# CompassWidget

VTKExamples/Python/Widgets/CompassWidget

### Description

Draws an interactive compass.

- Contributed by Jothy

==Build Requirements== VTK_USE_GEOVIS:BOOL=ON (For VTK < VTK 5.4).

### Code

CompassWidget.py

    #!/usr/bin/env python

    import vtk

    # sphere
    sphereSource = vtk.vtkSphereSource()
    sphereSource.SetCenter(0.0, 0.0, 0.0)
    sphereSource.SetRadius(4.0)

    mapper = vtk.vtkPolyDataMapper()
    if vtk.VTK_MAJOR_VERSION <= 5:
        mapper.SetInput(sphereSource.GetOutput())
    else:
        mapper.SetInputConnection(sphereSource.GetOutputPort())

    actor = vtk.vtkActor()
    actor.SetMapper(mapper)

    # a renderer and render window
    renderer = vtk.vtkRenderer()
    renderWindow = vtk.vtkRenderWindow()
    renderWindow.AddRenderer(renderer)

    # an interactor
    renderWindowInteractor = vtk.vtkRenderWindowInteractor()
    renderWindowInteractor.SetRenderWindow(renderWindow)

    # Create the widget and its representation
    compassRepresentation = vtk.vtkCompassRepresentation()

    compassWidget = vtk.vtkCompassWidget()
    compassWidget.SetInteractor(renderWindowInteractor)
    compassWidget.SetRepresentation(compassRepresentation)

    # add the actors to the scene
    renderer.AddActor(actor)
    renderer.SetBackground(1, 1, 1) # Background color white
    renderWindow.Render()
    compassWidget.EnabledOn()

    style = vtk.vtkInteractorStyleTrackballCamera()
    renderWindowInteractor.SetInteractorStyle(style)

    # begin interaction
    renderWindowInteractor.Start()
    renderWindowInteractor.Initialize()