Merge branch 'add_medium_type' into 'master'

Add medium type, as new property (air, water, rock...)

See merge request AirShowerPhysics/corsika!265

.gitignore

@@ -7,3 +7,4 @@ flymd.html
 flymd.md
 Testing
 tags
+Environment/GeneratedMediaProperties.inc

CMakeLists.txt

@@ -77,7 +77,7 @@ endif (NOT CMAKE_BUILD_TYPE AND NOT CMAKE_CONFIGURATION_TYPES)
 # enable warnings and disallow non-standard language
 # configure the various build types here, too
 # FYI: optimizer flags: -O2 would not trade speed for size, neither O2/3 use fast-math
-# debug: O0, relwithdebinfo: 02, release: O3, minsizerel: Os (all defaults)
+# debug: O0, relwithdebinfo: 02, release: O3, minsizerel: Os (all defaults), coverage -> O0
 set (CMAKE_CXX_FLAGS "-Wall -pedantic -Wextra -Wno-ignored-qualifiers")
 set (CMAKE_Fortran_FLAGS "-std=legacy -Wfunction-elimination")
 
@@ -104,7 +104,9 @@ if (CMAKE_BUILD_TYPE STREQUAL Coverage)
   find_package (Perl REQUIRED)
 
   # compile coverage under -O2 to remove unused functions
-  add_compile_options ("-O2")
+  #  add_compile_options ("-O2")
+  # compile coverage under -O0 to avoid any optimization, function elimation etc.
+  add_compile_options ("-O0")
   
   set (GCOV gcov CACHE STRING "gcov executable" FORCE)
   set (LCOV_BIN_DIR "${PROJECT_SOURCE_DIR}/ThirdParty/lcov/bin")

Documentation/Examples/CMakeLists.txt

@@ -67,7 +67,6 @@ if (Pythia8_FOUND)
     ProcessPythia8
     ProcessUrQMD
     CORSIKAcascade
-    ProcessCONEXSourceCut
     ProcessEnergyLoss
     ProcessTrackWriter
     ProcessStackInspector
@@ -106,7 +105,38 @@ if (Pythia8_FOUND)
     ProcessOnShellCheck
     ProcessStackInspector
     ProcessLongitudinalProfile
+    CORSIKAprocesses
+    CORSIKAcascade
+    CORSIKAparticles
+    CORSIKAgeometry
+    CORSIKAenvironment
+    CORSIKAprocesssequence
+    CORSIKAhistory # for HistoryObservationPlane
+    )
+
+  CORSIKA_ADD_EXAMPLE (hybrid_MC RUN_OPTIONS 4 2 10000.)
+  target_link_libraries (hybrid_MC
+    CORSIKAsetup
+    CORSIKAunits
+    CORSIKAlogging
+    CORSIKArandom
+    CORSIKAhistory
     ProcessCONEXSourceCut
+    ProcessInteractionCounter
+    ProcessSibyll
+    ProcessPythia8
+    ProcessUrQMD
+    CORSIKAcascade
+    ProcessPythia8
+    ProcessObservationPlane
+    ProcessInteractionCounter
+    ProcessTrackWriter
+    ProcessEnergyLoss
+    ProcessTrackingLine
+    ProcessParticleCut
+    ProcessOnShellCheck
+    ProcessStackInspector
+    ProcessLongitudinalProfile
     CORSIKAprocesses
     CORSIKAcascade
     CORSIKAparticles
@@ -146,7 +176,6 @@ target_link_libraries (em_shower
   ProcessPythia8
   ProcessUrQMD
   CORSIKAcascade
-  ProcessCONEXSourceCut
   ProcessEnergyLoss
   ProcessObservationPlane
   ProcessInteractionCounter

Documentation/Examples/boundary_example.cc

@@ -45,7 +45,6 @@ using namespace corsika::process;
 using namespace corsika::units;
 using namespace corsika::particles;
 using namespace corsika::random;
-using namespace corsika::setup;
 using namespace corsika::geometry;
 using namespace corsika::environment;
 
@@ -95,7 +94,7 @@ int main() {
   random::RNGManager::GetInstance().RegisterRandomStream("cascade");
 
   // setup environment, geometry
-  using EnvType = Environment<setup::IEnvironmentModel>;
+  using EnvType = setup::Environment;
   EnvType env;
   auto& universe = *(env.GetUniverse());
 
@@ -105,12 +104,16 @@ int main() {
   auto world = EnvType::CreateNode<Sphere>(
       Point{rootCS, 0_m, 0_m, 0_m}, 1_km * std::numeric_limits<double>::infinity());
 
-  auto const props =
-      world->SetModelProperties<environment::HomogeneousMedium<setup::IEnvironmentModel>>(
-          1_kg / (1_m * 1_m * 1_m),
-          environment::NuclearComposition(
-              std::vector<particles::Code>{particles::Code::Proton},
-              std::vector<float>{1.f}));
+  using MyHomogeneousModel =
+      environment::MediumPropertyModel<environment::UniformMagneticField<
+          environment::HomogeneousMedium<setup::EnvironmentInterface>>>;
+
+  auto const props = world->SetModelProperties<MyHomogeneousModel>(
+      environment::Medium::AirDry1Atm, Vector(rootCS, 0_T, 0_T, 0_T),
+      1_kg / (1_m * 1_m * 1_m),
+      environment::NuclearComposition(
+          std::vector<particles::Code>{particles::Code::Proton},
+          std::vector<float>{1.f}));
 
   // add a "target" sphere with 5km readius at 0,0,0
   auto target = EnvType::CreateNode<Sphere>(Point{rootCS, 0_m, 0_m, 0_m}, 5_km);

Documentation/Examples/cascade_example.cc

@@ -45,7 +45,6 @@ using namespace corsika::process;
 using namespace corsika::units;
 using namespace corsika::particles;
 using namespace corsika::random;
-using namespace corsika::setup;
 using namespace corsika::geometry;
 using namespace corsika::environment;
 
@@ -57,7 +56,7 @@ using namespace corsika::units::si;
 //
 int main() {
 
-  logging::SetLevel(logging::level::debug);
+  logging::SetLevel(logging::level::info);
 
   std::cout << "cascade_example" << std::endl;
 
@@ -68,33 +67,34 @@ int main() {
   random::RNGManager::GetInstance().RegisterRandomStream("cascade");
 
   // setup environment, geometry
-  using EnvType = environment::Environment<setup::IEnvironmentModel>;
-  EnvType env;
+  setup::Environment env;
   auto& universe = *(env.GetUniverse());
 
   const CoordinateSystem& rootCS = env.GetCoordinateSystem();
 
-  auto outerMedium = EnvType::CreateNode<Sphere>(
+  auto world = setup::Environment::CreateNode<Sphere>(
       Point{rootCS, 0_m, 0_m, 0_m}, 1_km * std::numeric_limits<double>::infinity());
 
+  using MyHomogeneousModel =
+      environment::MediumPropertyModel<environment::UniformMagneticField<
+          environment::HomogeneousMedium<setup::EnvironmentInterface>>>;
+
   // fraction of oxygen
   const float fox = 0.20946;
-  auto const props =
-      outerMedium
-          ->SetModelProperties<environment::HomogeneousMedium<setup::IEnvironmentModel>>(
-              1_kg / (1_m * 1_m * 1_m),
-              environment::NuclearComposition(
-                  std::vector<particles::Code>{particles::Code::Nitrogen,
-                                               particles::Code::Oxygen},
-                  std::vector<float>{1.f - fox, fox}));
+  auto const props = world->SetModelProperties<MyHomogeneousModel>(
+      environment::Medium::AirDry1Atm, Vector(rootCS, 0_T, 0_T, 0_T),
+      1_kg / (1_m * 1_m * 1_m),
+      environment::NuclearComposition(
+          std::vector<particles::Code>{particles::Code::Nitrogen,
+                                       particles::Code::Oxygen},
+          std::vector<float>{1.f - fox, fox}));
 
-  auto innerMedium = EnvType::CreateNode<Sphere>(Point{rootCS, 0_m, 0_m, 0_m}, 5000_m);
+  auto innerMedium =
+      setup::Environment::CreateNode<Sphere>(Point{rootCS, 0_m, 0_m, 0_m}, 5000_m);
 
   innerMedium->SetModelProperties(props);
-
-  outerMedium->AddChild(std::move(innerMedium));
-
-  universe.AddChild(std::move(outerMedium));
+  world->AddChild(std::move(innerMedium));
+  universe.AddChild(std::move(world));
 
   // setup particle stack, and add primary particle
   setup::Stack stack;

Documentation/Examples/cascade_proton_example.cc

@@ -49,7 +49,6 @@ using namespace corsika::process;
 using namespace corsika::units;
 using namespace corsika::particles;
 using namespace corsika::random;
-using namespace corsika::setup;
 using namespace corsika::geometry;
 using namespace corsika::environment;
 
@@ -70,24 +69,26 @@ int main() {
   random::RNGManager::GetInstance().RegisterRandomStream("cascade");
 
   // setup environment, geometry
-  using EnvType = Environment<setup::IEnvironmentModel>;
+  using EnvType = setup::Environment;
   EnvType env;
   auto& universe = *(env.GetUniverse());
+  const CoordinateSystem& rootCS = env.GetCoordinateSystem();
+
+  auto theMedium = EnvType::CreateNode<Sphere>(
+      Point{rootCS, 0_m, 0_m, 0_m}, 1_km * std::numeric_limits<double>::infinity());
 
-  auto theMedium =
-      EnvType::CreateNode<Sphere>(Point{env.GetCoordinateSystem(), 0_m, 0_m, 0_m},
-                                  1_km * std::numeric_limits<double>::infinity());
+  using MyHomogeneousModel =
+      environment::MediumPropertyModel<environment::UniformMagneticField<
+          environment::HomogeneousMedium<setup::EnvironmentInterface>>>;
 
-  using MyHomogeneousModel = HomogeneousMedium<IMediumModel>;
   theMedium->SetModelProperties<MyHomogeneousModel>(
+      environment::Medium::AirDry1Atm, geometry::Vector(rootCS, 0_T, 0_T, 1_T),
       1_kg / (1_m * 1_m * 1_m),
       NuclearComposition(std::vector<particles::Code>{particles::Code::Hydrogen},
                          std::vector<float>{(float)1.}));
 
   universe.AddChild(std::move(theMedium));
 
-  const CoordinateSystem& rootCS = env.GetCoordinateSystem();
-
   // setup particle stack, and add primary particle
   setup::Stack stack;
   stack.Clear();

Documentation/Examples/em_shower.cc

@@ -42,7 +42,6 @@ using namespace corsika::process;
 using namespace corsika::units;
 using namespace corsika::particles;
 using namespace corsika::random;
-using namespace corsika::setup;
 using namespace corsika::geometry;
 using namespace corsika::environment;
 
@@ -55,6 +54,9 @@ void registerRandomStreams() {
   random::RNGManager::GetInstance().SeedAll();
 }
 
+template <typename T>
+using MyExtraEnv = environment::MediumPropertyModel<environment::UniformMagneticField<T>>;
+
 int main(int argc, char** argv) {
 
   logging::SetLevel(logging::level::info);
@@ -68,11 +70,15 @@ int main(int argc, char** argv) {
   registerRandomStreams();
 
   // setup environment, geometry
-  using EnvType = Environment<setup::IEnvironmentModel>;
+  using EnvType = setup::Environment;
   EnvType env;
   const CoordinateSystem& rootCS = env.GetCoordinateSystem();
   Point const center{rootCS, 0_m, 0_m, 0_m};
-  environment::LayeredSphericalAtmosphereBuilder builder{center};
+  auto builder = environment::make_layered_spherical_atmosphere_builder<
+      setup::EnvironmentInterface,
+      MyExtraEnv>::create(center, units::constants::EarthRadius::Mean,
+                          environment::Medium::AirDry1Atm,
+                          geometry::Vector{rootCS, 0_T, 0_T, 1_T});
   builder.setNuclearComposition(
       {{particles::Code::Nitrogen, particles::Code::Oxygen},
        {0.7847f, 1.f - 0.7847f}}); // values taken from AIRES manual, Ar removed for now
@@ -82,7 +88,6 @@ int main(int argc, char** argv) {
   builder.addExponentialLayer(1305.5948_g / (1_cm * 1_cm), 636143.04_cm, 40_km);
   builder.addExponentialLayer(540.1778_g / (1_cm * 1_cm), 772170.16_cm, 100_km);
   builder.addLinearLayer(1e9_cm, 112.8_km);
-
   builder.assemble(env);
 
   // setup particle stack, and add primary particle
@@ -162,16 +167,16 @@ int main(int argc, char** argv) {
   EAS.Run();
 
   cut.ShowResults();
-  em_continuous.ShowResults();
+  em_continuous.showResults();
   observationLevel.ShowResults();
   const HEPEnergyType Efinal = cut.GetCutEnergy() + cut.GetInvEnergy() +
-                               cut.GetEmEnergy() + em_continuous.GetEnergyLost() +
+                               cut.GetEmEnergy() + em_continuous.energyLost() +
                                observationLevel.GetEnergyGround();
   cout << "total cut energy (GeV): " << Efinal / 1_GeV << endl
        << "relative difference (%): " << (Efinal / E0 - 1) * 100 << endl;
   observationLevel.Reset();
   cut.Reset();
-  em_continuous.Reset();
+  em_continuous.reset();
 
   auto const hists = proposalCounted.GetHistogram();
   hists.saveLab("inthist_lab_emShower.npz");

Documentation/Examples/vertical_EAS.cc

@@ -53,7 +53,6 @@ using namespace corsika::process;
 using namespace corsika::units;
 using namespace corsika::particles;
 using namespace corsika::random;
-using namespace corsika::setup;
 using namespace corsika::geometry;
 using namespace corsika::environment;
 
@@ -76,6 +75,9 @@ void registerRandomStreams(const int seed) {
     random::RNGManager::GetInstance().SeedAll(seed);
 }
 
+template <typename T>
+using MyExtraEnv = environment::MediumPropertyModel<environment::UniformMagneticField<T>>;
+
 int main(int argc, char** argv) {
 
   logging::SetLevel(logging::level::info);
@@ -95,11 +97,15 @@ int main(int argc, char** argv) {
   registerRandomStreams(seed);
 
   // setup environment, geometry
-  using EnvType = Environment<setup::IEnvironmentModel>;
+  using EnvType = setup::Environment;
   EnvType env;
   const CoordinateSystem& rootCS = env.GetCoordinateSystem();
   Point const center{rootCS, 0_m, 0_m, 0_m};
-  environment::LayeredSphericalAtmosphereBuilder builder{center};
+  auto builder = environment::make_layered_spherical_atmosphere_builder<
+      setup::EnvironmentInterface,
+      MyExtraEnv>::create(center, units::constants::EarthRadius::Mean,
+                          environment::Medium::AirDry1Atm,
+                          geometry::Vector{rootCS, 0_T, 0_T, 1_T});
   builder.setNuclearComposition(
       {{particles::Code::Nitrogen, particles::Code::Oxygen},
        {0.7847f, 1.f - 0.7847f}}); // values taken from AIRES manual, Ar removed for now
@@ -109,7 +115,6 @@ int main(int argc, char** argv) {
   builder.addExponentialLayer(1305.5948_g / (1_cm * 1_cm), 636143.04_cm, 40_km);
   builder.addExponentialLayer(540.1778_g / (1_cm * 1_cm), 772170.16_cm, 100_km);
   builder.addLinearLayer(1e9_cm, 112.8_km);
-
   builder.assemble(env);
 
   // setup particle stack, and add primary particle
@@ -245,16 +250,16 @@ int main(int argc, char** argv) {
   EAS.Run();
 
   cut.ShowResults();
-  em_continuous.ShowResults();
+  em_continuous.showResults();
   observationLevel.ShowResults();
   const HEPEnergyType Efinal = cut.GetCutEnergy() + cut.GetInvEnergy() +
-                               cut.GetEmEnergy() + em_continuous.GetEnergyLost() +
+                               cut.GetEmEnergy() + em_continuous.energyLost() +
                                observationLevel.GetEnergyGround();
   cout << "total cut energy (GeV): " << Efinal / 1_GeV << endl
        << "relative difference (%): " << (Efinal / E0 - 1) * 100 << endl;
   observationLevel.Reset();
   cut.Reset();
-  em_continuous.Reset();
+  em_continuous.reset();
 
   auto const hists = sibyllCounted.GetHistogram() + sibyllNucCounted.GetHistogram() +
                      urqmdCounted.GetHistogram() + proposalCounted.GetHistogram();

Environment/CMakeLists.txt

+add_custom_command (
+  OUTPUT  ${PROJECT_BINARY_DIR}/Environment/GeneratedMediaProperties.inc
+  COMMAND ${PROJECT_SOURCE_DIR}/Environment/readProperties.py 
+          ${PROJECT_SOURCE_DIR}/Environment/properties8.dat
+  DEPENDS readProperties.py
+          properties8.dat
+  WORKING_DIRECTORY
+          ${PROJECT_BINARY_DIR}/Environment
+  COMMENT "Read NIST properties8 data file and produce C++ source code GeneratedMediaProperties.inc"
+  VERBATIM
+  )
+
+
 set (
   ENVIRONMENT_SOURCES
-  LayeredSphericalAtmosphereBuilder.cc
   ShowerAxis.cc
 )
 
@@ -25,6 +37,10 @@ set (
   UniformMagneticField.h
   IRefractiveIndexModel.h
   UniformRefractiveIndex.h
+  IMediumPropertyModel.h
+  MediumProperties.h
+  MediumPropertyModel.h
+  ${PROJECT_BINARY_DIR}/Environment/GeneratedMediaProperties.inc # this one is auto-generated
   )
 
 set (
@@ -43,6 +59,19 @@ set_target_properties (
   PUBLIC_HEADER "${ENVIRONMENT_HEADERS}"
   )
 
+# ....................................................
+# since GeneratedMediaProperties.inc is an automatically produced file in the build directory,
+# create a symbolic link into the source tree, so that it can be found and edited more easily
+# this is not needed for the build to succeed! .......
+add_custom_command (
+  OUTPUT  ${CMAKE_CURRENT_SOURCE_DIR}/GeneratedParticleProperties.inc
+  COMMAND ${CMAKE_COMMAND} -E create_symlink ${PROJECT_BINARY_DIR}/include/corsika/environment/GeneratedMediaProperties.inc ${CMAKE_CURRENT_SOURCE_DIR}/GeneratedMediaProperties.inc
+  COMMENT "Generate link in source-dir: ${CMAKE_CURRENT_SOURCE_DIR}/GeneratedMediaProperties.inc"
+  )
+add_custom_target (SourceDirLinkMedia DEPENDS ${PROJECT_BINARY_DIR}/Environment/GeneratedMediaProperties.inc)
+add_dependencies (CORSIKAenvironment SourceDirLinkMedia)
+# .....................................................
+
 # target dependencies on other libraries (also the header onlys)
 target_link_libraries (
   CORSIKAenvironment

Environment/Environment.h

@@ -38,8 +38,6 @@ namespace corsika::environment {
         , fUniverse(std::make_unique<BaseNodeType>(
               std::make_unique<Universe>(fCoordinateSystem))) {}
 
-    // using IEnvironmentModel = corsika::setup::IEnvironmentModel;
-
     auto& GetUniverse() { return fUniverse; }
     auto const& GetUniverse() const { return fUniverse; }
 
@@ -61,7 +59,4 @@ namespace corsika::environment {
     typename BaseNodeType::VTNUPtr fUniverse;
   };
 
-  // using SetupBaseNodeType = VolumeTreeNode<corsika::setup::IEnvironmentModel>;
-  // using SetupEnvironment = Environment<corsika::setup::IEnvironmentModel>;
-
 } // namespace corsika::environment

Environment/IMediumPropertyModel.h

+/*
+ * (c) Copyright 2020 CORSIKA Project, corsika-project@lists.kit.edu
+ *
+ * This software is distributed under the terms of the GNU General Public
+ * Licence version 3 (GPL Version 3). See file LICENSE for a full version of
+ * the license.
+ */
+
+#pragma once
+
+#include <corsika/environment/MediumProperties.h>
+
+#include <corsika/geometry/Point.h>
+#include <corsika/units/PhysicalUnits.h>
+
+namespace corsika::environment {
+
+  /**
+   * An interface for type of media, needed e.g. to determine energy losses
+   *
+   * This is the base interface for media types.
+   *
+   */
+  template <typename Model>
+  class IMediumPropertyModel : public Model {
+
+  public:
+    /**
+     * Evaluate the medium type at a given location.
+     *
+     * @param  point    The location to evaluate at.
+     * @returns    The media type
+     */
+    virtual Medium medium(corsika::geometry::Point const&) const = 0;
+
+    /**
+     * A virtual default destructor.
+     */
+    virtual ~IMediumPropertyModel() = default;
+
+  }; // END: class IMediumTypeModel
+
+} // namespace corsika::environment

Environment/LayeredSphericalAtmosphereBuilder.cc

-/*
- * (c) Copyright 2020 CORSIKA Project, corsika-project@lists.kit.edu
- *
- * This software is distributed under the terms of the GNU General Public
- * Licence version 3 (GPL Version 3). See file LICENSE for a full version of
- * the license.
- */
-
-#include <corsika/environment/FlatExponential.h>
-#include <corsika/environment/HomogeneousMedium.h>
-#include <corsika/environment/LayeredSphericalAtmosphereBuilder.h>
-#include <corsika/environment/SlidingPlanarExponential.h>
-
-using namespace corsika::environment;
-
-void LayeredSphericalAtmosphereBuilder::checkRadius(units::si::LengthType r) const {
-  if (r <= previousRadius_) {
-    throw std::runtime_error("radius must be greater than previous");
-  }
-}
-
-void LayeredSphericalAtmosphereBuilder::setNuclearComposition(
-    NuclearComposition composition) {
-  composition_ = std::make_unique<NuclearComposition>(composition);
-}
-
-void LayeredSphericalAtmosphereBuilder::addExponentialLayer(
-    units::si::GrammageType b, units::si::LengthType c,
-    units::si::LengthType upperBoundary) {
-  auto const radius = earthRadius_ + upperBoundary;
-  checkRadius(radius);
-  previousRadius_ = radius;
-
-  auto node = std::make_unique<VolumeTreeNode<IMediumModel>>(
-      std::make_unique<geometry::Sphere>(center_, radius));
-
-  auto const rho0 = b / c;
-  std::cout << "rho0 = " << rho0 << ", c = " << c << std::endl;
-
-  node->SetModelProperties<SlidingPlanarExponential<IMediumModel>>(
-      center_, rho0, -c, *composition_, earthRadius_);
-
-  layers_.push(std::move(node));
-}
-
-void LayeredSphericalAtmosphereBuilder::addLinearLayer(
-    units::si::LengthType c, units::si::LengthType upperBoundary) {
-  using namespace units::si;
-
-  auto const radius = earthRadius_ + upperBoundary;
-  checkRadius(radius);
-  previousRadius_ = radius;
-
-  units::si::GrammageType constexpr b = 1 * 1_g / (1_cm * 1_cm);
-  auto const rho0 = b / c;
-
-  std::cout << "rho0 = " << rho0;
-
-  auto node = std::make_unique<VolumeTreeNode<environment::IMediumModel>>(
-      std::make_unique<geometry::Sphere>(center_, radius));
-  node->SetModelProperties<HomogeneousMedium<IMediumModel>>(rho0, *composition_);
-
-  layers_.push(std::move(node));
-}
-
-Environment<IMediumModel> LayeredSphericalAtmosphereBuilder::assemble() {
-  Environment<IMediumModel> env;
-  assemble(env);
-  return env;
-}
-
-void LayeredSphericalAtmosphereBuilder::assemble(Environment<IMediumModel>& env) {
-  auto& universe = env.GetUniverse();
-  auto* outmost = universe.get();
-
-  while (!layers_.empty()) {
-    auto l = std::move(layers_.top());
-    auto* tmp = l.get();
-    outmost->AddChild(std::move(l));
-    layers_.pop();
-    outmost = tmp;
-  }
-}

Environment/LayeredSphericalAtmosphereBuilder.h

@@ -7,52 +7,213 @@
  */
 
 #include <corsika/environment/Environment.h>
+#include <corsika/environment/FlatExponential.h>
+#include <corsika/environment/HomogeneousMedium.h>
 #include <corsika/environment/IMediumModel.h>
 #include <corsika/environment/NuclearComposition.h>
+#include <corsika/environment/SlidingPlanarExponential.h>
 #include <corsika/environment/VolumeTreeNode.h>
+
 #include <corsika/geometry/Point.h>
 #include <corsika/units/PhysicalConstants.h>
 #include <corsika/units/PhysicalUnits.h>
 
+#include <functional>
 #include <memory>
 #include <stack>
+#include <tuple>
+#include <type_traits>
 
 namespace corsika::environment {
 
+  // forward-decl
+  template <typename TMediumInterface, template <typename> typename MExtraEnvirnoment>
+  struct make_layered_spherical_atmosphere_builder;
+
+  /**
+   * Helper class to setup concentric spheres of layered atmosphere
+   * with spcified density profiles (exponential, linear, ...).
+   *
+   * This can be used most importantly to replicate CORSIKA7
+   * atmospheres.
+   *
+   * Each layer by definition has a density profile and a (constant)
+   * nuclear composition model.
+   *
+   */
+
+  namespace detail {
+
+    struct NoExtraModelInner {};
+
+    template <typename M>
+    struct NoExtraModel {};
+
+    template <template <typename> typename M>
+    struct has_extra_models : std::true_type {};
+
+    template <>
+    struct has_extra_models<NoExtraModel> : std::false_type {};
+
+  } // namespace detail
+
+  template <typename TMediumInterface = environment::IMediumModel,
+            template <typename> typename TMediumModelExtra = detail::NoExtraModel,
+            typename... TModelArgs>
   class LayeredSphericalAtmosphereBuilder {
     std::unique_ptr<NuclearComposition> composition_;
     geometry::Point center_;
     units::si::LengthType previousRadius_{units::si::LengthType::zero()};
     units::si::LengthType earthRadius_;