add frustum navigation

Core/include/Acts/Navigation/DetectorNavigator.hpp

@@ -19,6 +19,8 @@
 #include "Acts/Propagator/Propagator.hpp"
 #include "Acts/Surfaces/BoundaryCheck.hpp"
 #include "Acts/Surfaces/Surface.hpp"
+#include "Acts/Utilities/BoundingBox.hpp"
+#include "Acts/Utilities/Frustum.hpp"
 #include "Acts/Utilities/Logger.hpp"
 
 #include <iomanip>
@@ -30,12 +32,20 @@
 #include <boost/container/small_vector.hpp>
 
 namespace Acts::Experimental {
+  using Frustum3 = Acts::Frustum<Acts::ActsScalar, 3, 3>;
+  using BoundingBox =
+  Acts::AxisAlignedBoundingBox<DetectorVolume,
+                                Acts::ActsScalar, 3>;
 
 class DetectorNavigator {
  public:
   struct Config {
     /// Detector for this Navigation
     const Detector* detector = nullptr;
+     /// The octree for the world
+    const BoundingBox* topBox = nullptr;
+    /// The current frustum
+    std::shared_ptr<Frustum3> frustum = nullptr;
 
     /// Configuration for this Navigator
     /// stop at every sensitive surface (whether it has material or not)
@@ -44,6 +54,8 @@ class DetectorNavigator {
     bool resolveMaterial = true;
     /// stop at every surface regardless what it is
     bool resolvePassive = false;
+    /// using the frustum navigator
+    bool frustumNavigator = false;
   };
 
   /// Nested State struct
@@ -147,6 +159,16 @@ class DetectorNavigator {
     if (nState.currentDetector == nullptr) {
       ACTS_VERBOSE("Assigning detector from the config.");
       nState.currentDetector = m_cfg.detector;
+      if (m_cfg.frustumNavigator) {
+        if (!m_cfg.topBox) {
+            throw std::invalid_argument("DetectorNavigator: no octree assigned for frustum navigator");
+        }
+        ACTS_VERBOSE("Assigning top box of the octree for frustum navigator.");
+        nState.topBox = m_cfg.topBox;
+        nState.frustum = m_cfg.frustum;
+      } else if (m_cfg.topBox) {
+          throw std::invalid_argument("DetectorNavigator: octree assigned but frustum navigator not enabled");
+      }
     }
     if (nState.currentDetector == nullptr) {
       throw std::invalid_argument("DetectorNavigator: no detector assigned");

Core/include/Acts/Navigation/NavigationState.hpp

@@ -12,7 +12,9 @@
 #include "Acts/Definitions/Units.hpp"
 #include "Acts/Geometry/GeometryContext.hpp"
 #include "Acts/Surfaces/BoundaryCheck.hpp"
+#include "Acts/Utilities/BoundingBox.hpp"
 #include "Acts/Utilities/Delegate.hpp"
+#include "Acts/Utilities/Frustum.hpp"
 #include "Acts/Utilities/Intersection.hpp"
 
 #include <any>
@@ -21,13 +23,17 @@
 
 namespace Acts {
 
+using Frustum3 = Acts::Frustum<Acts::ActsScalar, 3, 3>;
 class Surface;
 
 namespace Experimental {
 
 class Portal;
 class Detector;
 class DetectorVolume;
+using BoundingBox =
+  Acts::AxisAlignedBoundingBox<DetectorVolume,
+                                Acts::ActsScalar, 3>;
 
 /// @brief A navigation state struct that is holding the current navigation information
 ///
@@ -80,6 +86,12 @@ struct NavigationState {
   /// The current portal, i.e the position is on portal
   const Portal* currentPortal = nullptr;
 
+  /// The octree for the world
+  const BoundingBox* topBox = nullptr;
+
+  /// The current frustum
+  std::shared_ptr<Frustum3> frustum = nullptr;
+
   /// That are the candidate surfaces to process
   SurfaceCandidates surfaceCandidates = {};
   std::size_t surfaceCandidateIndex = 0;

Core/include/Acts/Navigation/SurfaceCandidatesUpdaters.hpp

@@ -91,6 +91,65 @@ struct AllPortalsAndSurfacesImpl : public INavigationDelegate {
   }
 };
 
+struct FrustumNavigation : public IInternalNavigation {
+  /// The frustum navigation
+  ///
+  /// @param gctx is the Geometry context of this call
+  /// @param nState is the navigation state to be updated
+  ///
+  /// @note that the intersections are ordered, such that the
+  /// smallest intersection pathlength >= overstep tolerance is the lowest
+  ///
+  /// @return an ordered list of portal and surface candidates
+  inline void update(const GeometryContext& gctx,
+                     NavigationState& nState) const {
+    if (nState.currentDetector == nullptr) {
+      throw std::runtime_error(
+          "FrustumNavigation: no detector volume set to navigation state.");
+    }
+    // Create the frustum if it's not set
+    if (nState.frustum == nullptr) {
+      nState.frustum = std::make_shared<Frustum3>(nState.position, nState.direction, M_PI/4);
+    }
+    //Check if we leave the frustum, reset candidates if so
+    const auto& normals = nState.frustum->normals();
+    const bool outside = std::any_of(normals.begin(), normals.end(), [&nState](const auto& normal){
+      return (nState.position - nState.frustum->origin()).dot(normal) >= 0;});
+    if(outside){
+      nState.surfaceCandidates.clear();
+      nState.frustum = std::make_shared<Frustum3>(nState.position, nState.direction, M_PI/4);
+    }
+
+    // A volume switch has happened, or we left the frustum, update list of portals & surfaces
+    if (nState.surfaceCandidates.empty()) {
+      // Fill internal portals if existing
+      auto topBoxCopy = nState.topBox;
+      while(topBoxCopy){
+        if(topBoxCopy->intersect(*nState.frustum)){
+          if(topBoxCopy->hasEntity()){
+            const auto& portals = topBoxCopy->entity()->portals();
+            const auto& surfaces = topBoxCopy->entity()->surfaces();
+            PortalsFiller::fill(nState, portals);
+            SurfacesFiller::fill(nState, surfaces);
+            topBoxCopy = topBoxCopy->getSkip();
+          } else {
+              topBoxCopy = topBoxCopy->getLeftChild();
+            }  
+        } else {
+            topBoxCopy = topBoxCopy->getSkip();
+          }
+      } 
+    }
+    // Assign the new volume
+    const auto& portals = nState.currentVolume->portals();
+    const auto& surfaces = nState.currentVolume->surfaces();
+    PortalsFiller::fill(nState, portals);
+    SurfacesFiller::fill(nState, surfaces);
+    // Update internal candidates
+    updateCandidates(gctx, nState);
+  }
+};
+
 /// Generate a provider for all portals
 ///
 /// @return a connected navigationstate updator
@@ -114,6 +173,16 @@ inline static SurfaceCandidatesUpdater tryAllPortalsAndSurfaces() {
   return nStateUpdater;
 }
 
+/// Generate a provider for portals and surfaces inside a frustum
+///
+/// @return a connected navigationstate updator
+inline static InternalNavigationDelegate tryFrustumPortalsAndSurfaces() {
+  auto fr = std::make_unique<const FrustumNavigation>();
+  InternalNavigationDelegate nStateUpdater;
+  nStateUpdater.connect<&FrustumNavigation::update>(std::move(fr));
+  return nStateUpdater;
+}
+
 /// @brief This holds and extracts a collection of surfaces without much
 /// checking, this could be e.g. support surfaces for layer structures,
 /// e.g.