# UNSTRUCTURED\_GRID: Points Gaussian OK. But Contour failed.
**URL:** https://discourse.paraview.org/t/unstructured-grid-points-gaussian-ok-but-contour-failed/6053
**Category:** ParaView Support
**Created:** [December 14, 2020, 2:46pm UTC](https://discourse.paraview.org/t/unstructured-grid-points-gaussian-ok-but-contour-failed/6053 "2020-12-14T14:46:53Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@Giovanni](https://discourse.paraview.org/u/Giovanni)
#### Post date: [December 14, 2020, 2:46pm UTC](https://discourse.paraview.org/t/unstructured-grid-points-gaussian-ok-but-contour-failed/6053/1 "2020-12-14T14:46:53Z")
Can ParaView render an isosurface = 1 from the UNSTRUCTURED\_GRID attached? “Points Gaussian” represents it correctly (screen shot 1). But “Contour” filter fails.
Many thanks.
**STEPS TO REPRODUCE ISSUE:**
1. Download [UG\_sample.vtk](https://discourse.paraview.org/uploads/short-url/xJ3qu3YKEjNpAUp8UymTHE1HHNw.vtk) (44.2 KB)
2. Open UG\_sample.vtk in “Legacy VTK Reader”
3. Select:
1. Add filter: “Contour”.
**Result** :
_Expected_:
- Renders isosurfaces ( = 1, for 8 spheres).
- “Contour → Information” same as as “UG\_sample.vtk \> Information”.
_Observed_:
- Renders no surfaces.
- Contour “Information”:
Number of cells 0
Number of points 0
Data range: Not available
_Output Messages_:
- None.
1. Optional additional attempts:
Repeat steps above for:
- [UG\_minimal-VTK\_VERTEX\_only.vtk](https://discourse.paraview.org/uploads/short-url/fjjlLekel2SmNOlR4sLiXq7jkGQ.vtk) (5.9 KB) ,
- [UG\_minimal-VTK\_HEXAHEDRON\_and\_VTK\_VERTEX.vtk](https://discourse.paraview.org/uploads/short-url/3rb1loHitgHYvmtf94VxAkfkyxs.vtk) (615 Bytes) , or
- [UG\_minimal-VTK\_POLY\_VERTEX\_and\_VTK\_VERTEX.vtk](https://discourse.paraview.org/uploads/short-url/m38hlxpyI1bICJSxRHgumSqkitU.vtk) (614 Bytes)
**Result** :
Same as above (issue persists).
**MY SETUP:**
> ```
> - ParaView Version 5.9.0-RC2 (Dec 10 2020, from https://www.paraview.org/download/ )
> - Macbook Pro Big Sur 11.0.1 (20B29)
> - Graphics: Radeon Pro 560 4 GB
>
> ```
Fig. 1 UG\_sample:
Fig. 2 UG\_minimal-VTK\_VERTEX only:
Fig. 3 UG\_minimal-VTK\_HEXAHEDRON\_and\_VTK\_VERTEX:
Fig. 4 UG\_minimal-VTK\_POLY\_VERTEX\_and\_VTK\_VERTEX:
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [December 14, 2020, 3:04pm UTC](https://discourse.paraview.org/t/unstructured-grid-points-gaussian-ok-but-contour-failed/6053/2 "2020-12-14T15:04:49Z")
You can’t run isosurfaces on vertices, you need 2D or 3D cells.
---
### Author:  [@Giovanni](https://discourse.paraview.org/u/Giovanni)
#### Post date: [December 14, 2020, 3:33pm UTC](https://discourse.paraview.org/t/unstructured-grid-points-gaussian-ok-but-contour-failed/6053/3 "2020-12-14T15:33:47Z")
My impression (I am new to ParaView) was the data controls the decision to use vertices VS other type of cell. How all that data can be represented in 2D or 3D cells?
Is there a toy sample ascii file of ANY unstructured .vtk (showing 2D or 3D cells) that successfully renders an isosurface, so I can learn?
---
### Author:  [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [December 14, 2020, 3:37pm UTC](https://discourse.paraview.org/t/unstructured-grid-points-gaussian-ok-but-contour-failed/6053/4 "2020-12-14T15:37:26Z")
Sure, here you go.
[UG\_sample\_wave.vtk](https://discourse.paraview.org/uploads/short-url/mVbarHETKaUmNMqsHpfvQhvRPLE.vtk) (1.5 MB)
---
### Author:  [@Giovanni](https://discourse.paraview.org/u/Giovanni)
#### Post date: [December 14, 2020, 9:40pm UTC](https://discourse.paraview.org/t/unstructured-grid-points-gaussian-ok-but-contour-failed/6053/5 "2020-12-14T21:40:29Z")
Thanks for your answer, Mathieu. Issue resolved. I used Delaunay 3D filter to generate a 3D mesh from my point cloud (Poly-vertex).
