# questions of unstructured grid vtk (legacy formats)

**URL:** https://discourse.paraview.org/t/questions-of-unstructured-grid-vtk-legacy-formats/6390
**Category:** ParaView Support
**Created:** [February 4, 2021, 3:38pm UTC](https://discourse.paraview.org/t/questions-of-unstructured-grid-vtk-legacy-formats/6390 "2021-02-04T15:38:00Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![marine3454](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/m/b9e5f3/32.png) [@marine3454](https://discourse.paraview.org/u/marine3454)
#### Post date: [February 4, 2021, 3:38pm UTC](https://discourse.paraview.org/t/questions-of-unstructured-grid-vtk-legacy-formats/6390/1 "2021-02-04T15:38:00Z")

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Hi,  
I am having an issue when import vtk file (unstructured grid based on legacy format) into ParaView.  
I use Abaqus to perform FEA and try to plot outputs in ParaView.  
The geometry is like a tunnel (circular excavation at center)  
The model has 13440 nodes, 12000 elements C3D8R (8 nodes)  
Here is the issue. Please see below.  
Surface data representation is a problem. Not sure what was wrong.

 ![Screenshot (51)](https://discourse.paraview.org/uploads/default/original/2X/4/4ba586c6fdf5cf5f7fcb1cb1b94fa81d23df991f.png)  
This is what the mesh looks like in Abaqus.  
 ![Screenshot (52)](https://discourse.paraview.org/uploads/default/original/2X/7/7068b2c2287e1d6c64093b2d59587ad8cdc98238.png)  
This is a structure in vtk legacy format I used.

# vtk DataFile Version 3.0

UNSTRUCTURED\_GRID(C3D8R\_HEXAHEDRALMESH)  
ASCII  
DATASET UNSTRUCTURED\_GRID  
POINTS 13440 double  
3. 3. 10. \<---- nodal info (x,y,z)  
… … … … …  
CELLS 12000 108000  
8 152 1373 4929 841 1 33 689 78 \<---- cell connectivity info  
… … … … …  
CELL\_TYPES 12000 \<---- cell type info  
12  
12  
… … … … …

Please find attached vtk file.  
[TemplateMesh3D\_UNSTR.vtk](https://discourse.paraview.org/uploads/short-url/eYk03Agm9mCnqfNvf2AxdybrEDJ.vtk) (1.1 MB)  
Thank you.

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<div class="post-metadata">

### Author: ![Kenneth\_Moreland](https://discourse.paraview.org/user_avatar/discourse.paraview.org/kenneth_moreland/32/15033_2.png) [@Kenneth\_Moreland](https://discourse.paraview.org/u/Kenneth_Moreland)
#### Post date: [February 4, 2021, 5:17pm UTC](https://discourse.paraview.org/t/questions-of-unstructured-grid-vtk-legacy-formats/6390/2 "2021-02-04T17:17:48Z")

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It looks like your data file is malformed. I believe the indices in your `CELLS` array is wrong. It looks like you are indexing points using 1-based indices when VTK uses 0-based indices. So, for example, the `CELLS` array would start like this:

```auto
CELLS 12000 108000
8 151 1372 4928 840 0 32 688 77
… … … … …

```

I note that when I change the indices of the first cell like this, the first cell looks correct when loaded in ParaView.