Hi all, I’m new to drone mapping but have been flying drones for a few years now. I am taking on some landscape work on my property and also mapping to watch for erosion from a creek there.
Here’s a drone shot (this isn’t a map but a single shot to show the area):
Basically, I have no probably doing a nadir map at 150 ft, but really want I want to be able to create is a 3d model I can “walk through”. I understand doing a POI oblique shot helps particularly with facade details on structures - but in this case I don’t care too much about the structures there but about be able to scroll the landscape in a 3d model.
I can do manual shots from the “inside” (the field in the middle). Or can I just fly the drone inside the tree cover and add that as a “walkthrough”?
Essentially I’m looking for help on what to do after capturing the nadir images from bird’s eye view. And also on those nadir images, is -90 degree gimbal angle best, or will something slightly less give better depth perception for the 3d model?
I plan to do all the capturing this weekend. Thanks very much in advance!
I don’t know that you will be able to create a clean walkthrough with that many trees but you could flight plan to get a decent amount out from the open areas. Just off the top of my head we would approach it something like this.
Standard nadir 75ft above the tallest object with 75/65 overlaps.
Enhanced 3D same altitude w/ crosshatch and no perimeter, 70/70 overlaps and a 65deg gimbal
Go to each spot that you can drop down in and manually spin with a 45deg gimbal as if you were making a pano but just one row around. At each spin let it sit for a second or two to let the GPS and orientation values to settle. You might do this at two different altitudes if it looks like that would help.
Thanks @MichaelL really appreciate your feedback. I have a few follow up questions.
Also, just to clarify, I am using Dronelink for the capture and then uploading my footage into DroneDeploy. This is just because the drone I use is an Air2s and as far as I know it’s not supported in DroneDeploy yet.
On this standard nadir, do I use 90 deg gimbal angle or something a little less like 80/85 ? Do I do this without the ‘enhanced 3d’ setting? I actually don’t even know what this setting is in Dronelink as I don’t see it like I do in DroneDeploy
Same question as above, I don’t see an ‘enchanced 3d’ setting for Dronelink. They do have ‘grid’ though which I’m guessing is the crosshatch you’re mentioning? No perimeter means I remove the outer lines for the flight path?
Does the altitude matter on this part? Or does it have to be the same at each spot I drop down?
You’ll need to stay clear enough to maintain GPS but the exact altitudes don’t really matter. I wouldn’t go much lower than about 100ft lower than your mapping altitude. You could go a little further but I have seen issues in the past where a large difference in altitudes caused some noisy issues.
Hello! Have you ran your flights yet? I wanted to come in to add, you can get much better results by trying your best at the following:
Fly as slow as possible while taking your shots. Like 2mph. Steady. Even stopping for each shot can get great results with the types of cameras drones usually have.
Get nadir and oblique runs in. If you use dji pilot pe or any software, just go 80 all the way around. Start your missions when the sun is at nadir, overcast days are your friend.
Agisoft has cloud based software that is very affordable especially for scenes like this.
When the leaves drop you should do another run. That will give you all the terrain.
The newer electronic shutters with the latest algorithms don’t really need to run that slow. At 150-200ft AGL an average of 10 mph has provided just as good of results as our Phantoms. I imagine you are running so much slower because of your extremely high overlaps. In our experience anything over 70% sidelaps does nothing but drive up file sizes and increase processing time. We run 80/65 and drop the frontlap as low as 75% or until the flight lines land right where we want them.
Agisoft Cloud requires you to have Metashape Pro correct?
Thanks MichaelL. Agisoft cloud does require Metashape pro. They offer a long free trial and the experience is much more engaging. Drone deploy does just fine for basic orthomosaics. The OP was interested in building a 3d model for a personal project. In any project, data is king, and I would still fly slow as heck for a low altitude oblique mission. For one because of the trees, and two for the motion blur mostly seen in these low altitude passes. At 120 plus feet you can really move and let the algorithm handle the noise.
