# DataAnimation

VTKExamples/Cxx/Utilities/DataAnimation

### Description

This causes one point of the sphere to be moved outwards at each iteration.

### Code

DataAnimation.cxx

    #include <vtkSmartPointer.h>
    #include <vtkSphereSource.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkProgrammableFilter.h>
    #include <vtkCallbackCommand.h>

    void TimerCallbackFunction ( vtkObject* caller, long unsigned int eventId, void* clientData, void* callData );

    // Globals
    unsigned int counter2 = 0;

    void AdjustPoints2(void* arguments)
    {
      std::cout << "AdjustPoints2" << std::endl;
      vtkProgrammableFilter* programmableFilter =
          static_cast<vtkProgrammableFilter*>(arguments);

      vtkPoints* inPts = programmableFilter->GetPolyDataInput()->GetPoints();
      vtkIdType numPts = inPts->GetNumberOfPoints();
      vtkSmartPointer<vtkPoints> newPts =
          vtkSmartPointer<vtkPoints>::New();
      newPts->SetNumberOfPoints(numPts);

      for(vtkIdType i = 0; i < numPts; i++)
      {
        double p[3];
        inPts->GetPoint(i, p);
        newPts->SetPoint(i, p);
      }

      double p0[3];
      inPts->GetPoint(0, p0);
      p0[2] = p0[2] + counter2 * 0.1;
      newPts->SetPoint(0, p0);

      programmableFilter->GetPolyDataOutput()->CopyStructure(programmableFilter->GetPolyDataInput());
      programmableFilter->GetPolyDataOutput()->SetPoints(newPts);
    }

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

      vtkSmartPointer<vtkProgrammableFilter> programmableFilter =
        vtkSmartPointer<vtkProgrammableFilter>::New();
      programmableFilter->SetInputConnection(sphereSource->GetOutputPort());

      programmableFilter->SetExecuteMethod(AdjustPoints2, programmableFilter);

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

      // 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);

      // Initialize must be called prior to creating timer events.
      renderWindowInteractor->Initialize();
      renderWindowInteractor->CreateRepeatingTimer(500);

      vtkSmartPointer<vtkCallbackCommand> timerCallback =
        vtkSmartPointer<vtkCallbackCommand>::New();
      timerCallback->SetCallback ( TimerCallbackFunction );
      timerCallback->SetClientData(programmableFilter);

      renderWindowInteractor->AddObserver ( vtkCommand::TimerEvent, timerCallback );

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

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

      return EXIT_SUCCESS;
    }

    void TimerCallbackFunction ( vtkObject* caller, long unsigned int vtkNotUsed(eventId), void* clientData, void* vtkNotUsed(callData) )
    {
      cout << "timer callback" << endl;

      vtkSmartPointer<vtkProgrammableFilter> programmableFilter =
          static_cast<vtkProgrammableFilter*>(clientData);

      vtkRenderWindowInteractor *iren =
        static_cast<vtkRenderWindowInteractor*>(caller);

      programmableFilter->Modified();

      iren->Render();

      counter2++;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

    project(DataAnimation)

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

### Download and Build DataAnimation

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

    cd DataAnimation/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:

    ./DataAnimation

WINDOWS USERS

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