I am trying the Crystal Eyes for stereo display on Windows NT 4.0, and have some problems.

In terms of  Crystal Eyes, there is a black internal between the above image ( left-eye ) and below image ( right eye ), e.g., there is 38 blank internal for 1024*768 on my computer. I viewed the VTK source code, and  did not find any code lines to process this black internal.
( it seems there no considering of  black internal as the vertical viewport is divided by 2 for VTK_Stereo_Crystal_Eyes ). Am I right?

I am using VTK on June 16, 1999 and Visual C++ 6.0.

The tested source file is as follows. ( modified from the example Mace3.cpp )
//////////////////////////////////////////////////////////////////////
 // create the rendering objects
  vtkRenderer *ren1 = vtkRenderer::New();
  vtkRenderWindow *renWin = vtkRenderWindow::New();

     renWin->StereoCapableWindowOn();  // added by me

    renWin->AddRenderer(ren1);
  vtkRenderWindowInteractor *iren = vtkRenderWindowInteractor::New();
    iren->SetRenderWindow(renWin);

  // create the pipline, ball and spikes
  vtkSphereSource *sphere = vtkSphereSource::New();
    sphere->SetThetaResolution(7); sphere->SetPhiResolution(7);
  vtkPolyDataMapper *sphereMapper = vtkPolyDataMapper::New();
    sphereMapper->SetInput(sphere->GetOutput());
  vtkActor *sphereActor = vtkActor::New();
    sphereActor->SetMapper(sphereMapper);
//  sphereActor->GetProperty()->SetColor(0.8,0.8,0.8);

  vtkConeSource *cone = vtkConeSource::New();
    cone->SetResolution(5);
  vtkGlyph3D *glyph = vtkGlyph3D::New();
    glyph->SetInput(sphere->GetOutput());
    glyph->SetSource(cone->GetOutput());
    glyph->SetVectorModeToUseNormal();
    glyph->SetScaleModeToScaleByVector();
    glyph->SetScaleFactor(0.25);
  vtkPolyDataMapper *spikeMapper = vtkPolyDataMapper::New();
    spikeMapper->SetInput(glyph->GetOutput());
  vtkActor *spikeActor = vtkActor::New();
    spikeActor->SetMapper(spikeMapper);
//  spikeActor->GetProperty()->SetColor(0.8,0.8,0.8);

  ren1->AddActor(sphereActor);
  ren1->AddActor(spikeActor);
  ren1->SetBackground(0.2,0.3,0.4);
  renWin->SetSize(300,300);

  renWin->StereoRenderOn();
  renWin->SetStereoTypeToCrystalEyes();
  renWin->Render();
  iren->Start();

///////////////////////////////////////////////////////////////////////

Could somebody give me some solutions?

Thanks in advance

Jianhua