HighlightSelection

VTKEx/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.

Question

If you have a simple question about this example contact us at VTKExProject If your question is more complex and may require extended discussion, please use the VTK Discourse Forum

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->SelectedActor->GetProperty()->SetRepresentationToWireframe();

      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->SetPhiResolution(21);
    source->SetThetaResolution(40);
    source->Update();
    polyData = source->GetOutput();
  }
  return polyData;
}
} // namespace

CMakeLists.txt¶

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(HighlightSelection)

find_package(VTK COMPONENTS 
  vtkvtkCommonColor
  vtkvtkCommonCore
  vtkvtkCommonDataModel
  vtkvtkFiltersCore
  vtkvtkFiltersExtraction
  vtkvtkFiltersGeneral
  vtkvtkFiltersGeometry
  vtkvtkFiltersSources
  vtkvtkIOGeometry
  vtkvtkIOLegacy
  vtkvtkIOPLY
  vtkvtkIOXML
  vtkvtkInteractionStyle
  vtkvtkRenderingContextOpenGL2
  vtkvtkRenderingCore
  vtkvtkRenderingFreeType
  vtkvtkRenderingGL2PSOpenGL2
  vtkvtkRenderingOpenGL2 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.