# Format for volumetric tetrahedral meshes
**URL:** https://discourse.paraview.org/t/format-for-volumetric-tetrahedral-meshes/455
**Category:** ParaView Support
**Created:** [August 21, 2018, 12:34pm UTC](https://discourse.paraview.org/t/format-for-volumetric-tetrahedral-meshes/455 "2018-08-21T12:34:21Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@AnderBiguri](https://discourse.paraview.org/u/AnderBiguri)
#### Post date: [August 21, 2018, 12:34pm UTC](https://discourse.paraview.org/t/format-for-volumetric-tetrahedral-meshes/455/1 "2018-08-21T12:34:21Z")
Hi there,
I have some custom-created tetrahedral volume meshes of a domain with individual tetrahedron values that I’d like to visualize (clip, color, etc). They are a priori unstructured, but I can easily build a graph to represent them.
However, I have these meshes in MATLAB, so I need to save them in a format that Paraview would accept/read before continuing.
Which open source format would paraview support that I can save tetrahedral meshes on?
Best
Ander
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### Author:  [@utkarsh.ayachit](https://discourse.paraview.org/u/utkarsh.ayachit)
#### Post date: [August 23, 2018, 3:21pm UTC](https://discourse.paraview.org/t/format-for-volumetric-tetrahedral-meshes/455/2 "2018-08-23T15:21:44Z")
Several file formats fit the bill. The choice often depends on the size of the data, runs etc. To get you started, Legacy VTK files or VTK XML file formats are fairly easy to write and can be easily imported into ParaView.
An easy way to generate example files for these formats is to generate (or import) a comparable dataset into ParaView and then save it out as the appropriate format. e.g. create the **Wavelet** source, apply **Tetrahedralize** filter to convert it to a mesh of tets and then save that out as Legacy VTK files or XML VTK files.
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### Author:  [@AnderBiguri](https://discourse.paraview.org/u/AnderBiguri)
#### Post date: [August 23, 2018, 3:25pm UTC](https://discourse.paraview.org/t/format-for-volumetric-tetrahedral-meshes/455/3 "2018-08-23T15:25:10Z")
Thanks! In fact I did ended up using VTK UnstructuredCells and they work very nicely and are also easy to create.
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### Author:  [@ofbodur](https://discourse.paraview.org/u/ofbodur)
#### Post date: [June 5, 2020, 5:57am UTC](https://discourse.paraview.org/t/format-for-volumetric-tetrahedral-meshes/455/4 "2020-06-05T05:57:01Z")
Can we also decrease the resolution of tetrahedra meshes? (Decimate?)
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [June 5, 2020, 6:13am UTC](https://discourse.paraview.org/t/format-for-volumetric-tetrahedral-meshes/455/5 "2020-06-05T06:13:26Z")
You can use `Filters -> Decimate.`
If you have further questions, please open your own topic.
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [June 5, 2020, 6:13am UTC](https://discourse.paraview.org/t/format-for-volumetric-tetrahedral-meshes/455/6 "2020-06-05T06:13:29Z")