VTK/Examples/Cxx/PolyData/PolyDataIsoLines

PolyDataIsoLines.cxx

#include <vtkSmartPointer.h>
#include <vtkCellArray.h>
#include <vtkFloatArray.h>
#include <vtkPointData.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkXMLPolyDataReader.h>
#include <vtkXMLPolyDataWriter.h>
#include <vtkCamera.h>
#include <vtkBandedPolyDataContourFilter.h>
 
int main(int argc, char *argv[])
{
  // Parse command line arguments
  if(argc != 2)
    {
    std::cout << "Required arguments: Filename" << std::endl;
    return EXIT_FAILURE;
    }

  vtkSmartPointer<vtkXMLPolyDataReader> reader = 
      vtkSmartPointer<vtkXMLPolyDataReader>::New();
  reader->SetFileName(argv[1]);
  reader->Update();
  
  //float range[2];
  double range[2];
  reader->GetOutput()->GetPointData()->GetScalars()->GetRange(range);
  //std::cout << "Range: " << range[0] << " , " << range[1] << std::endl;
  
  vtkSmartPointer<vtkBandedPolyDataContourFilter> bf = 
    vtkSmartPointer<vtkBandedPolyDataContourFilter>::New();
  bf->SetInputConnection(reader->GetOutputPort());
  int numContours = 30;
  bf->GenerateValues(numContours, range);
  bf->GenerateContourEdgesOn();
  bf->Update();
  
  // Color the contours
  bf->GetOutput(1)->GetPointData()->SetScalars(bf->GetOutput()->GetPointData()->GetScalars());

  // Make sure the mapper uses the new colors
  bf->GetOutput(0)->GetPointData()->SetActiveScalars("Scalars");

  {
  vtkSmartPointer<vtkXMLPolyDataWriter> writer = 
    vtkSmartPointer<vtkXMLPolyDataWriter>::New();
  writer->SetInputConnection(bf->GetOutputPort());
  writer->SetFileName("output.vtp");
  writer->Update();
  }
  
  {
  vtkSmartPointer<vtkXMLPolyDataWriter> writer = 
    vtkSmartPointer<vtkXMLPolyDataWriter>::New();
  writer->SetInputConnection(bf->GetOutputPort(1));
  writer->SetFileName("ContourEdges.vtp");
  writer->Update();
  }
  
  /*
  // See which isocontours are being generated
  double values[10];
  bf->GetValues(values);
  for(unsigned int i = 0; i < 10; i++)
    {
    cout << values[i] << " ";
    }
  cout << endl;
  */
  
  
  // Color actor
  vtkSmartPointer<vtkPolyDataMapper> colorMapper = 
    vtkSmartPointer<vtkPolyDataMapper>::New();
  colorMapper->SetInputConnection(bf->GetOutputPort(0));
  colorMapper->SetScalarRange(range);

  vtkSmartPointer<vtkActor> colorActor = 
    vtkSmartPointer<vtkActor>::New();
  colorActor->SetMapper(colorMapper);
  
  // Edge actor
  vtkSmartPointer<vtkPolyDataMapper> edgeMapper = 
    vtkSmartPointer<vtkPolyDataMapper>::New();
  edgeMapper->SetInputConnection(bf->GetOutputPort(1));
  edgeMapper->SetScalarRange(range);

  vtkSmartPointer<vtkActor> edgeActor = 
      vtkSmartPointer<vtkActor>::New();
  edgeActor->SetMapper(edgeMapper);

  // Create the RenderWindow, Renderer and both Actors

  vtkSmartPointer<vtkRenderer> renderer = 
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow = 
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);
  vtkSmartPointer<vtkRenderWindowInteractor> interactor = 
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  interactor->SetRenderWindow(renderWindow);

  // Add the actors to the renderer
  renderer->AddActor(colorActor);
  renderer->AddActor(edgeActor);
  
  renderWindow->Render();
  
  interactor->Start();
  
  return EXIT_SUCCESS;
}

Please try the new VTKExamples website.

CMakeLists.txt

cmake_minimum_required(VERSION 2.8)

PROJECT(PolyDataIsoLines)

find_package(VTK REQUIRED)
include(${VTK_USE_FILE})

add_executable(PolyDataIsoLines MACOSX_BUNDLE PolyDataIsoLines.cxx)

if(VTK_LIBRARIES)
  target_link_libraries(PolyDataIsoLines ${VTK_LIBRARIES})
else()
  target_link_libraries(PolyDataIsoLines vtkHybrid vtkWidgets)
endif()

Download and Build PolyDataIsoLines

Click here to download PolyDataIsoLines. and its CMakeLists.txt file.

Once the tarball PolyDataIsoLines.tar has been downloaded and extracted,

cd PolyDataIsoLines/build 

• If VTK is installed:

cmake ..

• If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:

cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

Build the project:

make

and run it:

./PolyDataIsoLines

WINDOWS USERS PLEASE NOTE: Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.