VTK/Examples/Cxx/IO/ReadUnknownTypeXMLFile

#include <vtkSmartPointer.h>
#include <vtkPolyData.h>
#include <vtkUnstructuredGrid.h>
#include <vtkDataSetMapper.h>
#include <vtkActor.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkXMLGenericDataObjectReader.h>
 
int main(int argc, char *argv[])
{
  // Ensure a filename was specified
  if(argc < 2)
    {
    std::cerr << "Required arguments: InputFilename" << std::endl;
    return EXIT_FAILURE;
    }
 
  // Get the filename from the command line
  std::string inputFilename = argv[1];
 
  // Get all data from the file
  vtkSmartPointer<vtkXMLGenericDataObjectReader> reader =
    vtkSmartPointer<vtkXMLGenericDataObjectReader>::New();
  reader->SetFileName(inputFilename.c_str());
  reader->Update();
 
  // All of the standard data types can be checked and obtained like this:
  if(vtkPolyData::SafeDownCast(reader->GetOutput()))
    {
    std::cout << "File is a polydata" << std::endl;
    }
  else if(vtkUnstructuredGrid::SafeDownCast(reader->GetOutput()))
    {
    std::cout << "File is an unstructured grid" << std::endl;
    }
 
  // Visualize
  vtkSmartPointer<vtkDataSetMapper> mapper =
    vtkSmartPointer<vtkDataSetMapper>::New();
  mapper->SetInputConnection(reader->GetOutputPort());
 
  vtkSmartPointer<vtkActor> actor =
    vtkSmartPointer<vtkActor>::New();
  actor->SetMapper(mapper);
 
  vtkSmartPointer<vtkRenderer> renderer =
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);
  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetRenderWindow(renderWindow);
 
  renderer->AddActor(actor);
  renderer->SetBackground(.3, .6, .3); // Background color green
 
  renderWindow->Render();
  renderWindowInteractor->Start();
 
  return EXIT_SUCCESS;
}