[vtk-developers] Bug/feature request for Widgets/vtkSphereWidget

[Prabhu Ramachandran]

Hi,

I just discovered a small problem with the vtkSphereWidget.  It
appears that vtkSphereWidget could be a subclass of
vtkPolyDataSourceWidget but this is not the case neither is the
vtkLineWidget or vtkPointWidget.  OTOH, vtkPlaneWidget is a subclass
of vtkPolyDataSourceWidget.

Anyway, the problem is that vtkSphereWidget does not have an
UpdatePlacement method.  So if you set the sphere's position like so:

 w = vtkSphereWidget()
 w.SetCenter(x,y,z)
 pd = vtkPolyData()
 w.GetPolyData(pd)

Then, unless you interact with the sphere, the GetPolyData method
produces poly data that is not up-to-date.  Essentially,
this->SphereSource->Update(); needs to be called for the poly data to
be in sync.

My request is that either vtkSphereWidget be re-written to be a
subclass of vtkPolyDataSourceWidget or atleast an UpdatePlacement be
added to it.

It would be great if this were added to the 5.0 branch as well.

Thanks.
cheers,
prabhu