VTK/Examples/Cxx/Widgets/Slider

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VTK Examples Baseline Widgets TestSlider.png

3D Slider

This example demonstrates how to use a 3D slider widget. Here, the slider controls the resolution of the sphere. The slider is positioned in world coordinates - so if you rotate/translate/scale the scene, the slider will change orientation/position/size. Contrast this with the 2D slider widget that remains at a fixed location in the window.

If the callback is connected to InteractionEvent, the scene will update whenever the mouse is moved on the slider. This is not ideal if the re-rendering takes significant time as it will make the interaction very choppy. If you want to move the slider and have the scene update when the mouse button is released, connect the callback to EndInteractionEvent instead.

Slider.cxx

#include <vtkSphereSource.h>
#include <vtkSmartPointer.h>
#include <vtkPolyData.h>
#include <vtkSliderWidget.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkRenderWindow.h>
#include <vtkRenderer.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkPolyData.h>
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkCommand.h>
#include <vtkWidgetEvent.h>
#include <vtkCallbackCommand.h>
#include <vtkWidgetEventTranslator.h>
#include <vtkInteractorStyleTrackballCamera.h>
#include <vtkSliderWidget.h>
#include <vtkSliderRepresentation3D.h>
#include <vtkProperty.h>
 
// The callback does the work.
// The callback keeps a pointer to the sphere whose resolution is
// controlled. After constructing the callback, the program sets the
// SphereSource of the callback to 
// the object to be controlled.
class vtkSliderCallback : public vtkCommand
{
public:
  static vtkSliderCallback *New() 
    {
    return new vtkSliderCallback;
    }
  virtual void Execute(vtkObject *caller, unsigned long, void*)
    {
    vtkSliderWidget *sliderWidget = 
      reinterpret_cast<vtkSliderWidget*>(caller);
    this->SphereSource->SetPhiResolution(static_cast<vtkSliderRepresentation *>(sliderWidget->GetRepresentation())->GetValue()/2);
    this->SphereSource->SetThetaResolution(static_cast<vtkSliderRepresentation *>(sliderWidget->GetRepresentation())->GetValue());
    }
  vtkSliderCallback():SphereSource(0) {}
  vtkSphereSource *SphereSource;
};
 
int main (int, char *[])
{
  // A sphere
  vtkSmartPointer<vtkSphereSource> sphereSource =
    vtkSmartPointer<vtkSphereSource>::New();
  sphereSource->SetCenter(0.0, 0.0, 0.0);
  sphereSource->SetRadius(4.0);
  sphereSource->SetPhiResolution(4);
  sphereSource->SetThetaResolution(8);
 
  vtkSmartPointer<vtkPolyDataMapper> mapper =
    vtkSmartPointer<vtkPolyDataMapper>::New();
  mapper->SetInputConnection(sphereSource->GetOutputPort());
 
  vtkSmartPointer<vtkActor> actor =
    vtkSmartPointer<vtkActor>::New();
  actor->SetMapper(mapper);
  actor->GetProperty()->SetInterpolationToFlat();
 
  // A renderer and render window
  vtkSmartPointer<vtkRenderer> renderer =
    vtkSmartPointer<vtkRenderer>::New();
  vtkSmartPointer<vtkRenderWindow> renderWindow =
    vtkSmartPointer<vtkRenderWindow>::New();
  renderWindow->AddRenderer(renderer);
 
  // An interactor
  vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
    vtkSmartPointer<vtkRenderWindowInteractor>::New();
  renderWindowInteractor->SetRenderWindow(renderWindow);
 
  // Add the actors to the scene
  renderer->AddActor(actor);
 
  // Render an image (lights and cameras are created automatically)
  renderWindow->Render();
 
  vtkSmartPointer<vtkSliderRepresentation3D> sliderRep =
    vtkSmartPointer<vtkSliderRepresentation3D>::New();
  sliderRep->SetMinimumValue(3.0);
  sliderRep->SetMaximumValue(50.0);
  sliderRep->SetValue(sphereSource->GetThetaResolution());
  sliderRep->SetTitleText("Sphere Resolution");
  sliderRep->GetPoint1Coordinate()->SetCoordinateSystemToWorld();
  sliderRep->GetPoint1Coordinate()->SetValue(-4,6,0);
  sliderRep->GetPoint2Coordinate()->SetCoordinateSystemToWorld();
  sliderRep->GetPoint2Coordinate()->SetValue(4,6,0);
  sliderRep->SetSliderLength(0.075);
  sliderRep->SetSliderWidth(0.05);
  sliderRep->SetEndCapLength(0.05);
 
  vtkSmartPointer<vtkSliderWidget> sliderWidget =
    vtkSmartPointer<vtkSliderWidget>::New();
  sliderWidget->SetInteractor(renderWindowInteractor);
  sliderWidget->SetRepresentation(sliderRep);
  sliderWidget->SetAnimationModeToAnimate();
  sliderWidget->EnabledOn();
 
  vtkSmartPointer<vtkSliderCallback> callback =
    vtkSmartPointer<vtkSliderCallback>::New();
  callback->SphereSource = sphereSource;
 
  sliderWidget->AddObserver(vtkCommand::InteractionEvent,callback);
 
  renderWindowInteractor->Initialize();
  renderWindow->Render();
 
  renderWindowInteractor->Start();
 
  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 2.6)
 
PROJECT(Slider)
 
FIND_PACKAGE(VTK REQUIRED)
INCLUDE(${VTK_USE_FILE})
 
ADD_EXECUTABLE(Slider Slider.cxx)
TARGET_LINK_LIBRARIES(Slider vtkHybrid vtkWidgets)
Retrieved from "http://www.vtk.org/Wiki/VTK/Examples/Cxx/Widgets/Slider"
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