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« on: October 16, 2020, 03:13:25 PM »
2-3m between camera positions is probably too great a distance in such an enclosed area.
I have used spherical imaging inside a large old church, with a spacing of about 5m and that worked ok because when you move 5m and look up you still see almost the same thing from almost the same angle. Also in an old church everything is textured and full of details for metashape to find and match between images.
Between the 2 images you shared, I can see that you only moved ~2m but the only thing common to the two images with any detail for metashape to work with is the timber framing, and the angle and distance to it is quite different in each image, so it will have a hard time making the connection. The ceiling and floor are also common to both images, but again the distance you moved means that potentially 'matchable' areas look too different to be matched.
I would suggest trying the images at more like 0.5m spacing. If you can't get back to the property to do that, then the other option is to add markers to your images, which will help metashape align them, and might help it find other matching points (i'm not too sure about that last part).
If you do the marker based approach, i suggest attempting to align all images as normal, and if any do align badly then reset their alignment (right click -> reset camera alignment). If you aren't sure if they're aligned correctly, then reset the alignment too. If none align, then that's ok.
Methodically start adding a small number of markers to a small number of images. The easiest way to add markers to two images is to open the first image by double clicking on it, as normal, then for the 2nd image right-click on it and select 'open in new tab'. Now right click on the new tab that opened and select 'move to other tab group'. Then you can see them side by side. I suggest finding two images that you believe should align, and add ~5-8 markers to each of them, well distributed across the images. Then select the two images and right click -> align selected cameras. If that works, then try adding your ~5-8 markers to another image that you believe should align to the first two. If you have to add more markers to the first two to get 5-8 in the 3rd image that's ok, but you will need ~5-8 markers in all three images to get the 3rd to align. If you can't find an image containing any 5-8 features that exist in the aligned two images, then it's just never going to work. 5-8 is just a number i made up, and you might get away with fewer, but obviously you can't go much lower! The fewer markers you use the less chance of making mistakes and getting in a muddle (hence the 5 in 5-8) but I think probably you should aim for at least 8.
For all subsequent images, you need to add 5-8 markers that exist in at least two other aligned images. If you can add markers to more than three images then you should do. The easiest way once you have a few images aligned is to select a marker, then right click -> filter by markers, and then cycle through the photos using page up/page down and it will automatically center on the estimated marker location, which you can then refine by clicking/dragging. If you just see a red-white line instead of an estimated marker position then it means it is only placed in one aligned image (not two or more) so in the current image metashape is saying it could exist anywhere along that line (although it could be somewhere off the line if the alignment is bad!)
Save often, and after aligning each new image click the 'optimise' button. This will adjust the alignment of all currently aligned images to take into account the newly aligned images and newly added markers if any. It's important to save as optimize can't be undone, and if you misplaced any markers or did something else wrong the alignment could all go wrong.
This is the most fun you can have with a computer as far as i am concerned. It's great. If you get in a muddle you probably added too many markers to too many images and there are some misplaced ones in there which are contradicting the well placed ones.
At the end you will probably have a set of aligned images but still very few points in your pointcloud. That's because the walls of the apartment are all painted white and there are no points that can be matched between images, because white is white wherever you see it on the wall. You will have a big 'cloud' of markers though, and if you're 3d minded you could export these points to something like blender and manually build the geometry, if geometry is what you are after.
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