VTK/Examples/Cxx/Filtering/AppendFilter

#include <vtkVersion.h>
#include <vtkSmartPointer.h>
 
#include <vtkActor.h>
#include <vtkAppendFilter.h>
#include <vtkDataSetMapper.h>
#include <vtkPointSource.h>
#include <vtkPoints.h>
#include <vtkPolyData.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkUnstructuredGrid.h>
 
int main(int, char *[])
{
  // Create 5 points (vtkPolyData)
  vtkSmartPointer<vtkPointSource> pointSource =
    vtkSmartPointer<vtkPointSource>::New();
  pointSource->SetNumberOfPoints(5);
  pointSource->Update();
 
  vtkSmartPointer<vtkPolyData> polydata = pointSource->GetOutput();
 
  std::cout << "There are " << polydata->GetNumberOfPoints()
            << " points in the polydata." << std::endl;
 
  // Create 2 points in a vtkUnstructuredGrid
 
  vtkSmartPointer<vtkPoints> points =
    vtkSmartPointer<vtkPoints>::New();
  points->InsertNextPoint(0,0,0);
  points->InsertNextPoint(0,0,1);
 
  vtkSmartPointer<vtkUnstructuredGrid> ug =
    vtkSmartPointer<vtkUnstructuredGrid>::New();
  ug->SetPoints(points);
 
  std::cout << "There are " << ug->GetNumberOfPoints()
            << " points in the unstructured grid." << std::endl;
 
  // Combine the two data sets
  vtkSmartPointer<vtkAppendFilter> appendFilter =
    vtkSmartPointer<vtkAppendFilter>::New();
#if VTK_MAJOR_VERSION <= 5
  appendFilter->AddInput(polydata);
  appendFilter->AddInput(ug);
#else
  appendFilter->AddInputData(polydata);
  appendFilter->AddInputData(ug);
#endif
  appendFilter->Update();
 
  vtkSmartPointer<vtkUnstructuredGrid> combined =
    appendFilter->GetOutput();
  std::cout << "There are " << combined->GetNumberOfPoints()
            << " points combined." << std::endl;
 
  // Create a mapper and actor
  vtkSmartPointer<vtkDataSetMapper> mapper =
    vtkSmartPointer<vtkDataSetMapper>::New();
  mapper->SetInputConnection(appendFilter->GetOutputPort());
 
  vtkSmartPointer<vtkActor> actor =
    vtkSmartPointer<vtkActor>::New();
  actor->SetMapper(mapper);
  actor->GetProperty()->SetPointSize(5);
 
  // Create a renderer, render window, and interactor
  vtkSmartPointer<vtkRenderer> renderer =
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);
  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetRenderWindow(renderWindow);
 
  // Add the actor to the scene
  renderer->AddActor(actor);
  renderer->SetBackground(.2, .3, .4);
 
  // Render and interact
  renderWindow->Render();
  renderWindowInteractor->Start();
 
  return EXIT_SUCCESS;
}