src/BarrelCalorimeterInterlayers_geo.cpp

@@ -21,7 +21,7 @@ using namespace dd4hep;
 using namespace dd4hep::detail;
 
 typedef ROOT::Math::XYPoint Point;
-// fiber placement helpers, defined in BarrelCalorimeterHybrid_geo
+// fiber placement helpers, defined below
 vector<vector<Point>> fiberPositions(double radius, double x_spacing, double z_spacing,
                                      double x, double z, double phi, double spacing_tol = 1e-2);
 std::pair<int, int> getNdivisions(double x, double z, double dx, double dz);
@@ -205,7 +205,7 @@ void buildFibers(Detector& desc, SensitiveDetector &sens, Volume &s_vol, xml_com
     }
     double l_pos_y = line.front().y();
     // use assembly as intermediate volume container to reduce number of daughter volumes
-    Assembly lfibers(Form("fiber_array_line_%d", il));
+    Assembly lfibers(Form("fiber_array_line_%lu", il));
     for (auto &p : line) {
       int f_grid_id = -1;
       int f_id = -1;
@@ -277,23 +277,22 @@ void buildSupport(Detector& desc, Volume &mod_vol, xml_comp_t x_support,
   double beam_width       = 2. * trd_x1_support / (n_beams + 1); // quick hack to make some gap between T beams
   double beam_gap         = getAttrOrDefault(x_support, _Unicode(beam_gap), 3.*cm);
 
-  // build H-shape beam
+  // build T-shape beam
   double beam_space_x    = beam_width + beam_gap;
   double beam_space_z    = support_thickness - beam_thickness;
-  double cross_thickness = support_thickness - 2.*beam_thickness;
-  double beam_pos_z      = -beam_thickness / 2.;
-  double beam_center_z   = support_thickness / 2. + beam_pos_z;
+  double cross_thickness = support_thickness - beam_thickness;
+  double beam_pos_z      = beam_thickness / 2.;
+  double beam_center_z   = support_thickness / 2. - beam_pos_z;
 
-  Box        beam_vert_s(beam_thickness / 2. , trd_y, cross_thickness / 2.);
+  Box        beam_vert_s(beam_thickness / 2., trd_y, cross_thickness / 2.);
   Box        beam_hori_s(beam_width / 2., trd_y, beam_thickness / 2.);
-  UnionSolid T_beam_s(beam_hori_s, beam_vert_s, Position(0., 0., beam_space_z / 2.));
-  UnionSolid H_beam_s(T_beam_s, beam_hori_s, Position(0., 0., support_thickness - beam_thickness));
-  Volume H_beam_vol("H_beam", H_beam_s, desc.material(x_support.materialStr()));
+  UnionSolid T_beam_s(beam_hori_s, beam_vert_s, Position(0., 0., support_thickness / 2.));
+  Volume H_beam_vol("H_beam", T_beam_s, desc.material(x_support.materialStr()));
   H_beam_vol.setVisAttributes(desc, x_support.visStr());
   // place H beams first
   double beam_start_x = - (n_beams - 1) * (beam_width + beam_gap) / 2.;
   for (int i = 0; i < n_beams; ++i) {
-    Position beam_pos(beam_start_x + i * (beam_width + beam_gap), 0., - support_thickness / 2. - beam_pos_z);
+    Position beam_pos(beam_start_x + i * (beam_width + beam_gap), 0., - support_thickness / 2. + beam_pos_z);
     env_vol.placeVolume(H_beam_vol, beam_pos);
   }
 
@@ -303,10 +302,10 @@ void buildSupport(Detector& desc, Volume &mod_vol, xml_comp_t x_support,
   Volume cross_vol("cross_center_beam", cross_s, desc.material(x_support.materialStr()));
   cross_vol.setVisAttributes(desc, x_support.visStr());
   for (int i = 0; i < n_beams - 1; ++i) {
-    env_vol.placeVolume(cross_vol, Position(beam_start_x + beam_space_x * (i + 0.5), 0., 0.));
+    env_vol.placeVolume(cross_vol, Position(beam_start_x + beam_space_x * (i + 0.5), 0., beam_pos_z));
     for (int j = 1; j < n_cross_supports; j++) {
-      env_vol.placeVolume(cross_vol, Position(beam_start_x + beam_space_x * (i + 0.5), -j * grid_size, 0.));
-      env_vol.placeVolume(cross_vol, Position(beam_start_x + beam_space_x * (i + 0.5), j * grid_size, 0.));
+      env_vol.placeVolume(cross_vol, Position(beam_start_x + beam_space_x * (i + 0.5), -j * grid_size, beam_pos_z));
+      env_vol.placeVolume(cross_vol, Position(beam_start_x + beam_space_x * (i + 0.5), j * grid_size, beam_pos_z));
     }
   }
 
@@ -315,24 +314,135 @@ void buildSupport(Detector& desc, Volume &mod_vol, xml_comp_t x_support,
   double    cross_edge_x = trd_x1_support + beam_start_x - beam_thickness / 2.;
   double    cross_trd_x1 = cross_edge_x + std::tan(hphi) * beam_thickness;
   double    cross_trd_x2 = cross_trd_x1 + 2.* std::tan(hphi) * cross_thickness;
-  double    edge_pos_x   = beam_start_x - beam_thickness / 2. - cross_trd_x1 / 2.;
+  double    edge_pos_x   = beam_start_x - cross_trd_x1 / 2. - beam_thickness / 2;
   Trapezoid cross_s2_trd (cross_trd_x1 / 2., cross_trd_x2 / 2.,
                           beam_thickness / 2., beam_thickness / 2., cross_thickness / 2.);
-  Box       cross_s2_box ((cross_trd_x2 - cross_trd_x1)/2., beam_thickness / 2., cross_thickness / 2.);
-  SubtractionSolid cross_s2(cross_s2_trd, cross_s2_box, Position((cross_trd_x1 + cross_trd_x2) / 4., 0., 0.));
+  Box       cross_s2_box ((cross_trd_x2 - cross_trd_x1)/4., beam_thickness / 2., cross_thickness / 2.);
+  SubtractionSolid cross_s2(cross_s2_trd, cross_s2_box, Position((cross_trd_x2 + cross_trd_x1)/4., 0., 0.));
   Volume cross_vol2("cross_edge_beam", cross_s2, desc.material(x_support.materialStr()));
   cross_vol2.setVisAttributes(desc, x_support.visStr());
-  env_vol.placeVolume(cross_vol2, Position(edge_pos_x, 0., 0.));
-  env_vol.placeVolume(cross_vol2, Transform3D(Translation3D(-edge_pos_x, 0., 0.) * RotationZ(M_PI)));
+  env_vol.placeVolume(cross_vol2, Position(edge_pos_x, 0., beam_pos_z));
+  env_vol.placeVolume(cross_vol2, Transform3D(Translation3D(-edge_pos_x, 0., beam_pos_z) * RotationZ(M_PI)));
   for (int j = 1; j < n_cross_supports; j++) {
-    env_vol.placeVolume(cross_vol2, Position(edge_pos_x, -j * grid_size, 0.));
-    env_vol.placeVolume(cross_vol2, Position(edge_pos_x, j * grid_size, 0.));
-    env_vol.placeVolume(cross_vol2, Transform3D(Translation3D(-edge_pos_x, -j * grid_size, 0.) * RotationZ(M_PI)));
-    env_vol.placeVolume(cross_vol2, Transform3D(Translation3D(-edge_pos_x, j * grid_size, 0.) * RotationZ(M_PI)));
+    env_vol.placeVolume(cross_vol2, Position(edge_pos_x, -j * grid_size, beam_pos_z));
+    env_vol.placeVolume(cross_vol2, Position(edge_pos_x, j * grid_size, beam_pos_z));
+    env_vol.placeVolume(cross_vol2, Transform3D(Translation3D(-edge_pos_x, -j * grid_size, beam_pos_z) * RotationZ(M_PI)));
+    env_vol.placeVolume(cross_vol2, Transform3D(Translation3D(-edge_pos_x, j * grid_size, beam_pos_z) * RotationZ(M_PI)));
   }
 
   mod_vol.placeVolume(env_vol, Position(0.0, 0.0, l_pos_z + support_thickness/2.));
 }
 
+// Fill fiber lattice into trapezoid starting from position (0,0) in x-z coordinate system
+vector<vector<Point>> fiberPositions(double radius, double x_spacing, double z_spacing, double x, double z, double phi,
+                                     double spacing_tol)
+{
+  // z_spacing - distance between fiber layers in z
+  // x_spacing - distance between fiber centers in x
+  // x - half-length of the shorter (bottom) base of the trapezoid
+  // z - height of the trapezoid
+  // phi - angle between z and trapezoid arm
+
+  vector<vector<Point>> positions;
+  int z_layers = floor((z / 2 - radius - spacing_tol) / z_spacing); // number of layers that fit in z/2
+
+  double z_pos = 0.;
+  double x_pos = 0.;
+
+  for (int l = -z_layers; l < z_layers + 1; l++) {
+    vector<Point> xline;
+    z_pos                = l * z_spacing;
+    double x_max         = x + (z / 2. + z_pos) * tan(phi) - spacing_tol; // calculate max x at particular z_pos
+    (l % 2 == 0) ? x_pos = 0. : x_pos = x_spacing / 2;                    // account for spacing/2 shift
+
+    while (x_pos < (x_max - radius)) {
+      xline.push_back(Point(x_pos, z_pos));
+      if (x_pos != 0.)
+        xline.push_back(Point(-x_pos, z_pos)); // using symmetry around x=0
+      x_pos += x_spacing;
+    }
+    // Sort fiber IDs for a better organization
+    sort(xline.begin(), xline.end(), [](const Point& p1, const Point& p2) { return p1.x() < p2.x(); });
+    positions.emplace_back(std::move(xline));
+  }
+  return positions;
+}
+
+// Calculate number of divisions for the readout grid for the fiber layers
+std::pair<int, int> getNdivisions(double x, double z, double dx, double dz)
+{
+  // x and z defined as in vector<Point> fiberPositions
+  // dx, dz - size of the grid in x and z we want to get close to with the polygons
+  // See also descripltion when the function is called
+
+  double SiPMsize = 13.0 * mm;
+  double grid_min = SiPMsize + 3.0 * mm;
+
+  if (dz < grid_min) {
+    dz = grid_min;
+  }
+
+  if (dx < grid_min) {
+    dx = grid_min;
+  }
+
+  int nfit_cells_z = floor(z / dz);
+  int n_cells_z    = nfit_cells_z;
+
+  if (nfit_cells_z == 0)
+    n_cells_z++;
+
+  int nfit_cells_x = floor((2 * x) / dx);
+  int n_cells_x    = nfit_cells_x;
+
+  if (nfit_cells_x == 0)
+    n_cells_x++;
+
+  return std::make_pair(n_cells_x, n_cells_z);
+}
+
+// Calculate dimensions of the polygonal grid in the cartesian coordinate system x-z
+vector<tuple<int, Point, Point, Point, Point>> gridPoints(int div_x, int div_z, double x, double z, double phi)
+{
+  // x, z and phi defined as in vector<Point> fiberPositions
+  // div_x, div_z - number of divisions in x and z
+  double dz = z / div_z;
+
+  std::vector<std::tuple<int, Point, Point, Point, Point>> points;
+
+  for (int iz = 0; iz < div_z + 1; iz++) {
+    for (int ix = 0; ix < div_x + 1; ix++) {
+      double A_z = -z / 2 + iz * dz;
+      double B_z = -z / 2 + (iz + 1) * dz;
+
+      double len_x_for_z        = 2 * (x + iz * dz * tan(phi));
+      double len_x_for_z_plus_1 = 2 * (x + (iz + 1) * dz * tan(phi));
+
+      double dx_for_z        = len_x_for_z / div_x;
+      double dx_for_z_plus_1 = len_x_for_z_plus_1 / div_x;
+
+      double A_x = -len_x_for_z / 2. + ix * dx_for_z;
+      double B_x = -len_x_for_z_plus_1 / 2. + ix * dx_for_z_plus_1;
+
+      double C_z = B_z;
+      double D_z = A_z;
+      double C_x = B_x + dx_for_z_plus_1;
+      double D_x = A_x + dx_for_z;
+
+      int id = ix + div_x * iz;
+
+      auto A = Point(A_x, A_z);
+      auto B = Point(B_x, B_z);
+      auto C = Point(C_x, C_z);
+      auto D = Point(D_x, D_z);
+
+      // vertex points filled in the clock-wise direction
+      points.push_back(make_tuple(id, A, B, C, D));
+    }
+  }
+
+  return points;
+}
+
 DECLARE_DETELEMENT(athena_EcalBarrelInterlayers, create_detector)
 

src/BarrelTrackerWithFrame_geo.cpp

-/** \addtogroup VertexTracker Vertex Trackers
- * \brief Type: **SiVertexBarrel**.
+/** \addtogroup Trackers Trackers
+ * \brief Type: **BarrelTrackerWithFrame**.
  * \author W. Armstrong
- * \ingroup trackers
- *
  *
- * \code
- * \endcode
+ * \ingroup trackers
  *
  * @{
  */
@@ -15,135 +12,185 @@
 #include "DDRec/Surface.h"
 #include "DDRec/DetectorData.h"
 #include "XML/Layering.h"
-#include "Acts/Plugins/DD4hep/ActsExtension.hpp"
-#include "Acts/Surfaces/PlanarBounds.hpp"
-#include "Acts/Surfaces/RectangleBounds.hpp"
-#include "Acts/Surfaces/TrapezoidBounds.hpp"
-#include "Acts/Definitions/Units.hpp"
+#include "XML/Utilities.h"
+#include <array>
 
+#if defined(USE_ACTSDD4HEP)
+#include "ActsDD4hep/ActsExtension.hpp"
+#include "ActsDD4hep/ConvertMaterial.hpp"
+#else
+#include "Acts/Plugins/DD4hep/ActsExtension.hpp"
+#include "Acts/Plugins/DD4hep/ConvertDD4hepMaterial.hpp"
+#endif
 
 using namespace std;
 using namespace dd4hep;
 using namespace dd4hep::rec;
 using namespace dd4hep::detail;
 
-static Ref_t create_detector(Detector& description, xml_h e, SensitiveDetector sens) {
+
+/** Barrel Tracker with space frame.
+ *
+ * - Optional "support" tag within the detector element.
+ * 
+ * The shapes are created using createShape which can be one of many basic geomtries. 
+ * See the examples Check_shape_*.xml in 
+ * [dd4hep's examples/ClientTests/compact](https://github.com/AIDASoft/DD4hep/tree/master/examples/ClientTests/compact)
+ * directory.
+ *
+ *
+ * - Optional "frame" tag within the module element.
+ *
+ * \ingroup trackers
+ *
+ * \code
+ * \endcode
+ * 
+ *
+ * @author Whitney Armstrong
+ */
+static Ref_t create_BarrelTrackerWithFrame(Detector& description, xml_h e, SensitiveDetector sens) {
   typedef vector<PlacedVolume> Placements;
   xml_det_t                    x_det    = e;
   Material                     air      = description.air();
   int                          det_id   = x_det.id();
   string                       det_name = x_det.nameStr();
   DetElement                   sdet(det_name, det_id);
-  //Assembly                     assembly(det_name);
-  map<string, Volume>          volumes;
-  map<string, Placements>      sensitives;
-  map<string, std::vector<VolPlane>>        volplane_surfaces;
-  map<string, xml_h>      xmleles;
-  PlacedVolume                 pv;
-  dd4hep::xml::Dimension dimensions(x_det.dimensions());
 
+  map<string, Volume>                volumes;
+  map<string, Placements>            sensitives;
+  map<string, std::vector<VolPlane>> volplane_surfaces;
   map<string, std::array<double, 2>> module_thicknesses;
 
-  Acts::ActsExtension* detWorldExt = new Acts::ActsExtension();
-  detWorldExt->addType("barrel", "detector");
-  sdet.addExtension<Acts::ActsExtension>(detWorldExt);
-  Tube topVolumeShape(dimensions.rmin(), dimensions.rmax(), dimensions.length() * 0.5);
-  Volume assembly(det_name,topVolumeShape,air);
-
-
-//  The Cold Plate is approximately 30 mm wide and is based on the same carbon-ply layup
-//as for the IB Stave. Two pipes with an inner diameter of 2.67 mm and a wall thickness
-//of 64 μm have been used. The two pipes are interconnected at one end of the Cold Plate
-//providing a loop, whose inlet and outlet are on the same side and correspond to the
-//
-//requirements have led to an equilateral section of the frame with a 42 mm wide side, that
-//provides almost the same rigidity for all the possible Stave positions.
-//
-//                     module mat                um
-//
-//Aluminium                                      50
-//Polyimide                                      100
-//Carbon fibre                                   120
-//Silicon                                        50
-//Eccobond-45                                    100
-//
-//Metal layers                 Aluminium        200
-//Insulating layers            Polyimide        200
-//Glue Cooling tube wall       Eccobond-45      100
-//
-//Carbon fleece            40
-//Carbon paper             30
-//Polyimide                64
-//Water                    
-//Carbon fibre             120
-//Eccobond-45              100
+  PlacedVolume           pv;
+  dd4hep::xml::Dimension dimensions(x_det.dimensions());
 
+  // ACTS extension
+  {
+    Acts::ActsExtension* detWorldExt = new Acts::ActsExtension();
+    detWorldExt->addType("barrel", "detector");
+    // Add the volume boundary material if configured
+    for (xml_coll_t bmat(x_det, _Unicode(boundary_material)); bmat; ++bmat) {
+      xml_comp_t x_boundary_material = bmat;
+      Acts::xmlToProtoSurfaceMaterial(x_boundary_material, *detWorldExt, "boundary_material");
+    }
+    sdet.addExtension<Acts::ActsExtension>(detWorldExt);
+  }
 
+  Tube topVolumeShape(dimensions.rmin(), dimensions.rmax(), dimensions.length() * 0.5);
+  Volume assembly(det_name,topVolumeShape,air);
 
   sens.setType("tracker");
 
+  // Loop over the suports
+  for (xml_coll_t su(x_det, _U(support)); su; ++su) {
+    xml_comp_t x_support = su;
+    double      support_thickness = getAttrOrDefault(x_support, _U(thickness), 2.0 * mm);
+    double      support_length    = getAttrOrDefault(x_support, _U(length), 2.0 * mm);
+    double      support_rmin      = getAttrOrDefault(x_support, _U(rmin), 2.0 * mm);
+    double      support_zstart    = getAttrOrDefault(x_support, _U(zstart), 2.0 * mm);
+    std::string support_name      = getAttrOrDefault<std::string>(x_support, _Unicode(name), "support_tube");
+    std::string support_vis       = getAttrOrDefault<std::string>(x_support, _Unicode(vis), "AnlRed");
+    xml_dim_t  pos        (x_support.child(_U(position), false));
+    xml_dim_t  rot        (x_support.child(_U(rotation), false));
+    Solid support_solid;
+    if(x_support.hasChild("shape")){
+      xml_comp_t shape(x_support.child(_U(shape)));
+      string     shape_type = shape.typeStr();
+      support_solid  = xml::createShape(description, shape_type, shape);
+    } else {
+      support_solid = Tube(support_rmin, support_rmin + support_thickness, support_length / 2);
+    }
+    Transform3D tr = Transform3D(Rotation3D(),Position(0,0,(support_zstart + support_length / 2)));
+    if ( pos.ptr() && rot.ptr() )  {
+      Rotation3D  rot3D(RotationZYX(rot.z(0),rot.y(0),rot.x(0)));
+      Position    pos3D(pos.x(0),pos.y(0),pos.z(0));
+      tr = Transform3D(rot3D, pos3D);
+    }
+    else if ( pos.ptr() )  {
+      tr = Transform3D(Rotation3D(),Position(pos.x(0),pos.y(0),pos.z(0)));
+    }
+    else if ( rot.ptr() )  {
+      Rotation3D rot3D(RotationZYX(rot.z(0),rot.y(0),rot.x(0)));
+      tr = Transform3D(rot3D,Position());
+    }
+    Material    support_mat       = description.material(x_support.materialStr());
+    Volume      support_vol(support_name, support_solid, support_mat);
+    support_vol.setVisAttributes(description.visAttributes(support_vis));
+    pv = assembly.placeVolume(support_vol, tr);
+    // pv = assembly.placeVolume(support_vol, Position(0, 0, support_zstart + support_length / 2));
+  }
+
   // loop over the modules
   for (xml_coll_t mi(x_det, _U(module)); mi; ++mi) {
     xml_comp_t x_mod = mi;
-    xml_comp_t m_env = x_mod.child(_U(frame));
     string     m_nam = x_mod.nameStr();
-    xmleles[m_nam]  = x_mod;
-
-    // triangular volume envelope
-    double frame_thickness = m_env.thickness();
-    double frame_width     = m_env.width();
-    double frame_height    = getAttrOrDefault<double>(m_env, _U(height), 5.0 * mm);
-    double tanth           = frame_height/(frame_width/2.0);
-    double frame_height2   = frame_height-frame_thickness-frame_thickness/tanth;
-    double frame_width2    = 2.0*frame_height2/tanth;
-
-    Trd1 moduleframe_part1(frame_width / 2, 0.001 * mm, m_env.length() / 2,
-                           frame_height / 2);
-    Trd1 moduleframe_part2(frame_width2/2, 0.001 * mm,
-                           m_env.length() / 2 + 0.01 * mm, frame_height2/2);
-    SubtractionSolid moduleframe(moduleframe_part1, moduleframe_part2,Position(0.0,frame_thickness,0.0));
-    Volume v_module(m_nam+"_vol", moduleframe, description.material(m_env.materialStr()));
-    v_module.setVisAttributes(description, m_env.visStr());
-
-    int ncomponents   = 0;
-    int sensor_number = 1;
 
     if (volumes.find(m_nam) != volumes.end()) {
-      printout(ERROR, "SiTrackerBarrel", "Logics error in building modules.");
+      printout(ERROR, "BarrelTrackerWithFrame", string((string("Module with named ") + m_nam + string(" already exists."))).c_str() );
       throw runtime_error("Logics error in building modules.");
     }
+
+    int ncomponents   = 0;
+    int sensor_number = 1;
     double total_thickness = 0;
+
+    // Compute module total thickness from components
     xml_coll_t ci(x_mod, _U(module_component));
     for (ci.reset(), total_thickness = 0.0; ci; ++ci) {
       total_thickness += xml_comp_t(ci).thickness();
     }
-    // module assembly
+    // the module assembly volume
     Assembly m_vol( m_nam );
-    m_vol.placeVolume(v_module, Position(0.0,0.0,frame_height/2+total_thickness/2.0));
     volumes[m_nam] = m_vol;
     m_vol.setVisAttributes(description.visAttributes(x_mod.visStr()));
 
+    // Optional module frame.
+    if(x_mod.hasChild("frame")){
+      xml_comp_t m_frame = x_mod.child(_U(frame));
+      //xmleles[m_nam]  = x_mod;
+      double frame_thickness = m_frame.thickness();
+      double frame_width     = m_frame.width();
+      double frame_height    = getAttrOrDefault<double>(m_frame, _U(height), 5.0 * mm);
+      double tanth           = frame_height/(frame_width/2.0);
+      double frame_height2   = frame_height-frame_thickness-frame_thickness/tanth;
+      double frame_width2    = 2.0*frame_height2/tanth;
+
+      Trd1 moduleframe_part1(frame_width / 2, 0.001 * mm, m_frame.length() / 2,
+                             frame_height / 2);
+      Trd1 moduleframe_part2(frame_width2/2, 0.001 * mm,
+                             m_frame.length() / 2 + 0.01 * mm, frame_height2/2);
+
+      SubtractionSolid moduleframe(moduleframe_part1, moduleframe_part2,Position(0.0,frame_thickness,0.0));
+      Volume v_moduleframe(m_nam+"_vol", moduleframe, description.material(m_frame.materialStr()));
+      v_moduleframe.setVisAttributes(description, m_frame.visStr());
+      m_vol.placeVolume(v_moduleframe, Position(0.0, 0.0, frame_height / 2 + total_thickness / 2.0));
+    }
+
+
     double thickness_so_far = 0.0;
     double thickness_sum = -total_thickness/2.0;
     for (xml_coll_t ci(x_mod, _U(module_component)); ci; ++ci, ++ncomponents) {
-      xml_comp_t x_comp = ci;
-      xml_comp_t x_pos  = x_comp.position(false);
-      xml_comp_t x_rot  = x_comp.rotation(false);
-      string     c_nam  = _toString(ncomponents, "component%d");
-      Box        c_box(x_comp.width() / 2, x_comp.length() / 2, x_comp.thickness() / 2);
-      Volume     c_vol(c_nam, c_box, description.material(x_comp.materialStr()));
-
+      xml_comp_t   x_comp = ci;
+      xml_comp_t   x_pos  = x_comp.position(false);
+      xml_comp_t   x_rot  = x_comp.rotation(false);
+      const string c_nam  = _toString(ncomponents, "component%d");
+      Box          c_box(x_comp.width() / 2, x_comp.length() / 2, x_comp.thickness() / 2);
+      Volume       c_vol(c_nam, c_box, description.material(x_comp.materialStr()));
+
+      // Utility variable for the relative z-offset based off the previous components
+      const double zoff = thickness_sum+x_comp.thickness() / 2.0;
       if (x_pos && x_rot) {
-        Position c_pos(x_pos.x(0), x_pos.y(0), x_pos.z(0));
+        Position c_pos(x_pos.x(0), x_pos.y(0), x_pos.z(0) + zoff);
         RotationZYX c_rot(x_rot.z(0), x_rot.y(0), x_rot.x(0));
         pv = m_vol.placeVolume(c_vol, Transform3D(c_rot, c_pos));
       } else if (x_rot) {
-        Position c_pos(0, 0, thickness_sum + x_comp.thickness() / 2.0);
-        pv = m_vol.placeVolume(c_vol, Transform3D(RotationZYX(x_rot.z(0), x_rot.y(0), x_rot.x(0)),c_pos));
+        Position c_pos(0, 0, zoff);
+        pv = m_vol.placeVolume(c_vol, Transform3D(RotationZYX(x_rot.z(0), x_rot.y(0), x_rot.x(0)), c_pos));
       } else if (x_pos) {
-        pv = m_vol.placeVolume(c_vol, Position(x_pos.x(0), x_pos.y(0), x_pos.z(0)));
+        pv = m_vol.placeVolume(c_vol, Position(x_pos.x(0), x_pos.y(0), x_pos.z(0) + zoff));
       } else {
-        pv = m_vol.placeVolume(c_vol, Position(0,0,thickness_sum+x_comp.thickness()/2.0));
+        pv = m_vol.placeVolume(c_vol, Position(0, 0, zoff));
       }
       c_vol.setRegion(description, x_comp.regionStr());
       c_vol.setLimitSet(description, x_comp.limitsStr());
@@ -154,32 +201,34 @@ static Ref_t create_detector(Detector& description, xml_h e, SensitiveDetector s
         sensitives[m_nam].push_back(pv);
         module_thicknesses[m_nam] = {thickness_so_far + x_comp.thickness()/2.0, total_thickness-thickness_so_far - x_comp.thickness()/2.0};
 
+        // -------- create a measurement plane for the tracking surface attched to the sensitive volume -----
+        Vector3D u(-1., 0., 0.);
+        Vector3D v(0., -1., 0.);
+        Vector3D n(0., 0., 1.);
+        //    Vector3D o( 0. , 0. , 0. ) ;
 
-          // -------- create a measurement plane for the tracking surface attched to the sensitive volume -----
-          Vector3D u( 0. , 1. , 0. ) ;
-          Vector3D v( 0. , 0. , 1. ) ;
-          Vector3D n( 1. , 0. , 0. ) ;
-          //    Vector3D o( 0. , 0. , 0. ) ;
-
-          // compute the inner and outer thicknesses that need to be assigned to the tracking surface
-          // depending on wether the support is above or below the sensor
-          double inner_thickness = module_thicknesses[m_nam][0];
-          double outer_thickness = module_thicknesses[m_nam][1];
-
-          SurfaceType type( SurfaceType::Sensitive ) ;
+        // compute the inner and outer thicknesses that need to be assigned to the tracking surface
+        // depending on wether the support is above or below the sensor
+        double inner_thickness = module_thicknesses[m_nam][0];
+        double outer_thickness = module_thicknesses[m_nam][1];
 
-          //if( isStripDetector )
-          //  type.setProperty( SurfaceType::Measurement1D , true ) ;
+        SurfaceType type(SurfaceType::Sensitive);
 
-          VolPlane surf( c_vol , type , inner_thickness , outer_thickness , u,v,n ) ; //,o ) ;
-          volplane_surfaces[m_nam].push_back(surf);
-
-    //--------------------------------------------
+        // if( isStripDetector )
+        //  type.setProperty( SurfaceType::Measurement1D , true ) ;
 
+        VolPlane surf(c_vol, type, inner_thickness, outer_thickness, u, v, n); //,o ) ;
+        volplane_surfaces[m_nam].push_back(surf);
 
+        //--------------------------------------------
       }
       thickness_sum += x_comp.thickness();
       thickness_so_far += x_comp.thickness();
+      // apply relative offsets in z-position used to stack components side-by-side
+      if (x_pos) {
+        thickness_sum += x_pos.z(0);
+        thickness_so_far += x_pos.z(0);
+      }
     }
   }
 
@@ -208,19 +257,22 @@ static Ref_t create_detector(Detector& description, xml_h e, SensitiveDetector s
     double      z_dr       = z_layout.dr();       // Radial displacement parameter, of every other module.
 
     Volume      module_env = volumes[m_nam];
-    DetElement  lay_elt(sdet, _toString(x_layer.id(), "layer%d"), lay_id);
+    DetElement  lay_elt(sdet, lay_nam, lay_id);
     Placements& sensVols = sensitives[m_nam];
 
     // the local coordinate systems of modules in dd4hep and acts differ
     // see http://acts.web.cern.ch/ACTS/latest/doc/group__DD4hepPlugins.html
-    Acts::ActsExtension* layerExtension = new Acts::ActsExtension();
-    layerExtension->addType("sensitive cylinder", "layer");
-    //layerExtension->addValue(0, "r_min", "envelope");
-    //layerExtension->addValue(0, "r_max", "envelope");
-    //layerExtension->addValue(0, "z_min", "envelope");
-    //layerExtension->addValue(0, "z_max", "envelope");
-    //layerExtension->addType("axes", "definitions", "XzY");
-    lay_elt.addExtension<Acts::ActsExtension>(layerExtension);
+    {
+      Acts::ActsExtension* layerExtension = new Acts::ActsExtension();
+      // layer is simple tube so no need to set envelope
+      layerExtension->addType("sensitive cylinder", "layer");
+      // Add the proto layer material
+      for(xml_coll_t lmat(x_layer, _Unicode(layer_material)); lmat; ++lmat) {
+        xml_comp_t x_layer_material = lmat;
+        xmlToProtoSurfaceMaterial(x_layer_material, *layerExtension, "layer_material");
+      }
+      lay_elt.addExtension<Acts::ActsExtension>(layerExtension);
+    }
 
     // Z increment for module placement along Z axis.
     // Adjust for z0 at center of module rather than
@@ -252,16 +304,17 @@ static Ref_t create_detector(Detector& description, xml_h e, SensitiveDetector s
           PlacedVolume sens_pv = sensVols[ic];
           DetElement comp_de(mod_elt, std::string("de_") + sens_pv.volume().name(), module);
           comp_de.setPlacement(sens_pv);
-          Acts::ActsExtension* sensorExtension = new Acts::ActsExtension();
-          //sensorExtension->addType("sensor", "detector");
-          comp_de.addExtension<Acts::ActsExtension>(sensorExtension);
+          // ACTS extension
+          {
+            Acts::ActsExtension* sensorExtension = new Acts::ActsExtension();
+            //sensorExtension->addType("sensor", "detector");
+            comp_de.addExtension<Acts::ActsExtension>(sensorExtension);
+          }
           //comp_de.setAttributes(description, sens_pv.volume(), x_layer.regionStr(), x_layer.limitsStr(),
           //                      xml_det_t(xmleles[m_nam]).visStr());
           //
 
-      volSurfaceList( comp_de )->push_back( volplane_surfaces[m_nam][ic] ) ;
-
-
+          volSurfaceList(comp_de)->push_back(volplane_surfaces[m_nam][ic]);
         }
 
         /// Increase counters etc.
@@ -291,14 +344,13 @@ static Ref_t create_detector(Detector& description, xml_h e, SensitiveDetector s
   assembly.setVisAttributes(description.invisible());
   pv = description.pickMotherVolume(sdet).placeVolume(assembly);
   pv.addPhysVolID("system", det_id);  // Set the subdetector system ID.
-  pv.addPhysVolID("barrel", 1);       // Flag this as a barrel subdetector.
   sdet.setPlacement(pv);
   return sdet;
 }
 
 //@}
 // clang-format off
-DECLARE_DETELEMENT(BarrelTrackerWithFrame, create_detector)
-DECLARE_DETELEMENT(athena_VertexBarrel, create_detector)
-DECLARE_DETELEMENT(athena_TrackerBarrel, create_detector)
-DECLARE_DETELEMENT(refdet_SiVertexBarrel, create_detector)
+DECLARE_DETELEMENT(BarrelTrackerWithFrame, create_BarrelTrackerWithFrame)
+DECLARE_DETELEMENT(athena_TrackerBarrel,   create_BarrelTrackerWithFrame)
+DECLARE_DETELEMENT(athena_VertexBarrel,    create_BarrelTrackerWithFrame)
+DECLARE_DETELEMENT(athena_TOFBarrel,       create_BarrelTrackerWithFrame)

src/CompositeTracker_geo.cpp

+//==========================================================================
+//  Based off DD4hep_SubDetectorAssembly
+//
+//  This is a simple plugin to allow compositing different detectors
+//  into a single barrel or endcap for ACTS
+//  Note: positive/negative position strings differentiate between
+//        positive/negative endcaps
+//--------------------------------------------------------------------------
+
+#include "DD4hep/DetFactoryHelper.h"
+#include "DD4hep/Printout.h"
+#include "XML/Utilities.h"
+
+#if defined(USE_ACTSDD4HEP)
+#include "ActsDD4hep/ActsExtension.hpp"
+#else
+#include "Acts/Plugins/DD4hep/ActsExtension.hpp"
+#endif
+
+using namespace dd4hep;
+using namespace dd4hep::detail;
+
+static Ref_t create_element(Detector& description, xml_h e, Ref_t)
+{
+  xml_det_t         x_det(e);
+  const std::string det_name = x_det.nameStr();
+  DetElement        sdet(det_name, x_det.id());
+  Volume            vol;
+  Position          pos;
+
+  const bool usePos = x_det.hasChild(_U(position));
+
+  sdet.setType("compound");
+  xml::setDetectorTypeFlag(e, sdet);
+
+  const std::string actsType = getAttrOrDefault(x_det, _Unicode(actsType), "endcap");
+  printout(DEBUG, det_name, "+++ Creating composite tracking detector (type: " + actsType + ")");
+  assert(actsType == "barrel" || actsType == "endcap");
+
+  // ACTS extension
+  {
+    Acts::ActsExtension* detWorldExt = new Acts::ActsExtension();
+    detWorldExt->addType(actsType, "detector");
+    sdet.addExtension<Acts::ActsExtension>(detWorldExt);
+  }
+
+  if (usePos) {
+    pos = Position(x_det.position().x(), x_det.position().y(), x_det.position().z());
+  }
+  vol = Assembly(det_name);
+  vol.setAttributes(description, x_det.regionStr(), x_det.limitsStr(), x_det.visStr());
+
+  Volume       mother = description.pickMotherVolume(sdet);
+  PlacedVolume pv;
+  if (usePos) {
+    pv = mother.placeVolume(vol, pos);
+  } else {
+    pv = mother.placeVolume(vol);
+  }
+  sdet.setPlacement(pv);
+  for (xml_coll_t c(x_det, _U(composite)); c; ++c) {
+    xml_dim_t         component = c;
+    const std::string nam       = component.nameStr();
+    description.declareParent(nam, sdet);
+  }
+  return sdet;
+}
+
+DECLARE_DETELEMENT(athena_CompositeTracker, create_element)

src/CylinderTrackerBarrel_geo.cpp

@@ -2,20 +2,26 @@
 // Specialized generic detector constructor
 //==========================================================================
 
-#include "Acts/Plugins/DD4hep/ActsExtension.hpp"
-#include "Acts/Plugins/DD4hep/ConvertDD4hepMaterial.hpp"
 #include "DD4hep/DetFactoryHelper.h"
 #include "DD4hep/Printout.h"
 
+#if defined(USE_ACTSDD4HEP)
+#include "ActsDD4hep/ActsExtension.hpp"
+#include "ActsDD4hep/ConvertMaterial.hpp"
+#else
+#include "Acts/Plugins/DD4hep/ActsExtension.hpp"
+#include "Acts/Plugins/DD4hep/ConvertDD4hepMaterial.hpp"
+#endif
+
 using namespace std;
 using namespace dd4hep;
 using namespace dd4hep::detail;
 
 /** A barrel tracker with a module that is curved (not flat).
  *
- *
+ * \ingroup tracking
  */
-static Ref_t create_detector(Detector& description, xml_h e, SensitiveDetector sens)
+static Ref_t CylinderTrackerBarrel_create_detector(Detector& description, xml_h e, SensitiveDetector sens)
 {
   typedef vector<PlacedVolume> Placements;
   xml_det_t                    x_det = e;
@@ -48,7 +54,9 @@ static Ref_t create_detector(Detector& description, xml_h e, SensitiveDetector s
     auto     module_length    = m_env.length();
     auto     module_phi       = getAttrOrDefault(m_env, _Unicode(phi), 90.0);
 
-    Volume m_vol(m_nam, Tube(module_rmin, module_rmin + module_thickness, module_length / 2), air);
+    Volume m_vol(
+        m_nam,
+        Tube(module_rmin, module_rmin + module_thickness, module_length / 2, -module_phi / 2.0, module_phi / 2.0), air);
     int    ncomponents = 0, sensor_number = 1;
     module_assembly.placeVolume(m_vol, Position(-module_rmin, 0, 0));
     mod_volumes[m_nam] = module_assembly;
@@ -118,10 +126,10 @@ static Ref_t create_detector(Detector& description, xml_h e, SensitiveDetector s
     Volume     m_env    = mod_volumes[m_nam];
     DetElement lay_elt(sdet, _toString(x_layer.id(), "layer%d"), lay_id);
 
-    //Acts::ActsExtension* layerExtension = new Acts::ActsExtension();
-    //layerExtension->addType("sensitive cylinder", "layer");
-    //// layerExtension->addValue(10. * Acts::UnitConstants::mm, "r", "envelope");
-    //lay_elt.addExtension<Acts::ActsExtension>(layerExtension);
+    ///Acts::ActsExtension* layerExtension = new Acts::ActsExtension();
+    ///layerExtension->addType("sensitive cylinder", "layer");
+    /////// layerExtension->addValue(10. * Acts::UnitConstants::mm, "r", "envelope");
+    ///lay_elt.addExtension<Acts::ActsExtension>(layerExtension);
 
     Placements& sensVols = sensitives[m_nam];
 
@@ -158,7 +166,7 @@ static Ref_t create_detector(Detector& description, xml_h e, SensitiveDetector s
           PlacedVolume sens_pv = sensVols[ic];
           DetElement   comp_elt(mod_elt, sens_pv.volume().name(), module);
           comp_elt.setPlacement(sens_pv);
-          //Acts::ActsExtension* moduleExtension = new Acts::ActsExtension("YZX");
+          //Acts::ActsExtension* moduleExtension = new Acts::ActsExtension();
           //comp_elt.addExtension<Acts::ActsExtension>(moduleExtension);
         }
 
@@ -194,6 +202,8 @@ static Ref_t create_detector(Detector& description, xml_h e, SensitiveDetector s
 }
 
 // clang-format off
-DECLARE_DETELEMENT(refdet_CylinderTrackerBarrel, create_detector)
-DECLARE_DETELEMENT(refdet_MMTrackerBarrel, create_detector)
-DECLARE_DETELEMENT(refdet_RWellTrackerBarrel, create_detector)
+DECLARE_DETELEMENT(athena_CylinderTrackerBarrel, CylinderTrackerBarrel_create_detector)
+DECLARE_DETELEMENT(athena_MMTrackerBarrel,       CylinderTrackerBarrel_create_detector)
+DECLARE_DETELEMENT(athena_RWellTrackerBarrel,    CylinderTrackerBarrel_create_detector)
+DECLARE_DETELEMENT(athena_CylinderVertexBarrel,  CylinderTrackerBarrel_create_detector)
+

src/DIRC_geo.cpp

+#include "DD4hep/DetFactoryHelper.h"
+#include "DD4hep/OpticalSurfaces.h"
+#include "DD4hep/Printout.h"
+#include "DDRec/DetectorData.h"
+#include "DDRec/Surface.h"
+#include <XML/Helper.h>
+
+//////////////////////////////////
+// Central Barrel DIRC
+//////////////////////////////////
+
+using namespace std;
+using namespace dd4hep;
+
+// Fixed Trap constructor. This function is a workaround of this bug:
+// https://github.com/AIDASoft/DD4hep/issues/850
+// Should be used instead of dd4hep::Trap(pName, pZ, pY, pX, pLTX) constructor
+dd4hep::Trap MakeTrap( const std::string& pName, double pZ, double pY, double pX, double pLTX );
+
+static Ref_t createDetector(Detector& desc, xml_h e, SensitiveDetector sens)
+{
+  xml_det_t xml_det   = e;
+  string    det_name = xml_det.nameStr();
+  int       det_id   = xml_det.id();
+
+  // Main detector xml element
+  xml_dim_t dirc_dim   = xml_det.dimensions();
+  xml_dim_t dirc_pos   = xml_det.position();
+  xml_dim_t dirc_rot   = xml_det.rotation();
+  double    det_rin   = dirc_dim.rmin();
+  double    det_rout  = dirc_dim.rmax();
+  double    SizeZ = dirc_dim.length();
+
+  // DEBUG
+  // double mirror_r1 = x_det.attr<double>(_Unicode(r1));
+
+  // DIRC box:
+  xml_comp_t xml_box_module = xml_det.child(_U(module));
+
+  Material Vacuum = desc.material("Vacuum");
+  Material air = desc.material("AirOptical");
+  Material quartz = desc.material("Quartz");
+  Material epotek = desc.material("Epotek");
+  Material nlak33a = desc.material("Nlak33a");
+  auto& bar_material = quartz;
+  auto mirror_material = desc.material("Aluminum");  // mirror material
+
+  Tube     det_geo(det_rin, det_rout, SizeZ / 2., 0., 360.0 * deg);
+  //Volume   det_volume("DIRC", det_geo, Vacuum);
+  Assembly   det_volume("DIRC");
+  det_volume.setVisAttributes(desc.visAttributes(xml_det.visStr()));
+
+  DetElement   det(det_name, det_id);
+  Volume       mother_vol = desc.pickMotherVolume(det);
+
+  Transform3D  tr(RotationZYX(0, dirc_rot.theta(), 0.0), Position(0.0, 0.0, dirc_pos.z()));
+  PlacedVolume det_plvol = mother_vol.placeVolume(det_volume, tr);
+
+  det_plvol.addPhysVolID("system", det_id);
+  det.setPlacement(det_plvol);
+
+  // Parts Dimentions
+
+  int fLensId = 6; // focusing system
+                   // 0    no lens
+                   // 1    spherical lens
+                   // 3    3-layer spherical lens
+                   // 6    3-layer cylindrical lens
+                   // 10   ideal lens (thickness = 0, ideal focusing)
+  
+  int fGeomType = 0;  // Full DIRC - 0, 1 only one plate
+  int fRunType = 0;   // 0, 10 - simulation, 1, 5 - lookup table, 2,3,4 - reconstruction
+
+
+  double fPrizm[4];
+  fPrizm[0] = 360 * mm;
+  fPrizm[1] = 300 * mm;
+  fPrizm[3] = 50 * mm;
+  fPrizm[2] = fPrizm[3] + 300 * tan(32 * deg) * mm;
+  double fBarsGap = 0.15 * mm;
+
+  std::cout << "DIRC: fPrizm[2] " << fPrizm[2] << std::endl;
+
+  double fdTilt = 80 * deg;
+  double fPrizmT[6];
+  fPrizmT[0] = 390 * mm;
+  fPrizmT[1] = (400 - 290 * cos(fdTilt)) * mm; //
+  fPrizmT[2] = 290 * sin(fdTilt) * mm;       // hight
+  fPrizmT[3] = 50 * mm;                      // face
+  fPrizmT[4] = 290 * mm;
+  fPrizmT[5] = 290 * cos(fdTilt)* mm;
+
+  double fMirror[3];
+  fMirror[0] = 20 * mm;
+  fMirror[1] = fPrizm[0];
+  fMirror[2] = 1 * mm;
+  //  fPrizm[0] = 170; fPrizm[1] = 300; fPrizm[2] = 50+300*tan(45*deg); fPrizm[3] = 50;
+
+//  double fBar[3];
+//  fBar[0] = 17 * mm;
+//  fBar[1] = (fPrizm[0] - (fNBar - 1) * fBarsGap) / fNBar;
+//  fBar[2] = 1050 * mm; // 4200; //4200
+
+  double fMcpTotal[3];
+  double fMcpActive[3];
+  fMcpTotal[0] = fMcpTotal[1] = 53 + 4;
+  fMcpTotal[2] = 1*mm;
+  fMcpActive[0] = fMcpActive[1] = 53;
+  fMcpActive[2] = 1*mm;
+
+  double fLens[4];
+  fLens[0] = fLens[1] = 40 * mm;
+  fLens[2] = 10 * mm;
+  double fRadius = (det_rin + det_rout)/2;
+
+  double fBoxWidth = fPrizm[0];
+
+  double fFd[3];
+  fFd[0] = fBoxWidth;
+  fFd[1] = fPrizm[2];
+  fFd[2] = 1 * mm;
+
+  fLens[0] = fPrizm[3];
+  fLens[1] = fPrizm[0];
+  fLens[2] = 12 * mm;
+
+  // Getting box XML
+  const int fNBoxes = xml_box_module.repeat();
+  const double box_width = xml_box_module.width();
+  const double box_height = xml_box_module.height();
+  const double box_length = xml_box_module.length() + 550*mm;
+
+
+  // The DIRC
+  Assembly dirc_module("DIRCModule");
+
+  //Volume lDirc("lDirc", gDirc, air);
+  dirc_module.setVisAttributes(desc.visAttributes(xml_box_module.visStr()));
+
+
+  // FD... whatever F and D is
+  xml_comp_t xml_fd = xml_box_module.child(_Unicode(fd));
+  Box gFd("gFd", xml_fd.height()/2, xml_fd.width()/2, xml_fd.thickness()/2);
+  Volume lFd ("lFd", gFd, desc.material(xml_fd.materialStr()));
+  lFd.setVisAttributes(desc.visAttributes(xml_fd.visStr()));
+  //lFd.setSensitiveDetector(sens);
+
+
+  // The Bar
+  xml_comp_t xml_bar = xml_box_module.child(_Unicode(bar));
+  double bar_height = xml_bar.height();
+  double bar_width = xml_bar.width();
+  double bar_length = xml_bar.length();
+  Box gBar("gBar", bar_height/2, bar_width/2, bar_length/2);
+  Volume lBar("lBar", gBar, desc.material(xml_bar.materialStr()));
+  lBar.setVisAttributes(desc.visAttributes(xml_bar.visStr()));
+
+  // Glue
+  xml_comp_t xml_glue = xml_box_module.child(_Unicode(glue));
+  double glue_thickness = xml_glue.thickness();  // 0.05 * mm;
+  Box gGlue("gGlue", bar_height/2, bar_width/2, glue_thickness/2);
+  Volume lGlue("lGlue", gGlue, desc.material(xml_glue.materialStr()));
+  lGlue.setVisAttributes(desc.visAttributes(xml_glue.visStr()));
+
+  sens.setType("tracker");
+  lBar.setSensitiveDetector(sens);
+
+  int bars_repeat_z = 4;    // TODO parametrize!
+  double bar_assm_length = (bar_length + glue_thickness) * bars_repeat_z;
+  int fNBar = xml_bar.repeat();
+  double bar_gap = xml_bar.gap();
+  for (int y_index = 0; y_index < fNBar; y_index++) {
+    double shift_y = y_index * (bar_width + bar_gap) - 0.5 * box_width + 0.5 * bar_width;
+    for (int z_index = 0; z_index < bars_repeat_z; z_index++) {
+      double z = -0.5 * bar_assm_length + 0.5 * bar_length + (bar_length + glue_thickness) * z_index;
+      auto placed_bar = dirc_module.placeVolume(lBar, Position(0, shift_y, z));
+      dirc_module.placeVolume(lGlue, Position(0, shift_y, z + 0.5 * (bar_length + glue_thickness)));
+      placed_bar.addPhysVolID("section", z_index);
+      placed_bar.addPhysVolID("bar", y_index);
+    }
+  }
+
+
+  // The Mirror
+  xml_comp_t xml_mirror = xml_box_module.child(_Unicode(mirror));
+  Box gMirror("gMirror", xml_mirror.height()/2, xml_mirror.width()/2, xml_mirror.thickness()/2);
+  Volume lMirror("lMirror", gMirror, desc.material(xml_mirror.materialStr()));
+  dirc_module.placeVolume(lMirror, Position(0, 0, -0.5 * (bar_assm_length - xml_mirror.thickness())));
+  lMirror.setVisAttributes(desc.visAttributes(xml_mirror.visStr()));
+
+  // The mirror optical surface
+  OpticalSurfaceManager surfMgr = desc.surfaceManager();
+  auto surf = surfMgr.opticalSurface("MirrorOpticalSurface");
+  SkinSurface skin(desc, det, Form("dirc_mirror_optical_surface"), surf, lMirror);
+  skin.isValid();
+
+  // LENS
+  // Lens volumes
+  Volume lLens1;
+  Volume lLens2;
+  Volume lLens3;
+
+  double lensMinThikness = 2.0 * mm;
+  double layer12 = lensMinThikness * 2;
+
+  // r1 = (r1==0)? 27.45: r1;
+  // r2 = (r2==0)? 20.02: r2;
+
+  double r1 = 33 * mm;
+  double r2 = 24 * mm;
+  double shight = 25 * mm;
+
+  Position zTrans1(0, 0, -r1 - fLens[2] / 2. + r1 - sqrt(r1 * r1 - shight / 2. * shight / 2.) + lensMinThikness);
+  Position zTrans2(0, 0, -r2 - fLens[2] / 2. + r2 - sqrt(r2 * r2 - shight / 2. * shight / 2.) + layer12);
+
+  Box gfbox("fbox", 0.5 * fLens[0], 0.5 * fLens[1], 0.5 * fLens[2]);
+  Box gcbox("cbox", 0.5 * fLens[0], 0.5 * fLens[1] + 1*mm, 0.5 * fLens[2]);
+
+//  Volume gfbox_volume("gfbox_volume", gfbox, bar_material);
+//  lDirc.placeVolume(gfbox_volume, Position(0, 0, 0));
+//
+//  Volume gcbox_volume("gcbox_volume", gcbox, bar_material);
+//  lDirc.placeVolume(gcbox_volume, Position(0, 0, 50));
+
+
+  Position tTrans1(0.5 * (fLens[0] + shight), 0, -fLens[2] + layer12);
+  Position tTrans0(-0.5 * (fLens[0] + shight), 0, -fLens[2] + layer12);
+  SubtractionSolid tubox("tubox", gfbox, gcbox, tTrans1);
+  SubtractionSolid gubox("gubox", tubox, gcbox, tTrans0);
+
+//  Volume tubox_volume("tubox_volume", tubox, bar_material);
+//  lDirc.placeVolume(tubox_volume, Position(0, 0, 100));
+//
+//  Volume gubox_volume("gubox_volume", gubox, bar_material);
+//  lDirc.placeVolume(gubox_volume, Position(0, 0, 150));
+
+  Tube gcylinder1("Cylinder1", 0, r1, 0.5 * fLens[1], 0 * deg, 360 * deg);
+  Tube gcylinder2("Cylinder2", 0, r2, 0.5 * fLens[1] - 0.5*mm, 0 * deg, 360 * deg);
+  Tube gcylinder1c("Cylinder1c", 0, r1, 0.5 * fLens[1] + 0.5*mm, 0 * deg, 360 * deg);
+  Tube gcylinder2c("Cylinder2c", 0, r2, 0.5 * fLens[1] + 0.5*mm, 0 * deg, 360 * deg);
+  RotationX xRot(-M_PI / 2.);
+
+  IntersectionSolid gLens1("Lens1", gubox, gcylinder1, Transform3D(xRot, zTrans1));
+  SubtractionSolid gLenst("temp", gubox, gcylinder1c, Transform3D(xRot, zTrans1));
+
+//  Volume gLens1_volume("gLens1_volume", gLens1, bar_material);
+//  lDirc.placeVolume(gLens1_volume, Position(0, 0, 200));
+//
+//  Volume gLenst_volume("gLenst_volume", gLenst, bar_material);
+//  lDirc.placeVolume(gLenst_volume, Position(0, 0, 250));
+
+  IntersectionSolid gLens2("Lens2", gLenst, gcylinder2, Transform3D(xRot, zTrans2));
+  SubtractionSolid gLens3("Lens3", gLenst, gcylinder2c, Transform3D(xRot, zTrans2));
+
+  lLens1 = Volume("lLens1", gLens1, bar_material);
+  lLens2 = Volume("lLens2", gLens2, nlak33a);
+  lLens3 = Volume("lLens3", gLens3, bar_material);
+
+  lLens1.setVisAttributes(desc.visAttributes("DIRCLens1"));
+  lLens2.setVisAttributes(desc.visAttributes("DIRCLens2"));
+  lLens3.setVisAttributes(desc.visAttributes("DIRCLens3"));
+
+
+  double shifth = 0.5 * (bar_assm_length + fLens[2]);
+  // fmt::print("LENS HERE shifth={}\n", shifth);
+
+  lLens1.setVisAttributes(desc.visAttributes("AnlTeal"));
+  dirc_module.placeVolume(lLens1, Position(0, 0, shifth));
+  dirc_module.placeVolume(lLens2, Position(0, 0, shifth));
+  dirc_module.placeVolume(lLens3, Position(0, 0, shifth));
+  
+  // The Prizm
+  Trap gPrizm = MakeTrap("gPrizm", fPrizm[0], fPrizm[1], fPrizm[2], fPrizm[3]);
+  Volume lPrizm("lPrizm", gPrizm, bar_material);
+  lPrizm.setVisAttributes(desc.visAttributes("DIRCPrism"));
+
+  //G4RotationMatrix *fdRot = new G4RotationMatrix();
+  //G4RotationMatrix *fdrot = new G4RotationMatrix();
+  double evshiftz = 0.5 * bar_assm_length + fPrizm[1] + fMcpActive[2] / 2. + fLens[2];
+  double evshiftx = -3*mm;
+
+  double prism_shift_x = (fPrizm[2] + fPrizm[3]) / 4. - 0.5 * fPrizm[3] + 1.5*mm;
+  double prism_shift_z = 0.5 * (bar_assm_length + fPrizm[1]) + fLens[2];
+
+  Position  fPrismShift(prism_shift_x, 0, prism_shift_z);
+  dirc_module.placeVolume(lPrizm, Transform3D(xRot, fPrismShift));
+  dirc_module.placeVolume(lFd, Position(0.5 * fFd[1] - 0.5 * fPrizm[3] - evshiftx, 0, evshiftz));
+
+  double dphi = 2 * M_PI / (double)fNBoxes;
+  for (int i = 0; i < fNBoxes; i++) {
+    double phi = dphi * i;
+    double dx = -fRadius * cos(phi);
+    double dy = -fRadius * sin(phi);
+
+    //G4RotationMatrix *tRot = new G4RotationMatrix();
+
+    Transform3D  tr(RotationZ(phi+M_PI), Position(dx, dy, 0));
+    PlacedVolume box_placement = det_volume.placeVolume(dirc_module, tr);
+    box_placement.addPhysVolID("module", i);
+
+
+    // fmt::print("placing dircbox # {} -tphi={:.0f} dx={:.0f}, dy={:.0f}\n", i, phi/deg, dx/cm, dy/cm);
+
+    //new G4PVPlacement(tRot, G4ThreeVector(dx, dy, 0), lDirc, "wDirc", lExpHall, false, i);
+  }
+
+    
+  //////////////////
+  // DIRC Bars
+  //////////////////
+
+  // double bar_radius   = 83.65 * cm;
+  // double bar_length   = SizeZ;
+  // double bar_width    = 42. * cm;
+  // double bar_thicknes = 1.7 * cm;
+  // int    bar_count    = 2 * M_PI * bar_radius / bar_width;
+  // double bar_dphi     = 2 * 3.1415926 / bar_count;
+  // Material bar_material = desc.material("Quartz");
+
+  // Box    bar_geo(bar_thicknes / 2., bar_width / 2., bar_length / 2.);
+  // Volume bar_volume("cb_DIRC_bars_Logix", bar_geo, bar_material);
+  // bar_volume.setVisAttributes(desc.visAttributes(xml_det.visStr()));
+  // sens.setType("tracker");
+  // bar_volume.setSensitiveDetector(sens);
+
+  // for (int ia = 0; ia < bar_count; ia++) {
+  //   double phi = (ia * (bar_dphi));
+  //   double x   = -bar_radius * cos(phi);
+  //   double y   = -bar_radius * sin(phi);
+
+  //   Transform3D  tr(RotationZ(bar_dphi * ia), Position(x, y, 0));
+  //   PlacedVolume barPV = det_volume.placeVolume(bar_volume, tr);
+  //   barPV.addPhysVolID("module", ia);
+  // }
+  return det;
+}
+
+DECLARE_DETELEMENT(cb_DIRC, createDetector)
+
+dd4hep::Trap MakeTrap( const std::string& pName, double pZ, double pY, double pX, double pLTX )
+{
+    // Fixed Trap constructor. This function is a workaround of this bug:
+    // https://github.com/AIDASoft/DD4hep/issues/850
+    // Should be used instead of dd4hep::Trap(pName, pZ, pY, pX, pLTX) constructor
+
+    double fDz  = 0.5*pZ;
+    double fTthetaCphi = 0;
+    double fTthetaSphi = 0;
+    double fDy1 = 0.5*pY;
+    double fDx1 = 0.5*pX;
+    double fDx2 = 0.5*pLTX;
+    double fTalpha1 = 0.5*(pLTX - pX)/pY;
+    double fDy2 = fDy1;
+    double fDx3 = fDx1;
+    double fDx4 = fDx2;
+    double fTalpha2 = fTalpha1;
+
+    return Trap(pName, fDz,  fTthetaCphi,  fTthetaSphi,
+                fDy1,  fDx1,  fDx2,  fTalpha1,
+                fDy2,  fDx3,  fDx4,  fTalpha2);
+}
+

src/DRICH_geo.cpp

+//==========================================================================
+//  dRICh: Dual Ring Imaging Cherenkov Detector
+//--------------------------------------------------------------------------
+//
+// Author: Christopher Dilks (Duke University)
+//
+// - Design Adapted from Standalone Fun4all and GEMC implementations
+//   [ Evaristo Cisbani, Cristiano Fanelli, Alessio Del Dotto, et al. ]
+//
+//==========================================================================
+
+#include <XML/Helper.h>
+#include "TMath.h"
+#include "TString.h"
+#include "GeometryHelpers.h"
+#include "Math/Point2D.h"
+#include "DDRec/Surface.h"
+#include "DDRec/DetectorData.h"
+#include "DD4hep/OpticalSurfaces.h"
+#include "DD4hep/DetFactoryHelper.h"
+#include "DD4hep/Printout.h"
+
+using namespace dd4hep;
+using namespace dd4hep::rec;
+
+// create the detector
+static Ref_t createDetector(Detector& desc, xml::Handle_t handle, SensitiveDetector sens) {
+  xml::DetElement detElem = handle;
+  std::string detName = detElem.nameStr();
+  int detID = detElem.id();
+
+  DetElement det(detName, detID);
+  xml::Component dims = detElem.dimensions();
+  OpticalSurfaceManager surfMgr = desc.surfaceManager();
+
+  // attributes -----------------------------------------------------------
+  // - vessel
+  double  vesselZmin       =  dims.attr<double>(_Unicode(zmin));
+  double  vesselLength     =  dims.attr<double>(_Unicode(length));
+  double  vesselRmin0      =  dims.attr<double>(_Unicode(rmin0));
+  double  vesselRmin1      =  dims.attr<double>(_Unicode(rmin1));
+  double  vesselRmax0      =  dims.attr<double>(_Unicode(rmax0));
+  double  vesselRmax1      =  dims.attr<double>(_Unicode(rmax1));
+  double  vesselRmax2      =  dims.attr<double>(_Unicode(rmax2));
+  double  snoutLength      =  dims.attr<double>(_Unicode(snout_length));
+  int     nSectors         =  dims.attr<int>(_Unicode(nsectors));
+  double  wallThickness    =  dims.attr<double>(_Unicode(wall_thickness));
+  double  windowThickness  =  dims.attr<double>(_Unicode(window_thickness));
+  auto    vesselMat        =  desc.material(detElem.attr<std::string>(_Unicode(material)));
+  auto    gasvolMat        =  desc.material(detElem.attr<std::string>(_Unicode(gas)));
+  auto    vesselVis        =  desc.visAttributes(detElem.attr<std::string>(_Unicode(vis_vessel)));
+  auto    gasvolVis        =  desc.visAttributes(detElem.attr<std::string>(_Unicode(vis_gas)));
+  // - radiator (applies to aerogel and filter)
+  auto    radiatorElem        =  detElem.child(_Unicode(radiator));
+  double  radiatorRmin        =  radiatorElem.attr<double>(_Unicode(rmin));
+  double  radiatorRmax        =  radiatorElem.attr<double>(_Unicode(rmax));
+  double  radiatorPhiw        =  radiatorElem.attr<double>(_Unicode(phiw));
+  double  radiatorPitch       =  radiatorElem.attr<double>(_Unicode(pitch));
+  double  radiatorFrontplane  =  radiatorElem.attr<double>(_Unicode(frontplane));
+  // - aerogel
+  auto    aerogelElem       =  radiatorElem.child(_Unicode(aerogel));
+  auto    aerogelMat        =  desc.material(aerogelElem.attr<std::string>(_Unicode(material)));
+  auto    aerogelVis        =  desc.visAttributes(aerogelElem.attr<std::string>(_Unicode(vis)));
+  double  aerogelThickness  =  aerogelElem.attr<double>(_Unicode(thickness));
+  // - filter
+  auto    filterElem       =  radiatorElem.child(_Unicode(filter));
+  auto    filterMat        =  desc.material(filterElem.attr<std::string>(_Unicode(material)));
+  auto    filterVis        =  desc.visAttributes(filterElem.attr<std::string>(_Unicode(vis)));
+  double  filterThickness  =  filterElem.attr<double>(_Unicode(thickness));
+  // - mirror
+  auto    mirrorElem       =  detElem.child(_Unicode(mirror));
+  auto    mirrorMat        =  desc.material(mirrorElem.attr<std::string>(_Unicode(material)));
+  auto    mirrorVis        =  desc.visAttributes(mirrorElem.attr<std::string>(_Unicode(vis)));
+  auto    mirrorSurf       =  surfMgr.opticalSurface(mirrorElem.attr<std::string>(_Unicode(surface)));
+  double  mirrorBackplane  =  mirrorElem.attr<double>(_Unicode(backplane));
+  double  mirrorThickness  =  mirrorElem.attr<double>(_Unicode(thickness));
+  double  mirrorRmin       =  mirrorElem.attr<double>(_Unicode(rmin));
+  double  mirrorRmax       =  mirrorElem.attr<double>(_Unicode(rmax));
+  double  mirrorPhiw       =  mirrorElem.attr<double>(_Unicode(phiw));
+  double  focusTuneZ       =  mirrorElem.attr<double>(_Unicode(focus_tune_z));
+  double  focusTuneX       =  mirrorElem.attr<double>(_Unicode(focus_tune_x));
+  // - sensor module
+  auto    sensorElem       =  detElem.child(_Unicode(sensors)).child(_Unicode(module));
+  auto    sensorMat        =  desc.material(sensorElem.attr<std::string>(_Unicode(material)));
+  auto    sensorVis        =  desc.visAttributes(sensorElem.attr<std::string>(_Unicode(vis)));
+  auto    sensorSurf       =  surfMgr.opticalSurface(sensorElem.attr<std::string>(_Unicode(surface)));
+  double  sensorSide       =  sensorElem.attr<double>(_Unicode(side));
+  double  sensorGap        =  sensorElem.attr<double>(_Unicode(gap));
+  double  sensorThickness  =  sensorElem.attr<double>(_Unicode(thickness));
+  // - sensor sphere
+  auto    sensorSphElem     =  detElem.child(_Unicode(sensors)).child(_Unicode(sphere));
+  double  sensorSphRadius   =  sensorSphElem.attr<double>(_Unicode(radius));
+  double  sensorSphCenterX  =  sensorSphElem.attr<double>(_Unicode(centerx));
+  double  sensorSphCenterZ  =  sensorSphElem.attr<double>(_Unicode(centerz));
+  // - sensor sphere patch cuts
+  auto    sensorSphPatchElem  =  detElem.child(_Unicode(sensors)).child(_Unicode(sphericalpatch));
+  double  sensorSphPatchPhiw  =  sensorSphPatchElem.attr<double>(_Unicode(phiw));
+  double  sensorSphPatchRmin  =  sensorSphPatchElem.attr<double>(_Unicode(rmin));
+  double  sensorSphPatchRmax  =  sensorSphPatchElem.attr<double>(_Unicode(rmax));
+  double  sensorSphPatchZmin  =  sensorSphPatchElem.attr<double>(_Unicode(zmin));
+  // - debugging switches
+  int   debug_optics_mode  =  detElem.attr<int>(_Unicode(debug_optics));
+  bool  debug_mirror       =  mirrorElem.attr<bool>(_Unicode(debug));
+  bool  debug_sensors      =  sensorSphElem.attr<bool>(_Unicode(debug));
+
+  // if debugging optics, override some settings
+  bool debug_optics = debug_optics_mode > 0;
+  if(debug_optics) {
+    printout(WARNING,"DRich_geo","DEBUGGING DRICH OPTICS");
+    switch(debug_optics_mode) {
+      case 1: vesselMat = aerogelMat = filterMat = sensorMat = gasvolMat = desc.material("VacuumOptical"); break;
+      case 2: vesselMat = aerogelMat = filterMat = sensorMat = desc.material("VacuumOptical"); break;
+      default: printout(FATAL,"DRich_geo","UNKNOWN debug_optics_mode"); return det;
+    };
+    aerogelVis = sensorVis = mirrorVis;
+    gasvolVis = vesselVis = desc.invisible();
+  };
+
+
+  // BUILD VESSEL ====================================================================
+  /* - `vessel`: aluminum enclosure, the mother volume of the dRICh
+   * - `gasvol`: gas volume, which fills `vessel`; all other volumes defined below
+   *   are children of `gasvol`
+   * - the dRICh vessel geometry has two regions: the snout refers to the conic region
+   *   in the front, housing the aerogel, while the tank refers to the cylindrical
+   *   region, housing the rest of the detector components
+   */
+
+  // derived attributes
+  double tankLength = vesselLength - snoutLength;
+  double vesselZmax = vesselZmin + vesselLength;
+
+  // snout solids
+  double boreDelta = vesselRmin1 - vesselRmin0;
+  double snoutDelta = vesselRmax1 - vesselRmax0;
+  Cone vesselSnout(
+      snoutLength/2.0,
+      vesselRmin0,
+      vesselRmax0,
+      vesselRmin0 + boreDelta * snoutLength / vesselLength,
+      vesselRmax1
+      );
+  Cone gasvolSnout(
+      /* note: `gasvolSnout` extends a bit into the tank, so it touches `gasvolTank`
+       * - the extension distance is equal to the tank `windowThickness`, so the
+       *   length of `gasvolSnout` == length of `vesselSnout`
+       * - the extension backplane radius is calculated using similar triangles
+       */
+      snoutLength/2.0,
+      vesselRmin0 + wallThickness,
+      vesselRmax0 - wallThickness,
+      vesselRmin0 + boreDelta * (snoutLength-windowThickness) / vesselLength + wallThickness,
+      vesselRmax1 - wallThickness + windowThickness * (vesselRmax1 - vesselRmax0) / snoutLength
+      );
+
+  // tank solids
+  Cone vesselTank(
+      tankLength/2.0,
+      vesselSnout.rMin2(),
+      vesselRmax2,
+      vesselRmin1,
+      vesselRmax2
+      );
+  Cone gasvolTank(
+      tankLength/2.0 - windowThickness,
+      gasvolSnout.rMin2(),
+      vesselRmax2 - wallThickness,
+      vesselRmin1 + wallThickness,
+      vesselRmax2 - wallThickness
+      );
+
+  // snout + tank solids
+  UnionSolid vesselUnion(
+      vesselTank,
+      vesselSnout,
+      Position(0., 0., -vesselLength/2.)
+      );
+  UnionSolid gasvolUnion(
+      gasvolTank,
+      gasvolSnout,
+      Position(0., 0., -vesselLength/2. + windowThickness)
+      );
+
+  //  extra solids for `debug_optics` only
+  Box vesselBox(1001,1001,1001);
+  Box gasvolBox(1000,1000,1000);
+
+  // choose vessel and gasvol solids (depending on `debug_optics_mode` (0=disabled))
+  Solid vesselSolid, gasvolSolid;
+  switch(debug_optics_mode) {
+    case 0:  vesselSolid=vesselUnion;  gasvolSolid=gasvolUnion;  break; // `!debug_optics`
+    case 1:  vesselSolid=vesselBox;    gasvolSolid=gasvolBox;    break;
+    case 2:  vesselSolid=vesselBox;    gasvolSolid=gasvolUnion;  break;
+  };
+
+  // volumes
+  Volume vesselVol(detName, vesselSolid, vesselMat);
+  Volume gasvolVol(detName+"_gas", gasvolSolid, gasvolMat);
+  vesselVol.setVisAttributes(vesselVis);
+  gasvolVol.setVisAttributes(gasvolVis);
+
+  // reference positions
+  // - the vessel is created such that the center of the cylindrical tank volume
+  //   coincides with the origin; this is called the "origin position" of the vessel
+  // - when the vessel (and its children volumes) is placed, it is translated in
+  //   the z-direction to be in the proper ATHENA-integration location
+  // - these reference positions are for the frontplane and backplane of the vessel,
+  //   with respect to the vessel origin position
+  auto originFront = Position(0., 0., -tankLength/2.0 - snoutLength );
+  auto originBack =  Position(0., 0., tankLength/2.0 );
+
+  // initialize sensor centroids (used for mirror parameterization below); this is
+  // the average (x,y,z) of the placed sensors, w.r.t. originFront
+  double sensorCentroidX = 0;
+  double sensorCentroidZ = 0;
+  int sensorCount = 0;
+
+
+  // sensitive detector type
+  sens.setType("tracker");
+
+
+  // BUILD RADIATOR ====================================================================
+
+  // attributes
+  double airGap = 0.01*mm; // air gap between aerogel and filter (FIXME? actually it's currently a gas gap)
+
+  // solid and volume: create aerogel and filter
+  Cone aerogelSolid(
+      aerogelThickness/2,
+      radiatorRmin,
+      radiatorRmax,
+      radiatorRmin + boreDelta  * aerogelThickness / vesselLength,
+      radiatorRmax + snoutDelta * aerogelThickness / snoutLength
+      );
+  Cone filterSolid(
+      filterThickness/2,
+      radiatorRmin + boreDelta  * (aerogelThickness + airGap) / vesselLength,
+      radiatorRmax + snoutDelta * (aerogelThickness + airGap) / snoutLength,
+      radiatorRmin + boreDelta  * (aerogelThickness + airGap + filterThickness) / vesselLength,
+      radiatorRmax + snoutDelta * (aerogelThickness + airGap + filterThickness) / snoutLength
+      );
+
+  Volume aerogelVol( detName+"_aerogel", aerogelSolid, aerogelMat );
+  Volume filterVol(  detName+"_filter",  filterSolid,  filterMat );
+  aerogelVol.setVisAttributes(aerogelVis);
+  filterVol.setVisAttributes(filterVis);
+
+  // aerogel placement and surface properties
+  // TODO [low-priority]: define skin properties for aerogel and filter
+  auto radiatorPos = Position(0., 0., radiatorFrontplane) + originFront;
+  auto aerogelPV = gasvolVol.placeVolume(aerogelVol,
+        Translation3D(radiatorPos.x(), radiatorPos.y(), radiatorPos.z()) // re-center to originFront
+      * RotationY(radiatorPitch) // change polar angle to specified pitch // FIXME: probably broken (not yet in use anyway)
+      );
+  DetElement aerogelDE(det, "aerogel_de", 0);
+  aerogelDE.setPlacement(aerogelPV);
+  //SkinSurface aerogelSkin(desc, aerogelDE, "mirror_optical_surface", aerogelSurf, aerogelVol);
+  //aerogelSkin.isValid();
+
+  // filter placement and surface properties
+  if(!debug_optics) {
+    auto filterPV = gasvolVol.placeVolume(filterVol,
+          Translation3D(0., 0., airGap) // add an air gap
+        * Translation3D(radiatorPos.x(), radiatorPos.y(), radiatorPos.z()) // re-center to originFront
+        * RotationY(radiatorPitch) // change polar angle
+        * Translation3D(0., 0., (aerogelThickness+filterThickness)/2.) // move to aerogel backplane
+        );
+    DetElement filterDE(det, "filter_de", 0);
+    filterDE.setPlacement(filterPV);
+    //SkinSurface filterSkin(desc, filterDE, "mirror_optical_surface", filterSurf, filterVol);
+    //filterSkin.isValid();
+  };
+
+
+  // SECTOR LOOP //////////////////////////////////
+  for(int isec=0; isec<nSectors; isec++) {
+
+    // debugging filters, limiting the number of sectors
+    if( (debug_mirror||debug_sensors||debug_optics) && isec!=0) continue;
+
+    // sector rotation about z axis
+    double sectorRotation = isec * 360/nSectors * degree;
+    std::string secName = "sec" + std::to_string(isec);
+
+
+
+    // BUILD SENSORS ====================================================================
+
+    // if debugging sphere properties, restrict number of sensors drawn
+    if(debug_sensors) { sensorSide = 2*M_PI*sensorSphRadius / 64; };
+
+    // solid and volume: single sensor module
+    Box sensorSolid(sensorSide/2., sensorSide/2., sensorThickness/2.);
+    Volume sensorVol(detName+"_sensor_"+secName, sensorSolid, sensorMat);
+    sensorVol.setVisAttributes(sensorVis);
+
+    auto sensorSphPos = Position(sensorSphCenterX, 0., sensorSphCenterZ) + originFront;
+
+    // sensitivity
+    if(!debug_optics) sensorVol.setSensitiveDetector(sens);
+
+    // SENSOR MODULE LOOP ------------------------
+    /* ALGORITHM: generate sphere of positions
+     * - NOTE: there are two coordinate systems here:
+     *   - "global" the main ATHENA coordinate system
+     *   - "generator" (vars end in `Gen`) is a local coordinate system for
+     *     generating points on a sphere; it is related to the global system by
+     *     a rotation; we do this so the "patch" (subset of generated
+     *     positions) of sensors we choose to build is near the equator, where
+     *     point distribution is more uniform
+     * - PROCEDURE: loop over `thetaGen`, with subloop over `phiGen`, each divided evenly
+     *   - the number of points to generate depends how many sensors (+`sensorGap`)
+     *     can fit within each ring of constant `thetaGen` or `phiGen`
+     *   - we divide the relevant circumference by the sensor
+     *     size(+`sensorGap`), and this number is allowed to be a fraction,
+     *     because likely we don't care about generating a full sphere and
+     *     don't mind a "seam" at the overlap point
+     *   - if we pick a patch of the sphere near the equator, and not near
+     *     the poles or seam, the sensor distribution will appear uniform
+     */
+
+    // initialize module number for this sector
+    int imod=0;
+
+    // thetaGen loop: iterate less than "0.5 circumference / sensor size" times
+    double nTheta = M_PI*sensorSphRadius / (sensorSide+sensorGap);
+    for(int t=0; t<(int)(nTheta+0.5); t++) {
+      double thetaGen = t/((double)nTheta) * M_PI;
+
+      // phiGen loop: iterate less than "circumference at this latitude / sensor size" times
+      double nPhi = 2*M_PI * sensorSphRadius * std::sin(thetaGen) / (sensorSide+sensorGap);
+      for(int p=0; p<(int)(nPhi+0.5); p++) {
+        double phiGen = p/((double)nPhi) * 2*M_PI - M_PI; // shift to [-pi,pi]
+
+        // determine global phi and theta
+        // - convert {radius,thetaGen,phiGen} -> {xGen,yGen,zGen}
+        double xGen = sensorSphRadius * std::sin(thetaGen) * std::cos(phiGen);
+        double yGen = sensorSphRadius * std::sin(thetaGen) * std::sin(phiGen);
+        double zGen = sensorSphRadius * std::cos(thetaGen);
+        // - convert {xGen,yGen,zGen} -> global {x,y,z} via rotation
+        double x = zGen;
+        double y = xGen;
+        double z = yGen;
+        // - convert global {x,y,z} -> global {phi,theta}
+        double phi = std::atan2(y,x);
+        double theta = std::acos(z/sensorSphRadius);
+
+        // shift global coordinates so we can apply spherical patch cuts
+        double zCheck = z + sensorSphCenterZ;
+        double xCheck = x + sensorSphCenterX;
+        double yCheck = y;
+        double rCheck = std::hypot(xCheck,yCheck);
+        double phiCheck = std::atan2(yCheck,xCheck);
+
+        // patch cut
+        bool patchCut =
+          std::fabs(phiCheck) < sensorSphPatchPhiw
+          && zCheck > sensorSphPatchZmin
+          && rCheck > sensorSphPatchRmin
+          && rCheck < sensorSphPatchRmax;
+        if(debug_sensors) patchCut = std::fabs(phiCheck) < sensorSphPatchPhiw;
+        if(patchCut) {
+
+          // append sensor position to centroid calculation
+          if(isec==0) {
+            sensorCentroidX += xCheck;
+            sensorCentroidZ += zCheck;
+            sensorCount++;
+          };
+
+          // placement (note: transformations are in reverse order)
+          // - transformations operate on global coordinates; the corresponding
+          //   generator coordinates are provided in the comments
+          auto sensorPV = gasvolVol.placeVolume(sensorVol,
+                RotationZ(sectorRotation) // rotate about beam axis to sector
+              * Translation3D(sensorSphPos.x(), sensorSphPos.y(), sensorSphPos.z()) // move sphere to reference position
+              * RotationX(phiGen) // rotate about `zGen`
+              * RotationZ(thetaGen) // rotate about `yGen`
+              * Translation3D(sensorSphRadius, 0., 0.) // push radially to spherical surface
+              * RotationY(M_PI/2) // rotate sensor to be compatible with generator coords
+              * RotationZ(-M_PI/2) // correction for readout segmentation mapping
+              );
+
+          // generate LUT for module number -> sensor position, for readout mapping tests
+          //if(isec==0) printf("%d %f %f\n",imod,sensorPV.position().x(),sensorPV.position().y());
+
+          // properties
+          sensorPV.addPhysVolID("sector", isec).addPhysVolID("module", imod);
+          DetElement sensorDE(det, Form("sensor_de%d_%d", isec, imod), (imod<<3)|isec ); // id must match IRTAlgorithm usage
+          sensorDE.setPlacement(sensorPV);
+          if(!debug_optics) {
+            SkinSurface sensorSkin(desc, sensorDE, Form("sensor_optical_surface%d", isec), sensorSurf, sensorVol);
+            sensorSkin.isValid();
+          };
+
+          // increment sensor module number
+          imod++;
+
+        }; // end patch cuts
+      }; // end phiGen loop
+    }; // end thetaGen loop
+
+    // calculate centroid sensor position
+    if(isec==0) {
+      sensorCentroidX /= sensorCount;
+      sensorCentroidZ /= sensorCount;
+    };
+
+    // END SENSOR MODULE LOOP ------------------------
+
+
+    // BUILD MIRRORS ====================================================================
+
+    // derive spherical mirror parameters `(zM,xM,rM)`, for given image point
+    // coordinates `(zI,xI)` and `dO`, defined as the z-distance between the
+    // object and the mirror surface
+    // - all coordinates are specified w.r.t. the object point coordinates
+    // - this is point-to-point focusing, but it can be used to effectively steer
+    //   parallel-to-point focusing
+    double zM,xM,rM;
+    auto FocusMirror = [&zM,&xM,&rM](double zI, double xI, double dO) {
+      zM = dO*zI / (2*dO-zI);
+      xM = dO*xI / (2*dO-zI);
+      rM = dO - zM;
+    };
+
+    // attributes, re-defined w.r.t. IP, needed for mirror positioning
+    double zS = sensorSphCenterZ + vesselZmin; // sensor sphere attributes
+    double xS = sensorSphCenterX;
+    double rS = sensorSphRadius;
+    double B = vesselZmax - mirrorBackplane; // distance between IP and mirror back plane
+
+    // focus 1: set mirror to focus IP on center of sensor sphere `(zS,xS)`
+    /*double zF = zS;
+    double xF = xS;
+    FocusMirror(zF,xF,B);*/
+
+    // focus 2: move focal region along sensor sphere radius, according to `focusTuneLong`
+    // - specifically, along the radial line which passes through the approximate centroid
+    //   of the sensor region `(sensorCentroidZ,sensorCentroidX)`
+    // - `focusTuneLong` is the distance to move, given as a fraction of `sensorSphRadius`
+    // - `focusTuneLong==0` means `(zF,xF)==(zS,xS)`
+    // - `focusTuneLong==1` means `(zF,xF)` will be on the sensor sphere, near the centroid
+    /*
+    double zC = sensorCentroidZ + vesselZmin;
+    double xC = sensorCentroidX;
+    double slopeF = (xC-xS) / (zC-zS);
+    double thetaF = std::atan(std::fabs(slopeF));
+    double zF = zS + focusTuneLong * sensorSphRadius * std::cos(thetaF);
+    double xF = xS - focusTuneLong * sensorSphRadius * std::sin(thetaF);
+    //FocusMirror(zF,xF,B);
+
+    // focus 3: move along line perpendicular to focus 2's radial line,
+    // according to `focusTunePerp`, with the same numerical scale as `focusTuneLong`
+    zF += focusTunePerp * sensorSphRadius * std::cos(M_PI/2-thetaF);
+    xF += focusTunePerp * sensorSphRadius * std::sin(M_PI/2-thetaF);
+    FocusMirror(zF,xF,B);
+    */
+
+    // focus 4: use (z,x) coordinates for tune parameters
+    double zF = zS + focusTuneZ;
+    double xF = xS + focusTuneX;
+    FocusMirror(zF,xF,B);
+
+    // re-define mirror attributes to be w.r.t vessel front plane
+    double mirrorCenterZ = zM - vesselZmin;
+    double mirrorCenterX = xM;
+    double mirrorRadius = rM;
+
+    // spherical mirror patch cuts and rotation
+    double mirrorThetaRot = std::asin(mirrorCenterX/mirrorRadius);
+    double mirrorTheta1 = mirrorThetaRot - std::asin((mirrorCenterX-mirrorRmin)/mirrorRadius);
+    double mirrorTheta2 = mirrorThetaRot + std::asin((mirrorRmax-mirrorCenterX)/mirrorRadius);
+
+    // if debugging, draw full sphere
+    if(debug_mirror) { mirrorTheta1=0; mirrorTheta2=M_PI; /*mirrorPhiw=2*M_PI;*/ };
+
+    // solid : create sphere at origin, with specified angular limits;
+    // phi limits are increased to fill gaps (overlaps are cut away later)
+    Sphere mirrorSolid1(
+        mirrorRadius,
+        mirrorRadius + mirrorThickness,
+        mirrorTheta1,
+        mirrorTheta2,
+        -40*degree,
+        40*degree
+        );
+
+    /* CAUTION: if any of the relative placements or boolean operations below
+     * are changed, you MUST make sure this does not break access to the sphere
+     * primitive and positioning in Juggler `IRTAlgorithm`; cross check the
+     * mirror sphere attributes carefully!
+     */
+    /*
+    // PRINT MIRROR ATTRIBUTES (before any sector z-rotation)
+    printf("zM = %f\n",zM); // sphere centerZ, w.r.t. IP
+    printf("xM = %f\n",xM); // sphere centerX, w.r.t. IP
+    printf("rM = %f\n",rM); // sphere radius
+    */
+
+    // mirror placement transformation (note: transformations are in reverse order)
+    auto mirrorPos = Position(mirrorCenterX, 0., mirrorCenterZ) + originFront;
+    Transform3D mirrorPlacement(
+          Translation3D(mirrorPos.x(), mirrorPos.y(), mirrorPos.z()) // re-center to specified position
+        * RotationY(-mirrorThetaRot) // rotate about vertical axis, to be within vessel radial walls
+        );
+
+    // cut overlaps with other sectors using "pie slice" wedges, to the extent specified
+    // by `mirrorPhiw`
+    Tube pieSlice( 0.01*cm, vesselRmax2, tankLength/2.0, -mirrorPhiw/2.0, mirrorPhiw/2.0);
+    IntersectionSolid mirrorSolid2( pieSlice, mirrorSolid1, mirrorPlacement );
+
+    // mirror volume, attributes, and placement
+    Volume mirrorVol(detName+"_mirror_"+secName, mirrorSolid2, mirrorMat);
+    mirrorVol.setVisAttributes(mirrorVis);
+    auto mirrorPV2 = gasvolVol.placeVolume(mirrorVol,
+          RotationZ(sectorRotation) // rotate about beam axis to sector
+        * Translation3D(0,0,0)
+        );
+
+    // properties
+    DetElement mirrorDE(det, Form("mirror_de%d", isec), isec);
+    mirrorDE.setPlacement(mirrorPV2);
+    SkinSurface mirrorSkin(desc, mirrorDE, Form("mirror_optical_surface%d", isec), mirrorSurf, mirrorVol);
+    mirrorSkin.isValid();
+
+
+  }; // END SECTOR LOOP //////////////////////////
+
+
+  // place gas volume
+  PlacedVolume gasvolPV = vesselVol.placeVolume(gasvolVol,Position(0, 0, 0));
+  DetElement gasvolDE(det, "gasvol_de", 0);
+  gasvolDE.setPlacement(gasvolPV);
+
+  // place mother volume (vessel)
+  Volume motherVol = desc.pickMotherVolume(det);
+  PlacedVolume vesselPV = motherVol.placeVolume(vesselVol,
+      Position(0, 0, vesselZmin) - originFront
+      );
+  vesselPV.addPhysVolID("system", detID);
+  det.setPlacement(vesselPV);
+
+  return det;
+};
+
+// clang-format off
+DECLARE_DETELEMENT(athena_DRICH, createDetector)

src/FieldMapBrBz.cpp

 #include <DD4hep/DetFactoryHelper.h>
 #include <DD4hep/FieldTypes.h>
+#include <DD4hep/Printout.h>
 #include <XML/Utilities.h>
 
 #include <cstdlib>
@@ -12,6 +13,8 @@
 #include <tuple>
 namespace fs = std::filesystem;
 
+#include "FileLoaderHelper.h"
+
 using namespace dd4hep;
 
 
@@ -19,7 +22,7 @@ using namespace dd4hep;
 class FieldMapBrBz : public dd4hep::CartesianField::Object
 {
 public:
-    FieldMapBrBz(const std::string &field_type);
+    FieldMapBrBz(const std::string &field_type = "magnetic");
     void Configure(double rmin, double rmax, double rstep, double zmin, double zmax, double zstep);
     void LoadMap(const std::string &map_file, double scale);
     void GetIndices(double r, double z, int &ir, int &iz, double &dr, double &dz);
@@ -35,7 +38,7 @@ private:
 };
 
 // constructor
-FieldMapBrBz::FieldMapBrBz(const std::string &field_type = "magnetic")
+FieldMapBrBz::FieldMapBrBz(const std::string &field_type)
 {
     std::string ftype = field_type;
     for (auto &c : ftype) { c = tolower(c); }
@@ -185,20 +188,16 @@ static Ref_t create_field_map_brbz(Detector & /*lcdd*/, xml::Handle_t handle)
     std::string field_map_file = x_par.attr<std::string>(_Unicode(field_map));
     std::string field_map_url = x_par.attr<std::string>(_Unicode(url));
 
+    EnsureFileFromURLExists(field_map_url,field_map_file);
+
     double field_map_scale = x_par.attr<double>(_Unicode(scale));
 
     if( !fs::exists(fs::path(field_map_file))  ) {
-      auto ret = std::system(("mkdir -p fieldmaps && "
-                             "wget " +
-                             field_map_url + " -O " + field_map_file).c_str());
-
-      if (!fs::exists(fs::path(field_map_file))) {
-        std::cerr << "ERROR: file, " << field_map_file << ", does not exist\n";
-        std::quick_exit(1);
-      }
+        printout(ERROR, "FieldMapBrBz", "file " + field_map_file + " does not exist");
+        printout(ERROR, "FieldMapBrBz", "use a FileLoader plugin before the field element");
+        std::_Exit(EXIT_FAILURE);
     }
 
-
     auto map = new FieldMapBrBz(field_type);
     map->Configure(r_dim.rmin(), r_dim.rmax(), r_dim.step(), z_dim.zmin(), z_dim.zmax(), z_dim.step());
 

src/FileLoader.cpp

+#include <DD4hep/DetFactoryHelper.h>
+#include <DD4hep/Primitives.h>
+#include <DD4hep/Factories.h>
+#include <DD4hep/Printout.h>
+#include <XML/Utilities.h>
+
+#include <fmt/core.h>
+
+#include <filesystem>
+#include <iostream>
+#include <cstdlib>
+#include <string>
+
+#include "FileLoaderHelper.h"
+
+using namespace dd4hep;
+
+void usage(int argc, char** argv) {
+  std::cout <<
+    "Usage: -plugin <name> -arg [-arg]                                                  \n"
+    "     name:   factory name     FileLoader                                           \n"
+    "     cache:<string>           cache location (may be read-only)                    \n"
+    "     file:<string>            file location                                        \n"
+    "     url:<string>             url location                                         \n"
+    "     cmd:<string>             download command with {0} for url, {1} for output    \n"
+    "\tArguments given: " << arguments(argc,argv) << std::endl;
+  std::exit(EINVAL);
+}
+
+// Plugin to download files
+long load_file(
+    Detector& /* desc */,
+    int argc,
+    char** argv
+) {
+  // argument parsing
+  std::string cache, file, url;
+  std::string cmd("curl --retry 5 -f {0} -o {1}");
+  for (int i = 0; i < argc && argv[i]; ++i) {
+    if      (0 == std::strncmp("cache:", argv[i], 6)) cache = (argv[i] + 6);
+    else if (0 == std::strncmp("file:", argv[i], 5)) file = (argv[i] + 5);
+    else if (0 == std::strncmp("url:", argv[i], 4)) url = (argv[i] + 4);
+    else if (0 == std::strncmp("cmd:", argv[i], 4)) cmd = (argv[i] + 4);
+    else usage(argc, argv);
+  }
+  printout(DEBUG, "FileLoader", "arg cache: " + cache);
+  printout(DEBUG, "FileLoader", "arg file: " + file);
+  printout(DEBUG, "FileLoader", "arg url: " + url);
+  printout(DEBUG, "FileLoader", "arg cmd: " + cmd);
+
+  // if file or url is empty, do nothing
+  if (file.empty()) {
+    printout(WARNING, "FileLoader", "no file specified");
+    return 0;
+  }
+  if (url.empty()) {
+    printout(WARNING, "FileLoader", "no url specified");
+    return 0;
+  }
+
+  EnsureFileFromURLExists(url, file, cache, cmd);
+
+  return 0;
+}
+
+DECLARE_APPLY(FileLoader, load_file)

src/FileLoaderHelper.h

+#pragma once
+
+#include <DD4hep/DetFactoryHelper.h>
+#include <DD4hep/Primitives.h>
+#include <DD4hep/Factories.h>
+#include <DD4hep/Printout.h>
+
+#include <fmt/core.h>
+
+#include <filesystem>
+#include <iostream>
+#include <cstdlib>
+#include <string>
+
+namespace fs = std::filesystem;
+
+using namespace dd4hep;
+
+// Function to download files
+inline void
+EnsureFileFromURLExists(
+  std::string url,
+  std::string file,
+  std::string cache = "",
+  std::string cmd = "curl --retry 5 -f {0} -o {1}"
+) {
+  // parse cache for environment variables
+  auto pos = std::string::npos;
+  while ((pos = cache.find('$')) != std::string::npos) {
+    auto after = cache.find_first_not_of(
+      "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+      "abcdefghijklmnopqrstuvwxyz"
+      "0123456789"
+      "_",
+      pos + 1);
+    if (after == std::string::npos) after = cache.size(); // cache ends on env var
+    const std::string env_name(cache.substr(pos + 1, after - pos - 1));
+    auto env_ptr = std::getenv(env_name.c_str());
+    const std::string env_value(env_ptr != nullptr ? env_ptr : "");
+    cache.erase(pos, after - pos);
+    cache.insert(pos, env_value);
+    printout(INFO, "FileLoader", "$" + env_name + " -> " + env_value);
+  }
+
+  // create file path
+  fs::path file_path(file);
+
+  // create hash from url, hex of unsigned long long
+  std::string hash = fmt::format("{:016x}", dd4hep::detail::hash64(url)); // TODO: Use c++20 std::fmt
+
+  // create file parent path, if not exists
+  fs::path parent_path = file_path.parent_path();
+  if (!fs::exists(parent_path)) {
+    if (fs::create_directories(parent_path) == false) {
+      printout(ERROR, "FileLoader", "parent path " + parent_path.string() + " cannot be created");
+      printout(ERROR, "FileLoader", "check permissions and retry");
+      std::_Exit(EXIT_FAILURE);
+    }
+  }
+
+  // if file exists and is symlink to correct hash
+  fs::path hash_path(parent_path / hash);
+  if (fs::exists(file_path)
+   && fs::equivalent(file_path, hash_path)) {
+    printout(INFO, "FileLoader", "Link " + file + " -> hash " + hash + " already exists");
+    return;
+  }
+
+  // if hash does not exist, we try to retrieve file from cache
+  if (!fs::exists(hash_path)) {
+    // recursive loop into cache directory
+    fs::path cache_path(cache);
+    printout(INFO, "FileLoader", "Cache " + cache_path.string());
+    if (fs::exists(cache_path)) {
+      for (auto const& dir_entry: fs::recursive_directory_iterator(cache_path)) {
+        if (!dir_entry.is_directory()) continue;
+        fs::path cache_dir_path = cache_path / dir_entry;
+        printout(INFO, "FileLoader", "Checking " + cache_dir_path.string());
+        fs::path cache_hash_path = cache_dir_path / hash;
+        if (fs::exists(cache_hash_path)) {
+          // symlink hash to cache/.../hash
+          printout(INFO, "FileLoader", "File " + file + " with hash " + hash + " found in " + cache_hash_path.string());
+          try {
+            fs::create_symlink(cache_hash_path, hash_path);
+          } catch (const fs::filesystem_error&) {
+            printout(ERROR, "FileLoader", "unable to link from " + hash_path.string() + " to " + cache_hash_path.string());
+            printout(ERROR, "FileLoader", "check permissions and retry");
+            std::_Exit(EXIT_FAILURE);
+          }
+          break;
+        }
+      }
+    }
+  }
+
+  // if hash does not exist, we try to retrieve file from url
+  if (!fs::exists(hash_path)) {
+    cmd = fmt::format(cmd, url, hash_path.c_str()); // TODO: Use c++20 std::fmt
+    printout(INFO, "FileLoader", "Downloading " + file + " as hash " + hash + " with " + cmd);
+    // run cmd
+    auto ret = std::system(cmd.c_str());
+    if (!fs::exists(hash_path)) {
+      printout(ERROR, "FileLoader", "unable to run cmd " + cmd);
+      printout(ERROR, "FileLoader", "check command and retry");
+      printout(ERROR, "FileLoader", "hint: allow insecure connections with -k");
+      std::_Exit(EXIT_FAILURE);
+    }
+  }
+
+  // check if file already exists
+  if (fs::exists(file_path)) {
+    // file already exists
+    if (fs::is_symlink(file_path)) {
+      // file is symlink
+      if (fs::equivalent(hash_path, fs::read_symlink(file_path))) {
+        // link points to correct path
+        return;
+      } else {
+        // link points to incorrect path 
+        if (fs::remove(file_path) == false) {
+          printout(ERROR, "FileLoader", "unable to remove symlink " + file_path.string());
+          printout(ERROR, "FileLoader", "check permissions or remove manually");
+          std::_Exit(EXIT_FAILURE);
+        }
+      }
+    } else {
+      // file exists but not symlink
+      printout(ERROR, "FileLoader", "will not remove actual file " + file_path.string());
+      printout(ERROR, "FileLoader", "check content, remove manually, and retry");
+      std::_Exit(EXIT_FAILURE);
+    }
+  }
+  // file_path now does not exist
+
+  // symlink file_path to hash_path
+  try {
+    // use new path from hash so file link is local
+    fs::create_symlink(fs::path(hash), file_path);
+  } catch (const fs::filesystem_error&) {
+    printout(ERROR, "FileLoader", "unable to link from " + file_path.string() + " to " + hash_path.string());
+    printout(ERROR, "FileLoader", "check permissions and retry");
+    std::_Exit(EXIT_FAILURE);
+  }
+}

src/GaseousRICH_geo.cpp

@@ -75,7 +75,7 @@ static Ref_t createDetector(Detector& desc, xml::Handle_t handle, SensitiveDetec
     envVol.setVisAttributes(desc.visAttributes(detElem.visStr()));
 
     // sensitive detector type
-    sens.setType("photoncounter");
+    sens.setType("tracker");
 
     // @TODO: place a radiator
     // build_radiator(desc, envVol, detElement.child(_Unicode(radiator)), snout_front);

src/HomogeneousCalorimeter_geo.cpp

@@ -111,10 +111,10 @@ using namespace dd4hep;
  */
 
 // headers
-static void add_individuals(Detector& desc, Assembly &env, xml::Collection_t &plm, SensitiveDetector &sens, int id);
-static void add_array(Detector& desc, Assembly &env, xml::Collection_t &plm, SensitiveDetector &sens, int id);
-static void add_disk(Detector& desc, Assembly &env, xml::Collection_t &plm, SensitiveDetector &sens, int id);
-static void add_lines(Detector& desc, Assembly &env, xml::Collection_t &plm, SensitiveDetector &sens, int id);
+static std::tuple<int, int> add_individuals(Detector& desc, Assembly &env, xml::Collection_t &plm, SensitiveDetector &sens, int id);
+static std::tuple<int, int> add_array(Detector& desc, Assembly &env, xml::Collection_t &plm, SensitiveDetector &sens, int id);
+static std::tuple<int, int> add_disk(Detector& desc, Assembly &env, xml::Collection_t &plm, SensitiveDetector &sens, int id);
+static std::tuple<int, int> add_lines(Detector& desc, Assembly &env, xml::Collection_t &plm, SensitiveDetector &sens, int id);
 
 // helper function to get x, y, z if defined in a xml component
 template<class XmlComp>
@@ -133,7 +133,6 @@ Position get_xml_xyz(XmlComp &comp, dd4hep::xml::Strng_t name)
 // main
 static Ref_t create_detector(Detector& desc, xml::Handle_t handle, SensitiveDetector sens)
 {
-    static const std::string func = "HomogeneousCalorimeter";
     xml::DetElement detElem = handle;
     std::string detName = detElem.nameStr();
     int detID = detElem.id();
@@ -144,18 +143,35 @@ static Ref_t create_detector(Detector& desc, xml::Handle_t handle, SensitiveDete
 
     // module placement
     xml::Component plm = detElem.child(_Unicode(placements));
-    int sector = 1;
+    std::map<int, int> sectorModuleNumbers;
+    auto addModuleNumbers = [&sectorModuleNumbers] (int sector, int nmod) {
+        auto it = sectorModuleNumbers.find(sector);
+        if (it != sectorModuleNumbers.end()) {
+            it->second += nmod;
+        } else {
+            sectorModuleNumbers[sector] = nmod;
+        }
+    };
+    int sector_id = 1;
     for (xml::Collection_t mod(plm, _Unicode(individuals)); mod; ++mod) {
-        add_individuals(desc, assembly, mod, sens, sector++);
+        auto [sector, nmod] = add_individuals(desc, assembly, mod, sens, sector_id++);
+        addModuleNumbers(sector, nmod);
     }
     for (xml::Collection_t arr(plm, _Unicode(array)); arr; ++arr) {
-        add_array(desc, assembly, arr, sens, sector++);
+        auto [sector, nmod] = add_array(desc, assembly, arr, sens, sector_id++);
+        addModuleNumbers(sector, nmod);
     }
     for (xml::Collection_t disk(plm, _Unicode(disk)); disk; ++disk) {
-        add_disk(desc, assembly, disk, sens, sector++);
+        auto [sector, nmod] = add_disk(desc, assembly, disk, sens, sector_id++);
+        addModuleNumbers(sector, nmod);
     }
     for (xml::Collection_t lines(plm, _Unicode(lines)); lines; ++lines) {
-        add_lines(desc, assembly, lines, sens, sector++);
+        auto [sector, nmod] = add_lines(desc, assembly, lines, sens, sector_id++);
+        addModuleNumbers(sector, nmod);
+    }
+
+    for (auto [sector, nmods] : sectorModuleNumbers) {
+        desc.add(Constant(Form((detName + "_NModules_Sector%d").c_str(), sector), std::to_string(nmods)));
     }
 
     // detector position and rotation
@@ -202,11 +218,11 @@ std::tuple<Volume, Position> build_module(Detector &desc, xml::Collection_t &plm
 }
 
 // place modules, id must be provided
-static void add_individuals(Detector& desc, Assembly &env, xml::Collection_t &plm, SensitiveDetector &sens, int sid)
+static std::tuple<int, int> add_individuals(Detector& desc, Assembly &env, xml::Collection_t &plm, SensitiveDetector &sens, int sid)
 {
     auto [modVol, modSize] = build_module(desc, plm, sens);
     int sector_id = dd4hep::getAttrOrDefault<int>(plm, _Unicode(sector), sid);
-
+    int nmodules = 0;
     for (xml::Collection_t pl(plm, _Unicode(placement)); pl; ++pl) {
         Position pos(dd4hep::getAttrOrDefault<double>(pl, _Unicode(x), 0.),
                      dd4hep::getAttrOrDefault<double>(pl, _Unicode(y), 0.),
@@ -219,11 +235,14 @@ static void add_individuals(Detector& desc, Assembly &env, xml::Collection_t &pl
                        * RotationZYX(rot.z(), rot.y(), rot.x());
         auto modPV = env.placeVolume(modVol, tr);
         modPV.addPhysVolID("sector", sector_id).addPhysVolID("module", mid);
+        nmodules ++;
     }
+
+    return {sector_id, nmodules};
 }
 
 // place array of modules
-static void add_array(Detector& desc, Assembly &env, xml::Collection_t &plm, SensitiveDetector &sens, int sid)
+static std::tuple<int, int> add_array(Detector& desc, Assembly &env, xml::Collection_t &plm, SensitiveDetector &sens, int sid)
 {
     auto [modVol, modSize] = build_module(desc, plm, sens);
     int sector_id = dd4hep::getAttrOrDefault<int>(plm, _Unicode(sector), sid);
@@ -244,6 +263,7 @@ static void add_array(Detector& desc, Assembly &env, xml::Collection_t &plm, Sen
     // placement to mother
     auto pos = get_xml_xyz(plm, _Unicode(position));
     auto rot = get_xml_xyz(plm, _Unicode(rotation));
+    int nmodules = 0;
     for (int i = 0; i < nrow; ++i) {
         for (int j = 0; j < ncol; ++j) {
             if (std::find(removals.begin(), removals.end(), std::pair<int, int>(i, j)) != removals.end()) {
@@ -255,12 +275,14 @@ static void add_array(Detector& desc, Assembly &env, xml::Collection_t &plm, Sen
                            * Translation3D(pos.x() + px, pos.y() + py, pos.z());
             auto modPV = env.placeVolume(modVol, tr);
             modPV.addPhysVolID("sector", sector_id).addPhysVolID("module", i*ncol + j + id_begin);
+            nmodules ++;
         }
     }
+    return {sector_id, nmodules};
 }
 
 // place disk of modules
-static void add_disk(Detector& desc, Assembly &env, xml::Collection_t &plm, SensitiveDetector &sens, int sid)
+static std::tuple<int, int> add_disk(Detector& desc, Assembly &env, xml::Collection_t &plm, SensitiveDetector &sens, int sid)
 {
     auto [modVol, modSize] = build_module(desc, plm, sens);
     int sector_id = dd4hep::getAttrOrDefault<int>(plm, _Unicode(sector), sid);
@@ -281,10 +303,11 @@ static void add_disk(Detector& desc, Assembly &env, xml::Collection_t &plm, Sens
         auto modPV = env.placeVolume(modVol, tr);
         modPV.addPhysVolID("sector", sector_id).addPhysVolID("module", id_begin + mid++);
     }
+    return {sector_id, mid};
 }
 
 // place lines of modules (anchor point is the 0th module of this line)
-static void add_lines(Detector& desc, Assembly &env, xml::Collection_t &plm, SensitiveDetector &sens, int sid)
+static std::tuple<int, int> add_lines(Detector& desc, Assembly &env, xml::Collection_t &plm, SensitiveDetector &sens, int sid)
 {
     auto [modVol, modSize] = build_module(desc, plm, sens);
     int sector_id = dd4hep::getAttrOrDefault<int>(plm, _Unicode(sector), sid);
@@ -294,7 +317,7 @@ static void add_lines(Detector& desc, Assembly &env, xml::Collection_t &plm, Sen
     bool mirrorz = dd4hep::getAttrOrDefault<bool>(plm, _Unicode(mirrorz), false);
 
     // line placement
-    int mid = 1;
+    int mid = 0;
     for (xml::Collection_t pl(plm, _Unicode(line)); pl; ++pl) {
         Position pos(dd4hep::getAttrOrDefault<double>(pl, _Unicode(x), 0.),
                      dd4hep::getAttrOrDefault<double>(pl, _Unicode(y), 0.),
@@ -350,6 +373,7 @@ static void add_lines(Detector& desc, Assembly &env, xml::Collection_t &plm, Sen
             modPV.addPhysVolID("sector", sector_id).addPhysVolID("module", id_begin + mid++);
         }
     }
+    return {sector_id, mid};
 }
 //@}
 DECLARE_DETELEMENT(HomogeneousCalorimeter, create_detector)

src/HybridCalorimeter_geo.cpp

+//==========================================================================
+//  A general implementation for homogeneous calorimeter
+//  it supports three types of placements
+//  1. Individual module placement with module dimensions and positions
+//  2. Array placement with module dimensions and numbers of row and columns
+//  3. Disk placement with module dimensions and (Rmin, Rmax), and (Phimin, Phimax)
+//  4. Lines placement with module dimensions and (mirrorx, mirrory)
+//     (NOTE: anchor point is the 0th block of the line instead of line center)
+//--------------------------------------------------------------------------
+//  Author: Chao Peng (ANL)
+//  Date: 06/09/2021
+//==========================================================================
+
+#include "GeometryHelpers.h"
+#include "DD4hep/DetFactoryHelper.h"
+#include <XML/Helper.h>
+#include <iostream>
+#include <algorithm>
+#include <tuple>
+#include <math.h>
+#include <fmt/core.h>
+
+using namespace dd4hep;
+
+// main
+static Ref_t create_detector(Detector& desc, xml::Handle_t handle, SensitiveDetector sens)
+{
+
+  using namespace std;
+  using namespace fmt;
+
+    xml::DetElement detElem = handle;
+    std::string detName = detElem.nameStr();
+    int detID = detElem.id();
+    DetElement det(detName, detID);
+    sens.setType("calorimeter");
+
+    auto glass_material = desc.material("SciGlass");
+    auto crystal_material = desc.material("PbWO4");
+    auto air_material = desc.material("Air");
+
+    double ROut = desc.constantAsDouble("EcalEndcapN_rmax");
+    double RIn_el = desc.constantAsDouble("EcalEndcapN_rmin1");
+    double ionCutout_dphi = desc.constantAsDouble("EcalEndcapNIonCutout_dphi");
+    double RIn = desc.constantAsDouble("EcalEndcapN_rmin2");
+    double SizeZ = desc.constantAsDouble("EcalEndcapN_thickness");
+    double thickness = desc.constantAsDouble("EcalEndcapN_thickness");
+    double trans_radius = desc.constantAsDouble("EcalEndcapNCrystal_rmax");
+    double Glass_z0 = desc.constantAsDouble("GlassModule_z0");
+    double Glass_Width = desc.constantAsDouble("GlassModule_width");
+    double Glass_thickness = desc.constantAsDouble("GlassModule_length");
+    double Glass_Gap = desc.constantAsDouble("GlassModule_wrap");
+    double glass_distance = desc.constantAsDouble("GlassModule_distance");
+
+    double Crystal_Width = desc.constantAsDouble("CrystalModule_width");
+    double Crystal_thickness = desc.constantAsDouble("CrystalModule_length");
+    double Crystal_Gap = desc.constantAsDouble("CrystalModule_wrap");
+    double crystal_distance = desc.constantAsDouble("CrystalModule_distance");
+    double Crystal_z0 = desc.constantAsDouble("CrystalModule_z0");
+
+    // RIn and ROut will define outer tube embedding the calorimeter
+    // centers_rmin/out define the maximum radius of module centers
+    // so that modules are not overlapping with mother tube volume
+    const double glassHypotenuse = std::hypot(glass_distance, glass_distance)/2;
+    const double crystalHypotenuse = glassHypotenuse/2;
+    // Offset these values a bit so we don't miss edge-blocks
+    const double glassCenters_rmax  = ROut - glassHypotenuse + 1 * mm;
+    const double crystalCenters_rmin = RIn + crystalHypotenuse - 1 * mm;
+    // Also limits of the inner crystal blocks fill
+    const double cutout_tan = tan(ionCutout_dphi/2);
+    const double cutout_rmin = RIn_el + crystalHypotenuse - 1 * mm;
+
+    // Offset to align the modules at the zmin of the endcap,
+    const double Crystal_offset = -0.5 * (Crystal_thickness - thickness);
+    const double Glass_offset = -0.5*(Glass_thickness - thickness);
+
+    // envelope
+    // consists of an glass tube of the full thickness, and a crystal inner tube
+    // for the crystal that allows us to get closet to the beampipe without
+    // overlaps, and a partial electron tube that allows us to get closer to the
+    // electron beampipe in the region where there is no ion beampipe
+    Tube glass_tube(min(RIn + glassHypotenuse*2, trans_radius), ROut, SizeZ / 2.0, 0., 360.0 * deg);
+    Tube crystal_tube(RIn, min(RIn + glassHypotenuse*2, trans_radius), Crystal_thickness/ 2.0, 0., 360.0 * deg);
+    Tube electron_tube(RIn_el, RIn, Crystal_thickness / 2., ionCutout_dphi / 2., 360.0 * deg - ionCutout_dphi / 2);
+    UnionSolid outer_envelope(glass_tube, crystal_tube, Position(0,0,Crystal_offset));
+    UnionSolid envelope(outer_envelope, electron_tube, Position(0,0,Crystal_offset));
+    Volume ecal_vol("negative_ecal", envelope, air_material);
+    ecal_vol.setVisAttributes(desc.visAttributes("HybridEcalOuterVis"));
+
+    // TODO why 1cm and not something else?
+    double Glass_OuterR = ROut - 1 * cm ;
+    double Glass_InnerR = trans_radius;
+
+    // Geometry of modules
+    Box glass_box("glass_box", Glass_Width * 0.5, Glass_Width * 0.5, Glass_thickness * 0.5);
+    Volume glass_module("glass_module", glass_box, glass_material);
+    glass_module.setVisAttributes(desc.visAttributes("EcalEndcapNModuleVis"));
+    glass_module.setSensitiveDetector(sens);
+    
+    Box crystal_box("crystal_box",  Crystal_Width* 0.5, Crystal_Width * 0.5, Crystal_thickness * 0.5);
+    Volume crystal_module("crystal_module", crystal_box, crystal_material);
+    crystal_module.setVisAttributes(desc.visAttributes("EcalEndcapNModuleVis"));
+    crystal_module.setSensitiveDetector(sens);
+
+    // GLASS
+    double diameter = 2 * Glass_OuterR;
+
+    // Can we fit an even or odd amount of glass blocks within our rmax?
+    // This determines the transition points between crystal and glass as we need the
+    // outer crystal arangement to be in multiples of 2 (aligned with glass)
+    const int towersInRow = std::ceil((diameter + Glass_Gap) /  (Glass_Width + Glass_Gap));
+    const bool align_even = (towersInRow % 2);
+
+    // Is it odd or even number of towersInRow
+    double leftTowerPos, topTowerPos;
+    if(towersInRow%2) {
+      //             |
+      //      [ ][ ][ ][ ][ ]
+      //       ^     |
+      int towersInHalfRow = std::ceil(towersInRow/2.0);
+      topTowerPos = leftTowerPos = -towersInHalfRow * (Glass_Width + Glass_Gap);
+
+    } else {
+      //               |
+      //      [ ][ ][ ][ ][ ][ ]
+      //       ^      |
+      int towersInHalfRow = towersInRow/2;
+      topTowerPos = leftTowerPos = -(towersInHalfRow - 0.5) * (Glass_Width + Glass_Gap);
+    }
+
+    int moduleIndex = 0;
+
+    int glass_module_index = 0;
+    int cryst_module_index = 0;
+    for(int rowIndex=0; rowIndex < towersInRow; rowIndex++) {
+      for(int colIndex=0; colIndex < towersInRow; colIndex++) {
+        const double glass_x = leftTowerPos + colIndex * (Glass_Width + Glass_Gap);
+        const double glass_y = topTowerPos + rowIndex * (Glass_Width + Glass_Gap);
+        const double r = std::hypot(glass_x, glass_y);
+        // crystal if within the transition radius (as defined by the equivalent glass
+        // block)
+        if (r < trans_radius) {
+          for (const auto dx : {-1, 1}) {
+            for (const auto& dy : {-1, 1}) {
+              const double crystal_x = glass_x + dx * crystal_distance / 2;
+              const double crystal_y = glass_y + dy * crystal_distance / 2;
+              const double crystal_r = std::hypot(crystal_x, crystal_y);
+              // check if crystal in the main crystal ring?
+              const bool mainRing = (crystal_r > crystalCenters_rmin);
+              const bool innerRing = !mainRing && crystal_r > cutout_rmin;
+              const bool ionCutout = crystal_x > 0 && fabs(crystal_y / crystal_x) < cutout_tan;
+              if (mainRing || (innerRing && !ionCutout)) {
+                auto placement =
+                    ecal_vol.placeVolume(crystal_module, Position(crystal_x, crystal_y, Crystal_z0 + Crystal_offset));
+                placement.addPhysVolID("sector", 1);
+                placement.addPhysVolID("module", cryst_module_index++);
+              }
+            }
+          }
+        // Glass block if within the rmax
+        } else if (r < glassCenters_rmax) {
+          // glass module
+          auto placement = ecal_vol.placeVolume(glass_module, Position(glass_x, glass_y, Glass_z0 + Glass_offset));
+          placement.addPhysVolID("sector", 2);
+          placement.addPhysVolID("module", glass_module_index++);
+        }
+      }
+    }
+
+    desc.add(Constant("EcalEndcapN_NModules_Sector1", std::to_string(cryst_module_index)));
+    desc.add(Constant("EcalEndcapN_NModules_Sector2", std::to_string(glass_module_index)));
+//    fmt::print("Total Glass modules: {}\n", towerIndex);
+//    fmt::print("CE EMCAL GLASS END\n\n");
+
+     // detector position and rotation
+     auto pos = detElem.position();
+     auto rot = detElem.rotation();
+     Volume motherVol = desc.pickMotherVolume(det);
+     Transform3D tr(RotationZYX(rot.z(), rot.y(), rot.x()), Position(pos.x(), pos.y(), pos.z()));
+     PlacedVolume envPV = motherVol.placeVolume(ecal_vol, tr);
+     envPV.addPhysVolID("system", detID);
+     det.setPlacement(envPV);
+     return det;
+
+}
+
+//@}
+DECLARE_DETELEMENT(HybridCalorimeter, create_detector)
+

src/MRich.cpp

-//
-// Author     : Whit Armstrong (warmstrong@anl.gov)
-//
-#include <XML/Helper.h>
-#include "TMath.h"
-#include "TString.h"
-#include "DDRec/Surface.h"
-#include "DDRec/DetectorData.h"
-#include "DD4hep/OpticalSurfaces.h"
-#include "DD4hep/DetFactoryHelper.h"
-#include "DD4hep/Printout.h"
-#include "GeometryHelpers.h"
-#include "Math/Vector3D.h"
-#include "Math/AxisAngle.h"
-#include "Math/VectorUtil.h"
-
-using namespace std;
-using namespace dd4hep;
-using namespace dd4hep::rec;
-
-using Placements = vector<PlacedVolume>;
-
-
-
-static Ref_t createDetector(Detector& description, xml::Handle_t e, SensitiveDetector sens){
-  xml_det_t      x_det    = e;
-  Material       air      = description.material("AirOptical");
-  Material       vacuum   = description.vacuum();
-  string         det_name = x_det.nameStr();
-  //xml::Component pos      = x_det.position();
-  DetElement     sdet(det_name, x_det.id());
-  Assembly       assembly(det_name);
-  sens.setType("photoncounter");
-  OpticalSurfaceManager surfMgr = description.surfaceManager();
-
-  bool projective = getAttrOrDefault(x_det, _Unicode(projective), false);
-
-  PlacedVolume pv;
-
-  map<string, Volume>     modules;
-  map<string, Placements> sensitives;
-  map<string, Volume>     module_assemblies;
-  std::map<std::string,DetElement> module_assembly_delements;
-
-  int                     n_sensor = 1;
-
-  xml::Component dims   = x_det.dimensions();
-  auto           rmin   = dims.rmin();
-  auto           rmax   = dims.rmax();
-  auto           length = dims.length();
-  auto           zmin   = dims.zmin();
-
-  // expect only one module (for now)
-  xml_comp_t x_mod = x_det.child(_U(module));
-  string     mod_name            = x_mod.nameStr();
-  double     mod_width           = getAttrOrDefault(x_mod, _U(width), 130.0 * mm);
-  double     mod_height          = getAttrOrDefault(x_mod, _U(height), 130.0 * mm);
-  double     mod_length          = getAttrOrDefault(x_mod, _U(length), 130.0 * mm);
-
-  // various components
-  xml_comp_t x_frame    = x_mod.child(_Unicode(frame));
-  xml_comp_t x_aerogel  = x_mod.child(_Unicode(aerogel));
-  xml_comp_t x_lens     = x_mod.child(_Unicode(lens));
-  xml_comp_t x_mirror   = x_mod.child(_Unicode(mirror));
-  xml_comp_t x_photodet = x_mod.child(_Unicode(photodet));
-
-  // module
-  Box    m_solid(mod_width / 2.0, mod_height / 2.0, mod_length / 2.0);
-  Volume m_volume(mod_name, m_solid, air);
-  m_volume.setVisAttributes(description.visAttributes(x_mod.visStr()));
-  DetElement mod_de( mod_name + std::string("_mod_") + std::to_string(1), 1);
-
-  // todo module frame
-  double     frame_thickness  = getAttrOrDefault(x_frame, _U(thickness), 2.0 * mm);
-
-  // aerogel box
-  xml_comp_t x_aerogel_frame = x_aerogel.child(_Unicode(frame));
-  double     aerogel_width   = getAttrOrDefault(x_aerogel, _U(width), 130.0 * mm);
-  double     aerogel_length  = getAttrOrDefault(x_aerogel, _U(length), 130.0 * mm);
-  double     foam_thickness  = getAttrOrDefault(x_aerogel_frame, _U(thickness), 2.0 * mm);
-  Material   foam_mat        = description.material(x_aerogel_frame.materialStr());
-  Material   aerogel_mat     = description.material(x_aerogel.materialStr());
-  auto       aerogel_vis     = getAttrOrDefault<std::string>(x_aerogel, _U(vis), std::string("InvisibleWithDaughters"));
-  auto       foam_vis        = getAttrOrDefault<std::string>(x_aerogel_frame, _U(vis), std::string("RedVis"));
-
-  // aerogel foam frame
-  Box foam_box(aerogel_width / 2.0 + foam_thickness, aerogel_width / 2.0 + foam_thickness, (aerogel_length + foam_thickness) / 2.0);
-  Box aerogel_sub_box(aerogel_width / 2.0, aerogel_width / 2.0, (aerogel_length + foam_thickness) / 2.0);
-  SubtractionSolid foam_frame_solid(foam_box, aerogel_sub_box, Position(0, 0, foam_thickness));
-  Volume           foam_vol(mod_name+"_aerogel_frame", foam_frame_solid, foam_mat);
-  foam_vol.setVisAttributes(description.visAttributes(foam_vis));
-  double foam_frame_zpos = -mod_length / 2.0 + frame_thickness + (aerogel_length + foam_thickness) / 2.0;
-  m_volume.placeVolume(foam_vol,Position(0,0,foam_frame_zpos));
-
-  // aerogel
-  Box              aerogel_box(aerogel_width / 2.0, aerogel_width / 2.0, (aerogel_length) / 2.0);
-  Volume           aerogel_vol(mod_name+"_aerogel", aerogel_box, aerogel_mat);
-  aerogel_vol.setVisAttributes(description.visAttributes(aerogel_vis));
-  double aerogel_zpos = foam_frame_zpos + foam_thickness / 2.0;
-  pv = m_volume.placeVolume(aerogel_vol,Position(0,0,aerogel_zpos));
-  DetElement aerogel_de(mod_de, mod_name + std::string("_aerogel_de") + std::to_string(1), 1);
-  aerogel_de.setPlacement(pv);
-
-  auto aerogel_surf = surfMgr.opticalSurface(dd4hep::getAttrOrDefault(x_aerogel, _Unicode(surface), "MRICH_AerogelOpticalSurface"));
-  SkinSurface skin0(description, aerogel_de, Form("MRICH_aerogel_skin_surface_%d", 1), aerogel_surf, aerogel_vol);
-  skin0.isValid();
-
-  // Fresnel Lens
-  //  - The lens has a constant groove pitch (delta r) as opposed to fixing the groove height.
-  //  - The lens area outside of the effective diamtere is flat.
-  //  - The grooves are not curved, rather they are polycone shaped, ie a flat approximating the curvature.
-  auto   lens_vis       = getAttrOrDefault<std::string>(x_lens, _U(vis), std::string("AnlBlue"));
-  double groove_pitch   = getAttrOrDefault(x_lens, _Unicode(pitch), 0.5 * mm);
-  double lens_f         = getAttrOrDefault(x_lens, _Unicode(focal_length), 6.0*2.54*cm);
-  double eff_diameter   = getAttrOrDefault(x_lens, _Unicode(effective_diameter), 130.0 * mm);
-  double lens_width     = getAttrOrDefault(x_lens, _Unicode(width), 6.7*2.54*cm);
-  double center_thickness = getAttrOrDefault(x_lens, _U(thickness), 2.0 * mm);
-
-  double n_acrylic        = 1.49;
-  double lens_curvature   = 1.0 / (lens_f*(n_acrylic - 1.0));
-  double full_ring_rmax   = std::min(eff_diameter / 2.0, lens_width/2.0);
-
-  double N_grooves        = std::ceil((full_ring_rmax) / groove_pitch);
-  double groove_last_rmin = (N_grooves - 1) * groove_pitch;
-  double groove_last_rmax = N_grooves * groove_pitch;
-
-  auto   groove_sagitta = [&](double r) { return lens_curvature * std::pow(r, 2) / (1.0 + 1.0); };
-  double lens_thickness = groove_sagitta(groove_last_rmax) - groove_sagitta(groove_last_rmin) + center_thickness;
-
-  Material         lens_mat = description.material(x_lens.materialStr());
-  Box              lens_box(lens_width / 2.0, lens_width / 2.0, (center_thickness) / 2.0);
-  SubtractionSolid flat_lens(lens_box, Tube(0.0, full_ring_rmax, 2 * center_thickness));
-
-  Assembly lens_vol(mod_name + "_lens");
-  Volume   flatpart_lens_vol( "flatpart_lens", flat_lens, lens_mat);
-  lens_vol.placeVolume(flatpart_lens_vol);//,Position(0,0,lens_zpos));
-
-  Solid  fresnel_lens_solid;
-
-  int    i_groove           = 0;
-  double groove_rmax        = groove_pitch;
-  double groove_rmin        = 0;
-
-  while ( groove_rmax <= full_ring_rmax ) {
-    double   dZ = groove_sagitta(groove_rmax) - groove_sagitta(groove_rmin);
-    //std::cout << " dZ = " << dZ << ",  lens_thickness = " << lens_thickness << "\n";
-    //std::cout  << "groove_rmin = " << groove_rmin << "\n";
-    //std::cout  << "groove_rmax = " << groove_rmax << "\n";
-    Polycone groove_solid(0, 2.0 * M_PI,
-                          {groove_rmin, groove_rmin, groove_rmin},
-                          {groove_rmax, groove_rmax, groove_rmin},
-                          {-lens_thickness/2.0, lens_thickness/2.0-dZ, lens_thickness/2.0});
-    Volume   lens_groove_vol("lens_groove_" + std::to_string(i_groove), groove_solid, lens_mat);
-    lens_vol.placeVolume(lens_groove_vol); //,Position(0,0,lens_zpos));
-    //Volume   groove_vol(groove_solid, lens_mat, par->name.c_str(), 0, 0, 0);
-    //new G4PVPlacement(0, par->pos, Groove_log[i], par->name.c_str(), motherLV, false, 0, OverlapCheck());
-    //phi1 = phi1 + halfpi;  //g4 pre-defined: halfpi=pi/2
-    //Tube       sub_cylinder(r0, r1, 3*eff_diameter);
-    //IntersectionSolid groove_solid(lens_box,lens_sphere, Position(0,0,-eff_diameter/2.0 + lens_thickness/2.0+(t-lens_t)/2.0 ));
-    //IntersectionSolid lens_ring(groove_solid, sub_cylinder);
-    //if (i_groove == 0) {
-    //  fresnel_lens_solid = groove_solid;
-    //} else {
-    //  fresnel_lens_solid = UnionSolid(fresnel_lens_solid, groove_solid);
-    //}
-    //r0 = r1;
-    //if(i_groove > 3) { 
-    //  SubtractionSolid flat_lens(lens_box,Tube(0.0, r0, 3*eff_diameter));
-    //  fresnel_lens_solid = UnionSolid(fresnel_lens_solid, flat_lens);
-    //  break; // temporary
-    //}
-    i_groove++;
-    groove_rmin = (i_groove  )*groove_pitch;
-    groove_rmax = (i_groove+1)*groove_pitch;
-  }
-  //fresnel_lens_solid = UnionSolid(fresnel_lens_solid, flat_lens);
-  //Volume   lens_vol(mod_name + "_lens", fresnel_lens_solid, lens_mat);
-
-  lens_vol.setVisAttributes(description.visAttributes(lens_vis));
-  double lens_zpos = aerogel_zpos +aerogel_length/ 2.0 + foam_thickness + lens_thickness/2.0;
-  pv = m_volume.placeVolume(lens_vol,Position(0,0,lens_zpos));
-  DetElement lens_de(mod_de, mod_name + std::string("_lens_de") + std::to_string(1), 1);
-  lens_de.setPlacement(pv);
-
-  auto surf = surfMgr.opticalSurface(dd4hep::getAttrOrDefault(x_lens, _Unicode(surface), "MRICH_LensOpticalSurface"));
-  SkinSurface skin(description, lens_de, Form("MRichFresnelLens_skin_surface_%d", 1), surf, lens_vol);
-  skin.isValid();
-
-  // mirror
-  auto   mirror_vis      = getAttrOrDefault<std::string>(x_mirror, _U(vis), std::string("AnlGray"));
-  double mirror_x1      = getAttrOrDefault(x_mirror, _U(x1), 100.0 * mm);
-  double mirror_x2      = getAttrOrDefault(x_mirror, _U(x2), 80.0 * mm);
-  double mirror_length  = getAttrOrDefault(x_mirror, _U(length), 130.0 * mm);
-  double mirror_thickness  = getAttrOrDefault(x_mirror, _U(thickness), 2.0 * mm);
-  double outer_x1 = (mirror_x1+mirror_thickness)/2.0;
-  double outer_x2 = (mirror_x2+mirror_thickness)/2.0;
-  Trd2   outer_mirror_trd(outer_x1, outer_x2, outer_x1,  outer_x2, mirror_length/2.0);
-  Trd2   inner_mirror_trd(mirror_x1 / 2.0,  mirror_x2 / 2.0, mirror_x1 / 2.0,mirror_x2 / 2.0, mirror_length/2.0+0.1*mm);
-  SubtractionSolid mirror_solid(outer_mirror_trd, inner_mirror_trd);
-  Material   mirror_mat        = description.material(x_mirror.materialStr());
-  Volume           mirror_vol(mod_name+"_mirror", mirror_solid, mirror_mat);
-  double mirror_zpos = lens_zpos + lens_thickness/2.0 + foam_thickness + mirror_length/2.0;
-  pv = m_volume.placeVolume(mirror_vol,Position(0,0,mirror_zpos));
-  DetElement mirror_de(mod_de, mod_name + std::string("_mirror_de") + std::to_string(1), 1);
-  mirror_de.setPlacement(pv);
-
-  auto mirror_surf = surfMgr.opticalSurface(dd4hep::getAttrOrDefault(x_mirror, _Unicode(surface), "MRICH_MirrorOpticalSurface"));
-  SkinSurface skin1(description, mirror_de, Form("MRICH_mirror_skin_surface_%d", 1), mirror_surf, mirror_vol);
-  skin1.isValid();
-
-  // photon detector
-  xml_comp_t x_photodet_sensor  = x_photodet.child(_Unicode(sensor));
-  auto   photodet_vis      = getAttrOrDefault<std::string>(x_photodet, _U(vis), std::string("AnlRed"));
-  double     photodet_width     = getAttrOrDefault(x_photodet, _U(width), 130.0 * mm);
-  double     photodet_thickness = getAttrOrDefault(x_photodet, _U(thickness), 2.0 * mm);
-  double     sensor_thickness   = getAttrOrDefault(x_photodet_sensor, _U(thickness), 2.0 * mm);
-  Material   photodet_mat       = description.material(x_photodet.materialStr());
-  Material   sensor_mat         = description.material(x_photodet_sensor.materialStr());
-  int     sensor_nx   = getAttrOrDefault(x_photodet_sensor, _Unicode(nx), 2);
-  int     sensor_ny   = getAttrOrDefault(x_photodet_sensor, _Unicode(ny), 2);
-
-  Box    window_box(photodet_width/2.0,photodet_width/2.0,photodet_thickness/2.0);
-  Volume           window_vol(mod_name+"_window", window_box, photodet_mat);
-  window_vol.setSensitiveDetector(sens);
-  double window_zpos = mirror_zpos + mirror_length/2.0+photodet_thickness/2.0;
-  pv = m_volume.placeVolume(window_vol,Position(0,0,window_zpos));
-  DetElement   comp_de(mod_de, std::string("mod_sensor_de_") + std::to_string(1) ,  1);
-  comp_de.setPlacement(pv);
-  pv.addPhysVolID("sensor", n_sensor);
-
-  //for (size_t ic = 0; ic < sensVols.size(); ++ic) {
-  //  PlacedVolume sens_pv = sensVols[ic];
-  //  DetElement   comp_de(mod_de, std::string("de_") + sens_pv.volume().name(), ic + 1);
-  //  comp_de.setPlacement(sens_pv);
-  //  // Acts::ActsExtension* sensorExtension = new Acts::ActsExtension();
-  //  //// sensorExtension->addType("sensor", "detector");
-  //  // comp_de.addExtension<Acts::ActsExtension>(sensorExtension);
-  //  //// comp_de.setAttributes(description, sens_pv.volume(), x_layer.regionStr(),
-  //  //// x_layer.limitsStr(),
-  //  ////                      xml_det_t(xmleles[m_nam]).visStr());
-  //}
-  //DetElement window_de(sdet, mod_name + std::string("_window_de") + std::to_string(1), 1);
-  //window_de.setPlacement(pv);
-
-  window_vol.setSensitiveDetector(sens);
-  sensitives[mod_name].push_back(pv);
-  ++n_sensor;
-  modules[mod_name]                   = m_volume;
-  module_assembly_delements[mod_name] = mod_de;
-  // end module
-
-  int i_mod = 1;
-  // detector envelope
-  Tube   envShape(rmin, rmax, length / 2., 0., 2 * M_PI);
-  Volume envVol("MRICH_Envelope", envShape, air);
-  envVol.setVisAttributes(description.visAttributes(x_det.visStr()));
-
-  // place modules in the sectors (disk)
-  auto points = athena::geo::fillSquares({0., 0.}, mod_width, rmin, rmax);
-
-  // mod_name = ...
-  Placements& sensVols = sensitives[mod_name];
-  auto        mod_v    = modules[mod_name];
-  // determine module direction, always facing z = 0
-  double roty = dims.zmin() < 0. ? -M_PI : 0 ;
-  int    imod = 1;
-  for (auto& p : points) {
-    ROOT::Math::XYZVector x_location(p.x(), p.y(), zmin+std::signbit(zmin)*mod_length/2.0);
-    ROOT::Math::XYZVector z_dir(0, 0, 1);
-    ROOT::Math::XYZVector x_dir(1, 0, 0);
-    ROOT::Math::XYZVector rot_axis = x_location.Cross(z_dir);
-    double rot_angle = ROOT::Math::VectorUtil::Angle(z_dir,x_location);
-    ROOT::Math::AxisAngle proj_rot(rot_axis,-1.0*rot_angle);
-    ROOT::Math::AxisAngle grid_fix_rot(x_location,0.0*rot_angle);
-    auto new_x_dir = grid_fix_rot*x_dir;
-    // operations are inversely ordered
-    Transform3D tr = Translation3D(p.x(), p.y(), 0.) // move to position
-                     * RotationY(roty);              // facing z = 0.
-
-    if(projective) {
-      tr = Translation3D(p.x(), p.y(), 0.)              // move to position
-           * grid_fix_rot  // keep the modules oriented vertially
-           * proj_rot      // projective rotation
-           * RotationY(roty); // facing z = 0.
-    }
-    // mod placement
-    pv = envVol.placeVolume(mod_v, tr);
-    pv.addPhysVolID("module", i_mod);
-
-    auto mod_det_element  = module_assembly_delements[mod_name].clone(mod_name + "__" + std::to_string(i_mod));
-    mod_det_element.setPlacement(pv);
-    sdet.add(mod_det_element);
-    i_mod++;
-  }
-
-  // place envelope
-  Volume       motherVol = description.pickMotherVolume(sdet);
-  PlacedVolume envPV     = motherVol.placeVolume(envVol, Position(0, 0, zmin));
-  envPV.addPhysVolID("system", x_det.id());
-  sdet.setPlacement(envPV);
-  return sdet;
-}
-
-
-//void addModules(Volume &mother, xml::DetElement &detElem, Detector &description, SensitiveDetector &sens)
-//{
-//    xml::Component dims = detElem.dimensions();
-//    xml::Component mods = detElem.child(_Unicode(modules));
-//
-//    auto rmin = dims.rmin();
-//    auto rmax = dims.rmax();
-//
-//    auto mThick = mods.attr<double>(_Unicode(thickness));
-//    auto mWidth = mods.attr<double>(_Unicode(width));
-//    auto mGap = mods.attr<double>(_Unicode(gap));
-//
-//    auto modMat = description.material(mods.materialStr());
-//    auto gasMat = description.material("AirOptical");
-//
-//    // single module
-//    Box mShape(mWidth/2., mWidth/2., mThick/2. - 0.1*mm);
-//    Volume mVol("ce_MRICH_mod_Solid", mShape, modMat);
-//
-//    // a thin gas layer to detect optical photons
-//    Box modShape(mWidth/2., mWidth/2., mThick/2.);
-//    Volume modVol("ce_MRICH_mod_Solid_v", modShape, gasMat);
-//    // thin gas layer is on top (+z) of the material
-//    modVol.placeVolume(mVol, Position(0., 0., -0.1*mm));
-//
-//    modVol.setVisAttributes(description.visAttributes(mods.visStr()));
-//    sens.setType("photoncounter");
-//    modVol.setSensitiveDetector(sens);
-//
-//    // place modules in the sectors (disk)
-//    auto points = ref::utils::fillSquares({0., 0.}, mWidth + mGap, rmin - mGap, rmax + mGap);
-//
-//    // determine module direction, always facing z = 0
-//    double roty = dims.z() > 0. ? M_PI/2. : -M_PI/2.;
-//    int imod = 1;
-//    for (auto &p : points) {
-//        // operations are inversely ordered
-//        Transform3D tr = Translation3D(p.x(), p.y(), 0.)        // move to position
-//                       * RotationY(roty);                       // facing z = 0.
-//        auto modPV = mother.placeVolume(modVol, tr);
-//        modPV.addPhysVolID("sector", 1).addPhysVolID("module", imod ++);
-//    }
-//}
-
-// clang-format off
-DECLARE_DETELEMENT(athena_MRICH, createDetector)
-

src/MRich_geo.cpp

+//
+// Author     : Whit Armstrong (warmstrong@anl.gov)
+//
+#include <XML/Helper.h>
+#include "TMath.h"
+#include "TString.h"
+#include "DDRec/Surface.h"
+#include "DDRec/DetectorData.h"
+#include "DD4hep/OpticalSurfaces.h"
+#include "DD4hep/DetFactoryHelper.h"
+#include "DD4hep/Printout.h"
+#include "GeometryHelpers.h"
+#include "Math/Vector3D.h"
+#include "Math/AxisAngle.h"
+#include "Math/VectorUtil.h"
+
+using namespace std;
+using namespace dd4hep;
+using namespace dd4hep::rec;
+
+using Placements = vector<PlacedVolume>;
+
+
+
+static Ref_t createDetector(Detector& description, xml::Handle_t e, SensitiveDetector sens){
+  xml_det_t      x_det    = e;
+  Material       air      = description.material("AirOptical");
+  Material       vacuum   = description.vacuum();
+  string         det_name = x_det.nameStr();
+  DetElement     sdet(det_name, x_det.id());
+  Assembly       assembly(det_name);
+  sens.setType("tracker");
+  OpticalSurfaceManager surfMgr = description.surfaceManager();
+
+  bool projective = getAttrOrDefault(x_det, _Unicode(projective), false);
+  bool reflect    = x_det.reflect(true);
+
+  PlacedVolume pv;
+
+  map<string, Volume>     modules;
+  map<string, Placements> sensitives;
+  map<string, Volume>     module_assemblies;
+  std::map<std::string,DetElement> module_assembly_delements;
+
+  int                     n_sensor = 1;
+
+  // dimensions
+  xml::Component dims   = x_det.dimensions();
+  auto           rmin   = dims.rmin();
+  auto           rmax   = dims.rmax();
+  auto           length = dims.length();
+  auto           zmin   = dims.zmin();
+  auto           zpos   = zmin + length / 2;
+
+  // envelope
+  Tube   envShape(rmin, rmax, length / 2., 0., 2 * M_PI);
+  Volume envVol("MRICH_Envelope", envShape, air);
+  envVol.setVisAttributes(description.visAttributes(x_det.visStr()));
+  if (x_det.hasChild(_Unicode(envelope))) {
+    xml_comp_t x_envelope = x_det.child(_Unicode(envelope));
+    double thickness  = x_envelope.thickness();
+    Material material = description.material(x_envelope.materialStr());
+    Tube   envInsideShape(rmin + thickness, rmax - thickness, length / 2. - thickness);
+    SubtractionSolid envShellShape(envShape, envInsideShape);
+    Volume envShell("MRICH_Envelope_Inside", envShellShape, material);
+    envVol.placeVolume(envShell);
+  }
+
+  // expect only one module (for now)
+  xml_comp_t x_mod = x_det.child(_U(module));
+  string     mod_name            = x_mod.nameStr();
+  double     mod_width           = getAttrOrDefault(x_mod, _U(width), 130.0 * mm);
+  double     mod_height          = getAttrOrDefault(x_mod, _U(height), 130.0 * mm);
+  double     mod_length          = getAttrOrDefault(x_mod, _U(length), 130.0 * mm);
+
+  // module
+  Box    m_solid(mod_width / 2.0, mod_height / 2.0, mod_length / 2.0);
+  Volume m_volume(mod_name, m_solid, air);
+  m_volume.setVisAttributes(description.visAttributes(x_mod.visStr()));
+  DetElement mod_de( mod_name + std::string("_mod_") + std::to_string(1), 1);
+  double z_placement = - mod_length / 2.0;
+
+  // todo module frame
+  if (x_mod.hasChild(_Unicode(frame))) {
+    xml_comp_t x_frame    = x_mod.child(_Unicode(frame));
+    double     frame_thickness = getAttrOrDefault(x_frame, _U(thickness), 2.0 * mm);
+    Box        frame_inside(mod_width / 2.0 - frame_thickness, mod_height / 2.0 - frame_thickness, mod_length / 2.0 - frame_thickness);
+    SubtractionSolid frame_solid(m_solid, frame_inside);
+    Material   frame_mat       = description.material(x_frame.materialStr());
+    Volume     frame_vol(mod_name+"_frame", frame_solid, frame_mat);
+    auto       frame_vis       = getAttrOrDefault<std::string>(x_frame, _U(vis), std::string("GrayVis"));
+    frame_vol.setVisAttributes(description.visAttributes(frame_vis));
+    // update position
+    z_placement += frame_thickness / 2.0;
+    // place volume
+    m_volume.placeVolume(frame_vol);
+    // update position
+    z_placement += frame_thickness / 2.0;
+  }
+
+  // aerogel box
+  if (x_mod.hasChild(_Unicode(aerogel))) {
+    xml_comp_t x_aerogel  = x_mod.child(_Unicode(aerogel));
+    double     aerogel_width   = getAttrOrDefault(x_aerogel, _U(width), 130.0 * mm);
+    double     aerogel_length  = getAttrOrDefault(x_aerogel, _U(length), 130.0 * mm);
+    Material   aerogel_mat     = description.material(x_aerogel.materialStr());
+    auto       aerogel_vis     = getAttrOrDefault<std::string>(x_aerogel, _U(vis), std::string("InvisibleWithDaughters"));
+
+    xml_comp_t x_aerogel_frame = x_aerogel.child(_Unicode(frame));
+    double     foam_thickness  = getAttrOrDefault(x_aerogel_frame, _U(thickness), 2.0 * mm);
+    Material   foam_mat        = description.material(x_aerogel_frame.materialStr());
+    auto       foam_vis        = getAttrOrDefault<std::string>(x_aerogel_frame, _U(vis), std::string("RedVis"));
+
+    // foam frame
+    Box foam_box(aerogel_width / 2.0 + foam_thickness, aerogel_width / 2.0 + foam_thickness, (aerogel_length + foam_thickness) / 2.0);
+    Box foam_sub_box(aerogel_width / 2.0, aerogel_width / 2.0, (aerogel_length + foam_thickness) / 2.0);
+    SubtractionSolid foam_frame_solid(foam_box, foam_sub_box, Position(0, 0, foam_thickness));
+    Volume           foam_vol(mod_name+"_aerogel_frame", foam_frame_solid, foam_mat);
+    foam_vol.setVisAttributes(description.visAttributes(foam_vis));
+
+    // aerogel
+    Box              aerogel_box(aerogel_width / 2.0, aerogel_width / 2.0, (aerogel_length) / 2.0);
+    Volume           aerogel_vol(mod_name+"_aerogel", aerogel_box, aerogel_mat);
+    aerogel_vol.setVisAttributes(description.visAttributes(aerogel_vis));
+
+    // update position
+    z_placement += (aerogel_length + foam_thickness) / 2.0;
+    // place foam frame
+    pv = m_volume.placeVolume(foam_vol,Position(0,0,z_placement));
+    // place aerogel
+    z_placement += foam_thickness / 2.0;
+    pv = m_volume.placeVolume(aerogel_vol,Position(0,0,z_placement));
+    DetElement aerogel_de(mod_de, mod_name + std::string("_aerogel_de") + std::to_string(1), 1);
+    aerogel_de.setPlacement(pv);
+    // update position
+    z_placement += aerogel_length / 2.0;
+
+    // optical surfaces
+    auto aerogel_surf = surfMgr.opticalSurface(dd4hep::getAttrOrDefault(x_aerogel, _Unicode(surface), "MRICH_AerogelOpticalSurface"));
+    SkinSurface skin_surf(description, aerogel_de, Form("MRICH_aerogel_skin_surface_%d", 1), aerogel_surf, aerogel_vol);
+    skin_surf.isValid();
+  }
+
+  // Fresnel Lens
+  if (x_mod.hasChild(_Unicode(lens))) {
+    xml_comp_t x_lens     = x_mod.child(_Unicode(lens));
+
+    //  - The lens has a constant groove pitch (delta r) as opposed to fixing the groove height.
+    //  - The lens area outside of the effective diamtere is flat.
+    //  - The grooves are not curved, rather they are polycone shaped, ie a flat approximating the curvature.
+    auto   lens_vis       = getAttrOrDefault<std::string>(x_lens, _U(vis), std::string("AnlBlue"));
+    double groove_pitch   = getAttrOrDefault(x_lens, _Unicode(pitch), 0.2 * mm);// 0.5 * mm);
+    double lens_f         = getAttrOrDefault(x_lens, _Unicode(focal_length), 6.0*2.54*cm);
+    double eff_diameter   = getAttrOrDefault(x_lens, _Unicode(effective_diameter), 152.4 * mm);
+    double lens_width     = getAttrOrDefault(x_lens, _Unicode(width), 6.7*2.54*cm);
+    double center_thickness = getAttrOrDefault(x_lens, _U(thickness), 0.068 * 2.54 * cm);//2.0 * mm);
+
+    double n_acrylic        = 1.49;
+    double lens_curvature   = 1.0 / (lens_f*(n_acrylic - 1.0)); //confirmed
+    double full_ring_rmax   = std::min(eff_diameter / 2.0, lens_width/2.0);
+
+    double N_grooves        = std::ceil((full_ring_rmax) / groove_pitch);
+    double groove_last_rmin = (N_grooves - 1) * groove_pitch;
+    double groove_last_rmax = N_grooves * groove_pitch;
+
+    auto   groove_sagitta = [&](double r) { return lens_curvature * std::pow(r, 2) / (1.0 + 1.0); };
+    double lens_thickness = groove_sagitta(groove_last_rmax) - groove_sagitta(groove_last_rmin) + center_thickness;
+
+    Material         lens_mat = description.material(x_lens.materialStr());
+    Box              lens_box(lens_width / 2.0, lens_width / 2.0, (center_thickness) / 2.0);
+    SubtractionSolid flat_lens(lens_box, Tube(0.0, full_ring_rmax, 2 * center_thickness));
+
+    Assembly lens_vol(mod_name + "_lens");
+    Volume   flatpart_lens_vol( "flatpart_lens", flat_lens, lens_mat);
+    lens_vol.placeVolume(flatpart_lens_vol);
+
+    int    i_groove           = 0;
+    double groove_rmax        = groove_pitch;
+    double groove_rmin        = 0;
+
+    while ( groove_rmax <= full_ring_rmax ) {
+      double   dZ = groove_sagitta(groove_rmax) - groove_sagitta(groove_rmin);
+      Polycone groove_solid(0, 2.0 * M_PI,
+                            {groove_rmin, groove_rmin, groove_rmin},
+                            {groove_rmax, groove_rmax, groove_rmin},
+                            {-lens_thickness/2.0, lens_thickness/2.0-dZ, lens_thickness/2.0});
+      Volume   lens_groove_vol("lens_groove_" + std::to_string(i_groove), groove_solid, lens_mat);
+      lens_vol.placeVolume(lens_groove_vol);
+
+      i_groove++;
+      groove_rmin = (i_groove  )*groove_pitch;
+      groove_rmax = (i_groove+1)*groove_pitch;
+    }
+
+    lens_vol.setVisAttributes(description.visAttributes(lens_vis));
+
+    // update position
+    z_placement += lens_thickness/2.0;
+    // place volume
+    pv = m_volume.placeVolume(lens_vol,Position(0,0,z_placement));
+    DetElement lens_de(mod_de, mod_name + std::string("_lens_de") + std::to_string(1), 1);
+    lens_de.setPlacement(pv);
+    // update position
+    z_placement += lens_thickness/2.0;
+
+    // optical surfaces
+    auto lens_surf = surfMgr.opticalSurface(dd4hep::getAttrOrDefault(x_lens, _Unicode(surface), "MRICH_LensOpticalSurface"));
+    SkinSurface skin_surf(description, lens_de, Form("MRichFresnelLens_skin_surface_%d", 1), lens_surf, lens_vol);
+    skin_surf.isValid();
+  }
+
+  // mirror
+  if (x_mod.hasChild(_Unicode(space))) {
+    xml_comp_t x_space = x_mod.child(_Unicode(space));
+    z_placement += getAttrOrDefault(x_space, _U(thickness), 0.0 * mm);
+  }
+
+  // mirror
+  if (x_mod.hasChild(_Unicode(mirror))) {
+    xml_comp_t x_mirror   = x_mod.child(_Unicode(mirror));
+    auto   mirror_vis     = getAttrOrDefault<std::string>(x_mirror, _U(vis), std::string("AnlGray"));
+    double mirror_x1      = getAttrOrDefault(x_mirror, _U(x1), 100.0 * mm);
+    double mirror_x2      = getAttrOrDefault(x_mirror, _U(x2), 80.0 * mm);
+    double mirror_length  = getAttrOrDefault(x_mirror, _U(length), 130.0 * mm);
+    double mirror_thickness  = getAttrOrDefault(x_mirror, _U(thickness), 2.0 * mm);
+    double outer_x1 = (mirror_x1+mirror_thickness)/2.0;
+    double outer_x2 = (mirror_x2+mirror_thickness)/2.0;
+    Trd2   outer_mirror_trd(outer_x1, outer_x2, outer_x1,  outer_x2, mirror_length/2.0);
+    Trd2   inner_mirror_trd(mirror_x1 / 2.0,  mirror_x2 / 2.0, mirror_x1 / 2.0,mirror_x2 / 2.0, mirror_length/2.0+0.1*mm);
+    SubtractionSolid mirror_solid(outer_mirror_trd, inner_mirror_trd);
+    Material mirror_mat        = description.material(x_mirror.materialStr());
+    Volume   mirror_vol(mod_name+"_mirror", mirror_solid, mirror_mat);
+
+    // update position
+    z_placement += mirror_length/2.0;
+    // place volume
+    pv = m_volume.placeVolume(mirror_vol,Position(0,0,z_placement));
+    DetElement mirror_de(mod_de, mod_name + std::string("_mirror_de") + std::to_string(1), 1);
+    mirror_de.setPlacement(pv);
+    // update position
+    z_placement += mirror_length/2.0;
+
+    // optical surfaces
+    auto mirror_surf = surfMgr.opticalSurface(dd4hep::getAttrOrDefault(x_mirror, _Unicode(surface), "MRICH_MirrorOpticalSurface"));
+    SkinSurface skin_surf(description, mirror_de, Form("MRICH_mirror_skin_surface_%d", 1), mirror_surf, mirror_vol);
+    skin_surf.isValid();
+  }
+
+  // photon detector
+  if (x_mod.hasChild(_Unicode(photodet))) {
+    xml_comp_t x_photodet = x_mod.child(_Unicode(photodet));
+    auto       photodet_vis       = getAttrOrDefault<std::string>(x_photodet, _U(vis), std::string("AnlRed"));
+    double     photodet_width     = getAttrOrDefault(x_photodet, _U(width), 130.0 * mm);
+    double     photodet_thickness = getAttrOrDefault(x_photodet, _U(thickness), 2.0 * mm);
+    Material   photodet_mat       = description.material(x_photodet.materialStr());
+    Box        window_box(photodet_width/2.0,photodet_width/2.0,photodet_thickness/2.0);
+    Volume     window_vol(mod_name+"_window", window_box, photodet_mat);
+
+    // update position
+    z_placement += photodet_thickness/2.0;
+    // place volume
+    pv = m_volume.placeVolume(window_vol,Position(0,0,z_placement));
+    DetElement   comp_de(mod_de, mod_name + std::string("_sensor_de_") + std::to_string(1) ,  1);
+    comp_de.setPlacement(pv);
+    // update position
+    z_placement += photodet_thickness/2.0;
+
+    // sensitive
+    pv.addPhysVolID("sensor", n_sensor);
+    window_vol.setSensitiveDetector(sens);
+    sensitives[mod_name].push_back(pv);
+    ++n_sensor;
+
+    // sensor
+    xml_comp_t x_sensor  = x_photodet.child(_Unicode(sensor));
+    double     sensor_thickness   = getAttrOrDefault(x_sensor, _U(thickness), 2.0 * mm);
+    Material   sensor_mat         = description.material(x_sensor.materialStr());
+    int        sensor_nx          = getAttrOrDefault(x_sensor, _Unicode(nx), 2);
+    int        sensor_ny          = getAttrOrDefault(x_sensor, _Unicode(ny), 2);
+
+    // layers
+    int i_layer = 1;
+    for (xml_coll_t li(x_photodet, _Unicode(layer)); li; ++li) {
+      xml_comp_t x_layer = li;
+      Material layer_mat = description.material(x_layer.materialStr());
+      double   layer_thickness = x_layer.thickness();
+      Box      layer_box(photodet_width/2.0,photodet_width/2.0,layer_thickness/2.0);
+      Volume   layer_vol(mod_name + "_layer_" + std::to_string(i_layer), layer_box, layer_mat);
+
+      // update position
+      z_placement += layer_thickness / 2.0;
+      // place volume
+      pv = m_volume.placeVolume(layer_vol,Position(0,0,z_placement));
+      DetElement layer_de(mod_de, mod_name + std::string("_layer_de_") + std::to_string(i_layer),  1);
+      layer_de.setPlacement(pv);
+      // update position
+      z_placement += layer_thickness / 2.0;
+
+      i_layer++;
+    }
+  }
+
+  //for (size_t ic = 0; ic < sensVols.size(); ++ic) {
+  //  PlacedVolume sens_pv = sensVols[ic];
+  //  DetElement   comp_de(mod_de, std::string("de_") + sens_pv.volume().name(), ic + 1);
+  //  comp_de.setPlacement(sens_pv);
+  //  // Acts::ActsExtension* sensorExtension = new Acts::ActsExtension();
+  //  //// sensorExtension->addType("sensor", "detector");
+  //  // comp_de.addExtension<Acts::ActsExtension>(sensorExtension);
+  //  //// comp_de.setAttributes(description, sens_pv.volume(), x_layer.regionStr(),
+  //  //// x_layer.limitsStr(),
+  //  ////                      xml_det_t(xmleles[m_nam]).visStr());
+  //}
+  //DetElement window_de(sdet, mod_name + std::string("_window_de") + std::to_string(1), 1);
+  //window_de.setPlacement(pv);
+
+  modules[mod_name]                   = m_volume;
+  module_assembly_delements[mod_name] = mod_de;
+  // end module
+
+  // place modules in the sectors (disk)
+  auto points = athena::geo::fillSquares({0., 0.}, mod_width, rmin, rmax);
+
+  // mod_name = ...
+  Placements& sensVols = sensitives[mod_name];
+  auto        mod_v    = modules[mod_name];
+  // determine module direction, always facing z = 0
+  double roty = dims.zmin() < 0. ? -M_PI : 0 ;
+
+  // read module positions
+  std::vector<std::tuple<double,double,double>> positions;
+  for (xml_coll_t x_positions_i(x_det, _Unicode(positions)); x_positions_i; ++x_positions_i) {
+    xml_comp_t x_positions = x_positions_i;
+    for (xml_coll_t x_position_i(x_positions, _U(position)); x_position_i; ++x_position_i) {
+      xml_comp_t x_position = x_position_i;
+      positions.push_back(
+        std::make_tuple(x_positions.scale() * x_position.x() * mm,
+                        x_positions.scale() * x_position.y() * mm,
+                        -x_positions.z0()));
+    }
+  }
+  // if no positions, then autoplacement
+  if (positions.empty()) {
+    for (double x = mod_width / 2.0; x < rmax - mod_width / 2.0; x += mod_width) {
+      for (double y = mod_width / 2.0; y < rmax - mod_width / 2.0; y += mod_width) {
+        if (pow(x + mod_width / 2.0,2) + pow(y + mod_width / 2.0,2) > rmax*rmax) continue;
+        if (pow(x - mod_width / 2.0,2) + pow(y - mod_width / 2.0,2) < rmin*rmin) continue;
+        positions.push_back(std::make_tuple(x, y, 0));
+      }
+    }
+  }
+
+  // place modules
+  int i_mod = 1; // starts at 1
+  for (auto& p: positions) {
+
+    // get positions in one quadrant
+    double x = std::get<0>(p);
+    double y = std::get<1>(p);
+    double z0 = std::get<2>(p);
+
+    // and place in all quadrants (intentional shadowing)
+    for (auto& p: decltype(positions){{x,y,z0}, {y,-x,z0}, {-x,-y,z0}, {-y,x,z0}}) {
+
+      // get positions (intentional shadowing)
+      double x = std::get<0>(p);
+      double y = std::get<1>(p);
+      double z0 = std::get<2>(p);
+
+      Transform3D tr;
+      if(projective) {
+        double rotAngX = atan(y/z0);
+        double rotAngY = -1.*atan(x/z0);
+        tr = Translation3D(x, y, 0) * RotationX(rotAngX) * RotationY(rotAngY);
+      } else {
+        tr = Translation3D(x, y, 0) * RotationX(0);
+      }
+
+      // mod placement
+      pv = envVol.placeVolume(mod_v, tr);
+      pv.addPhysVolID("module", i_mod);
+
+      auto mod_det_element  = module_assembly_delements[mod_name].clone(mod_name + "__" + std::to_string(i_mod));
+      mod_det_element.setPlacement(pv);
+      sdet.add(mod_det_element);
+
+      i_mod++;
+    }
+  }
+
+  // additional layers
+  if (x_det.hasChild(_Unicode(layer))) {
+    xml_comp_t x_layer = x_det.child(_Unicode(layer));
+    double   layer_thickness = x_layer.thickness();
+    Material layer_mat = description.material(x_layer.materialStr());
+    Tube   frameShape(rmin, rmax, layer_thickness / 2., 0., 2 * M_PI);
+    Volume frameVol("MRICH_Frame", frameShape, layer_mat);
+    pv = envVol.placeVolume(frameVol, Position(0, 0, (length - layer_thickness) / 2.0));
+  }
+
+  // place envelope
+  Volume motherVol = description.pickMotherVolume(sdet);
+  if (reflect) {
+    pv = motherVol.placeVolume(envVol, Transform3D(RotationZYX(0, M_PI, 0), Position(0, 0, -zpos)));
+  } else {
+    pv = motherVol.placeVolume(envVol, Transform3D(RotationZYX(0,    0, 0), Position(0, 0, +zpos)));
+  }
+  pv.addPhysVolID("system", x_det.id());
+  sdet.setPlacement(pv);
+  return sdet;
+}
+
+
+//void addModules(Volume &mother, xml::DetElement &detElem, Detector &description, SensitiveDetector &sens)
+//{
+//    xml::Component dims = detElem.dimensions();
+//    xml::Component mods = detElem.child(_Unicode(modules));
+//
+//    auto rmin = dims.rmin();
+//    auto rmax = dims.rmax();
+//
+//    auto mThick = mods.attr<double>(_Unicode(thickness));
+//    auto mWidth = mods.attr<double>(_Unicode(width));
+//    auto mGap = mods.attr<double>(_Unicode(gap));
+//
+//    auto modMat = description.material(mods.materialStr());
+//    auto gasMat = description.material("AirOptical");
+//
+//    // single module
+//    Box mShape(mWidth/2., mWidth/2., mThick/2. - 0.1*mm);
+//    Volume mVol("ce_MRICH_mod_Solid", mShape, modMat);
+//
+//    // a thin gas layer to detect optical photons
+//    Box modShape(mWidth/2., mWidth/2., mThick/2.);
+//    Volume modVol("ce_MRICH_mod_Solid_v", modShape, gasMat);
+//    // thin gas layer is on top (+z) of the material
+//    modVol.placeVolume(mVol, Position(0., 0., -0.1*mm));
+//
+//    modVol.setVisAttributes(description.visAttributes(mods.visStr()));
+//    sens.setType("tracker");
+//    modVol.setSensitiveDetector(sens);
+//
+//    // place modules in the sectors (disk)
+//    auto points = ref::utils::fillSquares({0., 0.}, mWidth + mGap, rmin - mGap, rmax + mGap);
+//
+//    // determine module direction, always facing z = 0
+//    double roty = dims.z() > 0. ? M_PI/2. : -M_PI/2.;
+//    int imod = 1;
+//    for (auto &p : points) {
+//        // operations are inversely ordered
+//        Transform3D tr = Translation3D(p.x(), p.y(), 0.)        // move to position
+//                       * RotationY(roty);                       // facing z = 0.
+//        auto modPV = mother.placeVolume(modVol, tr);
+//        modPV.addPhysVolID("sector", 1).addPhysVolID("module", imod ++);
+//    }
+//}
+
+// clang-format off
+DECLARE_DETELEMENT(athena_MRICH, createDetector)
+

src/PFRICH_geo.cpp

+//----------------------------------
+//  pfRICH: Proximity Focusing RICH
+//  Author: C. Dilks
+//----------------------------------
+
+#include "DD4hep/DetFactoryHelper.h"
+#include "DD4hep/OpticalSurfaces.h"
+#include "DD4hep/Printout.h"
+#include "DDRec/DetectorData.h"
+#include "DDRec/Surface.h"
+#include "GeometryHelpers.h"
+#include "Math/Point2D.h"
+#include "TMath.h"
+#include "TString.h"
+#include <XML/Helper.h>
+
+using namespace dd4hep;
+using namespace dd4hep::rec;
+
+// create the detector
+static Ref_t createDetector(Detector& desc, xml::Handle_t handle, SensitiveDetector sens)
+{
+  xml::DetElement detElem = handle;
+  std::string     detName = detElem.nameStr();
+  int             detID   = detElem.id();
+
+  DetElement            det(detName, detID);
+  xml::Component        dims    = detElem.dimensions();
+  OpticalSurfaceManager surfMgr = desc.surfaceManager();
+
+  // attributes -----------------------------------------------------------
+  // - vessel
+  double vesselLength    = dims.attr<double>(_Unicode(length));
+  double vesselZmin      = dims.attr<double>(_Unicode(zmin));
+  double vesselZmax      = dims.attr<double>(_Unicode(zmax));
+  double vesselRmin0     = dims.attr<double>(_Unicode(rmin0));
+  double vesselRmin1     = dims.attr<double>(_Unicode(rmin1));
+  double vesselRmax0     = dims.attr<double>(_Unicode(rmax0));
+  double vesselRmax1     = dims.attr<double>(_Unicode(rmax1));
+  double wallThickness   = dims.attr<double>(_Unicode(wall_thickness));
+  double windowThickness = dims.attr<double>(_Unicode(window_thickness));
+  auto   vesselMat       = desc.material(detElem.attr<std::string>(_Unicode(material)));
+  auto   gasvolMat       = desc.material(detElem.attr<std::string>(_Unicode(gas)));
+  auto   vesselVis       = desc.visAttributes(detElem.attr<std::string>(_Unicode(vis_vessel)));
+  auto   gasvolVis       = desc.visAttributes(detElem.attr<std::string>(_Unicode(vis_gas)));
+  // - radiator (applies to aerogel and filter)
+  auto   radiatorElem       = detElem.child(_Unicode(radiator));
+  double radiatorRmin       = radiatorElem.attr<double>(_Unicode(rmin));
+  double radiatorRmax       = radiatorElem.attr<double>(_Unicode(rmax));
+  double radiatorPhiw       = radiatorElem.attr<double>(_Unicode(phiw));
+  double radiatorPitch      = radiatorElem.attr<double>(_Unicode(pitch));
+  double radiatorFrontplane = radiatorElem.attr<double>(_Unicode(frontplane));
+  // - aerogel
+  auto   aerogelElem      = radiatorElem.child(_Unicode(aerogel));
+  auto   aerogelMat       = desc.material(aerogelElem.attr<std::string>(_Unicode(material)));
+  auto   aerogelVis       = desc.visAttributes(aerogelElem.attr<std::string>(_Unicode(vis)));
+  double aerogelThickness = aerogelElem.attr<double>(_Unicode(thickness));
+  // - filter
+  auto   filterElem      = radiatorElem.child(_Unicode(filter));
+  auto   filterMat       = desc.material(filterElem.attr<std::string>(_Unicode(material)));
+  auto   filterVis       = desc.visAttributes(filterElem.attr<std::string>(_Unicode(vis)));
+  double filterThickness = filterElem.attr<double>(_Unicode(thickness));
+  // - sensor module
+  auto   sensorElem      = detElem.child(_Unicode(sensors)).child(_Unicode(module));
+  auto   sensorMat       = desc.material(sensorElem.attr<std::string>(_Unicode(material)));
+  auto   sensorVis       = desc.visAttributes(sensorElem.attr<std::string>(_Unicode(vis)));
+  auto   sensorSurf      = surfMgr.opticalSurface(sensorElem.attr<std::string>(_Unicode(surface)));
+  double sensorSide      = sensorElem.attr<double>(_Unicode(side));
+  double sensorGap       = sensorElem.attr<double>(_Unicode(gap));
+  double sensorThickness = sensorElem.attr<double>(_Unicode(thickness));
+  // - sensor plane
+  auto   sensorPlaneElem = detElem.child(_Unicode(sensors)).child(_Unicode(plane));
+  double sensorPlaneDist = sensorPlaneElem.attr<double>(_Unicode(sensordist));
+  double sensorPlaneRmin = sensorPlaneElem.attr<double>(_Unicode(rmin));
+  double sensorPlaneRmax = sensorPlaneElem.attr<double>(_Unicode(rmax));
+  // - debugging switches
+  int debug_optics_mode = detElem.attr<int>(_Unicode(debug_optics));
+
+  // if debugging optics, override some settings
+  bool debug_optics = debug_optics_mode > 0;
+  if (debug_optics) {
+    printout(WARNING, "PFRICH_geo", "DEBUGGING PFRICH OPTICS");
+    switch (debug_optics_mode) {
+    case 1:
+      vesselMat = aerogelMat = filterMat = sensorMat = gasvolMat = desc.material("VacuumOptical");
+      break;
+    case 2:
+      vesselMat = aerogelMat = filterMat = sensorMat = desc.material("VacuumOptical");
+      break;
+    default:
+      printout(FATAL, "PFRICH_geo", "UNKNOWN debug_optics_mode");
+      return det;
+    };
+    aerogelVis = sensorVis;
+    gasvolVis = vesselVis = desc.invisible();
+  };
+
+  // BUILD VESSEL //////////////////////////////////////
+  /* - `vessel`: aluminum enclosure, the mother volume of the pfRICH
+   * - `gasvol`: gas volume, which fills `vessel`; all other volumes defined below
+   *   are children of `gasvol`
+   */
+
+  // tank solids
+  double boreDelta = vesselRmin1 - vesselRmin0;
+  Cone vesselTank(vesselLength / 2.0, vesselRmin1, vesselRmax1, vesselRmin0, vesselRmax0);
+  Cone gasvolTank(vesselLength / 2.0 - windowThickness, vesselRmin1 + wallThickness, vesselRmax1 - wallThickness,
+                  vesselRmin0 + wallThickness, vesselRmax0 - wallThickness);
+
+  //  extra solids for `debug_optics` only
+  Box vesselBox(1001, 1001, 1001);
+  Box gasvolBox(1000, 1000, 1000);
+
+  // choose vessel and gasvol solids (depending on `debug_optics_mode` (0=disabled))
+  Solid vesselSolid, gasvolSolid;
+  switch (debug_optics_mode) {
+  case 0:
+    vesselSolid = vesselTank;
+    gasvolSolid = gasvolTank;
+    break; // `!debug_optics`
+  case 1:
+    vesselSolid = vesselBox;
+    gasvolSolid = gasvolBox;
+    break;
+  case 2:
+    vesselSolid = vesselBox;
+    gasvolSolid = gasvolTank;
+    break;
+  };
+
+  // volumes
+  Volume vesselVol(detName, vesselSolid, vesselMat);
+  Volume gasvolVol(detName + "_gas", gasvolSolid, gasvolMat);
+  vesselVol.setVisAttributes(vesselVis);
+  gasvolVol.setVisAttributes(gasvolVis);
+
+  // reference positions
+  // - the vessel is created such that the center of the cylindrical tank volume
+  //   coincides with the origin; this is called the "origin position" of the vessel
+  // - when the vessel (and its children volumes) is placed, it is translated in
+  //   the z-direction to be in the proper ATHENA-integration location
+  // - these reference positions are for the frontplane and backplane of the vessel,
+  //   with respect to the vessel origin position
+  auto originFront = Position(0., 0., vesselLength / 2.0);
+  auto originBack  = Position(0., 0., -vesselLength / 2.0);
+
+  // sensitive detector type
+  sens.setType("tracker");
+
+
+  // BUILD RADIATOR //////////////////////////////////////
+
+  // attributes
+  double airGap = 0.01*mm; // air gap between aerogel and filter (FIXME? actually it's currently a gas gap)
+
+  // solid and volume: create aerogel and filter
+  Cone aerogelSolid(
+      aerogelThickness/2,
+      radiatorRmin + boreDelta * aerogelThickness / vesselLength, /* at backplane */
+      radiatorRmax,
+      radiatorRmin, /* at frontplane */
+      radiatorRmax
+      );
+  Cone filterSolid(
+      filterThickness/2,
+      radiatorRmin + boreDelta * (aerogelThickness + airGap + filterThickness) / vesselLength, /* at backplane */
+      radiatorRmax,
+      radiatorRmin + boreDelta * (aerogelThickness + airGap) / vesselLength, /* at frontplane */
+      radiatorRmax
+      );
+  Volume aerogelVol(detName + "_aerogel", aerogelSolid, aerogelMat);
+  Volume filterVol(detName + "_filter", filterSolid, filterMat);
+  aerogelVol.setVisAttributes(aerogelVis);
+  filterVol.setVisAttributes(filterVis);
+
+  // aerogel placement and surface properties
+  // TODO [low-priority]: define skin properties for aerogel and filter
+  auto radiatorPos = Position(0., 0., radiatorFrontplane - 0.5 * aerogelThickness) + originFront;
+  auto aerogelPV = gasvolVol.placeVolume(
+      aerogelVol,
+      Translation3D(radiatorPos.x(), radiatorPos.y(), radiatorPos.z()) // re-center to originFront
+          * RotationY(radiatorPitch) // change polar angle to specified pitch // (FIXME: probably broken, currently not in use)
+  );
+  DetElement aerogelDE(det, "aerogel_de", 0);
+  aerogelDE.setPlacement(aerogelPV);
+  // SkinSurface aerogelSkin(desc, aerogelDE, "mirror_optical_surface", aerogelSurf, aerogelVol);
+  // aerogelSkin.isValid();
+
+  // filter placement and surface properties
+  if (!debug_optics) {
+    auto filterPV = gasvolVol.placeVolume(
+        filterVol,
+        Translation3D(0., 0., -airGap) // add an airgap (FIXME: actually a gas gap)
+            * Translation3D(radiatorPos.x(), radiatorPos.y(), radiatorPos.z())  // re-center to originFront
+            * RotationY(radiatorPitch) // change polar angle
+            * Translation3D(0., 0., -(aerogelThickness + filterThickness) / 2.) // move to aerogel backplane
+    );
+    DetElement filterDE(det, "filter_de", 0);
+    filterDE.setPlacement(filterPV);
+    // SkinSurface filterSkin(desc, filterDE, "mirror_optical_surface", filterSurf, filterVol);
+    // filterSkin.isValid();
+  };
+
+
+  // BUILD SENSORS ///////////////////////
+
+  // solid and volume: single sensor module
+  Box    sensorSolid(sensorSide / 2., sensorSide / 2., sensorThickness / 2.);
+  Volume sensorVol(detName + "_sensor", sensorSolid, sensorMat);
+  sensorVol.setVisAttributes(sensorVis);
+
+  // sensitivity
+  if (!debug_optics)
+    sensorVol.setSensitiveDetector(sens);
+
+  // sensor plane positioning: we want `sensorPlaneDist` to be the distance between the
+  // aerogel backplane (i.e., aerogel/filter boundary) and the sensor active surface (e.g, photocathode)
+  double sensorZpos     = radiatorFrontplane - aerogelThickness - sensorPlaneDist - 0.5 * sensorThickness;
+  auto   sensorPlanePos = Position(0., 0., sensorZpos) + originFront; // reference position
+  // miscellaneous
+  int    imod    = 0;           // module number
+  double tBoxMax = vesselRmax1; // sensors will be tiled in tBox, within annular limits
+
+  // SENSOR MODULE LOOP ------------------------
+  /* cartesian tiling loop
+   * - start at (x=0,y=0), to center the grid
+   * - loop over positive-x positions; for each, place the corresponding negative-x sensor too
+   * - nested similar loop over y positions
+   */
+  double sx, sy;
+  for (double usx = 0; usx <= tBoxMax; usx += sensorSide + sensorGap) {
+    for (int sgnx = 1; sgnx >= (usx > 0 ? -1 : 1); sgnx -= 2) {
+      for (double usy = 0; usy <= tBoxMax; usy += sensorSide + sensorGap) {
+        for (int sgny = 1; sgny >= (usy > 0 ? -1 : 1); sgny -= 2) {
+
+          // sensor (x,y) center
+          sx = sgnx * usx;
+          sy = sgny * usy;
+
+          // annular cut
+          if (std::hypot(sx, sy) < sensorPlaneRmin || std::hypot(sx, sy) > sensorPlaneRmax)
+            continue;
+
+          // placement (note: transformations are in reverse order)
+          auto sensorPV = gasvolVol.placeVolume(
+              sensorVol, Transform3D(Translation3D(sensorPlanePos.x(), sensorPlanePos.y(),
+                                                   sensorPlanePos.z()) // move to reference position
+                                     * Translation3D(sx, sy, 0.)       // move to grid position
+                                     ));
+
+          // generate LUT for module number -> sensor position, for readout mapping tests
+          // printf("%d %f %f\n",imod,sensorPV.position().x(),sensorPV.position().y());
+
+          // properties
+          sensorPV.addPhysVolID("module", imod);
+          DetElement sensorDE(det, Form("sensor_de_%d", imod), imod);
+          sensorDE.setPlacement(sensorPV);
+          if (!debug_optics) {
+            SkinSurface sensorSkin(desc, sensorDE, "sensor_optical_surface", sensorSurf,
+                                   sensorVol); // TODO: 3rd arg needs `imod`?
+            sensorSkin.isValid();
+          };
+
+          // increment sensor module number
+          imod++;
+        };
+      };
+    };
+  };
+  // END SENSOR MODULE LOOP ------------------------
+  //
+  // Add service material if desired
+  if (detElem.child("sensors").hasChild("services")) {
+    xml_comp_t x_service = detElem.child("sensors").child(_Unicode(services));
+    Assembly   service_vol("services");
+    service_vol.setVisAttributes(desc, x_service.visStr());
+
+    // Compute service total thickness from components
+    double     total_thickness = 0;
+    xml_coll_t ci(x_service, _Unicode(component));
+    for (ci.reset(), total_thickness = 0.0; ci; ++ci) {
+      total_thickness += xml_comp_t(ci).thickness();
+    }
+
+    int    ncomponents   = 0;
+    double thickness_sum = -total_thickness / 2.0;
+    for (xml_coll_t ci(x_service, _Unicode(component)); ci; ++ci, ncomponents++) {
+      xml_comp_t x_comp    = ci;
+      double     thickness = x_comp.thickness();
+      Tube       c_tube{sensorPlaneRmin, sensorPlaneRmax, thickness/2};
+      Volume     c_vol{_toString(ncomponents, "component%d"), c_tube, desc.material(x_comp.materialStr())};
+      c_vol.setVisAttributes(desc, x_comp.visStr());
+      service_vol.placeVolume(c_vol, Position(0, 0, thickness_sum + thickness / 2.0));
+      thickness_sum += thickness;
+    }
+    gasvolVol.placeVolume(service_vol,
+                          Transform3D(Translation3D(sensorPlanePos.x(), sensorPlanePos.y(),
+                                                    sensorPlanePos.z() - sensorThickness - total_thickness)));
+  }
+
+  // place gas volume
+  PlacedVolume gasvolPV = vesselVol.placeVolume(gasvolVol, Position(0, 0, 0));
+  DetElement   gasvolDE(det, "gasvol_de", 0);
+  gasvolDE.setPlacement(gasvolPV);
+
+  // place mother volume (vessel)
+  Volume       motherVol = desc.pickMotherVolume(det);
+  PlacedVolume vesselPV  = motherVol.placeVolume(vesselVol, Position(0, 0, vesselZmin) - originFront);
+  vesselPV.addPhysVolID("system", detID);
+  det.setPlacement(vesselPV);
+
+  return det;
+};
+
+// clang-format off
+DECLARE_DETELEMENT(athena_PFRICH, createDetector)

src/PolyhedraEndcapCalorimeter2_geo.cpp

@@ -11,7 +11,7 @@
 //
 //==========================================================================
 //
-// Modified for TOPSiDE detector
+// Modified for ATHENA detector
 //
 //==========================================================================
 #include "DD4hep/DetFactoryHelper.h"
@@ -32,7 +32,7 @@ static Ref_t create_detector(Detector& description, xml_h e, SensitiveDetector s
   int            numsides = dim.numsides();
   xml::Component pos      = x_det.position();
   double         rmin     = dim.rmin();
-  double         rmax     = dim.rmax() * std::cos(M_PI / numsides);
+  double         rmax     = dim.rmax();
   double         zmin     = dim.zmin();
   Layering       layering(x_det);
   double         totalThickness = layering.totalThickness();
@@ -128,4 +128,5 @@ static Ref_t create_detector(Detector& description, xml_h e, SensitiveDetector s
 }
 
 // clang-format off
-DECLARE_DETELEMENT(refdet_PolyhedraEndcapCalorimeter2, create_detector)
+DECLARE_DETELEMENT(athena_PolyhedraEndcapCalorimeter2, create_detector)
+DECLARE_DETELEMENT(athena_PolyhedraEndcapCalorimeter, create_detector)

src/ScFiCalorimeter_geo.cpp

+//==========================================================================
+//  Scintillating fiber calorimeter with tower shape blocks
+//  reference: https://github.com/adamjaro/lmon/blob/master/calo/src/WScFiZXv3.cxx
+//  Support disk placement
+//--------------------------------------------------------------------------
+//  Author: Chao Peng (ANL)
+//  Date: 07/19/2021
+//==========================================================================
+
+#include "GeometryHelpers.h"
+#include "DD4hep/DetFactoryHelper.h"
+#include <XML/Helper.h>
+#include <iostream>
+#include <algorithm>
+#include <tuple>
+#include <math.h>
+
+using namespace dd4hep;
+using Point =  ROOT::Math::XYPoint;
+
+std::tuple<Volume, Position> build_module(const Detector &desc, const xml::Component &mod_x, SensitiveDetector &sens);
+
+// helper function to get x, y, z if defined in a xml component
+template<class XmlComp>
+Position get_xml_xyz(const XmlComp &comp, dd4hep::xml::Strng_t name)
+{
+    Position pos(0., 0., 0.);
+    if (comp.hasChild(name)) {
+        auto child = comp.child(name);
+        pos.SetX(dd4hep::getAttrOrDefault<double>(child, _Unicode(x), 0.));
+        pos.SetY(dd4hep::getAttrOrDefault<double>(child, _Unicode(y), 0.));
+        pos.SetZ(dd4hep::getAttrOrDefault<double>(child, _Unicode(z), 0.));
+    }
+    return pos;
+}
+
+// main
+static Ref_t create_detector(Detector& desc, xml::Handle_t handle, SensitiveDetector sens)
+{
+    xml::DetElement detElem = handle;
+    std::string detName = detElem.nameStr();
+    int detID = detElem.id();
+    DetElement det(detName, detID);
+    sens.setType("calorimeter");
+    auto dim = detElem.dimensions();
+    auto rmin = dim.rmin();
+    auto rmax = dim.rmax();
+    auto length = dim.length();
+    auto phimin = dd4hep::getAttrOrDefault<double>(dim, _Unicode(phimin), 0.);
+    auto phimax = dd4hep::getAttrOrDefault<double>(dim, _Unicode(phimax), 2.*M_PI);
+    // envelope
+    Tube envShape(rmin, rmax, length/2., phimin, phimax);
+    Volume env(detName + "_envelope", envShape, desc.material("Air"));
+    env.setVisAttributes(desc.visAttributes(detElem.visStr()));
+
+    // build module
+    auto [modVol, modSize] = build_module(desc, detElem.child(_Unicode(module)), sens);
+    double modSizeR = std::sqrt(modSize.x() * modSize.x() + modSize.y() * modSize.y());
+    double assembly_rwidth = modSizeR*2.;
+    int nas = int((rmax - rmin) / assembly_rwidth) + 1;
+    std::vector<Assembly> assemblies;
+    // calorimeter block z-offsets (as blocks are shorter than the volume length)
+    const double block_offset = -0.5*(length - modSize.z());
+    for (int i = 0; i < nas; ++i) {
+        Assembly assembly(detName + Form("_ring%d", i + 1));
+        auto assemblyPV = env.placeVolume(assembly, Position{0., 0., block_offset});
+        assemblyPV.addPhysVolID("ring", i + 1);
+        assemblies.emplace_back(std::move(assembly));
+    }
+    // std::cout << assemblies.size() << std::endl;
+
+    int modid = 1;
+    for (int ix = 0; ix < int(2.*rmax / modSize.x()) + 1; ++ix) {
+        double mx = modSize.x() * ix - rmax;
+        for (int iy = 0; iy < int(2.*rmax / modSize.y()) + 1; ++iy) {
+            double my = modSize.y() * iy - rmax;
+            double mr = std::sqrt(mx*mx + my*my);
+            if (mr - modSizeR >= rmin && mr + modSizeR <= rmax) {
+                int ias = int((mr - rmin) / assembly_rwidth);
+                auto &assembly = assemblies[ias];
+                auto modPV = assembly.placeVolume(modVol, Position(mx, my, 0.));
+                modPV.addPhysVolID("module", modid++);
+            }
+        }
+    }
+
+    desc.add(Constant(detName + "_NModules", std::to_string(modid - 1)));
+
+    for (auto &assembly : assemblies) {
+        assembly.ptr()->Voxelize("");
+    }
+
+    // detector position and rotation
+    auto pos = get_xml_xyz(detElem, _Unicode(position));
+    auto rot = get_xml_xyz(detElem, _Unicode(rotation));
+    Volume motherVol = desc.pickMotherVolume(det);
+    Transform3D tr = Translation3D(pos.x(), pos.y(), pos.z()) * RotationZYX(rot.z(), rot.y(), rot.x());
+    PlacedVolume envPV = motherVol.placeVolume(env, tr);
+    envPV.addPhysVolID("system", detID);
+    det.setPlacement(envPV);
+    return det;
+}
+
+// helper function to build module with scintillating fibers
+std::tuple<Volume, Position> build_module(const Detector &desc, const xml::Component &mod_x, SensitiveDetector &sens)
+{
+    auto sx = mod_x.attr<double>(_Unicode(sizex));
+    auto sy = mod_x.attr<double>(_Unicode(sizey));
+    auto sz = mod_x.attr<double>(_Unicode(sizez));
+
+    Box modShape(sx/2., sy/2., sz/2.);
+    auto modMat = desc.material(mod_x.attr<std::string>(_Unicode(material)));
+    Volume modVol("module_vol", modShape, modMat);
+    if (mod_x.hasAttr(_Unicode(vis))) {
+        modVol.setVisAttributes(desc.visAttributes(mod_x.attr<std::string>(_Unicode(vis))));
+    }
+
+    if (mod_x.hasChild("fiber")) {
+      auto fiber_x  = mod_x.child(_Unicode(fiber));
+      auto fr       = fiber_x.attr<double>(_Unicode(radius));
+      auto fsx      = fiber_x.attr<double>(_Unicode(spacex));
+      auto fsy      = fiber_x.attr<double>(_Unicode(spacey));
+      auto foff     = dd4hep::getAttrOrDefault<double>(fiber_x, _Unicode(offset), 0.5*mm);
+      auto fiberMat = desc.material(fiber_x.attr<std::string>(_Unicode(material)));
+      Tube fiberShape(0., fr, sz/2.);
+      Volume fiberVol("fiber_vol", fiberShape, fiberMat);
+      fiberVol.setSensitiveDetector(sens);
+
+      // Fibers are placed in a honeycomb with the radius = sqrt(3)/2. * hexagon side length
+      // So each fiber is fully contained in a regular hexagon, which are placed as
+      //           ______________________________________
+      //           |          ____        ____          |
+      // even:     |         /    \      /    \         |
+      //           |    ____/      \____/      \____    |
+      //           |   /    \      /    \      /    \   |
+      // odd:      |  /      \____/      \____/      \  |
+      //           |  \      /    \      /    \      /  |
+      //           |   \____/      \____/      \____/   |
+      // even:     |        \      /    \      /        |
+      //           |         \____/      \____/      ___|___
+      //           |____________________________________|___offset
+      //                                              | |
+      //                                              |offset
+      // the parameters space x and space y are used to add additional spaces between the hexagons
+      double fside  = 2. / std::sqrt(3.) * fr;
+      double fdistx = 2. * fside + fsx;
+      double fdisty = 2. * fr + fsy;
+
+      // maximum numbers of the fibers, help narrow the loop range
+      int nx = int(sx / (2.*fr)) + 1;
+      int ny = int(sy / (2.*fr)) + 1;
+
+      // std::cout << sx << ", " << sy << ", " << fr << ", " << nx << ", " << ny << std::endl;
+
+      // place the fibers
+      double y0 = (foff + fside);
+      int nfibers = 0;
+      for (int iy = 0; iy < ny; ++iy) {
+          double y = y0 + fdisty * iy;
+          // about to touch the boundary
+          if ((sy - y) < y0) { break; }
+          double x0 = (iy % 2) ? (foff + fside) : (foff + fside + fdistx / 2.);
+          for (int ix = 0; ix < nx; ++ix) {
+              double x = x0 + fdistx * ix;
+              // about to touch the boundary
+              if ((sx - x) < x0) { break; }
+              auto fiberPV = modVol.placeVolume(fiberVol, nfibers++, Position{x - sx/2., y - sy/2., 0});
+              //std::cout << "(" << ix << ", " << iy << ", " << x - sx/2. << ", " << y - sy/2. << ", " << fr << "),\n";
+              fiberPV.addPhysVolID("fiber_x", ix + 1).addPhysVolID("fiber_y", iy + 1);
+          }
+      }
+    // if no fibers we make the module itself sensitive
+    } else {
+      modVol.setSensitiveDetector(sens);
+    }
+
+
+    return std::make_tuple(modVol, Position{sx, sy, sz});
+}
+
+DECLARE_DETELEMENT(ScFiCalorimeter, create_detector)
+

src/SimpleDiskTracker_geo.cpp → src/SimpleDiskDetector_geo.cpp

@@ -15,14 +15,20 @@
 //
 //==========================================================================
 #include "DD4hep/DetFactoryHelper.h"
+
+#if defined(USE_ACTSDD4HEP)
+#include "ActsDD4hep/ActsExtension.hpp"
+#include "ActsDD4hep/ConvertMaterial.hpp"
+#else
 #include "Acts/Plugins/DD4hep/ActsExtension.hpp"
 #include "Acts/Plugins/DD4hep/ConvertDD4hepMaterial.hpp"
+#endif
 
 using namespace std;
 using namespace dd4hep;
 using namespace dd4hep::detail;
 
-static Ref_t create_detector(Detector& description, xml_h e, SensitiveDetector sens)
+static Ref_t SimpleDiskDetector_create_detector(Detector& description, xml_h e, SensitiveDetector sens)
 {
   xml_det_t      x_det    = e;
   Material       air      = description.air();
@@ -126,6 +132,5 @@ static Ref_t create_detector(Detector& description, xml_h e, SensitiveDetector s
   return sdet;
 }
 
-DECLARE_DETELEMENT(athena_SimpleDiskTracker, create_detector)
-DECLARE_DETELEMENT(ref_DiskTracker, create_detector)
-DECLARE_DETELEMENT(ref_SolenoidEndcap, create_detector)
+DECLARE_DETELEMENT(ref_SolenoidEndcap, SimpleDiskDetector_create_detector)
+DECLARE_DETELEMENT(athena_SolenoidEndcap, SimpleDiskDetector_create_detector)

src/SimpleRectangularTracker_geo.cpp

-//==========================================================================
-//  AIDA Detector description implementation 
-//--------------------------------------------------------------------------
-// Copyright (C) Organisation europeenne pour la Recherche nucleaire (CERN)
-// All rights reserved.
-//
-// For the licensing terms see $DD4hepINSTALL/LICENSE.
-// For the list of contributors see $DD4hepINSTALL/doc/CREDITS.
-//
-// Author     : M.Frank
-// Modified   : W.Armstrong
-//
-//==========================================================================
-//
-// Specialized generic detector constructor
-// 
-//==========================================================================
-#include "DD4hep/DetFactoryHelper.h"
-
-using namespace std;
-using namespace dd4hep;
-using namespace dd4hep::detail;
-
-static Ref_t create_detector(Detector& description, xml_h e, SensitiveDetector sens)  {
-  xml_det_t  x_det     = e;
-  Material   air       = description.air();
-  string     det_name  = x_det.nameStr();
-  bool       reflect   = x_det.reflect();
-  DetElement sdet(det_name,x_det.id());
-  Assembly   assembly(det_name);
-  PlacedVolume pv;
-  int l_num = 0;
-  xml::Component  pos  = x_det.position();
-
-  for(xml_coll_t i(x_det,_U(layer)); i; ++i, ++l_num)  {
-    xml_comp_t x_layer    = i;
-    string     l_nam      = det_name + _toString(l_num, "_layer%d");
-    double     x_lay      = x_layer.x();
-    double     y_lay      = x_layer.y();
-    double     z          = 0;
-    double     zmin       = 0;
-    double     layerWidth = 0.;
-    int        s_num      = 0;
-    for(xml_coll_t j(x_layer,_U(slice)); j; ++j)  {
-      double thickness = xml_comp_t(j).thickness();
-      layerWidth += thickness;
-    }
-    Box    l_box(x_lay/2.0, y_lay/2.0, layerWidth/2.0 );
-    Volume l_vol(l_nam, l_box, air);
-    l_vol.setVisAttributes(description, x_layer.visStr());
-    for (xml_coll_t j(x_layer, _U(slice)); j; ++j, ++s_num) {
-      xml_comp_t x_slice = j;
-      double     thick   = x_slice.thickness();
-      Material   mat     = description.material(x_slice.materialStr());
-      string     s_nam   = l_nam + _toString(s_num, "_slice%d");
-      Volume     s_vol(s_nam, Box(x_lay/2.0, y_lay/2.0, thick/2.0), mat);
-      if (x_slice.isSensitive()) {
-        sens.setType("tracker");
-        s_vol.setSensitiveDetector(sens);
-      }
-      s_vol.setAttributes(description, x_slice.regionStr(), x_slice.limitsStr(), x_slice.visStr());
-      pv = l_vol.placeVolume(s_vol, Position(0, 0, z - zmin - layerWidth / 2 + thick / 2));
-      pv.addPhysVolID("slice", s_num);
-    }
-
-    DetElement layer(sdet,l_nam+"_pos",l_num);
-    pv = assembly.placeVolume(l_vol,Position(0,0,zmin+layerWidth/2.));
-    pv.addPhysVolID("layer",l_num);
-    pv.addPhysVolID("barrel",1);
-    layer.setPlacement(pv);
-    if ( reflect )  {
-      pv = assembly.placeVolume(l_vol,Transform3D(RotationY(M_PI),Position(0,0,-zmin-layerWidth/2)));
-      pv.addPhysVolID("layer",l_num);
-      pv.addPhysVolID("barrel",2);
-      DetElement layerR = layer.clone(l_nam+"_neg");
-      sdet.add(layerR.setPlacement(pv));
-    }
-  }
-  if ( x_det.hasAttr(_U(combineHits)) ) {
-    sdet.setCombineHits(x_det.attr<bool>(_U(combineHits)),sens);
-  }
-  pv = description.pickMotherVolume(sdet).placeVolume(assembly,Position(pos.x(),pos.y(),pos.z()));
-  pv.addPhysVolID("system", x_det.id());      // Set the subdetector system ID.
-  sdet.setPlacement(pv);
-  return sdet;
-}
-
-DECLARE_DETELEMENT(ref_RectangularTracker,create_detector)