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 <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()
    {
      this->meshMapper->SetInputData(this->data);
      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);
    }

    this->mappers[i]->SetInputData(polydata);
  }

    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 3.3 FATAL_ERROR)

project(DataStructureComparison)

find_package(VTK COMPONENTS 
  vtkCommonCore
  vtkCommonDataModel
  vtkFiltersFlowPaths
  vtkFiltersGeneral
  vtkFiltersSources
  vtkIOXML
  vtkInteractionStyle
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
  message("Skipping DataStructureComparison: ${VTK_NOT_FOUND_MESSAGE}")
  return ()
endif()
message (STATUS "VTK_VERSION: ${VTK_VERSION}")
if (VTK_VERSION VERSION_LESS "8.90.0")
  # old system
  include(${VTK_USE_FILE})
  add_executable(DataStructureComparison MACOSX_BUNDLE DataStructureComparison.cxx )
  target_link_libraries(DataStructureComparison PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(DataStructureComparison MACOSX_BUNDLE DataStructureComparison.cxx )
  target_link_libraries(DataStructureComparison PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS DataStructureComparison
    MODULES ${VTK_LIBRARIES}
    )
endif () 

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.