HighlightSelection

VTKExamples/Cxx/Picking/HighlightSelection


Description

This example demonstrates how to select and highlight cells using vtkInteractorStyleRubberBandPick. Press 'r' to enter selection mode. vtkExtractPolyDataGeometry selects all cells within the selected area. The cells include those on the visible surface as well as those that exist within the view frustum returned by the interactor.

The example accepts a geometry file as the first argument. Without an argument a vtkSphereSource will be used as the vtkPolyData.

Code

HighlightSelection.cxx

#include <vtkActor.h>
#include <vtkAreaPicker.h>
#include <vtkDataSetMapper.h>
#include <vtkDataSetSurfaceFilter.h>
#include <vtkExtractPolyDataGeometry.h>
#include <vtkIdFilter.h>
#include <vtkIdTypeArray.h>
#include <vtkInteractorStyleRubberBandPick.h>
#include <vtkNamedColors.h>
#include <vtkObjectFactory.h>
#include <vtkPlanes.h>
#include <vtkPointData.h>
#include <vtkPolyData.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkRendererCollection.h>
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkUnstructuredGrid.h>
#include <vtkVersion.h>
#include <vtkVertexGlyphFilter.h>

#if VTK_VERSION_NUMBER >= 89000000000ULL
#define VTK890 1
#endif

#include <vtkBYUReader.h>
#include <vtkOBJReader.h>
#include <vtkPLYReader.h>
#include <vtkPolyDataReader.h>
#include <vtkSTLReader.h>
#include <vtkXMLPolyDataReader.h>
#include <vtksys/SystemTools.hxx>

#define VTKISRBP_ORIENT 0
#define VTKISRBP_SELECT 1

namespace {
// Define interaction style
class HighlightInteractorStyle : public vtkInteractorStyleRubberBandPick
{
public:
  static HighlightInteractorStyle* New();
  vtkTypeMacro(HighlightInteractorStyle, vtkInteractorStyleRubberBandPick);

  HighlightInteractorStyle() : vtkInteractorStyleRubberBandPick()
  {
    this->SelectedMapper = vtkSmartPointer<vtkDataSetMapper>::New();
    this->SelectedActor = vtkSmartPointer<vtkActor>::New();
    this->SelectedActor->SetMapper(SelectedMapper);
  }

  virtual void OnLeftButtonUp() override
  {
    // Forward events
    vtkInteractorStyleRubberBandPick::OnLeftButtonUp();

    if (this->CurrentMode == VTKISRBP_SELECT)
    {
      auto colors = vtkSmartPointer<vtkNamedColors>::New();

      vtkPlanes* frustum =
          static_cast<vtkAreaPicker*>(this->GetInteractor()->GetPicker())
              ->GetFrustum();

      auto extractPolyDataGeometry =
          vtkSmartPointer<vtkExtractPolyDataGeometry>::New();
      extractPolyDataGeometry->SetInputData(this->PolyData);
      extractPolyDataGeometry->SetImplicitFunction(frustum);
      extractPolyDataGeometry->Update();

      std::cout << "Extracted "
                << extractPolyDataGeometry->GetOutput()->GetNumberOfCells()
                << " cells." << std::endl;
      this->SelectedMapper->SetInputData(extractPolyDataGeometry->GetOutput());
      this->SelectedMapper->ScalarVisibilityOff();

      //        vtkIdTypeArray* ids =
      //        dynamic_cast<vtkIdTypeArray*>(selected->GetPointData()->GetArray("OriginalIds"));

      this->SelectedActor->GetProperty()->SetColor(
          colors->GetColor3d("Tomato").GetData());
      this->SelectedActor->GetProperty()->SetPointSize(5);

      this->GetInteractor()
          ->GetRenderWindow()
          ->GetRenderers()
          ->GetFirstRenderer()
          ->AddActor(SelectedActor);
      this->GetInteractor()->GetRenderWindow()->Render();
      this->HighlightProp(NULL);
    }
  }

  void SetPolyData(vtkSmartPointer<vtkPolyData> polyData)
  {
    this->PolyData = polyData;
  }

private:
  vtkSmartPointer<vtkPolyData> PolyData;
  vtkSmartPointer<vtkActor> SelectedActor;
  vtkSmartPointer<vtkDataSetMapper> SelectedMapper;
};
vtkStandardNewMacro(HighlightInteractorStyle);

vtkSmartPointer<vtkPolyData> ReadPolyData(const char* fileName);
} // namespace


int main(int argc, char* argv[])
{
  auto polyData = ReadPolyData(argc > 1 ? argv[1] : "");
  ;

  auto colors = vtkSmartPointer<vtkNamedColors>::New();

  auto idFilter = vtkSmartPointer<vtkIdFilter>::New();
  idFilter->SetInputData(polyData);
#if VTK890
  idFilter->SetCellIdsArrayName("OriginalIds");
  idFilter->SetPointIdsArrayName("OriginalIds");
#else
  idFilter->SetIdsArrayName("OriginalIds");
#endif
  idFilter->Update();

  // This is needed to convert the ouput of vtkIdFilter (vtkDataSet) back to
  // vtkPolyData
  auto surfaceFilter = vtkSmartPointer<vtkDataSetSurfaceFilter>::New();
  surfaceFilter->SetInputConnection(idFilter->GetOutputPort());
  surfaceFilter->Update();

  vtkPolyData* input = surfaceFilter->GetOutput();

  // Create a mapper and actor
  auto mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
  mapper->SetInputData(polyData);
  mapper->ScalarVisibilityOff();

  auto actor = vtkSmartPointer<vtkActor>::New();
  actor->SetMapper(mapper);
  actor->GetProperty()->SetPointSize(5);
  actor->GetProperty()->SetDiffuseColor(
      colors->GetColor3d("Peacock").GetData());
  // Visualize
  auto renderer = vtkSmartPointer<vtkRenderer>::New();
  renderer->UseHiddenLineRemovalOn();

  auto renderWindow = vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);
  renderWindow->SetSize(640, 480);

  auto areaPicker = vtkSmartPointer<vtkAreaPicker>::New();
  auto renderWindowInteractor =
      vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetPicker(areaPicker);
  renderWindowInteractor->SetRenderWindow(renderWindow);

  renderer->AddActor(actor);
  renderer->SetBackground(colors->GetColor3d("Tan").GetData());

  renderWindow->Render();

  auto style = vtkSmartPointer<HighlightInteractorStyle>::New();
  style->SetPolyData(input);
  renderWindowInteractor->SetInteractorStyle(style);

  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}
namespace {
vtkSmartPointer<vtkPolyData> ReadPolyData(const char* fileName)
{
  vtkSmartPointer<vtkPolyData> polyData;
  std::string extension =
      vtksys::SystemTools::GetFilenameLastExtension(std::string(fileName));
  if (extension == ".ply")
  {
    auto reader = vtkSmartPointer<vtkPLYReader>::New();
    reader->SetFileName(fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".vtp")
  {
    auto reader = vtkSmartPointer<vtkXMLPolyDataReader>::New();
    reader->SetFileName(fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".obj")
  {
    auto reader = vtkSmartPointer<vtkOBJReader>::New();
    reader->SetFileName(fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".stl")
  {
    auto reader = vtkSmartPointer<vtkSTLReader>::New();
    reader->SetFileName(fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".vtk")
  {
    auto reader = vtkSmartPointer<vtkPolyDataReader>::New();
    reader->SetFileName(fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".g")
  {
    auto reader = vtkSmartPointer<vtkBYUReader>::New();
    reader->SetGeometryFileName(fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else
  {
    auto source = vtkSmartPointer<vtkSphereSource>::New();
    source->Update();
    polyData = source->GetOutput();
  }
  return polyData;
}
} // namespace

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(HighlightSelection)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkCommonDataModel
  vtkFiltersCore
  vtkFiltersExtraction
  vtkFiltersGeneral
  vtkFiltersGeometry
  vtkFiltersSources
  vtkIOGeometry
  vtkIOLegacy
  vtkIOPLY
  vtkIOXML
  vtkInteractionStyle
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
  message("Skipping HighlightSelection: ${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(HighlightSelection MACOSX_BUNDLE HighlightSelection.cxx )
  target_link_libraries(HighlightSelection PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(HighlightSelection MACOSX_BUNDLE HighlightSelection.cxx )
  target_link_libraries(HighlightSelection PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS HighlightSelection
    MODULES ${VTK_LIBRARIES}
    )
endif () 

Download and Build HighlightSelection

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

cd HighlightSelection/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:

./HighlightSelection

WINDOWS USERS

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