# SelectEnclosedPoints Tolerance
**URL:** https://discourse.vtk.org/t/selectenclosedpoints-tolerance/1161
**Category:** Support
**Created:** [June 17, 2019, 12:22pm UTC](https://discourse.vtk.org/t/selectenclosedpoints-tolerance/1161 "2019-06-17T12:22:21Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Caroline](https://discourse.vtk.org/u/Caroline)
#### Post date: [June 17, 2019, 12:22pm UTC](https://discourse.vtk.org/t/selectenclosedpoints-tolerance/1161/1 "2019-06-17T12:22:21Z")
Dear Forum,
I am looking for help in understanding how the tolerance for vtkSelectEnclosedPoints works please.
I have been using vtkSelectEnclosedPoints to identify which points on a rectilinear grid lie within a vtkPolyData set. It works I expect until the points of the rectilinear grid lie on the facets of the polydata.
I have created a simplified example using a 2 x 2 x 2 Box Source centred on 0,0,0 cleaned with the Clean filter to ensure it is a closed surface as my PolyData (green Surface). The rectilinear grid has 16x16x16 cells with dimensions 4 x 4 centred on 0,0,0 (wireframe). I used the output from vtkSelectEnclosedPoints as a variable on the rectilinear grid and used a Threshold of 0.5 to view my results (Grey Surface with Edges).
With the default tolerance for vtkSelectEnclosedPoints of 0.0001 I get this
With the default tolerance for vtkSelectEnclosedPoints of 0.1 I get this
Tolerance = 1.0 and I get what I expected
Unfortunately on a slightly more complex shape I have a choice of missing cells or outliers. Ship is 100 long, rectilinear cells are cells have 0.5 edge length
Tolerance = 1.0
Can anyone give me any ideas as to how I get the tolerance to behave in the same way for each point please?
Thank You
Caroline
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### Author:  [@Jay](https://discourse.vtk.org/u/Jay)
#### Post date: [January 2, 2020, 11:13pm UTC](https://discourse.vtk.org/t/selectenclosedpoints-tolerance/1161/2 "2020-01-02T23:13:19Z")
The comment posted here by @lorensen may be of some help.
[http://vtk.1045678.n5.nabble.com/vtkSelectEnclosedPoints-filter-inconsistent-output-of-IsInside-method-td5728587.html](http://vtk.1045678.n5.nabble.com/vtkSelectEnclosedPoints-filter-inconsistent-output-of-IsInside-method-td5728587.html)