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Animation

vtk-examples/Cxx/Utilities/Animation


Description

This example demonstrates how to create a simple animation. A timer is used to move a sphere across a scene.

Other languages

See (Python)

Question

If you have a question about this example, please use the VTK Discourse Forum

Code

Animation.cxx

#include <vtkActor.h>
#include <vtkCallbackCommand.h>
#include <vtkCamera.h>
#include <vtkCommand.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSphereSource.h>

namespace {
class vtkTimerCallback2 : public vtkCallbackCommand
{
public:
  vtkTimerCallback2() = default;

  static vtkTimerCallback2* New()
  {
    vtkTimerCallback2* cb = new vtkTimerCallback2;
    cb->TimerCount = 0;
    return cb;
  }

  virtual void Execute(vtkObject* caller, unsigned long eventId,
                       void* vtkNotUsed(callData))
  {
    if (vtkCommand::TimerEvent == eventId)
    {
      ++this->TimerCount;
    }
    std::cout << this->TimerCount << std::endl;
    actor->SetPosition(this->TimerCount, this->TimerCount, 0);
    if (this->TimerCount < this->maxCount)
    {

      vtkRenderWindowInteractor* iren =
          dynamic_cast<vtkRenderWindowInteractor*>(caller);
      iren->GetRenderWindow()->Render();
    }
    else
    {
      vtkRenderWindowInteractor* iren =
          dynamic_cast<vtkRenderWindowInteractor*>(caller);
      if (this->timerId > -1)
      {
        iren->DestroyTimer(this->timerId);
      }
    }
  }

private:
  int TimerCount = 0;

public:
  vtkActor* actor = nullptr;
  int timerId = 0;
  int maxCount = -1;
};
} // namespace

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

  // Create a sphere
  vtkNew<vtkSphereSource> sphereSource;
  sphereSource->SetCenter(0.0, 0.0, 0.0);
  sphereSource->SetRadius(2.0);
  sphereSource->SetPhiResolution(30);
  sphereSource->SetThetaResolution(30);

  // Create a mapper and actor
  vtkNew<vtkPolyDataMapper> mapper;
  mapper->SetInputConnection(sphereSource->GetOutputPort());
  vtkNew<vtkActor> actor;
  actor->SetMapper(mapper);
  actor->GetProperty()->SetSpecular(0.6);
  actor->GetProperty()->SetSpecularPower(30);
  actor->GetProperty()->SetColor(colors->GetColor3d("Peacock").GetData());

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

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

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

  // Render and interact
  renderWindow->Render();
  renderer->GetActiveCamera()->Zoom(0.8);
  renderWindow->Render();

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

  // Sign up to receive TimerEvent
  vtkNew<vtkTimerCallback2> cb;
  cb->actor = actor;
  renderWindowInteractor->AddObserver(vtkCommand::TimerEvent, cb);

  int timerId = renderWindowInteractor->CreateRepeatingTimer(500);
  std::cout << "timerId: " << timerId << std::endl;
  // Destroy the timer when maxCount is reached.
  cb->maxCount = 3;
  cb->timerId = timerId;
  // Start the interaction and timer
  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(Animation)

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

if (NOT VTK_FOUND)
  message(FATAL_ERROR "Animation: 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(Animation MACOSX_BUNDLE Animation.cxx )
  target_link_libraries(Animation PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
  TARGETS Animation
  MODULES ${VTK_LIBRARIES}
)

Download and Build Animation

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

cd Animation/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:

./Animation

WINDOWS USERS

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