[vtkusers] Flattening a probed surface

[Sebastien Jourdain]

Try to update the pipeline before accessing its data...

On Wed, May 30, 2012 at 8:50 AM, Jonathan Ruiz Peinado
<jonathan.ruiz3 at gmail.com> wrote:
> No , actually sampleVolume.GetOutput() doesn't have a method GetScalars(),
> and sampleVolume.GetOutput().GetPointData().GetScalars() returns null.
>
> Maybe I wrote it wrong in a previus mail.
>
> ¿ But could I get the scalars from the volume using the surface points as
> reference ?
>
> // Probe the volume with the extruded surface
> meshedSurface.SetInputConnection(1,
> dicomImage.getNormalized().GetOutputPort());
> meshedSurface.SetInput(0, surface);
>
> Scalar =
> dicomImage.getNormalized().GetOutput().GetScalarComponentAsDouble(surfacecoord.x, surfacecoord.x, surfacecoord.x,
> 0);
>
> 2012/5/30 Sebastien Jourdain <sebastien.jourdain at kitware.com>
>>
>> You previously told me that the following line was working
>>
>> sampleVolume.GetOutput().GetScalars()
>>
>> BTW sampleVolume is not a volume but a meshed surface.
>>
>> On Wed, May 30, 2012 at 6:41 AM, Jonathan Ruiz Peinado
>> <jonathan.ruiz3 at gmail.com> wrote:
>> > An update of the previous code, seems that setDimensions is going to
>> > be deprecate at some point and is just for backwards compatibility so
>> > this
>> > is how it's looks now using setExtent instead:
>> >
>> >  //image_data.SetDimensions(width, height, 1);
>> > image_data.SetExtent(0, width - 1 ,0,  height - 1, 0, 0);
>> > image_data.SetScalarTypeToDouble();
>> > image_data.SetNumberOfScalarComponents(1);
>> > image_data.SetSpacing(1.0, 1.0, 1.0);
>> > image_data.SetOrigin(0.0, 0.0, 0.0);
>> > image_data.SetScalarComponentFromDouble(0, 0, 0, 0, 200.0);
>> > image_data.AllocateScalars();
>> >
>> > Now I'm trying to figure out  how to get the scalars from the probed
>> > surface
>> >
>> > sampleVolume.GetOutput().GetPointData().GetScalars() it's returning me a
>> > null pointer...
>> > any suggestion?
>> >
>> > 2012/5/30 Jonathan Ruiz Peinado <jonathan.ruiz3 at gmail.com>
>> >>
>> >> Ok, so I misunderstand some basics of VTK.
>> >> I'm not sure about the meaning of cell or point, thanks it shows me
>> >> something more about it.
>> >> Is there some URL where I can go to get the basic theory about it ?
>> >>
>> >> This is how the code looks now, fisrt I'm going to show you how I'm
>> >> Building the surface:
>> >>
>> >> rows = spline.GetOutput().GetNumberOfPoints();
>> >> col =dicomImage.getNormalized().GetOutput().GetDimensions()[2];
>> >> for (int row = 0; row < rows; row++)
>> >>         {
>> >>             for (int col = 0; col < cols; col++)
>> >>             {
>> >>                 double [] p = new double [3];
>> >>                 line.GetPoint(row, p);
>> >>                 x[0] = p[0] + direction[0] * col * spacing;
>> >>                 x[1] = p[1] + direction[1] * col * spacing;
>> >>                 x[2] = p[2] + direction[2] * col * spacing;
>> >>                 points.InsertPoint(cnt++, x);
>> >>             }
>> >>         }
>> >>
>> >> An now how I've fixed the code that was wrong in my previous message:
>> >> vtkImageData image_data= new vtkImageData();
>> >>
>> >> int width = spline.GetOutput().GetNumberOfPoints();
>> >> int height = dicomImage.getNormalized().GetOutput().GetDimensions()[2];
>> >>
>> >>
>> >> image_data.SetDimensions(width, height, 1); // 1 because I just want an
>> >> slice by now
>> >> //image_data.SetSpacing();
>> >>
>> >>
>> >> Do I need to set the Spacing of the image_data or it has a valid
>> >> default
>> >> value?
>> >>
>> >>
>> >>
>> >>
>> >> 2012/5/29 Sebastien Jourdain <sebastien.jourdain at kitware.com>
>> >>>
>> >>> The dimension is related to the number of points....
>> >>>
>> >>> Meaning one dimension will be the number of points that compose your
>> >>> spline and the other will be the number of iteration the swipe is
>> >>> doing.
>> >>>
>> >>> Seb
>> >>>
>> >>> On Tue, May 29, 2012 at 12:46 PM, jruiz <jonathan.ruiz3 at gmail.com>
>> >>> wrote:
>> >>> > Thanks, I'm going to follow your instructions step by step, first
>> >>> > I'm
>> >>> > trying
>> >>> > to get de surface area to set the dimension of the image data.
>> >>> >
>> >>> > Is it even close ? I'm getting the length for the extruded spline as
>> >>> > "width"
>> >>> > and "height" is the length of the extrusion. I guess this values
>> >>> > need
>> >>> > to be
>> >>> > multiply by the spacing what I get from the source image.
>> >>> >
>> >>> > vtkImageData image_data= new vtkImageData();
>> >>> >
>> >>> > double[] spacing =
>> >>> > dicomImage.getNormalized().GetOutput().GetSpacing();
>> >>> >
>> >>> > double width = spline.GetLength() * spacing[0];
>> >>> > double height = surfaceHeight * spacing[2];
>> >>> >
>> >>> > image_data.SetDimensions(width, height, 1);
>> >>> >
>> >>> > --
>> >>> > View this message in context:
>> >>> >
>> >>> > http://vtk.1045678.n5.nabble.com/Flattening-a-probed-surface-tp5713443p5713466.html
>> >>> > Sent from the VTK - Users mailing list archive at Nabble.com.
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>> >>
>> >
>
>
>
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