[vtkusers] contour widget with live wire interpolation not working

[Jonathan Morra]

I actually just figured this out, I had to set the OutputSpacing and
OutputOriging of reslice.

On Wed, Oct 27, 2010 at 3:32 PM, Jonathan Morra <jonmorra at gmail.com> wrote:

> I have a vtkContourWidget and I wish to use a Live Wire method for drawing
> the lines.  When I make a contour widget without the live wire stuff
> everything looks fine.  However, when I add in the live wire stuff the line
> that is connecting two control points is not being shown.  Below is a
> snippet of my code that deals with the live wire part (I'm writing in Java).
>  Does anyone know why this is happening?
>
> Thanks
>
>         vtkImageAnisotropicDiffusion3D diffusion = new
> vtkImageAnisotropicDiffusion3D();
>         diffusion.SetInput(imageData);
>
>         // Gradient magnitude for edges
>         vtkImageGradientMagnitude grad = new vtkImageGradientMagnitude();
>         grad.SetDimensionality(3);
>         grad.HandleBoundariesOn();
>         grad.SetInputConnection(diffusion.GetOutputPort());
>         grad.Update();
>
>         double[] range = grad.GetOutput().GetScalarRange();
>
>         // Invert the gradient magnitude so that low costs are
>         // associated with strong edges and scale from 0 to 1
>         vtkImageShiftScale gradInvert = new vtkImageShiftScale();
>         gradInvert.SetShift(-1.0*range[1]);
>         gradInvert.SetScale(1.0 / (range[0] - range[1]));
>         gradInvert.SetOutputScalarTypeToFloat();
>         gradInvert.SetInputConnection(grad.GetOutputPort());
>         gradInvert.Update();
>         gradInverseData = gradInvert.GetOutput();
>
>         vtkContourWidget contourWidget = new vtkContourWidget();
>         contourWidget.FollowCursorOn();
>
>         vtkOrientedGlyphContourRepresentation rep = new
> vtkOrientedGlyphContourRepresentation();
>         rep.GetLinesProperty().SetLineWidth(5);
>         rep.GetProperty().SetPointSize(6);
>         rep.SetWorldTolerance(0.000005);
>
>         // The contour rep requires a suitable point placer
>         vtkImageActorPointPlacer placer = new vtkImageActorPointPlacer();
>         placer.SetImageActor(imageViewer.GetImageActor());
>
>         rep.SetPointPlacer(placer);
>         // Reslice the data because the gradient only works in 2D
>         int[] dims = imageViewer.GetImageActor().GetDisplayExtent();
>         vtkImageReslice reslice = new vtkImageReslice();
>         reslice.SetInput(gradDataInverse);
>         reslice.SetOutputExtent(dims);
>         reslice.Update();
>
>         // The line interpolator defines how intermediate points are
>         // generated between the representations nodes.  This
>         // interpolator uses Dijkstra's shortest path algorithm.
>         vtkDijkstraImageContourLineInterpolator interpolator = new
> vtkDijkstraImageContourLineInterpolator();
>         interpolator.SetCostImage(reslice.GetOutput());
>
>         interpolator.GetDijkstraImageGeodesicPath().StopWhenEndReachedOn();
>         // prevent contour segments from overlapping
>
>  interpolator.GetDijkstraImageGeodesicPath().RepelPathFromVerticesOn();
>
>         // weights are scaled from 0 to 1 as are associated cost
>         // components
>
>  interpolator.GetDijkstraImageGeodesicPath().SetCurvatureWeight(0.15);
>
>  interpolator.GetDijkstraImageGeodesicPath().SetEdgeLengthWeight(0.8);
>         interpolator.GetDijkstraImageGeodesicPath().SetImageWeight(1.0);
>
>         rep.SetLineInterpolator(interpolator);
>         contourWidget.SetRepresentation(rep);
>         contourWidget.SetInteractor(panel.getRenWin().getIren());
>         contourWidget.On();
>
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