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# DetermineActorType

VTKEx/Cxx/Utilities/DetermineActorType

Question

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### Code

DetermineActorType.cxx

    #include <vtkSmartPointer.h>

    #include <vtkActor.h>
    #include <vtkActorCollection.h>
    #include <vtkCubeAxesActor.h>
    #include <vtkPolyData.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkRenderer.h>
    #include <vtkSphereSource.h>

    int main(int, char *[])
    {
      // Sphere
      vtkSmartPointer<vtkSphereSource> sphereSource =
        vtkSmartPointer<vtkSphereSource>::New();
      sphereSource->Update();

      vtkSmartPointer<vtkPolyDataMapper> mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      mapper->SetInputConnection(sphereSource->GetOutputPort());

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

      // Cube axes
      vtkSmartPointer<vtkCubeAxesActor> cubeAxesActor =
        vtkSmartPointer<vtkCubeAxesActor>::New();

      // Create a renderer and render window
      vtkSmartPointer<vtkRenderer> renderer =
        vtkSmartPointer<vtkRenderer>::New();
      cubeAxesActor->SetCamera(renderer->GetActiveCamera());

      renderer->AddActor(actor);
      renderer->AddActor(cubeAxesActor);

      // Determine the types of the actors - method 1
      {
      std::cout << "Method 1:" << std::endl;
      vtkActorCollection* actorCollection = renderer->GetActors();
      actorCollection->InitTraversal();

      for(vtkIdType i = 0; i < actorCollection->GetNumberOfItems(); i++)
      {
        vtkActor* nextActor = actorCollection->GetNextActor();
        std::cout << "nextActor " << i << " : " << nextActor->GetClassName() << std::endl;
        std::string className = nextActor->GetClassName();
        std::string wantedClass = "vtkCubeAxesActor";
        if(className == wantedClass)
        {
          std::cout << "nextActor " << i << " is a vtkCubeAxesActor!" << std::endl;
        }
        else
        {
          std::cout << "nextActor " << i << " is NOT a vtkCubeAxesActor!" << std::endl;
        }
      }
      }

      // Determine the types of the actors - method 2
      {
      std::cout << "Method 2:" << std::endl;
      vtkActorCollection* actorCollection = renderer->GetActors();
      actorCollection->InitTraversal();

      for(vtkIdType i = 0; i < actorCollection->GetNumberOfItems(); i++)
      {
        vtkActor* nextActor = actorCollection->GetNextActor();
        std::cout << "nextActor " << i << " : " << nextActor->GetClassName() << std::endl;
        if(nextActor->IsA("vtkCubeAxesActor"))
        {
          std::cout << "nextActor " << i << " is a vtkCubeAxesActor!" << std::endl;
        }
        else
        {
          std::cout << "nextActor " << i << " is NOT a vtkCubeAxesActor!" << std::endl;
        }
      }
      }

      // Determine the types of the actors - method 3
      {
      std::cout << "Method 3:" << std::endl;
      vtkActorCollection* actorCollection = renderer->GetActors();
      actorCollection->InitTraversal();

      for(vtkIdType i = 0; i < actorCollection->GetNumberOfItems(); i++)
      {
        vtkActor* nextActor = actorCollection->GetNextActor();
        std::cout << "nextActor " << i << " : " << nextActor->GetClassName() << std::endl;

        if(dynamic_cast<vtkCubeAxesActor*>(nextActor) != 0)
        {
          std::cout << "nextActor " << i << " is a vtkCubeAxesActor!" << std::endl;
        }
        else
        {
          std::cout << "nextActor " << i << " is NOT a vtkCubeAxesActor!" << std::endl;
        }
      }
      }

      // Determine the types of the actors - method 4
      {
      std::cout << "Method 4:" << std::endl;
      vtkActorCollection* actorCollection = renderer->GetActors();
      actorCollection->InitTraversal();

      for(vtkIdType i = 0; i < actorCollection->GetNumberOfItems(); i++)
      {
        vtkActor* nextActor = actorCollection->GetNextActor();
        std::cout << "nextActor " << i << " : " << nextActor->GetClassName() << std::endl;

        if(dynamic_cast<vtkCubeAxesActor*>(nextActor) != 0)
        {
          std::cout << "nextActor " << i << " is a vtkCubeAxesActor!" << std::endl;
        }
        else
        {
          std::cout << "nextActor " << i << " is NOT a vtkCubeAxesActor!" << std::endl;
        }
      }
      }

      // Render the scene
      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->AddRenderer(renderer);

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

      renderer->ResetCamera();
      renderWindow->Render();
      renderWindowInteractor->Initialize();
      renderWindowInteractor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

    project(DetermineActorType)

    find_package(VTK COMPONENTS
      vtkvtkCommonCore
      vtkvtkCommonDataModel
      vtkvtkFiltersSources
      vtkvtkInteractionStyle
      vtkvtkRenderingAnnotation
      vtkvtkRenderingContextOpenGL2
      vtkvtkRenderingCore
      vtkvtkRenderingFreeType
      vtkvtkRenderingGL2PSOpenGL2
      vtkvtkRenderingOpenGL2 QUIET)
    if (NOT VTK_FOUND)
      message("Skipping DetermineActorType: ${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(DetermineActorType MACOSX_BUNDLE DetermineActorType.cxx )
      target_link_libraries(DetermineActorType PRIVATE ${VTK_LIBRARIES})
    else ()
      # include all components
      add_executable(DetermineActorType MACOSX_BUNDLE DetermineActorType.cxx )
      target_link_libraries(DetermineActorType PRIVATE ${VTK_LIBRARIES})
      # vtk_module_autoinit is needed
      vtk_module_autoinit(
        TARGETS DetermineActorType
        MODULES ${VTK_LIBRARIES}
        )
    endif ()

### Download and Build DetermineActorType

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

    cd DetermineActorType/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:

    ./DetermineActorType

WINDOWS USERS

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