refactor: Replace ParticleSmearing with TrackParameterSmearing in Examples

CI/physmon/workflows/physmon_trackfinding_1muon.py

@@ -18,7 +18,7 @@
 
 from acts.examples.reconstruction import (
     addSeeding,
-    ParticleSmearingSigmas,
+    TrackSmearingSigmas,
     SeedFinderConfigArg,
     SeedFinderOptionsArg,
     SeedingAlgorithm,
@@ -91,15 +91,15 @@ def run_ckf_tracking(label, seeding):
             s,
             setup.trackingGeometry,
             setup.field,
-            ParticleSmearingSigmas(  # only used by SeedingAlgorithm.TruthSmeared
+            TrackSmearingSigmas(  # only used by SeedingAlgorithm.TruthSmeared
                 # zero eveything so the CKF has a chance to find the measurements
-                d0=0,
-                d0PtA=0,
-                d0PtB=0,
-                z0=0,
-                z0PtA=0,
-                z0PtB=0,
-                t0=0,
+                loc0=0,
+                loc0PtA=0,
+                loc0PtB=0,
+                loc1=0,
+                loc1PtA=0,
+                loc1PtB=0,
+                time=0,
                 phi=0,
                 theta=0,
                 ptRel=0,

Examples/Algorithms/Generators/ActsExamples/Generators/EventGenerator.cpp

@@ -8,14 +8,19 @@
 
 #include "ActsExamples/Generators/EventGenerator.hpp"
 
+#include "Acts/Surfaces/PerigeeSurface.hpp"
 #include "ActsExamples/EventData/SimVertex.hpp"
+#include "ActsExamples/EventData/Track.hpp"
 #include "ActsExamples/Framework/AlgorithmContext.hpp"
 #include "ActsFatras/EventData/Barcode.hpp"
 #include "ActsFatras/EventData/Particle.hpp"
 
 #include <limits>
+#include <memory>
+#include <optional>
 #include <ostream>
 #include <stdexcept>
+#include <unordered_map>
 
 ActsExamples::EventGenerator::EventGenerator(const Config& cfg,
                                              Acts::Logging::Level lvl)
@@ -35,6 +40,7 @@ ActsExamples::EventGenerator::EventGenerator(const Config& cfg,
 
   m_outputParticles.initialize(m_cfg.outputParticles);
   m_outputVertices.initialize(m_cfg.outputVertices);
+  m_outputTrackParameters.maybeInitialize(m_cfg.outputTrackParameters);
 }
 
 std::string ActsExamples::EventGenerator::name() const {
@@ -115,8 +121,40 @@ ActsExamples::ProcessCode ActsExamples::EventGenerator::read(
                       << " n_primary_vertices=" << nPrimaryVertices
                       << " n_particles=" << particles.size());
 
+  if (m_outputTrackParameters.isInitialized()) {
+    std::unordered_map<SimBarcode, std::shared_ptr<Acts::PerigeeSurface>>
+        perigeeSurfaces;
+
+    for (auto&& [vtxId, vtxParticles] : groupBySecondaryVertex(particles)) {
+      // a group contains at least one particle by construction. assume that all
+      // particles within the group originate from the same position and use it
+      // to as the reference position for the perigee frame.
+      auto perigee = Acts::Surface::makeShared<Acts::PerigeeSurface>(
+          vtxParticles.begin()->position());
+      perigeeSurfaces[vtxId] = perigee;
+    }
+
+    // create track parameters from the particles
+    TrackParametersContainer trackParameters;
+    for (const auto& particle : particles) {
+      const auto vtxId = particle.particleId().vertexId();
+      const auto particleHypothesis = particle.hypothesis();
+      const auto phi = Acts::VectorHelpers::phi(particle.direction());
+      const auto theta = Acts::VectorHelpers::theta(particle.direction());
+      const auto qOverP = particle.qOverP();
+      const auto time = particle.time();
+
+      trackParameters.emplace_back(
+          perigeeSurfaces.at(vtxId),
+          Acts::BoundVector{0, 0, phi, theta, qOverP, time}, std::nullopt,
+          particleHypothesis);
+    }
+    m_outputTrackParameters(ctx, std::move(trackParameters));
+  }
+
   // move generated event to the store
   m_outputParticles(ctx, std::move(particles));
   m_outputVertices(ctx, std::move(vertices));
+
   return ProcessCode::SUCCESS;
 }

Examples/Algorithms/Generators/ActsExamples/Generators/EventGenerator.hpp

@@ -12,13 +12,13 @@
 #include "Acts/Utilities/Logger.hpp"
 #include "ActsExamples/EventData/SimParticle.hpp"
 #include "ActsExamples/EventData/SimVertex.hpp"
+#include "ActsExamples/EventData/Track.hpp"
 #include "ActsExamples/Framework/DataHandle.hpp"
 #include "ActsExamples/Framework/IReader.hpp"
 #include "ActsExamples/Framework/ProcessCode.hpp"
 #include "ActsExamples/Framework/RandomNumbers.hpp"
 
 #include <cstddef>
-#include <functional>
 #include <memory>
 #include <string>
 #include <utility>
@@ -93,8 +93,11 @@ class EventGenerator final : public ActsExamples::IReader {
   struct Config {
     /// Name of the output particles collection.
     std::string outputParticles;
-    /// Name of the vertex collection.
+    /// Name of the output vertex collection.
     std::string outputVertices;
+    /// Optional. Name of the output track parameters collection.
+    std::string outputTrackParameters;
+
     /// List of generators that should be used to generate the event.
     std::vector<Generator> generators;
     /// The random number service.
@@ -123,6 +126,8 @@ class EventGenerator final : public ActsExamples::IReader {
   WriteDataHandle<SimParticleContainer> m_outputParticles{this,
                                                           "OutputParticles"};
   WriteDataHandle<SimVertexContainer> m_outputVertices{this, "OutputVertices"};
+  WriteDataHandle<TrackParametersContainer> m_outputTrackParameters{
+      this, "OutputTrackParameters"};
 };
 
 }  // namespace ActsExamples