[vtkusers] Using vtkMarchingCubes3D with vtkContourWidget

[Jonathan Morra]

So after struggling with this for a while, I've come up with the following
code, which kinda does the job.

    public vtkPoints reorderPoints(vtkPolyData unorderedData) {
        vtkStripper stripper = new vtkStripper();
        stripper.SetInput(unorderedData);
        stripper.Update();
        vtkPolyData strippedData = stripper.GetOutput();

        vtkPoints points = new vtkPoints();
        // Here, we're trying to mimic the suggestion given here
        //
http://vtk.1045678.n5.nabble.com/question-about-vtkContourWidget-vtkContourRepresentation-td1255118.html#a3247766
        for (int i=0; i<strippedData.GetNumberOfCells(); i++) {
            vtkCell cell = strippedData.GetCell(i);
            for (int j=0; j<cell.GetPoints().GetNumberOfPoints()-1; j++) {
                points.InsertNextPoint(cell.GetPoints().GetPoint(j));
            }
        }
        return points;
    }
The points that are returned are in "better" order than having not run this
method, but it's still not the correct order.  It turns out that I cannot
upgrade to the newest version of VTK because we're using GDCM which isn't
yet integrated into the newest version of VTK, so I'm stuck with 5.6 for
now.  However, I did do a test on the head of GIT and I tried to use
Karthik's code suggested above, but I still couldn't get that working.  I
attempted to follow internally what vtkCellArray.GetNextCell() was doing,
and that's how I came up with the above function.

Can someone tell me why the above function isn't returning the vtkPoints in
the correct order for vtkContourWidget?

Thanks
On Sat, Nov 6, 2010 at 10:12 PM, Karthik Krishnan <
karthik.krishnan at kitware.com> wrote:

> Ah.. yes.. This method was added on May 19, 2010. Perhaps you are
> using a version of VTK prior to that.
>
> Please see :
>
> http://vtk.org/gitweb?p=VTK.git;a=commitdiff;h=068a064cea7ba0fc7a4c4f9d2f7dfed6eb093674
>
> Update your VTK.
>
>
> On Sat, Nov 6, 2010 at 10:54 PM, Jonathan Morra <jonmorra at gmail.com>
> wrote:
> > I couldn't find GetNextCell() at all in Java. I'm currently using version
> > 5.6. Do you have any other suggestions?
> >
> > On Nov 6, 2010 9:05 AM, "Karthik Krishnan" <karthik.krishnan at kitware.com
> >
> > wrote:
> >
> > Jonathan:
> >
> > Use the other signature of the method GetNextCell. [ int
> > GetNextCell(vtkIdList *pts) ]That should be wrapped...
> >
> > The code to re-order the points based on the connectivity information
> > would be written in java as :
> >
> >  vtkIdList idlist = new vtkIdList();
> >  unorderedPolyData.GetLines().GetNextCell(idlist);
> >  npts = idlist.GetNumberOfIds();
> >  for ( int i = 0;  i < ( npts-1 );  i ++)
> >    {
> >    points.InsertPoint(i, unorderedPolyData.GetPoints().GetPoint(pts[i]));
> >    }
> >
> > --
> > karthik
> >
> > On Wed, Nov 3, 2010 at 7:29 AM, Jonathan Morra <jonmorra at gmail.com>
> wrote:
> >> I have a 3D vtkPolyDat...
> >
> >> _______________________________________________
> >> Powered by www.kitware.com
> >>
> >> Visit other Kitwa...
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.vtk.org/pipermail/vtkusers/attachments/20101111/4dd3f3c6/attachment.htm>