BalloonWidget

vtk-examples/Cxx/Widgets/BalloonWidget

Description¶

This example creates a sphere and a regular polygon. The balloon text describes each object when you hover over it.

Note

This original source code for this example is here.

Other languages

See (Python), (Java)

Question

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

Code¶

BalloonWidget.cxx

#include <vtkActor.h>
#include <vtkBalloonRepresentation.h>
#include <vtkBalloonWidget.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyDataMapper.h>
#include <vtkProperty.h>
#include <vtkRegularPolygonSource.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSphereSource.h>

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

  // Sphere.
  vtkNew<vtkSphereSource> sphereSource;
  sphereSource->SetCenter(-4.0, 0.0, 0.0);
  sphereSource->SetRadius(4.0);
  sphereSource->Update();

  vtkNew<vtkPolyDataMapper> sphereMapper;
  sphereMapper->SetInputConnection(sphereSource->GetOutputPort());

  vtkNew<vtkActor> sphereActor;
  sphereActor->SetMapper(sphereMapper);
  sphereActor->GetProperty()->SetColor(
      colors->GetColor3d("MistyRose").GetData());

  // Regular Polygon.
  vtkNew<vtkRegularPolygonSource> regularPolygonSource;
  regularPolygonSource->SetCenter(4.0, 0.0, 0.0);
  regularPolygonSource->SetRadius(4.0);
  regularPolygonSource->Update();

  vtkNew<vtkPolyDataMapper> regularPolygonMapper;
  regularPolygonMapper->SetInputConnection(
      regularPolygonSource->GetOutputPort());

  vtkNew<vtkActor> regularPolygonActor;
  regularPolygonActor->SetMapper(regularPolygonMapper);
  regularPolygonActor->GetProperty()->SetColor(
      colors->GetColor3d("Cornsilk").GetData());

  // A renderer and render window.
  vtkNew<vtkRenderer> ren;
  vtkNew<vtkRenderWindow> renWin;
  renWin->AddRenderer(ren);
  renWin->SetWindowName("BalloonWidget");

  // An interactor.
  vtkNew<vtkRenderWindowInteractor> iRen;
  iRen->SetRenderWindow(renWin);

  // Create the widget.
  vtkNew<vtkBalloonRepresentation> balloonRep;
  balloonRep->SetBalloonLayoutToImageRight();

  vtkNew<vtkBalloonWidget> balloonWidget;
  balloonWidget->SetInteractor(iRen);
  balloonWidget->SetRepresentation(balloonRep);
  balloonWidget->AddBalloon(sphereActor, "This is a sphere", nullptr);
  balloonWidget->AddBalloon(regularPolygonActor, "This is a regular polygon",
                            nullptr);

  // Add the actors to the scene.
  ren->AddActor(sphereActor);
  ren->AddActor(regularPolygonActor);
  ren->SetBackground(colors->GetColor3d("SlateGray").GetData());

  // Render
  renWin->Render();

  balloonWidget->EnabledOn();

  // Begin mouse interaction.
  iRen->Initialize();
  iRen->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt¶

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(BalloonWidget)

find_package(VTK COMPONENTS 
)

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

Download and Build BalloonWidget¶

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

cd BalloonWidget/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:

./BalloonWidget

WINDOWS USERS

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