[vtkusers] Flickering with QVTKWidget

[Luis Roberto P. Paula]

Hi Clint,

I tried this, but if a just call the SetInput method, the image doesn't
change in the display when the slider moves.

How can I update the image using the same vtkRenderWindow?

On Sat, Oct 25, 2008 at 1:01 PM, Clinton Stimpson <clinton at elemtech.com>wrote:

> Hi All,
>>
>> I have developed a GUI with Qt and I am using the QVTKWidget to display a
>> 2D
>> image.
>>
>> This 2D image cames from a 3D image. I have a slider to control what is
>> the
>> slice to be displayed.
>>
>> The problem is that I am getting a flickering effect every time the image
>> is
>> changed.
>>
>> Here is a piece of code of what I am doing:
>>
>> void MyGui::moveBar() {
>>   ImageType2D::Pointer img =
>> myImage->getImage2DFrom3D(horizontalScrollBar->value());
>>
>>   vtkImageViewer* image_view = vtkImageViewer::New();
>>   image_view->SetInput(myImage->convertITKtoVTK(img));
>>
>>   vtkWidget->SetRenderWindow(image_view->GetRenderWindow());
>>
>>   image_view->SetColorLevel(138.5);
>>   image_view->SetColorWindow(233);
>>
>>   vtkWidget->show();
>> }
>>
>> This method is called every time the slider is moved.
>>
>> Does anybody knows how to get rid of this flickering effect?
>>
>
> The flicker comes from re-creating the vtkRenderWindow each time you have
> an image.
> Can't you use the same vtkImageViewer instance at all times, and just call
> SetInput when you change the image?
> And don't bother calling vtkWidget->SetRenderWindow() and vtkWidget->show()
> each time the slider moves.
>
> Clint
>
>
>
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