# Overlapping AMR Contour issues at AMR boundary?

**URL:** https://discourse.paraview.org/t/overlapping-amr-contour-issues-at-amr-boundary/17214
**Category:** ParaView Support
**Created:** [September 26, 2025, 4:46pm UTC](https://discourse.paraview.org/t/overlapping-amr-contour-issues-at-amr-boundary/17214 "2025-09-26T16:46:32Z")
**Posts on this page:** 4
**Page:** 1

<div class="post-metadata">

### Author: ![ccardina](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/c/85f322/32.png) [@ccardina](https://discourse.paraview.org/u/ccardina)
#### Post date: [September 26, 2025, 4:46pm UTC](https://discourse.paraview.org/t/overlapping-amr-contour-issues-at-amr-boundary/17214/1 "2025-09-26T16:46:32Z")

</div>

Hi!

I have overlapping AMR velocity data that uses the Chombo reader. I would like to generate smooth Q-criterion contours. I’m doing the filters in the following order:

ConvertAMRdatasettoMultiblock → MergeBlocks → Gradient → CellDatatoPointData → Countor

The issue is that I am not getting smooth contours between AMR levels. There are visible seams as shown below.

 ![Screenshot 2025-09-26 at 9.40.01 AM](https://discourse.paraview.org/uploads/default/original/3X/6/e/6e64d3106d42d5e83d5b665a4fdffbe2a4182b3c.png)

Are there recommended settings, alternative filter orders, or preprocessing steps that can help eliminate these artifacts and produce smooth contours across refinement levels?

Any guidance would be greatly appreciated!

---

<div class="post-metadata">

### Author: ![mwestphal](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mwestphal/32/17_2.png) [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [September 29, 2025, 2:38pm UTC](https://discourse.paraview.org/t/overlapping-amr-contour-issues-at-amr-boundary/17214/2 "2025-09-29T14:38:14Z")

</div>

HI @ccardina

What you need to get correct gradient computation is either a Gradient filter that operates on AMR data, or a filtre to convert a AMR data to a **dual** unstructured grid.

I’m afraid both these feature do not exists in ParaView yet.

---

<div class="post-metadata">

### Author: ![ccardina](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/c/85f322/32.png) [@ccardina](https://discourse.paraview.org/u/ccardina)
#### Post date: [October 6, 2025, 9:42pm UTC](https://discourse.paraview.org/t/overlapping-amr-contour-issues-at-amr-boundary/17214/3 "2025-10-06T21:42:22Z")

</div>

Hi @mwestphal

Thank you so much for your reply.

If I compute the Q-criterion inside my simulation so that the Q field itself is already smooth across the refinement boundaries, would ParaView then be able to produce smooth contours?

In other words, am I right in thinking that the seams I’m seeing come primarily from the discontinuity in the gradient computation, rather than from the contouring step itself? Or could CellDatatoPointData introduce cracks, so even a smooth field would show seams?

---

<div class="post-metadata">

### Author: ![mwestphal](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mwestphal/32/17_2.png) [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [October 7, 2025, 8:06am UTC](https://discourse.paraview.org/t/overlapping-amr-contour-issues-at-amr-boundary/17214/4 "2025-10-07T08:06:37Z")

</div>

> [@ccardina](#):
>
> , would ParaView then be able to produce smooth contours?

For that you need a contour filter thats works on AMR data, there is one but its very specific and may not work for your usecase. You may need a generic AMR contour, which doesnt exists in ParaView yet.