file with the standard name as configured with the /GDML/ parameter, but with an additional _nowires appended before the .gdml suffix
• SortingParameters (a parameter set; default: empty): this configuration is directly passed to the channel mapping algorithm (see geo::ChannelMapAlg); its content is dependent on the chosen implementation of geo::ChannelMapAlg

Definition at line 27 of file StandaloneGeometrySetup.cxx.

References fhicl::ParameterSet::get().

Referenced by lar::standalone::SetupGeometry().

{
  auto const bForceReload = true;

  //
  // create the geometry object
  //
  auto geom = std::make_unique<geo::GeometryCore>(pset);

  //
  // extract of relevant configuration parameters
  //
  std::string relPath = pset.get<std::string>("RelativePath", "");
  const bool disableWiresInG4 = pset.get<bool>("DisableWiresInG4", false);
  const std::string GDMLFileName = pset.get<std::string>("GDML");
  //  const std::string ROOTFileName   = pset.get<std::string>("ROOT"                   );

  // add a final directory separator ("/") to relPath if not already there
  if (!relPath.empty() && (relPath.back() != '/')) relPath += '/';

  // We are going to find files now.
  // cet::search_path constructor decides if the constructor argument is a path
  // or an environment variable (in this case, the latter)
  cet::search_path sp("FW_SEARCH_PATH");

  //
  // "GDML" file (for GEANT4)
  //
  // this is our hint for the path; start with the relative path:
  std::string GDMLFilePathHint = relPath + GDMLFileName;

  // special if geometry with no wires is used for GEANT4 simulation
  if (disableWiresInG4) {
    GDMLFilePathHint.insert(std::min(GDMLFilePathHint.rfind(".gdml"), GDMLFilePathHint.length()),
                            "_nowires");
  } // if disable wires

  std::string GDMLFilePath;
  if (!sp.find_file(GDMLFilePathHint, GDMLFilePath)) {
    throw cet::exception("StaticLoadGeometry")
      << "Can't find geometry file '" << GDMLFilePathHint << "' (for GEANT4)!\n";
  }

  //
  // "ROOT" file (for geometry)
  //
  // this is our hint for the path; start with the relative path:
  std::string ROOTFilePathHint = relPath + GDMLFileName;

  std::string ROOTFilePath;
  if (!sp.find_file(ROOTFilePathHint, ROOTFilePath)) {
    throw cet::exception("StaticLoadGeometry")
      << "Can't find geometry file '" << ROOTFilePathHint << "' (for geometry)!\n";
  }

  //
  // initialize the geometry with the files we have found
  //
  geom->LoadGeometryFile(GDMLFilePath, ROOTFilePath, bForceReload);

  //
  // create and apply channel mapping
  //

  geom->ApplyChannelMap(move(channelMap));

  return geom;
} // lar::standalone::SetupGeometryWithChannelMapping()