vtkSphereWidget

Section: Visualization Toolkit Widget Classes

Usage

This 3D widget defines a sphere that can be interactively placed in a scene.

To use this object, just invoke SetInteractor() with the argument of the method a vtkRenderWindowInteractor. You may also wish to invoke "PlaceWidget()" to initially position the widget. The interactor will act normally until the "i" key (for "interactor") is pressed, at which point the vtkSphereWidget will appear. (See superclass documentation for information about changing this behavior.) Events that occur outside of the widget (i.e., no part of the widget is picked) are propagated to any other registered obsevers (such as the interaction style). Turn off the widget by pressing the "i" key again (or invoke the Off() method).

The vtkSphereWidget has several methods that can be used in conjunction with other VTK objects. The Set/GetThetaResolution() and Set/GetPhiResolution() methods control the number of subdivisions of the sphere in the theta and phi directions; the GetPolyData() method can be used to get the polygonal representation and can be used for things like seeding streamlines. The GetSphere() method returns a sphere implicit function that can be used for cutting and clipping. Typical usage of the widget is to make use of the StartInteractionEvent, InteractionEvent, and EndInteractionEvent events. The InteractionEvent is called on mouse motion; the other two events are called on button down and button up (any mouse button).

Some additional features of this class include the ability to control the properties of the widget. You can set the properties of the selected and unselected representations of the sphere.

To create an instance of class vtkSphereWidget, simply invoke its constructor as follows

  obj = vtkSphereWidget

Methods

The class vtkSphereWidget has several methods that can be used. They are listed below. Note that the documentation is translated automatically from the VTK sources, and may not be completely intelligible. When in doubt, consult the VTK website. In the methods listed below, obj is an instance of the vtkSphereWidget class.