# Using tetrahedra ids to plot triangulated data (xdmf)

**URL:** https://discourse.paraview.org/t/using-tetrahedra-ids-to-plot-triangulated-data-xdmf/11310
**Category:** ParaView Support
**Created:** [January 31, 2023, 5:28pm UTC](https://discourse.paraview.org/t/using-tetrahedra-ids-to-plot-triangulated-data-xdmf/11310 "2023-01-31T17:28:40Z")
**Posts on this page:** 2
**Page:** 1

<div class="post-metadata">

### Author: ![nikolasborrel](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/n/a6a055/32.png) [@nikolasborrel](https://discourse.paraview.org/u/nikolasborrel)
#### Post date: [January 31, 2023, 5:28pm UTC](https://discourse.paraview.org/t/using-tetrahedra-ids-to-plot-triangulated-data-xdmf/11310/1 "2023-01-31T17:28:40Z")

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Hi,

I’m visualizing 3D field data over time using the xdmf format. Instead of applying Delaunay triangulation, I would like to exploit that I know the indexes for the tetrahedrals in the xdmf file (see below), but how do I apply this additional information in Paraview?

Thanks

```auto
...
<Grid Name="mesh" GridType="Uniform">
	<Geometry GeometryType="XYZ">
		<DataItem DataType="Float" Dimensions="28989 3" Format="HDF" Precision="8">
			wavefield_pred[0.9 0.75 1.].h5:/data0
		</DataItem>
	</Geometry>
	<Topology TopologyType="Tetrahedron" NumberOfElements="2363">
		<DataItem DataType="Int" Dimensions="2363 4" Format="HDF" Precision="4">
			wavefield_pred[0.9 0.75 1.].h5:/data1
		</DataItem>
	</Topology>
</Grid>

```

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<div class="post-metadata">

### Author: ![nikolasborrel](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/n/a6a055/32.png) [@nikolasborrel](https://discourse.paraview.org/u/nikolasborrel)
#### Post date: [February 2, 2023, 6:41am UTC](https://discourse.paraview.org/t/using-tetrahedra-ids-to-plot-triangulated-data-xdmf/11310/2 "2023-02-02T06:41:03Z")

</div>

I learned from [xdmf.org](https://www.xdmf.org/index.php/XDMF_Model_and_Format) that if the cell is a polyhedron, the list of data describing each polyhedron is:

- number of faces the polyhedron is made of
- for each face: the number of nodes of the face, and, the (ordered) list of each index of each node

However, I still cannot get Paraview to construct the elements after making this change.