Incomplete mesh in V1.71 where V1.65 was able to construct a closed mesh

[Andreas1206]

Hello!

In a project with a depth maps based reconstruction of a whole violin I am getting a mesh with holes in V1.71 where V1.65 was able to build a continuous closed mesh - this is independent of mesh interpolation turned on/off and Depth Map filterering paramter (mild vs. aggressive). I noticed in the log file, that a lot of images are not used in the depth maps generation due to:

"2021-02-09 10:30:33 filtering neighbors with too low common points, threshold=50..."

In V1.65 all images were used.

@Alexey: Is there maybe a Tweak to change the threshhold so images with less neighbors are used as well? Do other people experience similar problems, where meshes are reconstructed worse in V1.71 than in the previous version?

Thanks and best whishes!
Andreas

[Alexey Pasumansky]

Hello Andreas,

Unless I am mistaken the old depth maps generation method (in 1.6 version) also used the same 50 valid tie points threshold for the depth maps generation process.

You can try to reduce the default threshold for the new depth maps via the following tweak: BuildDepthMaps/pm_point_threshold, but if you do not succeed, it would be helpful, if you could share the dataset that we can use to reproduce the problem on our side.

[Andreas1206]

Hi Alexey,

thank you for your reply and the information. I tried again with the suggested tweak and several different common point threshold values down to 5 and even though more images are used, the holes in the mesh constructed by V1.71 persist.

Attached you find a screenshot of a reconstruction of part of a violin with V1.71 compared to V1.65. It's the exact same Metashape file with the exact same .dng images used, opened and processed in each corresponding version. This time interpolation is turned on, so the holes are closed, but the topography is much cleaner in V1.65.

What could be the reason, that V1.71 seems to have much more trouble reconstructing the surface from the exact same data set? I would like to send you the data set to verify the problem but it is a very large set with 655 .dng files - how could I transfer this to you?

thank you and best regards,
Andreas

[Alexey Pasumansky]

Hello Andreas,

Dataset would be helpful. If you can share it via any file transfer service, please send the link to support@agisoft.com. If not, please send the email requesting FTP account for the data upload on our server.

[Alexey Pasumansky]

Hello Andreas,

Thank you for sharing the problematic dataset.

It seems that the problem is similar to the issue reported in another thread:
https://www.agisoft.com/forum/index.php?topic=13075.0
The problem is caused by the presence of masks for the aligned images - due to bug in 1.7.1 it may lead to the incomplete depth maps generated in the project. The bug will be fixed in the version 1.7.2.

[jnb]

Hello,

Very good to know, as I also have this problem. Thank you for the fast resolve.
Are the errors in mesh reconstruction from depth maps as shown in attachement also linked to this specific issue ?

Thank you

[Mak11]

Hello,

Very good to know, as I also have this problem. Thank you for the fast resolve.
Are the errors in mesh reconstruction from depth maps as shown in attachement also linked to this specific issue ?

Thank you

Yup this is my main issue with 1.7.x I surely hope that this can get resolved sooner rather than later.

Mak

[Alexey Pasumansky]

Very good to know, as I also have this problem. Thank you for the fast resolve.
Are the errors in mesh reconstruction from depth maps as shown in attachement also linked to this specific issue ?

Hello jnb,

If you can send the sample data (original images and the project file with the alignment results) to support@agisoft.com, we will check, if there's any issue with the new depth maps or mesh generation for this problem.

[jnb]

Hello Alexey,

Thank you for looking into it. I can send you the data but the images are big (37 Go folder). Would it be possible to have an ftp acces on your servers ?

[Alexey Pasumansky]

Hello jnb,

I have sent FTP-access credentials via PM. Let me know, when the data is uplaoded.

[jnb]

Hello Alexey,

I have uploaded the data on your ftp and sent an email to support.
Thank you for your help

[Alexey Pasumansky]

Hello jnb,

Thank you for sharing the sample dataset.

Below is the screenshot of the same area for the depth maps + mesh generated in 1.7.2 pre-release (High quality and Mild filtering). So the problem could be related to the same issue mentioned before - depth maps generation with the presence of masks in 1.7.1.

Please check, if you are able to get proper results in 1.7.2 pre-release in Medium quality as well.

[Mak11]

Alexey,

1.7.2 still exhibits the same issues (maybe a bit less than 1.7.x ):



Mak

[jnb]

Thanks for your response.
For this particular area, the 1.7.2 seems to work (medium quality, mild filtering) but the main issue related to holes/incorrect reconstruction in the mesh is still present as stated by Mak.
See the top of the model in attachment.

[jnb]

Hello Alexey,

By any chance, did you have time to look further into this issue ?
I can confirm that such behaviour is present every time in 1.7.2 but with fluctuating strength.