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Author Topic: Align - Ref' Presel' - Sequential... With multiple or Interrupted sequences  (Read 1323 times)

CheeseAndJamSandwich

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My scans are usually one continuous track that I've 'flown' (swam).
If i enable Reference Preselection - Sequential, it then aligns much, much quicker, with the Selecting Pairs, etc stages happening very quickly.

BUT...
If in my scan track, i have an area of bad quality photos, it then only aligns up to that point.  And i haven't figured out how to align the rest.
Also, the nature of my project is that the dive site I'm mapping, is scanned in many dives, missions, 'flights'.  How can we get MS to sequentially align a project where there are 2 or more sequential scan tracks?  Which are adjacent to each other or crossing.

Is it possible to have MS make the most of massive speed gains of sequentially aligning, but also using it's traditional 'brute force' methods to align additional sequences/photos?
The speed gains seem to be too good to miss out on.

Thanks.

CheeseAndJamSandwich

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Also, Sequential fails to align U-pattern, 'mowing the lawn' scans, even when there's good side overlap.  Which is surprising, as this type of scanning is so, so common.
They're aligned sequentially, but when you look at the side overlaps, you see there's two surfaces, that are not joined...doh.
How come metashape can't sequentially align them, and then knowing that the two paths are overlapping along their sides, then align them...?

SimonBrown

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Remember two things; firstly sequential really works best when used in conjunction with other parameters - specifically high accuracy GPS position data - and secondly sequential will not align images across parallel tracks. The step you see in the surface is therefore expected.

Suggestion; Run sequential. Then re run alignment with sequential off (generic) and reset alignment ticked off. This should at least align parallel track images.

As for bad qualify photos...they should be removed from the project and play no part in reconstruction.
Agisoft endorsed online Metashape training - see: https://accupixel.co.uk/metashape-training-courses

CheeseAndJamSandwich

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Suggestion; Run sequential. Then re run alignment with sequential off (generic) and reset alignment ticked off. This should at least align parallel track images.

Just tried this, and the adjacent track, that had good overlap, created a hilariously bad '2nd skin'...  a few inches above the other one where they overlapped.

Will try again with 'Estimated' set...