Update PaalmanPingsAbsorptionCorrection (#39210)

* Update BeamProfileFactory

* Make requested changes

* Swapped integration volume and sample object when doing
Rasterize::calculate()

* Update PaalmanPings

* cppCheck and release notes

* fix whole sample illuminated by beam

* fix cppcheck

* address review comments

* fix cppcheck

* correct Raster::Calculate call

* fix cppcheck

* add comment for V3D comparison

* remove unused variable

---------

Co-authored-by: Daniel Caballero <dlcaballero16@gmail.com>

Author: searscr

Framework/Algorithms/inc/MantidAlgorithms/PaalmanPingsAbsorptionCorrection.h

@@ -10,6 +10,7 @@
 #include "MantidAPI/MatrixWorkspace_fwd.h"
 #include "MantidAlgorithms/DllConfig.h"
 #include "MantidGeometry/Objects/IObject.h"
+#include "MantidGeometry/Rasterize.h"
 #include "MantidKernel/Material.h"
 #include "MantidKernel/V3D.h"
 
@@ -73,6 +74,7 @@ class MANTID_ALGORITHMS_DLL PaalmanPingsAbsorptionCorrection final : public API:
   void defineProperties();
   void retrieveProperties();
   void initialiseCachedDistances();
+  Geometry::Raster rasterize(const Geometry::IObject *object);
 
   API::MatrixWorkspace_sptr m_inputWS;                  ///< A pointer to the input workspace
   const Geometry::IObject *m_sampleObject;              ///< Local cache of sample object.

Framework/Algorithms/src/PaalmanPingsAbsorptionCorrection.cpp

@@ -12,6 +12,7 @@
 #include "MantidAPI/SpectrumInfo.h"
 #include "MantidAPI/WorkspaceGroup.h"
 #include "MantidAPI/WorkspaceUnitValidator.h"
+#include "MantidAlgorithms/BeamProfileFactory.h"
 #include "MantidDataObjects/WorkspaceCreation.h"
 #include "MantidGeometry/IDetector.h"
 #include "MantidGeometry/Instrument.h"
@@ -35,6 +36,8 @@ using namespace Geometry;
 using HistogramData::interpolateLinearInplace;
 using namespace Kernel;
 using namespace Mantid::DataObjects;
+using Mantid::Algorithms::BeamProfileFactory;
+using Mantid::Geometry::Raster;
 
 namespace {
 // the maximum number of elements to combine at once in the pairwise summation
@@ -278,37 +281,46 @@ void PaalmanPingsAbsorptionCorrection::exec() {
   setProperty("OutputWorkspace", outWS);
 }
 
-/// Calculate the distances for L1 (for both self-absorption and
-/// absorption by other object) and element size for each element in
-/// the sample and container
-void PaalmanPingsAbsorptionCorrection::initialiseCachedDistances() {
-  // First, check if a 'gauge volume' has been defined. If not, it's the same as
-  // the sample.
-  auto integrationVolume = std::shared_ptr<const IObject>(m_sampleObject->clone());
+Raster PaalmanPingsAbsorptionCorrection::rasterize(const IObject *object) {
+  IObject_const_sptr integrationVolume;
   if (m_inputWS->run().hasProperty("GaugeVolume")) {
     integrationVolume = constructGaugeVolume();
+  } else {
+    try {
+      auto beamProfile = BeamProfileFactory::createBeamProfile(*m_inputWS->getInstrument(), Mantid::API::Sample());
+      integrationVolume = beamProfile->getIntersectionWithSample(*object);
+    } catch (const std::invalid_argument &) {
+      // If createBeamProfile fails, the beam parameters are not defined
+      // If getIntersectionWithSample fails, the beam misses the object
+      // In either case we will just fall back to using the whole sample below.
+    }
+    if (integrationVolume == nullptr) {
+      // If the beam profile is not defined, use the sample object
+      integrationVolume = std::shared_ptr<const IObject>(object->clone());
+    }
   }
 
-  auto raster = Geometry::Rasterize::calculate(m_beamDirection, *integrationVolume, *m_sampleObject, m_cubeSideSample);
+  return Geometry::Rasterize::calculate(m_beamDirection, *integrationVolume, *object, m_cubeSideSample);
+}
+
+/// Calculate the distances for L1 (for both self-absorption and
+/// absorption by other object) and element size for each element in
+/// the sample and container
+void PaalmanPingsAbsorptionCorrection::initialiseCachedDistances() {
+  auto raster = rasterize(m_sampleObject);
   m_sampleVolume = raster.totalvolume;
   if (raster.l1.size() == 0)
-    throw std::runtime_error("Failed to rasterize shape");
+    throw std::runtime_error("Failed to rasterize sample shape");
   // move over the information
   m_numSampleVolumeElements = raster.l1.size();
   m_sampleL1s = std::move(raster.l1);
   m_sampleElementPositions = std::move(raster.position);
   m_sampleElementVolumes = std::move(raster.volume);
-
   // now for the container
-  integrationVolume = std::shared_ptr<const IObject>(m_containerObject->clone());
-  if (m_inputWS->run().hasProperty("GaugeVolume")) {
-    integrationVolume = constructGaugeVolume();
-  }
-
-  raster = Geometry::Rasterize::calculate(m_beamDirection, *integrationVolume, *m_containerObject, m_cubeSideContainer);
+  raster = rasterize(m_containerObject);
   m_containerVolume = raster.totalvolume;
   if (raster.l1.size() == 0)
-    throw std::runtime_error("Failed to rasterize shape");
+    throw std::runtime_error("Failed to rasterize container shape");
   // move over the information
   m_numContainerVolumeElements = raster.l1.size();
   m_containerL1s = std::move(raster.l1);

Framework/Algorithms/src/SampleCorrections/IBeamProfile.cpp

@@ -80,10 +80,17 @@ Geometry::IObject_sptr IBeamProfile::getIntersectionWithSample(const Geometry::I
 
   try {
     intersectionBox = defineActiveRegion(sampleBB);
-  } catch (...) {
+  } catch (const std::invalid_argument &) {
+    // Exception means the beam missed the object and cannot create an intersection BoundingBox
     return nullptr;
   }
 
+  // If the intersection volume is the same as the sample volume use the sample volume instead of creating a new shape
+  // V3D operator== comparison is done with a 1.0e-6 tolerance
+  if ((sampleBB.minPoint() == intersectionBox.minPoint()) && (sampleBB.maxPoint() == intersectionBox.maxPoint())) {
+    return std::shared_ptr<Geometry::IObject>(sample.clone());
+  }
+
   double yExtent = intersectionBox.yMax() - intersectionBox.yMin();
   double xExtent = intersectionBox.xMax() - intersectionBox.xMin();
   double zExtent = intersectionBox.zMax() - intersectionBox.zMin();

Framework/Algorithms/test/IBeamProfileTest.h

@@ -183,6 +183,6 @@ class IBeamProfileTest : public CxxTest::TestSuite {
     const auto beamProfile = BeamProfileFactory::createBeamProfile(*experiment->getInstrument(), experiment->sample());
     const auto intersectionVolume = beamProfile->getIntersectionWithSample(*sample);
 
-    checkIntersectionVolume(intersectionVolume, 5., 20, 5.);
+    checkIntersectionVolume(intersectionVolume, 5., 20., 5.);
   }
 };