[vtkusers] vtkqt and vtkWindowToImageFilter

[Zisik, Herbert]

Hi All,

I use vtkqt and vtk 4.2 on Windows. Everything works fine, but using
vtkWindowToImageFilter, the mouse is flickering and the response time at
mouse movement ist very slow.

Here my example code:

#include "qvExample.h"

#include "vtkWindowToImageFilter.h"
#include "vtkJPEGWriter.h"
#include "vtkTIFFWriter.h"
#include "vtkRenderWindow.h"

QVExample::QVExample() {
    setCaption("Another Example for Qt and VTK together");

    QPopupMenu *popup = new QPopupMenu;
    popup->insertItem("Save", this, SLOT(saveFrame()));
    popup->insertItem("Exit", qApp, SLOT(quit()));
    
    QMenuBar *menuBar = new QMenuBar(this);
    menuBar->insertItem("File", popup);

    renderWindowLeft = new vtkQtRenderWindow(this);
    interactorLeft = vtkQtRenderWindowInteractor::New();
    interactorLeft->SetRenderWindow(renderWindowLeft);
    renderWindowLeft->show();

    interactorLeft->SetDesiredUpdateRate(3.0);
    interactorLeft->SetStillUpdateRate(0.1);

    leftRenderer = NULL;

    QHBoxLayout *layTop = new QHBoxLayout(this);
    layTop->addWidget(renderWindowLeft);
}

void QVExample::setLeftRenderer(vtkRenderer *renderer) {
    if (!renderer)
	return;
    if (leftRenderer)
	renderWindowLeft->RemoveRenderer(leftRenderer);
    leftRenderer = renderer;
    renderWindowLeft->AddRenderer(renderer);
}

void QVExample::saveFrame()
{
	renderWindowLeft->OffScreenRenderingOn();

	vtkWindowToImageFilter* w2i = vtkWindowToImageFilter::New();
	w2i->SetInput( renderWindowLeft );
//	w2i->Update();

	vtkJPEGWriter* jpegw = vtkJPEGWriter::New();
	jpegw->SetInput( w2i->GetOutput() );
	jpegw->SetFileName("whatever.jpg" );
	jpegw->ProgressiveOn();
	jpegw->SetQuality( 100 );
//	jpegw->Write();

	vtkTIFFWriter* tiffw = vtkTIFFWriter::New();
	tiffw->SetInput( w2i->GetOutput() );
	tiffw->SetFileName("whatever.tif" );
//	tiffw->Write();

	tiffw->Delete();
	jpegw->Delete();

	w2i->Delete();

	renderWindowLeft->OffScreenRenderingOff();
}

The red code lines marked as comment, causes the effect.

Mit freundlichen Grüßen / Best Regards

Herbert Zisik
MTU Aero Engines GmbH
Zerstörungsfreie Prüfverfahren (TEFP)
Advanced Non-Destructive Testing (TEFP)
Dachauer Str. 665
80995 München
Germany

Tel  +49 (0)89 14 89-42 91
Fax +49 (0)89 14 89-96283
mailto:Herbert.Zisik at muc.mtu.de
http://www.mtu.de