[vtkusers] Data pipeline between vtkContourFilter and vtkImageMapToColors

[Bill Lorensen]

vtkCutter can be used on the isosurface to produce isolines.

On Fri, Feb 6, 2015 at 8:48 AM, Iyas Hamdan <iyas.hamdan at gmail.com> wrote:
> Sorry for the late reply,
> And thanks for the info Bill!
> I added both actors to the renderer and it worked just fine.
>
> Another problem though, since i'm now working with 3D volumes, would
> ContourFilter still work in this case ?
> I tested it on 2D images and it works fine but when I try it a 3D imagedata
> the result is a bit strange.
>
> Actually, what I'm looking for is to show the CT volume slice by slice, and
> I want to show the isolines of the corresponding dose slice  on top of each
> CT one.
> But what I got is the whole isosurface shown over all the slices.
>
> So my question is, can the ContourFilter be used in my case ?
> or should I extract slices from my dose volume one by one, find the isolines
> in each slice then combine them all back in one volume and show this one on
> top of the CT ?
>
> Thanks in advance,
>
> Iyas
>
> On Tue, Feb 3, 2015 at 5:33 PM, Bill Lorensen <bill.lorensen at gmail.com>
> wrote:
>>
>> Each contour line has a scalar value associated with it (the iso value
>> for that line). You just need to create a lookup table for the
>> polydata mapper that maps the isovalues to the colors you want. No
>> need to use image blend. Just render the contour lines as polydata.
>>
>>
>> On Tue, Feb 3, 2015 at 11:21 AM, Iyas Hamdan <iyas.hamdan at gmail.com>
>> wrote:
>> > Hello vtkusers,
>> >
>> > I'm trying to visualize the RT dose on top of a CT image. To do so, I
>> > first
>> > find the iso-dose lines using vktContourFilter which works just fine.
>> > Then I want to add colors to those iso-lines depending on their value.
>> > So I
>> > creat a lookup table and then ( I think ) I have to map my image through
>> > this lookup table using vtkImageMapToColors.
>> > Afterwards, I have to use vtkImageBlend with two mappers as inputs ( one
>> > for
>> > iso-lines and one for the CT image).
>> >
>> > So it goes something like this:
>> >
>> > vtkSmartPointer<vtkImageMapToColors> DoseColorMapper =
>> > vtkSmartPointer<vtkImageMapToColors>::New();
>> > DoseColorMapper->SetInputData(contourFilter->GetOutput());
>> > DoseColorMapper->SetLookupTable(l_lut);
>> > DoseColorMapper->SetOutputFormatToRGB();
>> > /// ... the same for the CT image
>> > vtkSmartPointer<vtkImageBlend> imgBlender =
>> > vtkSmartPointer<vtkImageBlend>::New();
>> >  imgBlender->SetOpacity(0, 0.5);
>> >  imgBlender->SetOpacity(1, 0.5);
>> >  imgBlender->AddInputConnection(CtColorMapper->GetOutputPort());
>> >  imgBlender->AddInputConnection(DoseColorMapper->GetOutputPort());
>> >
>> >
>> >
>> > The problem is, when I trying doing passing the output of the
>> > ContourFilter
>> > to the mapper I get this error :
>> > vtkCompositeDataPipeline (037DBD78): Input for connection index 0 on
>> > input
>> > port index 0 for algorithm vtkImageMapToColors(037DBC50) is of type
>> > vtkPolyData, but a vtkImageData is required.
>> >
>> > So my question is, do I have to convert the output of ContourFilter from
>> > polydata to imagedata ?
>> > or is there another way around this by giving the mapper an input of
>> > type
>> > polydata ?
>> >
>> > any help would be really appreciated.
>> >
>> > Thanks in advance
>> >
>> > Iyas
>> >
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>>
>>
>> --
>> Unpaid intern in BillsBasement at noware dot com
>
>



-- 
Unpaid intern in BillsBasement at noware dot com