diff --git a/GUI/Views/RealSpaceWidgets/RealSpaceBuilder.cpp b/GUI/Views/RealSpaceWidgets/RealSpaceBuilder.cpp
index 26c107eb49b4f21610385b3062b688627b2e22c4..455a597a92a54c295f4bb2611d8b179ae472d92c 100644
--- a/GUI/Views/RealSpaceWidgets/RealSpaceBuilder.cpp
+++ b/GUI/Views/RealSpaceWidgets/RealSpaceBuilder.cpp
@@ -33,16 +33,28 @@
 #include <QDebug>
 
 namespace {
-std::unique_ptr<IInterference> GetInterference(const ParticleLayoutItem& layoutItem);
+
+std::unique_ptr<IInterference> GetInterference(const ParticleLayoutItem& layoutItem)
+{
+    auto interferenceItem = layoutItem.interference();
+    if (interferenceItem) {
+        auto P_interference = interferenceItem->createInterference();
+        if (P_interference)
+            return std::unique_ptr<IInterference>(P_interference.release());
+    }
+    return std::make_unique<InterferenceNone>();
 }
 
+} // namespace
+
+
 RealSpaceBuilder::RealSpaceBuilder(QWidget* parent) : QWidget(parent) {}
 
 RealSpaceBuilder::~RealSpaceBuilder() = default;
 
 void RealSpaceBuilder::populate(RealSpaceModel* model, const SessionItem& item,
                                 const SceneGeometry& sceneGeometry,
-                                const GUI::RealSpace::Camera::Position& cameraPosition)
+                                const GUI::RealSpace::Camera::Position& cameraPosition) const
 {
     // default value of cameraPosition is in RealSpaceBuilder.h
 
@@ -57,15 +69,14 @@ void RealSpaceBuilder::populate(RealSpaceModel* model, const SessionItem& item,
     else if (item.hasModelType<ParticleLayoutItem>())
         populateLayout(model, dynamic_cast<const ParticleLayoutItem&>(item), sceneGeometry);
 
-    else if (item.hasModelType<ParticleItem>()
-             || item.hasModelType<ParticleCompositionItem>()
-             || item.hasModelType<ParticleCoreShellItem>()
-             || item.hasModelType<MesoCrystalItem>())
+    else if (item.hasModelType<ParticleItem>() || item.hasModelType<ParticleCompositionItem>()
+             || item.hasModelType<ParticleCoreShellItem>() || item.hasModelType<MesoCrystalItem>())
         populateParticleFromParticleItem(model, item);
 }
 
 void RealSpaceBuilder::populateMultiLayer(RealSpaceModel* model, const MultiLayerItem& mlayerItem,
-                                          const SceneGeometry& sceneGeometry, const QVector3D&)
+                                          const SceneGeometry& sceneGeometry,
+                                          const QVector3D&) const
 {
     double total_height(0.0);
     int index(0);
@@ -95,8 +106,8 @@ void RealSpaceBuilder::populateLayer(RealSpaceModel* model, const LayerItem& lay
 }
 
 void RealSpaceBuilder::populateLayout(RealSpaceModel* model, const ParticleLayoutItem& layoutItem,
-                                      const SceneGeometry& sceneGeometry, const QVector3D& origin)
-    const
+                                      const SceneGeometry& sceneGeometry,
+                                      const QVector3D& origin) const
 {
     // If there is no particle to populate
     if (layoutItem.particles().empty())
@@ -171,16 +182,3 @@ void RealSpaceBuilder::populateParticleFromParticle3DContainer(
         }
     }
 }
-
-namespace {
-std::unique_ptr<IInterference> GetInterference(const ParticleLayoutItem& layoutItem)
-{
-    auto interferenceItem = layoutItem.interference();
-    if (interferenceItem) {
-        auto P_interference = interferenceItem->createInterference();
-        if (P_interference)
-            return std::unique_ptr<IInterference>(P_interference.release());
-    }
-    return std::make_unique<InterferenceNone>();
-}
-} // namespace
diff --git a/GUI/Views/RealSpaceWidgets/RealSpaceBuilder.h b/GUI/Views/RealSpaceWidgets/RealSpaceBuilder.h
index 8b107472807ed3e122b8ade9e6bb4ed45aaa01d1..57d2ea8d81ae7b04d4d2fe8cc9b88fa9e98eb15a 100644
--- a/GUI/Views/RealSpaceWidgets/RealSpaceBuilder.h
+++ b/GUI/Views/RealSpaceWidgets/RealSpaceBuilder.h
@@ -41,10 +41,10 @@ public:
              const GUI::RealSpace::Camera::Position& cameraPosition =
                  GUI::RealSpace::Camera::Position(GUI::RealSpace::Vector3D(0, -200, 120), // eye
                                                   GUI::RealSpace::Vector3D(0, 0, 0),      // center
-                                                  GUI::RealSpace::Vector3D::_z));         // up
-
+                                                  GUI::RealSpace::Vector3D::_z))          // up
+        const;
     void populateMultiLayer(RealSpaceModel* model, const MultiLayerItem& mlayerItem,
-                            const SceneGeometry& sceneGeometry, const QVector3D& origin = {});
+                            const SceneGeometry& sceneGeometry, const QVector3D& origin = {}) const;
 
     void populateLayer(RealSpaceModel* model, const LayerItem& layerItem,
                        const SceneGeometry& sceneGeometry, const QVector3D& origin = {},