[vtkusers] Help updating a QVTKWidget

[André Prins]

You could try calling QVTKWidget::update(), which is Qt's method of
repainting the widget.
See for example: http://doc.trolltech.com/4.5/qwidget.html#update.

Regards,
André

On Mon, Nov 23, 2009 at 2:04 PM, Garrett Larson <garrett at unc.edu> wrote:
> I've created an application that contains a QVTKWidget linked to a
> vtkImageViewer2. Alterations to the vtkImageData before initializing the
> vtkImageViewer2 are visible as soon as I call viewer->Render(), but any
> changes I make later do not appear until I click inside the widget. In fact,
> this happens even if I run the exact same sequence of methods to make a new
> vtkImageViewer2 (as below). Is this a result of the QVTKWidget caching the
> image data, and if so, how can I make it update? Thanks!
>
> ==================
>
>   gridData = vtkImageData::New();
>
> // etc.
>
>   gridData->
> SetScalarTypeToFloat();
>   gridData->AllocateScalars();
>   gridData->GetPointData()->GetScalars()->FillComponent(0,0);
>
>
> // The vtkImageData *gridData is modified via calls to SetScalarComponent...
>
>
> gridData->SetScalarComponentFromDouble((int)pos[0],(int)pos[1],0,0,intensity);
>
>   viewer = vtkImageViewer2::New();
>   viewer->SetInput(gridData);
>   viewer->SetupInteractor(this->ui->qvtkWidget->GetInteractor());
>   viewer->SetRenderWindow(this->ui->qvtkWidget->GetRenderWindow());
>   viewer->Render();
>
> // ... and the modified image is displayed correctly.
>
> // But if the vtkImageData *gridData is further modified via calls to
> SetScalarComponent...
>
>
> gridData->SetScalarComponentFromDouble((int)pos[0],(int)pos[1],0,0,intensity);
>
>   viewer = vtkImageViewer2::New();
>   viewer->SetInput(gridData);
>   viewer->SetupInteractor(this->ui->qvtkWidget->GetInteractor());
>   viewer->SetRenderWindow(this->ui->qvtkWidget->GetRenderWindow());
>   viewer->Render();
>
> // ...the new changes are still not visible until I click the image.
>
> ===================
>
> -Garrett Larson
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