# Calculation of the volume of hexahedral cells

**URL:** https://discourse.vtk.org/t/calculation-of-the-volume-of-hexahedral-cells/3842
**Category:** Support
**Created:** [July 23, 2020, 4:02pm UTC](https://discourse.vtk.org/t/calculation-of-the-volume-of-hexahedral-cells/3842 "2020-07-23T16:02:11Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![rodrigomologni](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/r/54ee81/32.png) [@rodrigomologni](https://discourse.vtk.org/u/rodrigomologni)
#### Post date: [July 23, 2020, 4:02pm UTC](https://discourse.vtk.org/t/calculation-of-the-volume-of-hexahedral-cells/3842/1 "2020-07-23T16:02:11Z")

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I would like to know the difference between `vtkMeshQuality` and `vtkCellSizeFilter` for computing the volume of hexahedron cells. According to the VTK Documentation, `vtkCellSizeFilter` uses `vtkMeshQuality` for triangles, quadrilaterals, tetrahedrons and hexahedrons. However, in my test, both classes have produced different volumes.

`vtkMeshQualify` = 1.0 and `vtkCellSizeFilter` = 1.0 for:

 ![image](https://discourse.vtk.org/uploads/default/original/2X/8/87bd724d4e2e8f117eeb1867911b71b4534e2bfc.png)

`vtkMeshQuality` = 0.75 and `vtkCellSizeFilter` = 0.84 for:

 ![image](https://discourse.vtk.org/uploads/default/original/2X/d/dcc8e08352ad643745cab159521a0b7065f490e5.png)

`vtkMeshQuality` = 0.75 and `vtkCellSizeFilter` = 0.67 for:

 ![image](https://discourse.vtk.org/uploads/default/original/2X/6/6c11598bda81d85c356e210fbecbf71c561873e9.png)

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<div class="post-metadata">

### Author: ![rodrigomologni](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/r/54ee81/32.png) [@rodrigomologni](https://discourse.vtk.org/u/rodrigomologni)
#### Post date: [July 31, 2020, 12:18pm UTC](https://discourse.vtk.org/t/calculation-of-the-volume-of-hexahedral-cells/3842/2 "2020-07-31T12:18:38Z")

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Does anyone know the difference? 😟