I have noticed that on the last couple of orthomosaic maps, I’ve noticed a couple of ‘melty’ warped elements in the finished jpg that’s not present in the original images. I have attached a couple of examples. Any advice, please.
Thanks
The first thing we need to understand is that an orthomosaic is a 2D image of a 3D model. The reason you are seeing the melted effect is because the sharp corners and vertical faces were not well captured and there were not enough points in the cloud. Depending upon your goal for your maps you may want to try processing in structure mode. I also encourage you to visit drone deploys support site and read up on making successful maps. Please feel free to search the forum as well since this is a question that has come up many times.
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I did do some research prior to the flight and spent some time going through the help files afterwards
and even set a slower speed down to setting a slower speed. I couldn’t find any reference 'avoiding melty moments. Furthermore. the first image is from an assignment I flew with a P4PV2 and the second, a few days earlier, was with a Mavic Pro 2 as the DJI geofence unlock procedure wouldn’t accept the controller serial number for the P4PV2despite reading it directly from the app.
I have appended the settings for this assignment.
Basic Settings
Advanced settings
It is still about coverage. Running a mission with oblique images is the only guaranteed way to cleanup the transition from the horizontal to vertical faces. Something like the Auto Flight Modes app in the market will allow you to run a Crosshatch mission with a defined oblique pitch on the camera. For smaller projects 10ac and under I use the standard structure mode which will run a nadir flight and then orbit the entire perimeter. You can use this on larger projects as well, but should probably split it into sections to make sure you get all the vertical faces from different angles.
I see the second image appears to have a parapet? These are particularly tough because the top of the parapet is so narrow that it is hard to collect enough points to make a 4-6in horizontal surface.
Ok thanks, Michael. It’s a learning curve:)
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For sure. I just finished a corridor street rehab that has some big oaks on the ROW. I flew the nadir with DroneDeploy and then an oblique route with Litchi. This is a tough one and may require some ground shots. Just mounting drone on the top of my SUV and set Litchi to take shots every two seconds up one side and down the other. I just shared this to exhibit how every job is different and takes some creativity and 3D vision on how to approach it. I’ll share the map once it is done to see what we get.
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Thanks again. I am trying to get permission to go back and shoot the Manor House, this time with 3d in mind and the autoflight mode in structure mode. It’s an ideal structure I think to practice on. I’ve appended my flight plan below. Do you think you could use ‘Photoplan’ to obtain additional infill by setting DJI camera setting to an image every 2 seconds? I have used this approach in Litchie and DJI Go 4 on orbits/waypoint and POI to take stills whilst I concentrate on flying and the gimbal.
Thanks again
Looking good. If you have Litchi then I would just do a couple of orbits. Nice thing with Litchi is that you can increase/decrease the radius and altitude as it is running. If you take any manual shots of specific features make sure to get at least 5 photos of each side you can access.
Appended is the link to the test flight output from yesterdays exercise
https://bit.ly/2H7RTOf I’m quite happy with that for a first. My approach was to use the tools in DD. See settings below. Then, setting the camera to take an image every 2 secs, I walked with the drone around the outside at two separate heights to infill where the roof meets the vertical wall and then just the wall to the ground floor. Decided not to use Litchi for the last part as the building is surrounded by trees up to about 130’ and with the drone in ‘Tripod’ mode it was easy to keep up and fly whilst the shutter fired every two seconds. Feel free to comment
Plus
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Hi Paul,
One thing that will improve your results further is to turn off “Live Map” when you don’t need a real time result. If you do so, the drone will fly in a slightly oblique double grid pattern when using the roof app.
James
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