(part of) Muon is finally in sim

PR1144

• MCH geometry
• MCH (very) basic hits

Progressive enhancement philosophy :

start simple and then refine...

Geometry

Hits

Tried to get minimal interfaces/exports

├── include
│   └── MCHSimulation

│       ├── Detector.h
│       ├── Geometry.h
│       ├── GeometryTest.h
│       └── Hit.h

├── macros
│   ├── drawMCHGeometry.C
├── src
│   ├── Detector.cxx
│   ├── Geometry.cxx
│   ├── GeometryTest.cxx
│   ├── Hit.cxx
│   ├── Materials.cxx
│   ├── Materials.h
│   ├── Station1Geometry.cxx
│   ├── Station1Geometry.h
│   ├── Station2Geometry.cxx
│   ├── Station2Geometry.h
│   ├── Station345Geometry.cxx
│   ├── Station345Geometry.h
│   ├── Stepper.cxx
│   └── Stepper.h
└── test
    ├── CMakeLists.txt
    └── testGeometry.cxx

Geometry.h

namespace o2 { namespace mch {

/// createGeometry creates MCH geometry and attach it to existing topVolume
void createGeometry(TGeoVolume& topVolume);

/// get a list of MCH sensitive volumes
std::vector<TGeoVolume*> getSensitiveVolumes();

/// get the local-to-global transformation for a given detection element
o2::Transform3D getTransformation(int detElemId, const TGeoManager& geo);

}}

Hit.h

Maybe too minimal

Will have to see when implementing digitizer

namespace o2 { namespace mch {

class Hit : public ::o2::BasicXYZEHit<float>
{
 public:
  Hit(int trackId = 0, 
      short detElemId = 0, 
      Point3D<float> entrancePoint = {}, 
      const Point3D<float> exitPoint = {},
      float eloss = 0.0, 
      float length = 0.0, 
      float tof = 0.0);  

  Point3D<float> entrancePoint() const;
  Point3D<float> exitPoint() const;

  short detElemId() const;

 private:
  float mLength = {};
  Point3D<float> mExitPoint = {};
  ClassDefNV(Hit, 1);
};

}}

Separation of concerns

Detector = {geo creation (functions), hit creation (class)}

namespace o2 { namespace mch {

Detector::Detector(bool active)
  : o2::Base::DetImpl<Detector>("MCH", active), mStepper{ new o2::mch::Stepper } {}

void Detector::defineSensitiveVolumes() {
  for (auto* vol : getSensitiveVolumes()) {
    AddSensitiveVolume(vol);
  }
}

void Detector::Initialize() {
  defineSensitiveVolumes();
  o2::Base::Detector::Initialize();
}

void Detector::ConstructGeometry() {
  createGeometry(*top);
}

Bool_t Detector::ProcessHits(FairVolume* v) {
  mStepper->process(*fMC);
  return kTRUE;
}

std::vector<o2::mch::Hit>* Detector::getHits(int i) {
  if (i == 0) {
    return mStepper->getHits();
  }
  return nullptr;
}

void Detector::Register()
{
  // TODO : get another way to do I/O (i.e. separate concerns)

  mStepper->registerHits(addNameTo("Hit").c_str());
}

void Detector::EndOfEvent() { mStepper->resetHits(); }

}}

GeometryTest.h

Mostly debug utilities for geometry development

namespace o2 { namespace mch { namespace test {

/// creates MCH geometry from scratch (i.e. from a null TGeoManager)
/// usefull for tests or drawing for instance.
void createStandaloneGeometry();

/// tree like textual dump of the geometry nodes
void showGeometryAsTextTree(const char* fromPath = "", int maxdepth = 2, std::ostream& out = std::cout);

/// basic drawing of the geometry
void drawGeometry();

/// set the volume and daughter visibility for all volumes with a name matching the regexp pattern
void setVolumeVisibility(const char* pattern, bool visible, bool visibleDaughters);

/// set the volume line and fill for all volumes with a name matching the regexp pattern
void setVolumeColor(const char* pattern, int lineColor, int fillColor);
inline void setVolumeColor(const char* pattern, int color)
{
  setVolumeColor(pattern, color, color);
}

/// get a radlen radiograph of a given detection element within box with the given granularity
TH2* getRadio(int detElemId, float xmin, float ymin, float xmax, float ymax, float xstep, float ystep, float thickness = 5 /* cm */);

}}}

Currently in the works

Geometry fixes

Uniformize level of details (St 2 < St345 < St1) ?

Global positioning adjustments

Adding electronic chips

Hit pos fix

Currently in the works

Radiographer

To get a map of <X/X0> for detection elements

To be added to tests

Next in the works

MID geometry

MID hits

On a longer term

Digitizer

Improved hits

Both are linked

Ideally informed by next test beam

Not before automn ?

Misc

aka Backup slides

TGeo vs TVirtualMC

create geometry w/o a prior VMC instance

PR1113

not completely successfull

but functional

Compact geo creation

void createStandaloneGeometry()
{
  if (gGeoManager && gGeoManager->GetTopVolume()) {
    std::cerr << "Can only call this function with an empty geometry, i.e. gGeoManager==nullptr "
              << " or gGeoManager->GetTopVolume()==nullptr\n";
  }
  TGeoManager* g = new TGeoManager("MCH-ONLY", "ALICE MCH Standalone Geometry");
  TGeoVolume* top = createAirVacuumCave("cave");
  g->SetTopVolume(top);
  o2::mch::createGeometry(*top);
}

no VMC needed here

easy to include in a unit test

Buckets dependencies snag

Change 1 MCH sim file

[build] Starting build
[proc] Executing command: /usr/local/bin/cmake --build /Users/laurent/alice/sw/BUILD/O2-latest-dpl-mch-test/O2 --config RelWithDebInfo --target all -- -j 10
[build] [1/11] Running utility command for svnheader
[build] [2/11] Building CXX object Detectors/MUON/MCH/Simulation/CMakeFiles/MCHSimulation.dir/src/GeometryTest.cxx.o
[build] [3/11] Linking CXX shared library lib/libMCHSimulation.dylib
[build] [4/11] Linking CXX executable bin/o2sim_parallel
[build] [5/11] Linking CXX executable bin/o2sim
[build] [6/11] Linking CXX executable bin/o2ITSClusterizers
[build] [7/11] Linking CXX executable bin/runTPC
[build] [8/11] Linking CXX executable bin/o2TPCSimulation
[build] [9/11] Linking CXX executable bin/O2HitMergerRunner
[build] [10/11] Linking CXX executable bin/O2PrimaryServerDeviceRunner
[build] [11/11] Linking CXX executable bin/O2SimDeviceRunner
[build] Build finished with exit code 0

Get a relink of too many executables ?

showGeometryAsTextTree

root [0] o2::mch::test::createStandaloneGeometry()
root [1] o2::mch::test::showGeometryAsTextTree("/cave",2)
cave_1
├──SC01I_0
│  ├──Quadrant (chamber 1)_101
│  └──Quadrant (chamber 1)_102
├──SC01O_1
│  ├──Quadrant (chamber 1)_100
│  └──Quadrant (chamber 1)_103
...
├──SC05I_8
│  ├──Chamber 5 support panel_8
│  ├──122000SR1_500
│  ├──112200SR2_501
│  ├──122200S_502
│  ├──222000N_503
│  ├──220000N_504
│  ├──220000N_514