[vtkusers] Problem with vtkPolyDataToImageStencil in 5.8

[David Gobbi]

Hi Jothy,

Remove the extrude filter from the pipeline.

 - David


On Fri, Mar 9, 2012 at 1:29 PM, Jothybasu Selvaraj <jothybasu at gmail.com> wrote:
> Hi David,
>
> I am still not able to fix this issue.
>
> This is how I create the polydata and other pipeline.
>
> vtkSmartPointer<vtkPoints> points =
>
>                        vtkSmartPointer<vtkPoints>::New();
>
>                  vtkSmartPointer<vtkCellArray> cells =
>
>                          vtkSmartPointer<vtkCellArray>::New();
>
>                points->SetNumberOfPoints(npts+1);
>
>                cells->InsertNextCell(npts+1);
>
>                for(int p=0;p<npts;p++)
>
>                {
>
>
>
>                    points->SetPoint( p, Xp, Yp,Zp );
>
>                    cells->InsertCellPoint( p );
>
>                }
>
>                cells->InsertCellPoint(npts);
>
>                points->SetPoint(npts,pts[0],pts[1],pts[2]);//close contour
>
>
>                vtkSmartPointer<vtkPolyData>polydataContour=
>
>                        vtkSmartPointer<vtkPolyData>::New();
>
>                polydataContour->Initialize();
>
>                polydataContour->SetLines(cells);
>
>                polydataContour->SetPoints(points);
>
>
> //Here all contours are appended to vtkAppendPolydataFilter
>
>                vtkSmartPointer<vtkPolyDataToImageStencil> sts=
>                        vtkSmartPointer<vtkPolyDataToImageStencil>::New();
>               sts->SetTolerance(1e-6);//very important
>                sts->SetInformationInput(binary_image);
>                vtkSmartPointer<vtkLinearExtrusionFilter> extrude=
>                        vtkSmartPointer<vtkLinearExtrusionFilter>::New();
>                extrude->SetInput(appender->GetOutput());
>                extrude->CappingOff();//also tried ON
>                extrude->SetVector(0, 0,-zSpacing);//Correct Z spacing is
> important
>                //qDebug()<<-zSpacing<<"-ve zSpacing";
>                sts->SetInput(extrude->GetOutput());
>
>
>                //qDebug()<<t->currentTime()<<"Stencil start";
>                vtkSmartPointer<vtkImageStencil> stencil=
>                        vtkSmartPointer<vtkImageStencil>::New();
>                stencil->SetStencil(sts->GetOutput());
>                stencil->SetInput(binary_image);
>                stencil->ReverseStencilOn();
>                stencil->Update();
>
>
> I am able to visualize the contour by setting appendFilter->GetOutput() to a
> vtkPolyDataMapper.
>
> Is there any thing wrong.
>
> Thanks very much!
>
> Jothy
>
>
>
>
> On Tue, Mar 6, 2012 at 3:48 PM, David Gobbi <david.gobbi at gmail.com> wrote:
>>
>> You'd have to use SetLines() instead of SetPolys().  And for
>> polylines, the final point in the polyline has to connect to the first
>> line to create a closed loop, so polylines cell arrays need an extra
>> entry as compared to polygon cell arrays.
>>
>> On Tue, Mar 6, 2012 at 8:36 AM, Jothybasu Selvaraj <jothybasu at gmail.com>
>> wrote:
>> > I ma creating the polydat per conoutr like this
>> >
>> > vtkSmartPointer<vtkPolyData>polydataContour=
>> >
>> >      vtkSmartPointer<vtkPolyData>::New();
>> >
>> > polydataContour->Initialize();
>> >
>> > polydataContour->SetPolys( cells );//vtkCellArray
>> >
>> > polydataContour->SetPoints( points);//vtkPoints
>> >
>> >
>> > How should I do that?
>> >
>> > Thanks very much
>> >
>> > Jothy
>> >
>> >
>> > On Tue, Mar 6, 2012 at 3:31 PM, David Gobbi <david.gobbi at gmail.com>
>> > wrote:
>> >>
>> >> The contours must be polylines, not polygons, or it won't work.
>> >>
>> >> On Tue, Mar 6, 2012 at 6:29 AM, Jothybasu Selvaraj
>> >> <jothybasu at gmail.com>
>> >> wrote:
>> >> > Yes, I have one contour for each z slice as a vtkPolyData. I will try
>> >> > removing that.
>> >> >
>> >> > Thanks
>> >> >
>> >> >
>> >> > On Tue, Mar 6, 2012 at 1:26 PM, David Gobbi <david.gobbi at gmail.com>
>> >> > wrote:
>> >> >>
>> >> >> Do you have one contour for each Z slice?  If so, then try removing
>> >> >> the Extrude filter from your pipeline.
>> >> >>
>> >> >>
>> >> >> On Tue, Mar 6, 2012 at 2:51 AM, Jothybasu Selvaraj
>> >> >> <jothybasu at gmail.com>
>> >> >> wrote:
>> >> >> > Another point here,
>> >> >> >
>> >> >> > I am creating a vtkPolyData for each contour and then adding it to
>> >> >> > the
>> >> >> > vtkAppendPolydataFilter, then the output of vtkAppenPolydataFilter
>> >> >> > is
>> >> >> > set as
>> >> >> > input to vtkPolydataToImageStencil.
>> >> >> >
>> >> >> > Could this make any difference?
>> >> >> >
>> >> >> > Thanks
>> >> >> >
>> >> >> > Jothy
>> >> >> >
>> >> >> >
>> >> >> > On Mon, Mar 5, 2012 at 7:49 PM, Jothybasu Selvaraj
>> >> >> > <jothybasu at gmail.com>
>> >> >> > wrote:
>> >> >> >>
>> >> >> >> No, it doesn't fix the problem.
>> >> >> >>
>> >> >> >> But it seems to work fine for contours with z-spacing in steps of
>> >> >> >> 1mm.
>> >> >> >>
>> >> >> >> It is working well for a dataset with 3mm spacing but fails for
>> >> >> >> 2.5
>> >> >> >> mm.
>> >> >> >>
>> >> >> >> Maybe I need to test it thoroughly. Can I use those cxx and .h
>> >> >> >> from
>> >> >> >> 5.6
>> >> >> >> in
>> >> >> >> 5.8, that would be a easy workaround.
>> >> >> >>
>> >> >> >> Thanks
>> >> >> >>
>> >> >> >> Jothy
>> >> >> >>
>> >> >> >>
>> >> >> >> On Mon, Mar 5, 2012 at 4:01 PM, David Gobbi
>> >> >> >> <david.gobbi at gmail.com>
>> >> >> >> wrote:
>> >> >> >>>
>> >> >> >>> Hi Jothy,
>> >> >> >>>
>> >> >> >>> It underwent significant changes, but the only change I can
>> >> >> >>> think
>> >> >> >>> of that might have affected your pipeline is the way that it
>> >> >> >>> does
>> >> >> >>> rounding, it used to use a Floor() method that provided a small
>> >> >> >>> tolerance even if you did SetTolerance(0).  Try calling
>> >> >> >>> SetTolerance(1e-6) on your PolyDataToImageStencil object, it
>> >> >> >>> might help.
>> >> >> >>>
>> >> >> >>>  - David
>> >> >> >>>
>> >> >> >>> On Mon, Mar 5, 2012 at 3:17 AM, Jothybasu Selvaraj
>> >> >> >>> <jothybasu at gmail.com>
>> >> >> >>> wrote:
>> >> >> >>> > Hi all,
>> >> >> >>> >
>> >> >> >>> > I was able to create a mesh using the following pipeline in
>> >> >> >>> > 5.6
>> >> >> >>> > and
>> >> >> >>> > it
>> >> >> >>> > worked well
>> >> >> >>> >
>> >> >> >>> >
>> >> >> >>> >
>> >> >> >>> >
>> >> >> >>> >
>> >> >> >>> > vtkPolyDataToImageStencil->vtkLinearExtrusionFilter->vtkImageStencil->vtkDiscreteMarchingCubes
>> >> >> >>> >
>> >> >> >>> > Now, I have updated vtk to 5.8 and I am getting gaps in the
>> >> >> >>> > mesh
>> >> >> >>> > along
>> >> >> >>> > the z
>> >> >> >>> > axis. I am really puzzled, I have tried with different data
>> >> >> >>> > sets
>> >> >> >>> > as
>> >> >> >>> > well.
>> >> >> >>> >
>> >> >> >>> > I have read somewhere that vtkPolyDataToImageStencil had some
>> >> >> >>> > changes
>> >> >> >>> > in
>> >> >> >>> > 5.8, does it has anything to do with this problem, or am I
>> >> >> >>> > doing
>> >> >> >>> > anything wrong?
>> >> >> >>> >
>> >> >> >>> > I have contours of constant z-spacing.
>> >> >> >>> >
>> >> >> >>> > Any hints?
>> >> >> >>> >
>> >> >> >>> > Thanks
>> >> >> >>> >
>> >> >> >>> > --
>> >> >> >>> > Jothy
>> >> >> >>
>> >> >> >>
>> >> >> >>
>> >> >> >>
>> >> >> >> --
>> >> >> >> Jothy
>> >> >> >>
>> >> >> >
>> >> >> >
>> >> >> >
>> >> >> > --
>> >> >> > Jothy
>> >> >> >
>> >> >
>> >> >
>> >> >
>> >> >
>> >> > --
>> >> > Jothy
>> >> >
>> >
>> >
>> >
>> >
>> > --
>> > Jothy
>> >
>
>
>
>
> --
> Jothy
>