Remove physics only invisible objects after joining

src/tracks/track.cpp

@@ -2149,7 +2149,15 @@ void Track::loadTrackModel(bool reverse_track, unsigned int mode_id)
     for (auto* to : m_track_object_manager->getObjects().m_contents_vector)
     {
         if (to->joinToMainTrack())
+        {
             m_track_object_manager->removeDriveableObject(to);
+            TrackObjectPresentationSceneNode* ts =
+                to->getPresentation<TrackObjectPresentationSceneNode>();
+            // physicial only node is always hidden, remove it from stk after
+            // joining to track mesh
+            if (ts && ts->isAlwaysHidden())
+                m_track_object_manager->removeObject(to);
+        }
     }
 
     createPhysicsModel(main_track_count);

src/tracks/track_object_presentation.hpp

@@ -147,6 +147,7 @@ public:
         TrackObjectPresentation(xyz, hpr, scale)
     {
         m_node = node;
+        m_force_always_hidden = false;
     }   // TrackObjectPresentationSceneNode
 
     // ------------------------------------------------------------------------
@@ -166,6 +167,8 @@ public:
     // ------------------------------------------------------------------------
     /** Returns a pointer to the scene node, const version. */
     const scene::ISceneNode* getNode() const { return m_node; }
+    // ------------------------------------------------------------------------
+    bool isAlwaysHidden() const { return m_force_always_hidden; }
 };   // class TrackObjectPresentationSceneNode
 
 // ============================================================================