Clip closed surface filter over multiple open structures

fashing · October 2, 2023, 2:39am

Hi Paraview,
I tested clip closed filter on a superquadric (donut) and I found something weird.
With default setting (Origin: 0, 0, 0; Normal: 1, 0, 0), one of the holes is not completely closed.

However, as I modify the parameters, sometimes it works and sometimes it doesn’t.

I can open a report if someone confirms this issue. Thank you!

[Update]
There’s another related issue, the quality difference between clip filter (left) and clip closed filter (right) is huge. Is this normal or can it be avoided with some additional setting?

mwestphal · October 2, 2023, 6:02am

I can open a report if someone confirms this issue. Thank you!

Please do, looks like a bug

the quality difference

Missing normals, can be recomputed with GenerateSurfaceNormals, but this should not be needed, no reason to remove the normals.

fashing · October 2, 2023, 6:35am

The issue has been reported.
Error in clip closed surface filter on multiple open structures (#22327) · Issues · ParaView / ParaView · GitLab (kitware.com)

no reason to remove the normals.

I didn’t remove the normals, maybe this is another issue of the filter.
This quality drop doesn’t happen on my other testing though (only on superquadric).

mwestphal · October 2, 2023, 7:14am

Not reason for **the filter ** to remove the normals, looks like a bug.

This quality drop doesn’t happen on my other testing though

In which situtation does it not appear ?

fashing · October 2, 2023, 9:02am

In my previous post, the quality did not drop.
Clip closed surface filter over contour filter - ParaView Support - ParaView

I think this information suggests clip close surface filter use clip filter for contour output.

Should I open another issue about the normal removal, or append this in the previous issue?

mwestphal · October 3, 2023, 6:28am

Normals do not matter for a box.

Clip closed surface actually remove all arrays as it would need to compute them for new cells. That’s possible but more of a missing feature than a bug.

fashing · October 3, 2023, 6:45am

Actually, it’s not a regular cuboid, but a round box from a contour filter.
And I was wrong, the image quality also drops in this case.

(vdb → contour filter)

(vdb → contour filter → clip closed surface)