Tweaks for VTK RectilinearGrid import

Modules/LemmaCore/include/RectilinearGridVTKImporter.h

 
         /**
          *  Performs the actual grid conversion
+         *  @param[in] xshift is additional offset to apply in x direction.
+         *  @param[in] yshift is additional offset to apply in y direction.
+         *  @param[in] zshift is additional offset to apply in z direction.
          */
-        void ConvertGrid( );
+        void ConvertGrid( const Real& xshift, const Real& yshift, const Real& zshift );
 
+        /**
+         *  @return smart pointer to RectilinearGrid class
+         */
+        std::shared_ptr<RectilinearGrid> GetGrid() {
+            return this->rGrid;
+        }
 
         // ====================  INQUIRY       =======================
         /**
         /** VTK file to import */
         vtkSmartPointer<vtkRectilinearGrid> vtkGrid;
 
-        std::shared_ptr<RectilinearGrid>  rGrid;
+        /** container to hold imported grid */
+        std::shared_ptr<RectilinearGrid>  rGrid = nullptr;
 
     }; // -----  end of class  RectilinearGridVTKImporter  -----
 

Modules/LemmaCore/src/RectilinearGridVTKImporter.cpp

     //       Class:  RectilinearGridVTKImporter
     //      Method:  ConvertGrid
     //--------------------------------------------------------------------------------------
-    void RectilinearGridVTKImporter::ConvertGrid (  ) {
+    void RectilinearGridVTKImporter::ConvertGrid ( const Real& shiftx, const Real& shifty, const Real& shiftz  ) {
+
         rGrid = RectilinearGrid::NewSP();
 
         int dims[3];
         }
 
         rGrid->SetDimensions( dims[0], dims[1], dims[2] );
-        rGrid->SetOffset( xcoords->GetTuple1(0), ycoords->GetTuple1(0), zcoords->GetTuple1(0) );
+        rGrid->SetOffset( xcoords->GetTuple1(0)+shiftx, ycoords->GetTuple1(0)+shifty, zcoords->GetTuple1(0)+shiftz );
         rGrid->SetSpacing( dx, dy, dz  );
 
         return ;