Hello! So I’ve been following this software and technology for quite some time for making 3d models, and decided to get myself a Mavic Mini a couple of months ago. Yesterday I finally made my first missions to capture some images of some structures.
I made a single flight with parallel lines pattern with 80% front and 70% side overlap, at about 40-50mts of height from ground.
Then processed the images with no additional parameters and got these results:
The orthophotos are great, but the 3d models not so. It was somewhat windy, and it was sunny (the house photos were at sunset which I know it’s not the best time to get the images). I know some improvements I can do (flying in overcast weather, and with no wind so there’s less gps error?), but I think there’s more room for improvment.
I believe it is difficult for the software to map vertical surfaces from only nadir photos. Is this the case? If so, is it useful to add another flight with oblique photos as well? Does ODM need to “know” if photos are oblique or nadir? (Like some inclination angle parameter in the img file).
Also, if I make another flight of a portion of the area of interest with lower altitude, to get more texture/model quality of that specific area and feed ODM those images along with the main area images straight away, will that sub area in the 3d model be more detailed?
Thank you for the reply! Yes, those results were very good for being the first ones.
I couldn’t find any info about camera angle in my picture’s EXIF, I guess that if I feed it with angled images, the algorithm will sort it out?
You mean to join the photos of both flight plans, with the new one having 45-65º vertical angle? And what about also changing the orientation of the 2nd flight plan, would that help?
I will play a bit with these and will tell the results
Okay, so, I’ve found a cool place to take photos without problems (which was harder than i thought), took images with various patterns (6, with 470 pics, maybe i could reduce that a bit and keep the quality), and made the processing. So as promised, here are the results.
They are very promising given there were no params and post processing:
Hello again!
I am playing with some params and discovering what they do. Do you know if there’s any way to define the boundaries of the area of for processing?
So I can focus the resources and polygon limit on only the very area of interest. There are some buildings and trees around which were captured in the images but are irrelevant. I’ve googled and looked in the docs but couldn’t find anything.
So then i processed it without params, but and got an error.
[ERROR] Uh oh! Processing stopped because of strange values in the reconstruction. This is often a sign that the input data has some issues or the software cannot deal with it. Have you followed best practices for data acquisition? See https://docs.opendronemap.org/flying.html
Do you know what it can be?
I’m experimenting with ODM to try to find the best conditions to get the best quality models possible for certain kind of places, i’d love to share any result I find.
I’ve been trying to find a streamlined process to make multiple mask images (haven’t found one yet, photoshop batch image processing is kinda a headache), if you know any program or tool would you let me know pls?
Anyway, I’ve tried a tiny example (3 images) to see how masks work, and the output was the same as without masks (the masked areas are present in the model and orthophoto). I feel dumb, am I doing something wrong?
Oh, apparently masks doesn’t work in some recent versions of ODM for another person here too:
I have 2.6.1, so it must not work for this version. I should check ODM 2.0.0.
Edit: I think I will stick with this version and try to find other ways to achieve masking… I’m afraid for losing important features added in the recent updates.
I’ve tried manually masking the actual images again like the pic I’ve shown 3 days ago, but this time with the tiny dataset of 3 pictures, and it worked. It worked both with sharp rectangles or with the manual brush.
But still, the “full” collection of said pic above throws that “strange values” error. I’ve removed the pair of images that made that error appear, 4 times. It always finds another pair of images to throw that error, one pair even didn’t have any sort of masking.
how embarassing. Sorry for bothering when the documentation was at hand 
