Sparser Point Cloud with ODM 2.8.6?

[Agrobit]

Hi everybody,

I have processed one dataset of photos taken by a tablet.
I am using WebODM and I have noticed that the point cloud I get with ODM 2.8.6 is sparser than the one I got with previous versions using the same processing parameters:

end-with: odm_georeferencing, feature-quality: medium, feature-type: hahog, pc-filter: 0, pc-quality: ultra, pc-sample: 0.035, resize-to: -1

This is the point cloud I got with previous ODM versions → 1.laz - Google Drive

This is what I get now (same parameters, same Cloud Compare version, same PC) → 2.laz - Google Drive

Any ideas about this issue? If it can help, I had a similar issue some months ago that has been reported and fixed here.

Thank you for your support!

Simone

[Agrobit]

Update: I tried with pc-sample=0 and the results are quite similar to the older ones. Could be the pc-sample unit of measure that have been changed in the last version of ODM?

[pierotofy]

I don’t think we have changed pc-sample behavior in newer releases, but perhaps something did get fixed and now pc-sampling is actually working properly. (0.03 means you’ll get a point every ~3cm).

[Agrobit]

Thank you pierotofy. In fact I measured the distance and I got 1 mm for the old point cloud and 35mm for the newer one. So probably it was something in the older version of ODM…

Old point cloud

New point cloud

Thanks

[smathermather]

It looks like the behavior is now correct (based this on your examples dataset, in fact). This is the pull request with the change: Patch pc resolution by smathermather · Pull Request #1435 · OpenDroneMap/ODM · GitHub

[Agrobit]

However I see some “holes” if I process with pc-sample=0.001. I expected a point every 1mm but in some zones this seems to be different:

This is the result with pc-sample=0

[smathermather]

The holes are probably missing matches. Is it mostly every 1mm with an occasional missing one?

[Agrobit]

yes, it is.