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RotateActor

Repository source: 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 question about this example, please use the VTK Discourse Forum

Code

RotateActor.cxx

#include <vtkActor.h>
#include <vtkConeSource.h>
#include <vtkInteractorStyleTrackballActor.h>
#include <vtkMatrix4x4.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSmartPointer.h>

#include <iostream>

namespace {

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

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

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

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

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

    vtkNew<vtkMatrix4x4> m;
    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);

} // namespace

int main(int, char*[])
{
  vtkNew<vtkNamedColors> colors;

  // Create a cone.
  vtkNew<vtkConeSource> coneSource;
  coneSource->Update();

  // Create a mapper and actor.
  vtkNew<vtkPolyDataMapper> mapper;
  mapper->SetInputConnection(coneSource->GetOutputPort());
  vtkNew<vtkActor> actor;
  actor->SetMapper(mapper);
  actor->RotateY(45);
  actor->GetProperty()->SetColor(colors->GetColor3d("Gold").GetData());

  // Create a renderer, render window, and interactor.
  vtkNew<vtkRenderer> renderer;
  vtkNew<vtkRenderWindow> renderWindow;
  renderWindow->AddRenderer(renderer);
  renderWindow->SetWindowName("RotateActor");

  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
  renderWindowInteractor->SetRenderWindow(renderWindow);

  vtkNew<MyInteractorStyle> style;
  style->SetActor(actor);

  renderWindowInteractor->SetInteractorStyle(style);

  // Add the actor to the scene.
  renderer->AddActor(actor);
  renderer->SetBackground(colors->GetColor3d("DarkSlateGray").GetData());

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

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(RotateActor)

find_package(VTK COMPONENTS 
  CommonColor
  CommonCore
  CommonMath
  FiltersSources
  InteractionStyle
  RenderingContextOpenGL2
  RenderingCore
  RenderingFreeType
  RenderingGL2PSOpenGL2
  RenderingOpenGL2
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "RotateActor: Unable to find the VTK build folder.")
endif()

# Prevent a "command line is too long" failure in Windows.
set(CMAKE_NINJA_FORCE_RESPONSE_FILE "ON" CACHE BOOL "Force Ninja to use response files.")
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}
)

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.