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.

Question

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

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 3.3 FATAL_ERROR)

project(RotateActor)

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

Download and Build RotateActor

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

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