[vtkusers] Problem with vtkPolyDataToImageStencil in 5.8

[Jothybasu Selvaraj]

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
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