[Output] Raw VTK output

src/vtk.cc

@@ -43,7 +43,7 @@ void MyVTKWriter<VertexBasis, CellBasis>::write(
   writer.addCellData(stressPointer);
 
   std::string const filename = prefix + std::to_string(record);
-  writer.write(filename.c_str());
+  writer.write(filename.c_str(), Dune::VTK::appendedraw);
 }
 
 #include "vtk_tmpl.cc"