[vtkusers] MIP help

[Jesús Spí­nola]

This is my MIP code and it works fine for me. Your problem might be you are
using a vtkColorTransferFunction when another vtkPieceWiseFunction should be
enough. Hope this helps :)

vtkPiecewiseFunction *opacityTransferFunction = vtkPiecewiseFunction::New();
        opacityTransferFunction->AddPoint( 20 , 0.0 );
        opacityTransferFunction->AddPoint( 255 , 1.0 );

        // Create a transfer function mapping scalar value to color (grey)
        vtkPiecewiseFunction *grayTransferFunction =
vtkPiecewiseFunction::New();
        grayTransferFunction->AddSegment( 0 , 0.0 , 255 , 1.0 );

        // Create a set of properties for mip
        vtkVolumeProperty *mipProperty;

        mipProperty = vtkVolumeProperty::New();
        mipProperty->SetScalarOpacity( opacityTransferFunction );
        mipProperty->SetColor( grayTransferFunction );
        mipProperty->SetInterpolationTypeToLinear();

        // creem la funció del raig MIP, en aquest cas maximitzem
l'opacitat, si fos Scalar value, ho faria pel valor
        vtkVolumeRayCastMIPFunction* mipFunction =
vtkVolumeRayCastMIPFunction::New();
        mipFunction->SetMaximizeMethodToOpacity();

        vtkVolumeRayCastMapper* volumeMapper =
vtkVolumeRayCastMapper::New();

        volumeMapper->SetVolumeRayCastFunction( mipFunction );
        volumeMapper->SetInput( m_imageCaster->GetOutput()  );

        vtkVolume* volume = vtkVolume::New();
        volume->SetMapper( volumeMapper );
        volume->SetProperty( mipProperty );

        m_renderer->AddViewProp( volume );
        m_renderer->Render();

2006/10/2, Michele Marco <michelegr at alice.it>:
>
>  I'm italian Student and i need help for setting MIP in VTK . I use vtk  vtkVolumeRayCastMIPFunction
> class to realize MIP but i have some problem to configure  "vtkPiecewiseFunction"
> and "vtkColorTransferFunction" .The code is :
>
>
> // Create the renderers, render window, and interactor
>
>   vtkRenderWindow *renWin = vtkRenderWindow::New();
>
>   vtkRenderer *ren = vtkRenderer::New();
>
>   vtkRenderWindowInteractor *iren = vtkRenderWindowInteractor::New();
>
>   renWin->AddRenderer(ren);
>
>
>
>
>
> vtkInteractorStyleTrackballCamera *aTrackBallCamera =
> vtkInteractorStyleTrackballCamera::New();
>
>   iren->SetInteractorStyle(aTrackBallCamera);
>
>   iren->SetRenderWindow(renWin);
>
>
>
> vtkDICOMImageReader *reader= vtkDICOMImageReader::New();
>
> reader->SetDirectoryName("C:/tac2");
>
> reader->Update();
>
>
>
> vtkImageCast *cast = vtkImageCast::New();
>
> cast->SetInputConnection(reader->GetOutputPort());
>
> cast->SetOutputScalarTypeToUnsignedChar();
>
>
>
> vtkPiecewiseFunction *opacityTransferFunction =
> vtkPiecewiseFunction::New();
>
>
>
> opacityTransferFunction->AddSegment(0, 0.1, 255, 0.9);
>
>
>
>
>
> vtkColorTransferFunction *colorTransferFunction =
> vtkColorTransferFunction::New();
>
> colorTransferFunction->AddRGBPoint(   0, 1.0, 0.0, 0.0 );
>
> colorTransferFunction->AddRGBPoint(  64, 1.0, 1.0, 0.0 );
>
> colorTransferFunction->AddRGBPoint( 128, 0.0, 1.0, 0.0 );
>
> colorTransferFunction->AddRGBPoint( 192, 0.0, 1.0, 1.0 );
>
> colorTransferFunction->AddRGBPoint( 255, 0.1, 0.5, 1.0 );
>
>
>
>
>
> vtkVolumeProperty *volumeProperty = vtkVolumeProperty::New();
>
> volumeProperty->SetColor(colorTransferFunction);
>
> volumeProperty->SetScalarOpacity(opacityTransferFunction);
>
> volumeProperty->SetInterpolationTypeToLinear();
>
>
>
>
>
> vtkVolumeRayCastMIPFunction *compositeMipFunction =
> vtkVolumeRayCastMIPFunction::New();
>
> compositeMipFunction->SetMaximizeMethodToScalarValue();
>
>
>
>
>
> vtkVolumeRayCastMapper *volumeRaycastMapper =
> vtkVolumeRayCastMapper::New();
>
>
> volumeRaycastMapper->SetVolumeRayCastFunction(compositeMipFunction);
>
>
> volumeRaycastMapper->SetInputConnection(cast->GetOutputPort());
>
>
>
>             vtkVolume *volume = vtkVolume::New();
>
>             volume->SetMapper(volumeRaycastMapper);
>
>             volume->SetProperty(volumeProperty);
>
>             volume->VisibilityOn();
>
>             volume->Update();
>
>
>
> ren->AddVolume(volume);
>
> renWin->SetSize(500,500);
>
> ren->ResetCamera();
>
> ren->GetActiveCamera()->Zoom(1.5);
>
>
>
> iren->Initialize();
>
> renWin->Render();
>
> iren->Start();
>
>
>
> HELP ME PLEASE!!!!!!!!!!!
>
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