# How to construct body-fitted coordinate system in Paraview

**URL:** https://discourse.paraview.org/t/how-to-construct-body-fitted-coordinate-system-in-paraview/11089
**Category:** ParaView Support
**Created:** [December 31, 2022, 5:16am UTC](https://discourse.paraview.org/t/how-to-construct-body-fitted-coordinate-system-in-paraview/11089 "2022-12-31T05:16:19Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![Ying](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/y/fbc32d/32.png) [@Ying](https://discourse.paraview.org/u/Ying)
#### Post date: [December 31, 2022, 5:16am UTC](https://discourse.paraview.org/t/how-to-construct-body-fitted-coordinate-system-in-paraview/11089/1 "2022-12-31T05:16:19Z")

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Hi, I have a series of vtk files storing the flow field information, representing a vibrating body (only along y-axis) in a large domain. So the locations of body and mesh grid would change with time.

For example, at t = 0.01, the body is located above y=0.  
 ![1672463464664](https://discourse.paraview.org/uploads/default/original/2X/d/d2492ce891f2008469373d79d6ca5595f96434a5.png)

At t=0.05, the body is below y=0.  
 ![1672463604536](https://discourse.paraview.org/uploads/default/original/2X/f/f110157bcd3601464e2a0f17698a355dae176198.png)

If I want to take the center of body as the origin point, is there any way in Paraview to construct such body-fitted coordinate system, so that I can project all the flow field snapshots onto it and extract information to do proper orthogonal decomposition?

Any suggestion is welcome! Thanks!