Possible mesh truncation at edge of Region of Interest in Pix4Dmatic 2.0.0

[maal]

Dear Pix4D Support Team,

first of all, thank you for your continued great work on Pix4Dmatic. We are using it extensively in our daily production workflows, and overall the stability and quality have been excellent.

Today, I noticed a behavior in one project that I have not encountered before, and I would appreciate your insight.

It appears that the mesh is not being generated fully up to the edge of the Processing Area / Region of Interest (ROI). Specifically, a narrow strip is missing in the mesh directly along the boundary of the ROI.

To illustrate this clearly, I have attached two screenshots:

1. The point cloud with the Region of Interest displayed:

   

2. The resulting mesh with the same Region of Interest:

   

When comparing the two, it is clearly visible that valid point cloud data exists in this area, yet the corresponding mesh geometry is missing along a narrow band at the ROI boundary.

My questions are:

• Is this behavior known or reproducible?

• Are there any known changes or potential issues related to ROI handling or mesh generation in Pix4Dmatic version 2.0.0?

• Are there any recommended settings or workarounds I should try?

I would be happy to provide additional project details, logs, or files if needed. We have uploaded the project in the cloud, so you can see the details there: https://cloud.pix4d.com/site/117011/dataset/2517510/model?shareToken=441de134-079b-4b07-a03a-e79b123e2ccb

Thank you very much for your time and support, and once again compliments to the team for the ongoing improvements to the software.

Kind regards,
Manuel Allinger

[Anastasis_Spachos]

Hello Manuel,

Thank you for your kind words regarding PIX4Dmatic.

Regarding the issue with the Mesh and the ROI, I tested internally using a small project that also includes roads + buildings. As you can see from the images below, I was not able to reproduce a behavior similar to yours:

1. The point cloud with the ROI enabled in 2 different parts of the project
   A.

   

   B.

   

2. The Mesh with the same ROI enabled in the same 2 parts of the project
   A.

   

   B.

   

This leads me to believe that the reported issue may be project-specific. Would it be possible to attach the Quality Report of this project so I can take a look at the settings used? Maybe the solution is in the Processing settings

Best regards,

Spachos Anastasis

[maal]

Dear Spachos,

thank you very much for taking the time to test this internally and for sharing your results. I appreciate the effort and your detailed comparison.

What makes this case confusing for me is that this is not just a similar project, but exactly the same project with exactly the same Region of Interest. I have processed this project using the identical ROI more than 30 times in the past, and this is the very first time I am seeing this behavior.

Importantly, the issue appeared for the first time after reinstalling Pix4Dmatic and updating to version 2.0.0. With previous versions, the mesh was always generated correctly up to the ROI boundary in this project.

At the moment, I am also not able to reproduce the issue in other projects, which is why I am wondering whether this could be a very specific edge case or something related to changes introduced in version 2.0.0, even if it only occurs under certain conditions.

Regarding the Quality Report: although the project itself is shared via Pix4D Cloud, I understand now that the Quality Report needs to be generated and attached separately. I am happy to provide it if that helps your investigation. Please let me know if there are any specific processing settings or parameters you would like me to review in the meantime. But also these settings were succesfully used more than 20 times….

My main question would be whether similar cases have been reported internally, or if there are known situations where mesh generation close to the ROI boundary may behave like this.

Thank you again for your support and for looking into this.

quality_report.pdf (2.2 MB)

@Rhea_Garratt @andrea.dotti

Kind regards,
Manuel Allinger

[Anastasis_Spachos]

Hello @maal

Thank you for sharing more information and the Quality Report.

Based on the Mesh settings you used, I was wondering what the reason was that you switched the Deghosting option from Weak (default) to Strong. Are there a lot of moving objects (cars, trucks, for example) in the project area?

If you have the time, can you please run the same processing Mesh settings but with the Deghosting set to Weak?

About your question:

We have not faced similar issues internally, and no other user has reported something similar so far. Since your post, we are keeping a close eye on the Mesh-ROI topic.

Best regards,

Spachos Anastasis