# Locate cell containing a point

**URL:** https://discourse.vtk.org/t/locate-cell-containing-a-point/3588
**Category:** Development
**Created:** [June 18, 2020, 12:32pm UTC](https://discourse.vtk.org/t/locate-cell-containing-a-point/3588 "2020-06-18T12:32:07Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![SimonFuet](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/s/e95f7d/32.png) [@SimonFuet](https://discourse.vtk.org/u/SimonFuet)
#### Post date: [June 18, 2020, 12:32pm UTC](https://discourse.vtk.org/t/locate-cell-containing-a-point/3588/1 "2020-06-18T12:32:07Z")

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Hi

I’m trying to locate a point (with xyz coordinates) in a grid (i.e. find the cell containing that point). It can be any type of grid: image data, structured, explicit structured, unstructured. My goal is to get interpolation weigths to interpolate vertex data.

I’m using the FindCell method of vtkDataSet ([https://vtk.org/doc/nightly/html/classvtkDataSet.html#a2221c10d3c4cca44e82c5ef70e4e1cbd](https://vtk.org/doc/nightly/html/classvtkDataSet.html#a2221c10d3c4cca44e82c5ef70e4e1cbd), see code below).

It works fine when the dataset is an image data, but for StructuredGrids, I have a crash (see stack trace below).

Am I doing something wrong? Or is there a better way to do what I’m trying to do?

Any help will be greatly appreciated

Thanks

Simon

Code:

```
// Get the cell containing the point
int sub_id;
double pcoords[3];
vtkIdType cell_id = dataSet->FindCell(point, nullptr, -1, 0, sub_id, pcoords, nullptr);

//Get the number of points of the cell
vtkNew<vtkIdList> cell_points;
dataSet->GetCellPoints(cell_id, cell_points);
vtkIdType nb_points = cell_points->GetNumberOfIds();

//Get the interpolation weights
dataSet->FindCell(point, nullptr, cell_id, 0, sub_id, pcoords, weights);

```

Stacktrace error:  
… my method  
7 0x7fe7ebe82c61 vtkPointSet::FindCell(double\*, vtkCell\*, long long, double, int&, double\*, double\*) + 99  
6 0x7fe7ebe82bb2 vtkPointSet::FindCell(double\*, vtkCell\*, vtkGenericCell\*, long long, double, int&, double\*, double\*) + 188  
5 0x7fe7ebc96afd vtkClosestPointStrategy::FindCell(double\*, vtkCell\*, vtkGenericCell\*, long long, double, int&, double\*, double\*) + 805  
4 0x7fe7ebc967af /home/fuet/SPDE/ParaView/ParaView57/build/lib/libvtkCommonDataModel-pv5.7.so.1(+0x1e97af) [0x7fe7ebc967af]  
3 0x7fe7ebc96624 /home/fuet/SPDE/ParaView/ParaView57/build/lib/libvtkCommonDataModel-pv5.7.so.1(+0x1e9624) [0x7fe7ebc96624]  
2 0x7fe7ebd13a90 vtkHexahedron::EvaluatePosition(double const\*, double\*, int&, double\*, double&, double\*) + 738  
1 0x7fe7ebd14382 vtkHexahedron::InterpolationFunctions(double const\*, double\*) + 114  
0 0x7fe7f4153f20 /lib/x86\_64-linux-gnu/libc.so.6(+0x3ef20) [0x7fe7f4153f20]  
( 29.308s) [paraview] :0 FATL| Signal: SIGSEGV  
Erreur de segmentation (core dumped)

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<div class="post-metadata">

### Author: ![SimonFuet](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/s/e95f7d/32.png) [@SimonFuet](https://discourse.vtk.org/u/SimonFuet)
#### Post date: [June 26, 2020, 6:17am UTC](https://discourse.vtk.org/t/locate-cell-containing-a-point/3588/2 "2020-06-26T06:17:45Z")

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The answer to this question is here:

[https://discourse.paraview.org/t/locate-cell-containing-a-point/4670](https://discourse.paraview.org/t/locate-cell-containing-a-point/4670)