# negative volume in all cell data
**URL:** https://discourse.paraview.org/t/negative-volume-in-all-cell-data/14758
**Category:** ParaView Support
**Created:** [June 4, 2024, 2:02am UTC](https://discourse.paraview.org/t/negative-volume-in-all-cell-data/14758 "2024-06-04T02:02:45Z")
**Posts on this page:** 8
**Page:** 1
### Author:  [@Basant\_Regmi](https://discourse.paraview.org/u/Basant_Regmi)
#### Post date: [June 4, 2024, 2:02am UTC](https://discourse.paraview.org/t/negative-volume-in-all-cell-data/14758/1 "2024-06-04T02:02:45Z")
I was trying to post process my CFD result of a blood vessel using paraview, When I was trying to check the volume using integrate variables, it is showing me the negative value for volume. I could not figure out the issue, I checked the cell size filter and notice that all the cell has the negative volume. Could anyone help me in this problem?
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [June 4, 2024, 7:50am UTC](https://discourse.paraview.org/t/negative-volume-in-all-cell-data/14758/2 "2024-06-04T07:50:24Z")
You cells are problably inverted, with point order in the wrong order.
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### Author:  [@Basant\_Regmi](https://discourse.paraview.org/u/Basant_Regmi)
#### Post date: [June 4, 2024, 1:32pm UTC](https://discourse.paraview.org/t/negative-volume-in-all-cell-data/14758/3 "2024-06-04T13:32:47Z")
How can I solve this issue? Could you please provide some information on how to invert the cells in correct order.
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [June 4, 2024, 1:35pm UTC](https://discourse.paraview.org/t/negative-volume-in-all-cell-data/14758/4 "2024-06-04T13:35:17Z")
Please share your data
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### Author:  [@Basant\_Regmi](https://discourse.paraview.org/u/Basant_Regmi)
#### Post date: [June 4, 2024, 1:55pm UTC](https://discourse.paraview.org/t/negative-volume-in-all-cell-data/14758/5 "2024-06-04T13:55:04Z")
You can access the data .vtk file using the link:
[link](https://drive.google.com/file/d/1ilcORiPAPNsuzXMGGoswzm4tM2AvJh6l/view?usp=sharing)
Thank you!
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [June 6, 2024, 8:10am UTC](https://discourse.paraview.org/t/negative-volume-in-all-cell-data/14758/6 "2024-06-06T08:10:22Z")
Im afraid such a filter does not exist, although it could be implemented.
You could just invert the sign of the result or fix your mesh during generation.
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### Author:  [@Christos\_Tsolakis](https://discourse.paraview.org/u/Christos_Tsolakis)
#### Post date: [June 6, 2024, 1:14pm UTC](https://discourse.paraview.org/t/negative-volume-in-all-cell-data/14758/7 "2024-06-06T13:14:16Z")
As Mathieu mentioned there is no filter to do this. You can try however to modify the way you write the mesh. In particular, you will need to change the order of the vertices for each cell to match the VTK format:
For example for tetrahedra in the image above the normal of the triangle (012) based on the right hand rule points to the same direction of that point 3 is.
On the other hand on this tetrahedron extracted form your data it is the opposite:
compare also the wedge with the reference one
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### Author:  [@Basant\_Regmi](https://discourse.paraview.org/u/Basant_Regmi)
#### Post date: [June 6, 2024, 7:09pm UTC](https://discourse.paraview.org/t/negative-volume-in-all-cell-data/14758/8 "2024-06-06T19:09:21Z")
Thank you so much for the clarification.