# Unable to use filters in a 3d mesh
**URL:** https://discourse.paraview.org/t/unable-to-use-filters-in-a-3d-mesh/8577
**Category:** ParaView Support
**Created:** [December 7, 2021, 10:18am UTC](https://discourse.paraview.org/t/unable-to-use-filters-in-a-3d-mesh/8577 "2021-12-07T10:18:47Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@ruffi92](https://discourse.paraview.org/u/ruffi92)
#### Post date: [December 7, 2021, 10:18am UTC](https://discourse.paraview.org/t/unable-to-use-filters-in-a-3d-mesh/8577/1 "2021-12-07T10:18:47Z")
Hi to all, i starting to use Paraview few days ago and i’m not so expert so sorry if the question is trivial.
I obtain this 3d mesh from FreeFem++ and i want to take a slice of my domain, visualizing the tetrahedra and not the triangle. But all the filters are blocked and says “requires an input”.
What can i do to solve this problem? Am i do some error in save the .vtk file?
Thanks for any help!
This is the link to download the file:
> **[fast3D\_adapt.vtk](https://www.dropbox.com/s/9czjb8jcfcc82db/fast3D_adapt.vtk?dl=0)**
>
> Shared with Dropbox
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [December 7, 2021, 12:52pm UTC](https://discourse.paraview.org/t/unable-to-use-filters-in-a-3d-mesh/8577/2 "2021-12-07T12:52:48Z")
> [@I've just opened my dataset. I can't add filters, and everything is greyed out](https://discourse.paraview.org/t/ive-just-opened-my-dataset-i-cant-add-filters-and-everything-is-greyed-out/4511):
>
> Make sure your dataset is selected in the Pipeline Browser Click apply (in the Properties tab) if the apply button is green
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### Author:  [@ruffi92](https://discourse.paraview.org/u/ruffi92)
#### Post date: [December 7, 2021, 1:20pm UTC](https://discourse.paraview.org/t/unable-to-use-filters-in-a-3d-mesh/8577/3 "2021-12-07T13:20:40Z")
thank you! Now filters is available. But i believe that in my mesh there was some tetrahedra (MMG3d says that i have about 900k in this mesh) but if i try to view with “volume” appear the error message “Encountered non-tetrahedra cell!”
I have to set some other options to visualize these elements?
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### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [December 7, 2021, 1:24pm UTC](https://discourse.paraview.org/t/unable-to-use-filters-in-a-3d-mesh/8577/4 "2021-12-07T13:24:22Z")
The dataset you shared only contains 2d cells.
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### Author:  [@Christos\_Tsolakis](https://discourse.paraview.org/u/Christos_Tsolakis)
#### Post date: [December 7, 2021, 2:12pm UTC](https://discourse.paraview.org/t/unable-to-use-filters-in-a-3d-mesh/8577/5 "2021-12-07T14:12:50Z")
The default `Label` array seams to cause this. Try picking `Solid Color` or your `FluxFast` array from the highlighted menu
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### Author:  [@ruffi92](https://discourse.paraview.org/u/ruffi92)
#### Post date: [December 7, 2021, 5:01pm UTC](https://discourse.paraview.org/t/unable-to-use-filters-in-a-3d-mesh/8577/6 "2021-12-07T17:01:08Z")
unfortunatly also with flux fast and solidcolor obtain the same error. It’s vey strange, i’m sure i compute tetrahedra on Freeefem++. Maybe there is some option to add in the command “savevtk”?
Anyway, i can’t add tetraedra on this mesh by paraview?
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### Author:  [@Christos\_Tsolakis](https://discourse.paraview.org/u/Christos_Tsolakis)
#### Post date: [December 7, 2021, 5:38pm UTC](https://discourse.paraview.org/t/unable-to-use-filters-in-a-3d-mesh/8577/7 "2021-12-07T17:38:30Z")
The tetrahedra are already present in your file. `Volume` representation is meant mainly for images. Try setting the representation to `Surface` / `Surface With Edges` / `Wireframe` which is better suited for meshes.