Mapping Workflow- Drone Deploy specific

[BigAl07]

I've created many "othomosaics" over the last few years but none of them required any "Structure Details" (mostly land or tree farms) but now I need to "map/model" a structure as it's being built. My question is, for those who "do this" what options are you using to improve your final result?

I did a "standard" Ortho/Map of the structure and used all DEFAULT items and the building looks like it's "Melting" because all photos were taken at 90deg. So I know I need some additional images but I'm curious to know if I need to enable

* Perimeter 3D images (this does a single orbit with the camera at approx. 65deg in addition to the standard lawnmower pattern at 90deg but adds a large # of images and time to the process)
AND
* CrossHhatch 3D (this basically DOUBLES the # of images and flight time)

Or
* Perimeter 3D images only



Using M2P and Drone Deploy for the acquisition of data and MetaShape for Processing.

Any suggestions from those who do Building Models? I'm looking to create the ORTHO and upload it to SketchFab in order to share it with my international clients.

 

[Dave Pitman]

I would try this.

Mission planning for complex structures

Agisoft Metashape Professional provides functionality for generating drone flight plans for objects with complex geometry. The tutorial below describes basic workflow steps, under which you will be able to use the Plan Mission tool and create the...

agisoft.freshdesk.com

 

[R.Perry]

That is incredible. I wish I had that a few years ago.

 

[MapMaker53]

Amazing detail. I would need a one-on-one lesson from someone to walk me through that process as described in the demo video. I've only attempted a model in Map Pilot Pro which I think came out quite nice with just a cross-hatch flight. Certainly not the detail I think you are needing, BigAl07, but I definitely would recommend using the cross-hatch flight option.

 

[BigAl07]

Amazing detail. I would need a one-on-one lesson from someone to walk me through that process as described in the demo video. I've only attempted a model in Map Pilot Pro which I think came out quite nice with just a cross-hatch flight. Certainly not the detail I think you are needing, BigAl07, but I definitely would recommend using the cross-hatch flight option.

Thanks for the input my friend. I'm going to utilize Cross Hatch and Perimeter 3D on some tests later this week and see how they process. I may actually do sample of each and see which options give the best results.

 

[Enorda]

When modeling structures, I do cross hatch with obliques. nadir is great for orthos, but anything with depth you need oblique. Also, things like houses I will generally take a bunch of manual images to capture under the eaves, in between trees, etc. You have to be careful not to get the horizon as that messes up the photogrammetry. So low, like 10' or less (even level with roof) above the structure, 15-25 degree angle all around. I've been flying corn fields this summer, so I am sure I'm forgetting something, but I've done a bunch of 1 to 2 story buildings, and had to hone my skill.

Then 30 degree, then 45 or 60 depending on The quality you want. It is a bunch of images. But without LIDaR, you have to give each point multiple reference points that overlap from different POV and altitudes.

I didn't read the link, but it is probably saying the same thing.

 

[JimD]

I do condo inspections all the time. You make a map overhead with 3-D enhancement then you do facades on all four sides. Drone deploy knows how to stitch these together into a very nice 3-D image.

 

[BigAl07]

When modeling structures, I do cross hatch with obliques. nadir is great for orthos, but anything with depth you need oblique. Also, things like houses I will generally take a bunch of manual images to capture under the eaves, in between trees, etc. You have to be careful not to get the horizon as that messes up the photogrammetry. So low, like 10' or less (even level with roof) above the structure, 15-25 degree angle all around. I've been flying corn fields this summer, so I am sure I'm forgetting something, but I've done a bunch of 1 to 2 story buildings, and had to hone my skill.

Then 30 degree, then 45 or 60 depending on The quality you want. It is a bunch of images. But without LIDaR, you have to give each point multiple reference points that overlap from different POV and altitudes.

I didn't read the link, but it is probably saying the same thing.

I did a test run yesterday using -65 deg and utilized Cross Hatch and a Perimeter orbit and it turned out pretty good. There's still a couple of places that are missing data which I need to work on. One of them, a corner of the structure is partially blocked by large trees so I'm not sure how to get around that hurdle.

I need to practice more and go back to the same structure and do another duplicate flight but possibly lower and a shallower angle maybe?

When you say "Manual Images" do you mean literally single images of certain areas (like you stated under eaves etc or complete orbits?

Here is my "test subject" and you can see several areas of "Missing Data" that I need to work on.
Heart Theater AUG 2023 - 3D model by BigAl07

 

[WildDoktor]

I would try this.

Mission planning for complex structures

Agisoft Metashape Professional provides functionality for generating drone flight plans for objects with complex geometry. The tutorial below describes basic workflow steps, under which you will be able to use the Plan Mission tool and create the...

agisoft.freshdesk.com

Wow!!

 

[adm_geomatics]

I find that facade inspection type imagery is required if you want really crisp structural models. This require get a sampling distance of no greater than 0.5in/px but more important mapping vertical as you would the ground with nadir imagery. It is actually very simple to do these flight paths manually which I would suggest because running automated missions this close to structure with surrounding structures or things like tower cranes is just not a safe manner of capture. The tip is to plan you positions using a map and landmarks that you can see from the drone in the field. Always start at the bottom. Set you flight mode to slow or cinematic and your capture interval at 2 seconds. Gimbal pitch depends on the structure but I typically run between 33 and 45 degrees. This is a double win for the client because they not only have a great 3D model but facade inspection imagery. Pretty simple once you have done it a couple of times.

 

[BigAl07]

I find that facade inspection type imagery is required if you want really crisp structural models. This require get a sampling distance of no greater than 0.5in/px but more important mapping vertical as you would the ground with nadir imagery. It is actually very simple to do these flight paths manually which I would suggest because running automated missions this close to structure with surrounding structures or things like tower cranes is just not a safe manner of capture. The tip is to plan you positions using a map and landmarks that you can see from the drone in the field. Always start at the bottom. Set you flight mode to slow or cinematic and your capture interval at 2 seconds. Gimbal pitch depends on the structure but I typically run between 33 and 45 degrees. This is a double win for the client because they not only have a great 3D model but facade inspection imagery. Pretty simple once you have done it a couple of times.

I'm going to give this method a go this weekend when we go back to the jobsite for a walk-through. No cranes etc will be there so it's possible I could do it automatically but I will try MANUAL first and then go from there. The key is figuring out what distance will give me 0.5in/px resolution.

 

[adm_geomatics]

I'm going to give this method a go this weekend when we go back to the jobsite for a walk-through. No cranes etc will be there so it's possible I could do it automatically but I will try MANUAL first and then go from there. The key is figuring out what distance will give me 0.5in/px resolution.

https://s3.amazonaws.com/mics.pix4d.com/KB/documents/Pix4D_GSD_Calculator.xlsx

There's a couple of GSD Calculators online but they don't always have all the right models. This will let you plug in anything.