attach vtk context to gcompose

src/HEP/Geant/GeantEvent.h

@@ -26,6 +26,7 @@
 #ifndef U_GEANTEVENT_H
 #define U_GEANTEVENT_H
 
+#include "Core/Object.h"
 #include "Core/Types.h"
 #include "Core/Vector.h"
 #include "Math/Dense.h"
@@ -46,10 +47,12 @@ class SteppingAction;
 /// recording the change of momentum and direction at each step boundary.
 ///////////////////////////////////////////////////////////////////////////////
 
-class GeantEvent {
+class GeantEvent : public Object {
   
 public:
 
+  virtual const char* GetClassName() const override { return "Geant.GeantEvent"; }
+
   /// A single interaction step along the muon path.
   struct Delta {
     Scalarf     m_Length;     ///< step length through the solid