# RotateActor

VTKExamples/Cxx/Visualization/RotateActor

### Description

This example shows how to rotate an actor. It also shows how to get the current transformation of the actor so it can then be applied to the actual object if so desired.

### Code

RotateActor.cxx

    #include <vtkConeSource.h>
    #include <vtkPolyData.h>
    #include <vtkSmartPointer.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkInteractorStyleTrackballActor.h>
    #include <vtkObjectFactory.h>
    #include <vtkMatrix4x4.h>

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

        virtual void OnLeftButtonDown()
        {
          std::cout << "Pressed left mouse button." << std::endl;

          vtkSmartPointer<vtkMatrix4x4> m =
              vtkSmartPointer<vtkMatrix4x4>::New();
          this->Actor->GetMatrix(m);
          std::cout << "Matrix: " << endl << *m << std::endl;

          // Forward events
          vtkInteractorStyleTrackballActor::OnLeftButtonDown();
        }

        virtual void OnLeftButtonUp()
        {
          std::cout << "Released left mouse button." << std::endl;

          vtkSmartPointer<vtkMatrix4x4> m =
              vtkSmartPointer<vtkMatrix4x4>::New();
          this->Actor->GetMatrix(m);
          std::cout << "Matrix: " << endl << *m << std::endl;

          // Forward events
          vtkInteractorStyleTrackballActor::OnLeftButtonUp();
        }

        void SetActor(vtkSmartPointer<vtkActor> actor) {this->Actor = actor;}

      private:
        vtkSmartPointer<vtkActor> Actor;

    };
    vtkStandardNewMacro(MyInteractorStyle);

    int main(int, char *[])
    {
      // Create a sphere
      vtkSmartPointer<vtkConeSource> coneSource =
        vtkSmartPointer<vtkConeSource>::New();
      coneSource->Update();

      // Create a mapper and actor
      vtkSmartPointer<vtkPolyDataMapper> mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      mapper->SetInputConnection(coneSource->GetOutputPort());
      vtkSmartPointer<vtkActor> actor =
        vtkSmartPointer<vtkActor>::New();
      actor->SetMapper(mapper);
      actor->RotateY(45);

      // Create a renderer, render window, and interactor
      vtkSmartPointer<vtkRenderer> renderer =
        vtkSmartPointer<vtkRenderer>::New();
      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->AddRenderer(renderer);
      vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      renderWindowInteractor->SetRenderWindow(renderWindow);

      vtkSmartPointer<MyInteractorStyle> style =
        vtkSmartPointer<MyInteractorStyle>::New();
      style->SetActor(actor);

      renderWindowInteractor->SetInteractorStyle( style );

      // Add the actor to the scene
      renderer->AddActor(actor);
      renderer->SetBackground(1,1,1); //white

      // Render and interact
      renderWindow->Render();
      renderWindowInteractor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(RotateActor)

    find_package(VTK REQUIRED)
    include(${VTK_USE_FILE})

    add_executable(RotateActor MACOSX_BUNDLE RotateActor.cxx)

    target_link_libraries(RotateActor ${VTK_LIBRARIES})

### Download and Build RotateActor

Danger

The generation of tar files has not been ported to the new VTKExamples. Some tarballs may be missing or out-of-date.

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

    cd RotateActor/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:

    ./RotateActor

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