I used the default option on everything and experienced distortion on metal roofs and roof edges on the orthos.
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Welcome!
You can try the Buildings preset, but this amount of distortion looks like maybe your overlap/sidelap are not sufficient.
Do you know the settings of your flightplan?
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If your drone has an electronic shutter try slowing down your capture speed and lifting your shutter speed above 800.
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We also have Rolling Shutter Distortion Correction, which may help a bit.
We are always looking for sensor data contributions to improve it.
Mavic 3E all default settings. Here is the latest one that looks horrible. You can see one roof type is TPO and the other is metal roof. The software has a hard time with metal roofs. See picture attached.
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Another thing I noticed is that the quality report states that there are missing photos but when I check it in another program, all photos are there. See the ODM report.
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Here is the other report that shows it is in fact complete coverage.
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My mistake it was not the default settings. Here are the specs from Drone
Deploy which was used to run the mission.
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What settings are you using in WebODM?
You might also want to bump frontal overlap up higher, which may help at the cost of a bit more storage space.
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Ace4ME, glad youâre here and leading this investigation with your dataset.
So: quick protocol review. Rather than declaring software is bad with metal roofs, step back and instead ask a question. This is a community of folks working together, not a product behind a walled garden with a free trial, but real software developed by some of the folks who even spend time help here on the forum. And even folks who arenât the core developers are real experts who can help you get your desired outcome from UAV imagery, and are interested in doing so by default.
So, you might approach your inquiry here as such:
- I have a dataset that isnât performing as I had hoped.
- Here are my settings
- Here is my data collection process
- (Bonus points if itâs a dataset you can share for others to try processing)
- What do you recommend to improve the output?
Iâm this case, we would likely respond with:
Your overlap is lower than recommended for OpenDroneMap, particularly for a surface like a metal roof. Given the flights donât meet our specification (even if they meet the specification of other similar software), there may be limits to how much we can improve this. But letâs try the following, as we should be able to do better than what you have displayed:
- Try the building preset
- Try performing rolling shutter correction as well
If that doesnât work, then we have a few further things to try. Let us know how these settings change your output and we can iterate from there.
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Smathermather,
Thank you for your advice. I meant no disrespect and I am grateful for any help understanding what I am doing wrong. I have a trial for DJI Terra and processed it through that and it looks worse. The settings above were the settings requested by the client. They do their own processing but I am trying to see what it looks like in my output. I am willing to keep trying so I can get better outputs. I will run a smaller project with the default settings flying with the DJI app then DroneDeploy separately and re-post those details. I have had better results when I enabled 3d crosshatch. If that doesnt work Ill try the recommendations above. Thank you for the input. Your efforts are greatly appreciated.
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Saijin_Naib,
I used the default settings in WebODM. I also tried the enabling the shutter correction in the 2nd attempt with slightly better results but the same issues on the metal roofs. I will try the default fly settings in DJI and DroneDeploy then try your recommendations. Thank you for your suggestions.
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No worries!
It can take a bit of iteration and getting used to any software, but some photogrammetric subjects are a pain, like anything shiny/spectral (looking at you, snow and water)
We have just recently merged some changes that will adjust the reconstruction of the orthophoto around edges and overhangs using a better inpainting approach Piero implemented.
However, much like the above tweaks, I think these will be welcome refinements, but I do think your flightplan will be where the biggest improvements will be had.
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For what itâs worth, I get this same artifacting on most of my scans. I didnât think about it being related to metals roofs. I do think that youâre going to see it more in materials with straight line seams like a standing seam metal roof and even in bricks.
This is a much smaller building, and I think the effect you are seeing is mainly because you have such small lines in such a large area (moire effect)
Here are my flight plan settings to compare:
Flown on a MavicMini
I ran this path three times, one at 90deg camera angel, again at 75, and finally at 45.
I did not use rolling shutter correction on this because I did not know that was a thing when I processed this! I may have to go back and find that and try it again with it on!
Hope this helps, and good luck!
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As long as you didnât use a really fast shutter speed, I donât think rolling shutter correction should be used in this case, as the Mavic 3E has a mechanical shutter.
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Did we get you sorted or at least closer, or do you need more investigation?
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