Structure from motion fails with no error?

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Nathaniel Duncan

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Aug 21, 2021, 12:48:18 AM8/21/21
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For some reason with this dataset, when I get to the SfM stage it always goes red, and never seems to give me any error message.

I had previously managed to get a finished mesh in the 2019 version, but the quality was very low (bounding box shaped cube). Now I have updated to 2021 and I can't seem to progress.

Any help would be greatly appreciated, as it took the better part of a month to process the preceeding nodes and I would hate to have to start over.

SfM log here: https://pastebin.com/yW4NdcHz

Attributes panels below

Screenshot 2021-08-21 164227.pngScreenshot 2021-08-21 164324.png
Screenshot 2021-08-21 164125.png
Screenshot 2021-08-21 163932.png

Screenshot 2021-08-21 163804.png

Nathaniel Duncan

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Aug 21, 2021, 9:16:39 PM8/21/21
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Update: I've just finished testing it with two other datasets, same result every time.

Stefan Szekeres

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Aug 22, 2021, 9:35:08 AM8/22/21
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Hi Nathaniel,

I'd try the following, using a small dataset:

1. Disable Cross Matching in FeatureMatching
2. Use sift and akaze in FeatureExtraction
Optionally:
4. Worst case, add sift_float and/or sift_upright etc to the FeatureExtraction step.
3. Worst worst case, disable Grid Filtering in FeatureExtraction

Lemme know what worked for you.

Cheers!
Stefan

Nathaniel Duncan

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Aug 25, 2021, 12:49:29 AM8/25/21
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Hi Stefan,

Thanks kindly for your suggestions, unfortunately in all cases it still fails at the Structure From Motion node. Is there anything else I can try?

Stefan Szekeres

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Aug 29, 2021, 1:28:27 PM8/29/21
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Hello Nathaniel,

1. Best to tinker with the feature count, make it custom, instead of ultra, and change it to 1.000.000.
2. Maybe you can also test with 2 images,  check and see if you find matches. Then other 2 images. Then with groups of 3 images. And so on.
3. What settings did you try?
4. Can you share a sample of your database to see what we're talking about?

Regards,
Stefan

Fabien Castan

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Aug 29, 2021, 3:10:56 PM8/29/21
to Stefan Szekeres, AliceVision
Don't increase the feature count too much. In most cases, ULTRA will decrease the overall quality.
If you have too many features, it reduces the inliers/outliers ratio.

You could try your dataset with dspsift, instead of sift (which will become the default value in the next release).

It's not really possible to provide recommendations without any information on the dataset.
For most use cases, the default values are the best. Customization only makes sense for specific needs.


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Nathaniel Duncan

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Aug 30, 2021, 11:15:13 PM8/30/21
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Hi Stefan and Fabien,

As I mentioned in my initial post, meshroom has no trouble finding matches, the node where it stops is StructureFromMotion. I tried using all of your suggestions including disabling cross matching, using sift and akaze together, using the other sift types, disabling grid filtering and using dpsift. I have also tried this on both ultra and normal for describer quality and density, and I've tried using several different datasets, some of which have worked in the past using previous versions of meshroom.

This particular dataset "worked" initially with default settings, and I got a very promising point cloud, but during meshing it produced a bounding box shaped cube. I tried to redo it with some settings changed and since then I have been unable to pass structurefrommotion at all, even with default settings.

I've restarted my computer, I've reinstalled meshroom, I'm at a total loss as to how I can get this to work.

Fabien Castan

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Aug 31, 2021, 4:55:02 AM8/31/21
to Nathaniel Duncan, AliceVision
Hi,
If you think that shows a regression, I would be interested to test the dataset.
Best,


De : alice...@googlegroups.com <alice...@googlegroups.com> de la part de Nathaniel Duncan <nathani...@gmail.com>
Envoyé : mardi 31 août 2021 05:15

Nathaniel Duncan

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Aug 31, 2021, 5:11:24 AM8/31/21
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Hi Fabien, 

I've just asked permission from the subject to share the dataset, where can I privately send it to you?
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