[vtkusers] vtkBoxWidget GetPlane Function Bug ?

[naresh]

Hi

Thank Eric and David for help . I understand now.




----- Original Message ----- 
From: "Eric E. Monson" <emonson at cs.duke.edu>
To: "naresh" <naresh at winner.co.in>
Cc: <vtkusers at vtk.org>
Sent: Monday, August 09, 2010 7:09 PM
Subject: Re: [vtkusers] vtkBoxWidget GetPlane Function Bug ?


I think this should work:

/ Get the planes
m_BoxWidget->GetPlanes(m_Planes);

// Access by index
m_Planes->GetPlane(0, m_PlaneMinX);
m_Planes->GetPlane(1, m_PlaneMaxX);

Since this way you're creating a separate instance of vtkPlane in which to 
put each result.

-Eric


On Aug 9, 2010, at 9:29 AM, naresh wrote:

> Dear Eric
>
> You are right . I am sorry for saying radom data rather i should say it 
> returns same data as last one.  I tried to debug it and check the two 
> pointer of vtkPlane . In stack both become same at last. So i think it 
> points same address .
>
> So what would be the solution  do i copy the value assining to new address 
> everytime ?
>
>
>
>
> ----- Original Message ----- From: "Eric E. Monson" <emonson at cs.duke.edu>
> To: "naresh" <naresh at winner.co.in>
> Cc: <vtkusers at vtk.org>
> Sent: Monday, August 09, 2010 6:51 PM
> Subject: Re: [vtkusers] vtkBoxWidget GetPlane Function Bug ?
>
>
> Hey Naresh,
>
> I don't know if this is your problem, but the documentation for vtkPlanes 
> (and looking at the source code) says that GetPlane(int i) will always 
> return a pointer to the same vtkPlane object (internal to vtkBoxWidget):
>
> http://www.vtk.org/doc/nightly/html/classvtkPlanes.html
>
> "Create and return a pointer to a vtkPlane object at the ith position. 
> Asking for a plane outside the allowable range returns NULL. This method 
> always returns the same object. Use GetPlane(int i, vtkPlane plane) 
> instead"
>
> So, I would try using the other GetPlane method to make sure you are 
> getting different planes each time.
>
> This shouldn't give you random data, though, so maybe something just isn't 
> initialized by the time you are accessing it... Did you follow the 
> examples for vtkBoxWidget for initializing everything? (something like 
> this from Examples and Tests in 
> http://www.vtk.org/doc/nightly/html/classvtkBoxWidget.html)
>
> vtkBoxWidget *boxWidget = vtkBoxWidget::New();
> boxWidget->SetInteractor(iren);
> boxWidget->SetPlaceFactor(1.25);
> boxWidget->SetProp3D(actor);
> (or, boxWidget->SetInput(filter->GetOutput()); )
> boxWidget->PlaceWidget();
> vtkMyCallback *callback = vtkMyCallback::New();
> boxWidget->AddObserver(vtkCommand::InteractionEvent, callback);
> boxWidget->On();
>
> Hope this helps,
> -Eric
>
> ------------------------------------------------------
> Eric E Monson
> Duke Visualization Technology Group
>
>
> On Aug 9, 2010, at 8:53 AM, naresh wrote:
>
>> Hi
>>
>> I have problem with vtkBoxwidget->GetPlane function. It returns the radom 
>> data of normal values. Is these bug or i am doing anything wrong ?
>>
>> Here is code of it. I tried to debug it . In first time and second time 
>> values changes as radomly in normal value.
>>
>>
>> for(int i=0; i<2; i++)
>> {
>> // Get the planes
>> m_BoxWidget->GetPlanes(m_Planes);
>>
>> // Access by index
>> m_PlaneMinX = m_Planes->GetPlane(0);
>> m_PlaneMaxX = m_Planes->GetPlane(1);
>> }
>>
>>
>>
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