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EllipticalButton

vtk-examples/Cxx/Interaction/EllipticalButton

Description

This example creates a 3D button using vtkEllipsoidalButton. Interaction is done by assigning the button to a vtkProp3DButtonRepresentation. Then a callback for a vtkButtonWidget controls the color of the button and the displayed geometry. Click on the button to see the color of both the button and geometry change.

Warning

There is a bug in vtkEllipticalButtonSource. If CircumferentialResolution is odd, improper geometry is created.

Warning

Values close to 1.0 for RadialRatio can cause shading artifacts at the corners of the button.

Question

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

Code

EllipticalButton.cxx

#include <vtkActor.h>
#include <vtkButtonWidget.h>
#include <vtkCommand.h>
#include <vtkCoordinate.h>
#include <vtkEllipticalButtonSource.h>
#include <vtkImageData.h>
#include <vtkImageReader2.h>
#include <vtkImageReader2Factory.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPolyDataMapper.h>
#include <vtkProp3DButtonRepresentation.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSmartPointer.h>
#include <vtkSuperquadricSource.h>
#include <vtkTexture.h>

// Callback for the interaction
namespace {

class vtkButtonCallback : public vtkCommand
{
public:
  static vtkButtonCallback* New()
  {
    return new vtkButtonCallback;
  }

  virtual void Execute(vtkObject* caller, unsigned long, void*)
  {
    auto buttonWidget = reinterpret_cast<vtkButtonWidget*>(caller);
    auto rep = reinterpret_cast<vtkProp3DButtonRepresentation*>(
        buttonWidget->GetRepresentation());
    int state = rep->GetState();
    this->Actor->GetProperty()->SetColor(
        reinterpret_cast<vtkActor*>(rep->GetButtonProp(state))
            ->GetProperty()
            ->GetColor());
    std::cout << "State: " << state << "\n";
  }

  vtkButtonCallback() : Actor(0)
  {
  }

  vtkActor* Actor;
};

vtkSmartPointer<vtkActor> CreateButtonActor(const char* textureFile);

} // namespace

int main(int argc, char* argv[])
{
  vtkNew<vtkNamedColors> color;

  if (argc < 2)
  {
    std::cout << "Usage: " << argv[0] << " imageFilename e.g. YinYang.png"
              << std::endl;
    return EXIT_FAILURE;
  }

  vtkNew<vtkSuperquadricSource> source;
  source->SetPhiResolution(64);
  source->SetThetaResolution(64);
  source->SetThetaRoundness(1.5);
  source->SetThickness(1.5);
  source->SetSize(2);
  source->Update();

  vtkNew<vtkPolyDataMapper> mapper;
  mapper->SetInputConnection(source->GetOutputPort());

  vtkNew<vtkActor> actor;
  actor->SetMapper(mapper);

  vtkNew<vtkRenderer> renderer;
  renderer->AddActor(actor);
  renderer->SetBackground(color->GetColor3d("Burlywood").GetData());

  vtkNew<vtkRenderWindow> renderWindow;
  renderWindow->SetSize(200, 200);
  renderWindow->AddRenderer(renderer);
  renderWindow->SetWindowName("EllipticalButton");

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

  // Create the widget and its representation
  vtkSmartPointer<vtkActor> buttonActor1 = CreateButtonActor(argv[1]);
  buttonActor1->GetProperty()->SetColor(color->GetColor3d("Tomato").GetData());
  vtkSmartPointer<vtkActor> buttonActor2 = CreateButtonActor(argv[1]);
  buttonActor2->GetProperty()->SetColor(color->GetColor3d("Banana").GetData());

  vtkNew<vtkProp3DButtonRepresentation> buttonRepresentation;
  buttonRepresentation->SetNumberOfStates(2);
  buttonRepresentation->SetButtonProp(0, buttonActor1);
  buttonRepresentation->SetButtonProp(1, buttonActor2);
  buttonRepresentation->FollowCameraOn();

  vtkNew<vtkButtonCallback> callback;
  callback->Actor = actor;
  actor->GetProperty()->SetColor(
      reinterpret_cast<vtkActor*>(buttonRepresentation->GetButtonProp(0))
          ->GetProperty()
          ->GetColor());

  renderWindowInteractor->Initialize();

  vtkNew<vtkButtonWidget> buttonWidget;
  buttonWidget->SetInteractor(renderWindowInteractor);
  buttonWidget->SetRepresentation(buttonRepresentation);
  buttonWidget->AddObserver(vtkCommand::StateChangedEvent, callback);
  buttonWidget->SetEnabled(1);

  renderer->ResetCamera();
  renderer->Render();

  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

namespace {

vtkSmartPointer<vtkActor> CreateButtonActor(const char* textureFile)
{
  vtkNew<vtkImageReader2Factory> readerFactory;
  vtkSmartPointer<vtkImageReader2> imageReader;
  imageReader.TakeReference(readerFactory->CreateImageReader2(textureFile));
  imageReader->SetFileName(textureFile);
  imageReader->Update();

  // Aspect ratio of image
  int dims[3];
  imageReader->GetOutput()->GetDimensions(dims);
  double aspect = static_cast<double>(dims[0]) / static_cast<double>(dims[1]);

  vtkNew<vtkTexture> texture;
  texture->SetInputConnection(imageReader->GetOutputPort());

  vtkNew<vtkEllipticalButtonSource> ellipticalButtonSource;
  ellipticalButtonSource->SetCircumferentialResolution(50);
  ellipticalButtonSource->SetShoulderResolution(10);
  ellipticalButtonSource->SetTextureResolution(10);
  ellipticalButtonSource->SetRadialRatio(1.05);
  ellipticalButtonSource->SetShoulderTextureCoordinate(0.0, 0.0);
  ellipticalButtonSource->SetTextureDimensions(dims[0], dims[1]);
  ellipticalButtonSource->SetTextureStyleToProportional();
  ellipticalButtonSource->TwoSidedOn();
  ellipticalButtonSource->SetWidth(aspect);
  ellipticalButtonSource->SetHeight(1.0);
  ellipticalButtonSource->SetDepth(.15);
  ellipticalButtonSource->SetCenter(2, 2, 0);

  ellipticalButtonSource->SetOutputPointsPrecision(
      vtkAlgorithm::SINGLE_PRECISION);

  vtkNew<vtkPolyDataMapper> buttonMapper;
  buttonMapper->SetInputConnection(ellipticalButtonSource->GetOutputPort());

  vtkNew<vtkActor> buttonActor;
  buttonActor->SetMapper(buttonMapper);
  buttonActor->SetTexture(texture);

  return buttonActor;
}

} // namespace

CMakeLists.txt

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(EllipticalButton)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkCommonDataModel
  vtkFiltersSources
  vtkIOImage
  vtkInteractionStyle
  vtkInteractionWidgets
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2
  QUIET
)

if (NOT VTK_FOUND)
  message("Skipping EllipticalButton: ${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(EllipticalButton MACOSX_BUNDLE EllipticalButton.cxx )
  target_link_libraries(EllipticalButton PRIVATE ${VTK_LIBRARIES})
else()
  # 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(EllipticalButton MACOSX_BUNDLE EllipticalButton.cxx )
  target_link_libraries(EllipticalButton PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS EllipticalButton
    MODULES ${VTK_LIBRARIES}
    )
endif()

Download and Build EllipticalButton

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

cd EllipticalButton/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:

./EllipticalButton

WINDOWS USERS

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