[vtkusers] vtkPointLocator Problem

[Andy Bauer]

It works for my python script:

from vtk import *
s = vtkSphereSource()
s.SetPhiResolution(40)
s.Update()
pd = s.GetOutput()
pd.GetNumberOfPoints()
loc = vtkPointLocator()
loc.SetDataSet(pd)
id = vtkIdList()
pt = [0,0,0]
loc.FindPointsWithinRadius(5, pt, id)
id.GetNumberOfIds()
pd.GetNumberOfPoints()


What version of vtk are you using?  If you send me a test code that fails
with a data set I'll check it out.

Andy


> Date: Wed, 9 Jun 2010 23:50:08 +0300
> From: "A. Burak Yoldemir" <yoldemir at gmail.com>
> Subject: Re: [vtkusers] vtkPointLocator Problem
> To: Bill Lorensen <bill.lorensen at gmail.com>, vtkusers at vtk.org
> Message-ID:
>        <AANLkTikyCw5WIypHmpkjkZgnroGkfmtcij5R7_AaGFa4 at mail.gmail.com>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Yes, I am aware of that example, but I have no solution to my problem. What
> I want is to use a vtkPolyData object as the dataset of a vtkPointLocator.
> Here is my problem in a nutshell:
>
> - I have a number of points in a vtkPoints object.
> - Then, I create a vtkPolyData object and use the SetPoints function of it
> to define the point coordinates.
> - Next, I create a vtkPointLocator object and use the SetDataSet function
> of
> it to build the locator from these points.
> - Finally, I use FindPointsWithinRadius function for a point which has many
> neighbors (just manually checked), but no neighbors are returned.
> - I also tried FindClosestPoint function for each of my points. At each
> time, the closest point ID turns out to be 0, however it actually is not.
>
> What might I be missing?
>
>
> - Ahmet Burak Yoldemir
>
>
> On Wed, Jun 9, 2010 at 1:04 AM, Bill Lorensen <bill.lorensen at gmail.com
> >wrote:
>
> > Have you looked at this example:
> > http://www.vtk.org/Wiki/VTK/Examples/PointLocator_Radius
> >
> >
> > On Tue, Jun 8, 2010 at 4:49 PM, A. Burak Yoldemir <yoldemir at gmail.com>
> > wrote:
> > > Hello all,
> > >
> > > I am having a problem with FindPointsWithinRadius function of
> > > vtkPointLocator class. I have a bunch of points in a certain volume,
> with
> > no
> > > specific topology. Using the following code snippet, I create a point
> > > locator object and specify its data set:
> > >
> > > vtkPoints* edge_pts = vtkPoints::New();
> > >
> > > for(int i = 0; i < someLimit; i++)
> > >
> > > {
> > >
> > > edge_pts->InsertNextPoint(somePoint);
> > >
> > > }
> > >
> > > vtkPolyData* edge_pts_set = vtkPolyData::New();
> > >
> > > edge_pts_set->SetPoints(edge_pts);
> > >
> > > edge_pts_set->Update();
> > >
> > > vtkPointLocator* NeighborLocator = vtkPointLocator::New();
> > >
> > > NeighborLocator->SetDataSet(edge_pts_set);
> > >
> > > NeighborLocator->BuildLocator();
> > >
> > > Then, I use the FindPointsWithinRadius function of NeighborLocator,
> where
> > I
> > > (manually) made sure that there are several neighbors of the query
> point.
> > > However, the aforementioned function returns no neighbors. Any ideas on
> > > where the problem could be?
> > >
> > > Regards,
> > >
> > >
> > > Burak
>
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