# QCriterion in Paraview

**URL:** <https://discourse.paraview.org/t/qcriterion-in-paraview/2355>\
**Category:** ParaView Support\
**Created:** [August 3, 2019, 3:49pm UTC](https://discourse.paraview.org/t/qcriterion-in-paraview/2355 "2019-08-03T15:49:32Z")\
**Posts on this page:** 4\
**Page:** 2

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**Author:** ![Muhammad\_Zangeneh](https://discourse.paraview.org/user_avatar/discourse.paraview.org/muhammad_zangeneh/32/1844_2.png) [@Muhammad\_Zangeneh](https://discourse.paraview.org/u/Muhammad_Zangeneh)\
**Post date:** [September 12, 2020, 5:28pm UTC](https://discourse.paraview.org/t/qcriterion-in-paraview/2355/22 "2020-09-12T17:28:09Z")

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It depends on the number of your grids.You can only extract the flow near the wall by different extraction filters in order to reduce the computation time.

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**Author:** ![mwestphal](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mwestphal/32/17_2.png) [@mwestphal](https://discourse.paraview.org/u/mwestphal)\
**Post date:** [February 3, 2021, 9:19am UTC](https://discourse.paraview.org/t/qcriterion-in-paraview/2355/23 "2021-02-03T09:19:04Z")

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Use the calculator to create a vector, then use it in the Gradient filter.

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**Author:** ![idrees](https://discourse.paraview.org/user_avatar/discourse.paraview.org/idrees/32/12432_2.png) [@idrees](https://discourse.paraview.org/u/idrees)\
**Post date:** [November 16, 2023, 11:25pm UTC](https://discourse.paraview.org/t/qcriterion-in-paraview/2355/24 "2023-11-16T23:25:26Z")

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Hello,  
I am also facing difficulty to get Q-criteria in 3d, could you please guide me where I can find the filter Gradient of Unstructured Data set?

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**Author:** ![cory.quammen](https://discourse.paraview.org/user_avatar/discourse.paraview.org/cory.quammen/32/11193_2.png) [@cory.quammen](https://discourse.paraview.org/u/cory.quammen)\
**Post date:** [November 21, 2023, 3:39am UTC](https://discourse.paraview.org/t/qcriterion-in-paraview/2355/25 "2023-11-21T03:39:38Z")

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In recent versions of ParaView, there is just the **Gradient** filter, and it handles unstructured grids as input.

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