[vtkusers] Question about contour widget

[Karthik Krishnan]

You need to add the bounding planes to confine it to a single plane.
Something like :

  placer.RemoveAllBoundingPlanes();
  placer.SetProjectionNormalToZAxis();

  imageActor.GetBounds(bounds);
  plane = new vtkPLane()
  plane->SetOrigin( bounds[0], bounds[2], bounds[4] );
  plane->SetNormal( 0.0, 0.0, 1.0 );
  this->Placer->AddBoundingPlane( plane );

  plane2 = vtkPlane::New();
  plane2->SetOrigin( bounds[1], bounds[3], bounds[5] );
  plane2->SetNormal( 0.0, 0.0, -1.0 );
  placer.AddBoundingPlane( plane2 );

On Tue, Oct 12, 2010 at 9:04 PM, Jonathan Morra <jonmorra at gmail.com> wrote:

> Thanks for your help, I replaced the placer as you suggested, and now my
> code looks like the following
>
> vtkBoundedPlanePointPlacer placer = new vtkBoundedPlanePointPlacer();
>         placer.SetProjectionNormalToZAxis();
>
>  placer.SetProjectionPosition(panel.getImageViewer().GetImageActor().GetCenter()[2]);
>         rep.SetPointPlacer(placer);
>
> This is almost right.  The contour now appears on the plane that I drew it
> on and the plane above it and that is it.  I just want the contour on the
> plane I drew it on.  I tried playing around with placer.SetPixelTolerance()
> but that didn't make a difference.
>
> On Tue, Oct 12, 2010 at 2:33 AM, Karthik Krishnan <
> karthik.krishnan at kitware.com> wrote:
>
>> On Tue, Oct 12, 2010 at 10:33 AM, Jonathan Morra <jonmorra at gmail.com>wrote:
>>
>>> I have a vtkImageViewer2 and wish to use vtkContourWidget to draw a
>>> contour on the image.  The data I'm loading is a 3D DICOM CT volume.  I have
>>> found the following question
>>> http://vtk.1045678.n5.nabble.com/vtkContourWidget-with-vtkImageViewer2-td1236295.html and
>>> created the following code as a result (in Java)
>>>
>>>         vtkContourWidget contourWidget = new vtkContourWidget();
>>>         contourWidget.SetInteractor(panel.getRenWin().getIren());
>>>         contourWidget.FollowCursorOn();
>>>
>>>         vtkOrientedGlyphContourRepresentation rep = new
>>> vtkOrientedGlyphContourRepresentation();
>>>         contourWidget.SetRepresentation(rep);
>>>
>>>         vtkImageActorPointPlacer placer = new vtkImageActorPointPlacer();
>>>         placer.SetImageActor(panel.getImageViewer().GetImageActor());
>>>         rep.SetPointPlacer(placer);
>>>
>>
>> What this point placer does is to constrain the contour to the plane
>> defined by the ImageActor. However, given that the same image actor is used
>> for multiple slices, when you change the slice, the position of the image
>> actor effectively changes and the contour updates itself to lie on the new
>> plane.
>>
>> What you need is to use a vtkBoundedPlanePointPlacer with the bounding
>> planes de-lienating the bounds of the image actor when the contour is
>> defined. That way it won't change when you change the slice.
>>
>> Also to manage visibility of the contour (the contour will be visible for
>> all slices in front of the defined slice), you could subclass the contour
>> representation, insert a clipper that clips the polydata based on the
>> bounding planes, that way, visibility is implicitly managed by the
>> representation.
>>
>> --
>> karthik
>>
>>         contourWidget.EnabledOn();
>>>         contourWidget.ProcessEventsOn();
>>>
>>> When I do this and draw a contour and then scroll through the image
>>> planes the same contour appears on every plane.  Ideally I'd like a
>>> different contour on every plane.  If I don't use the
>>> vtkImageActorPointPlacer then the contour only appears on one plane but it's
>>> the same plane regardless of which plane is being viewed, which is also
>>> wrong.
>>>
>>> Any suggestions about how to do this correctly would be greatly
>>> appreciated.
>>>
>>> Thanks
>>>
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>>
>
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