# Vtkpolydata inside another one

**URL:** https://discourse.vtk.org/t/vtkpolydata-inside-another-one/6725
**Category:** Support
**Created:** [September 29, 2021, 8:06pm UTC](https://discourse.vtk.org/t/vtkpolydata-inside-another-one/6725 "2021-09-29T20:06:59Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![Hanxin\_Hua](https://discourse.vtk.org/user_avatar/discourse.vtk.org/hanxin_hua/32/3787_2.png) [@Hanxin\_Hua](https://discourse.vtk.org/u/Hanxin_Hua)
#### Post date: [September 29, 2021, 8:06pm UTC](https://discourse.vtk.org/t/vtkpolydata-inside-another-one/6725/1 "2021-09-29T20:06:59Z")

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Hello Everyone, I have a question.

I define two polydata p1 and p2.  
If p2 is in p1, then I do nothing.  
If p2 has some part outside p1, then I use vtkBooleanOperationPolyDataFilter to calculate the union of p1 and p2 and set p1 as the output.

I’m wondering if there is a way to check the inclusion fast. Right now, I don’t have any clue for it  
Thank you!