RotatingSphere

VTKExamples/Cxx/Animation/RotatingSphere

Description¶

This example demonstrates how to create a rotating sphere. A timer is used to rotate a sphere along z-axis.

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¶

RotatingSphere.cxx

#include <vtkActor.h>
#include <vtkNamedColors.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>

class vtkTimerCallback2 : public vtkCommand
{
public:
  vtkTimerCallback2() = default;
  ~vtkTimerCallback2() = default;

  int timerId = 0;
  static vtkTimerCallback2* New()
  {
    vtkTimerCallback2* cb = new vtkTimerCallback2;
    cb->TimerCount = 0;
    return cb;
  }
  virtual void Execute(vtkObject* caller, unsigned long eventId,
                       void* vtkNotUsed(callData))
  {
    vtkRenderWindowInteractor* iren =
        dynamic_cast<vtkRenderWindowInteractor*>(caller);
    if (vtkCommand::TimerEvent == eventId)
    {
      ++this->TimerCount;
    }
    if (TimerCount < 36)
    {
      actor->RotateZ(5);
      iren->GetRenderWindow()->Render();
    }
    else
    {
      iren->DestroyTimer();
    }
  }

private:
  int TimerCount = 0;

public:
  vtkActor* actor;
};

int main(int, char*[])
{
  auto colors = vtkSmartPointer<vtkNamedColors>::New();

  // Create a sphere
  auto sphereSource = vtkSmartPointer<vtkSphereSource>::New();
  sphereSource->SetCenter(0.0, 0.0, 0.0);
  sphereSource->SetRadius(1.0);
  sphereSource->SetThetaResolution(15);
  sphereSource->SetPhiResolution(15);
  sphereSource->Update();

  // Create a mapper and actor
  auto mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
  mapper->SetInputConnection(sphereSource->GetOutputPort());
  auto actor = vtkSmartPointer<vtkActor>::New();
  actor->SetMapper(mapper);
  actor->RotateX(90);
  actor->GetProperty()->SetRepresentationToWireframe();

  // Create a renderer, render window, and interactor
  auto renderer = vtkSmartPointer<vtkRenderer>::New();
  auto renderWindow = vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);
  renderWindow->SetSize(640, 480);

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

  // Add the actor to the scene
  renderer->AddActor(actor);

  renderer->SetBackground(colors->GetColor3d("Seashell").GetData());
  // Render and interact
  renderWindow->Render();

  // Initialize must be called prior to creating timer events.
  renderWindowInteractor->Initialize();

  // Sign up to receive TimerEvent
  auto cb = vtkSmartPointer<vtkTimerCallback2>::New();
  cb->actor = actor;

  renderWindowInteractor->AddObserver(vtkCommand::TimerEvent, cb);
  int timerId = renderWindowInteractor->CreateRepeatingTimer(100);
  cb->timerId = timerId;

  // Start the interaction and timer
  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt¶

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(RotatingSphere)

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

Download and Build RotatingSphere¶

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

cd RotatingSphere/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:

./RotatingSphere

WINDOWS USERS

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