DataStructureComparison

VTKExamples/Cxx/DataStructures/DataStructureComparison


Description

Prior to August 20, 2010, the vtkModifiedBSPTree.cxx did not produce a proper data representation. To operate properly, update your vtk source tree.

Use the 'n' key (for 'N'ext) and the 'p' key (for 'P'revious) to navigate the levels of the trees.

Code

DataStructureComparison.cxx

#include <vtkVersion.h>
#include <vtkSmartPointer.h>
#include <vtkPointSource.h>
#include <vtkObjectFactory.h>
#include <vtkRendererCollection.h>
#include <vtkPolyData.h>
#include <vtkActor.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkPolyDataMapper.h>
#include <vtkXMLPolyDataReader.h>
#include <vtkSphereSource.h>
#include <vtkProperty.h>
#include <vtkCamera.h>
#include <vtkInteractorStyleTrackballCamera.h>

#include <vtkKdTreePointLocator.h>
#include <vtkOctreePointLocator.h>
#include <vtkOBBTree.h>
#include <vtkModifiedBSPTree.h>

#include <vector>

class KeyPressInteractorStyle : public vtkInteractorStyleTrackballCamera
{
  public:
    static KeyPressInteractorStyle* New();
    vtkSmartPointer<vtkPolyData> data;
    std::vector<vtkRenderer*> renderers;
    std::vector<vtkSmartPointer<vtkLocator> > trees;
    std::vector<vtkSmartPointer<vtkPolyDataMapper> > mappers;
    std::vector<vtkSmartPointer<vtkActor> > actors;

    vtkSmartPointer<vtkPolyDataMapper> meshMapper;
    vtkSmartPointer<vtkActor> meshActor;

    void Initialize()
    {
#if VTK_MAJOR_VERSION <= 5
      this->meshMapper->SetInputConnection(this->data->GetProducerPort());
#else
      this->meshMapper->SetInputData(this->data);
#endif
      for(unsigned int i = 0; i < 4; i++)
      {
    vtkSmartPointer<vtkPolyDataMapper> mapper =
      vtkSmartPointer<vtkPolyDataMapper>::New();
    this->mappers.push_back(mapper);
    vtkSmartPointer<vtkActor> actor =
      vtkSmartPointer<vtkActor>::New();
    actor->SetMapper(mapper);
    actor->GetProperty()->SetRepresentationToWireframe();
    this->actors.push_back(actor);
    this->renderers[i]->AddActor(actor);

        this->renderers[i]->AddActor(meshActor);
      }
      this->Level = 1;
      std::cout << "Level = " << this->Level << std::endl;
      this->ReDraw();
    }

    KeyPressInteractorStyle()
    {
      this->Level = 1;

      vtkSmartPointer<vtkLocator> tree0 = vtkSmartPointer<vtkKdTreePointLocator>::New();
      this->trees.push_back(tree0);
      vtkSmartPointer<vtkLocator> tree1 = vtkSmartPointer<vtkOBBTree>::New();
      this->trees.push_back(tree1);
      vtkSmartPointer<vtkLocator> tree2 = vtkSmartPointer<vtkOctreePointLocator>::New();
      this->trees.push_back(tree2);
      vtkSmartPointer<vtkLocator> tree3 = vtkSmartPointer<vtkModifiedBSPTree>::New();
      this->trees.push_back(tree3);

      this->meshMapper = vtkSmartPointer<vtkPolyDataMapper>::New();
      this->meshActor = vtkSmartPointer<vtkActor>::New();
      this->meshActor->SetMapper(this->meshMapper);

    }

    virtual void OnChar()
    {
      char ch = this->Interactor->GetKeyCode() ;

      switch (ch)
      {
        case 'n':
          this->Level++;
          break;
        case 'p':
          if(this->Level > 1)
          {
            this->Level--;
          }
          break ;
        default:
          std::cout << "An unhandled key was pressed." << std::endl;
          break;
      }

       this->ReDraw();

      // forward events
      if(ch != 'p') //don't forward the "pick" command
      {
    vtkInteractorStyleTrackballCamera::OnChar();
      }
    }

 void ReDraw()
 {

   std::cout << "Level " << this->Level << std::endl;
  for(unsigned i = 0; i < 4; i++)
  {

    vtkSmartPointer<vtkLocator> tree = this->trees[i];
    //vtkRenderer* renderer = this->renderers[i];

    tree->SetDataSet(data);
    tree->BuildLocator();

    vtkSmartPointer<vtkPolyData> polydata =
      vtkSmartPointer<vtkPolyData>::New();
    std::cout << "Tree " << i << " has " << tree->GetLevel() << " levels." << std::endl;

    if(this->Level > tree->GetLevel())
    {
      tree->GenerateRepresentation(tree->GetLevel(), polydata);
    }
    else
    {
      tree->GenerateRepresentation(this->Level, polydata);
    }

#if VTK_MAJOR_VERSION <= 5
    this->mappers[i]->SetInputConnection(polydata->GetProducerPort());
#else
    this->mappers[i]->SetInputData(polydata);
#endif
  }

    this->Interactor->GetRenderWindow()->Render();

 }

  private:
    int Level;

};

vtkStandardNewMacro(KeyPressInteractorStyle);

int main(int argc, char *argv[])
{
  vtkSmartPointer<vtkPolyData> originalMesh =
    vtkSmartPointer<vtkPolyData>::New();

  if(argc > 1) //If a file name is specified, open and use the file.
  {
    vtkSmartPointer<vtkXMLPolyDataReader> reader =
      vtkSmartPointer<vtkXMLPolyDataReader>::New();
    reader->SetFileName(argv[1]);
    reader->Update();
    originalMesh->ShallowCopy(reader->GetOutput());
  }
  else //If a file name is not specified, create a sphere
  {
    //vtkSmartPointer<vtkSphereSource> sphereSource =
      //vtkSmartPointer<vtkSphereSource>::New();
    vtkSmartPointer<vtkPointSource> sphereSource =
      vtkSmartPointer<vtkPointSource>::New();
      sphereSource->SetNumberOfPoints(1000);

    sphereSource->Update();
    originalMesh->ShallowCopy(sphereSource->GetOutput());
  }

  double numberOfViewports = 4.;

  vtkSmartPointer<vtkRenderWindow> renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->SetSize(200* numberOfViewports,200); //(width, height)
  renderWindow->SetWindowName("Multiple ViewPorts");

  vtkSmartPointer<KeyPressInteractorStyle> style =
    vtkSmartPointer<KeyPressInteractorStyle>::New();
  style->data = originalMesh;

  vtkSmartPointer<vtkCamera> camera =
    vtkSmartPointer<vtkCamera>::New();

  for(unsigned int i = 0; i < 4; i++)
  {
    vtkSmartPointer<vtkRenderer> renderer =
      vtkSmartPointer<vtkRenderer>::New();
    renderWindow->AddRenderer(renderer);
    style->renderers.push_back(renderer);
    renderer->SetViewport(static_cast<double>(i)/numberOfViewports,0,
              static_cast<double>(i+1)/numberOfViewports,1);
    renderer->SetBackground(.2, .3, .4);
    renderer->SetActiveCamera(camera);
  }

  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
      vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetRenderWindow(renderWindow);
  renderWindowInteractor->SetInteractorStyle(style);
  style->Initialize();
  style->renderers[0]->ResetCamera();

  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 2.8)

PROJECT(DataStructureComparison)

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

add_executable(DataStructureComparison MACOSX_BUNDLE DataStructureComparison.cxx )

target_link_libraries(DataStructureComparison ${VTK_LIBRARIES})

Download and Build DataStructureComparison

Click here to download DataStructureComparison and its CMakeLists.txt file. Once the tarball DataStructureComparison.tar has been downloaded and extracted,

cd DataStructureComparison/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:

./DataStructureComparison

WINDOWS USERS

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