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# MoveAVertexUnstructuredGrid

VTKEx/Cxx/Interaction/MoveAVertexUnstructuredGrid

Question

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### Code

MoveAVertexUnstructuredGrid.cxx

    #include <vtkSmartPointer.h>
    #include <vtkPointPicker.h>
    #include <vtkSphereSource.h>
    #include <vtkGlyph3D.h>
    #include <vtkPointData.h>
    #include <vtkIdTypeArray.h>
    #include <vtkDataSetSurfaceFilter.h>
    #include <vtkRendererCollection.h>
    #include <vtkProperty.h>
    #include <vtkPlanes.h>
    #include <vtkObjectFactory.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkPolyData.h>
    #include <vtkPointSource.h>
    #include <vtkInteractorStyleTrackballActor.h>
    #include <vtkAreaPicker.h>
    #include <vtkExtractGeometry.h>
    #include <vtkDataSetMapper.h>
    #include <vtkUnstructuredGrid.h>
    #include <vtkVertexGlyphFilter.h>
    #include <vtkIdFilter.h>

    // Define interaction style
    class InteractorStyleMoveVertex : public vtkInteractorStyleTrackballActor
    {
    public:
      static InteractorStyleMoveVertex* New();
      vtkTypeMacro(InteractorStyleMoveVertex,vtkInteractorStyleTrackballActor);

      InteractorStyleMoveVertex()
      {
        this->Move = false;
        this->PointPicker = vtkSmartPointer<vtkPointPicker>::New();

        // Setup ghost glyph
        vtkSmartPointer<vtkPoints> points =
          vtkSmartPointer<vtkPoints>::New();
        points->InsertNextPoint(0,0,0);
        this->MovePolyData = vtkSmartPointer<vtkPolyData>::New();
        this->MovePolyData->SetPoints(points);
        this->MoveGlyphFilter = vtkSmartPointer<vtkVertexGlyphFilter>::New();
        this->MoveGlyphFilter->SetInputData(this->MovePolyData);
        this->MoveGlyphFilter->Update();

        this->MoveMapper = vtkSmartPointer<vtkPolyDataMapper>::New();
        this->MoveMapper->SetInputConnection(this->MoveGlyphFilter->GetOutputPort());

        this->MoveActor = vtkSmartPointer<vtkActor>::New();
        this->MoveActor->SetMapper(this->MoveMapper);
        this->MoveActor->VisibilityOff();
        this->MoveActor->GetProperty()->SetPointSize(10);
        this->MoveActor->GetProperty()->SetColor(1,0,0);
      }

      void OnMouseMove() override
      {
        if(!this->Move)
        {
          return;
        }

        vtkInteractorStyleTrackballActor::OnMouseMove();
      }

      void OnMiddleButtonUp() override
      {
        this->EndPan();

        this->Move = false;
        this->MoveActor->VisibilityOff();

        this->Data->GetPoints()->SetPoint(this->SelectedPoint, this->MoveActor->GetPosition());
        this->Data->Modified();
        this->GetCurrentRenderer()->Render();
        this->GetCurrentRenderer()->GetRenderWindow()->Render();
      }
      void OnMiddleButtonDown() override
      {
        // Get the selected point
        int x = this->Interactor->GetEventPosition()[0];
        int y = this->Interactor->GetEventPosition()[1];
        this->FindPokedRenderer(x, y);
        this->PointPicker->Pick(this->Interactor->GetEventPosition()[0],
                                this->Interactor->GetEventPosition()[1],
                                0,  // always zero.
                                this->Interactor->GetRenderWindow()->GetRenderers()->GetFirstRenderer());

        if(this->PointPicker->GetPointId() >= 0)
        {
          this->StartPan();
          this->MoveActor->VisibilityOn();
          this->Move = true;
          this->SelectedPoint = this->PointPicker->GetPointId();

          std::cout << "Dragging point " << this->SelectedPoint << std::endl;

          double p[3];
          this->Data->GetPoint(this->SelectedPoint, p);
          std::cout << "p: " << p[0] << " " << p[1] << " " << p[2] << std::endl;
          this->MoveActor->SetPosition(p);

          this->GetCurrentRenderer()->AddActor(this->MoveActor);
          this->InteractionProp = this->MoveActor;
        }
      }

      vtkUnstructuredGrid* Data;
      vtkPolyData* GlyphData;

      vtkSmartPointer<vtkPolyDataMapper> MoveMapper;
      vtkSmartPointer<vtkActor> MoveActor;
      vtkSmartPointer<vtkPolyData> MovePolyData;
      vtkSmartPointer<vtkVertexGlyphFilter> MoveGlyphFilter;

      vtkSmartPointer<vtkPointPicker> PointPicker;

      bool Move;
      vtkIdType SelectedPoint;
    };
    vtkStandardNewMacro(InteractorStyleMoveVertex);

    int main (int, char *[])
    {
      vtkSmartPointer<vtkPoints> points =
        vtkSmartPointer<vtkPoints>::New();
      points->InsertNextPoint(0,0,0);
      points->InsertNextPoint(1,0,0);
      points->InsertNextPoint(2,0,0);

      vtkSmartPointer<vtkUnstructuredGrid> input =
        vtkSmartPointer<vtkUnstructuredGrid>::New();
      input->SetPoints(points);

      vtkSmartPointer<vtkVertexGlyphFilter> glyphFilter =
        vtkSmartPointer<vtkVertexGlyphFilter>::New();
      glyphFilter->SetInputData(input);
      glyphFilter->Update();

      // Create a mapper and actor
      vtkSmartPointer<vtkPolyDataMapper> mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      mapper->SetInputConnection(glyphFilter->GetOutputPort());

      vtkSmartPointer<vtkActor> actor =
        vtkSmartPointer<vtkActor>::New();
      actor->SetMapper(mapper);
      actor->GetProperty()->SetPointSize(10);

      // Visualize
      vtkSmartPointer<vtkRenderer> renderer =
        vtkSmartPointer<vtkRenderer>::New();
      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->AddRenderer(renderer);

      vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      renderWindowInteractor->SetRenderWindow(renderWindow);

      renderer->AddActor(actor);
      //renderer->SetBackground(1,1,1); // Background color white

      renderWindow->Render();

      vtkSmartPointer<InteractorStyleMoveVertex> style =
        vtkSmartPointer<InteractorStyleMoveVertex>::New();
      renderWindowInteractor->SetInteractorStyle( style );
      style->Data = input;

      renderWindowInteractor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

    project(MoveAVertexUnstructuredGrid)

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

### Download and Build MoveAVertexUnstructuredGrid

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

    cd MoveAVertexUnstructuredGrid/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:

    ./MoveAVertexUnstructuredGrid

WINDOWS USERS

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