Forum

Author Topic: Dam in 3D - Mixing horizontal pictures and vertical  (Read 12155 times)

frejus

  • Newbie
  • *
  • Posts: 6
    • View Profile
Dam in 3D - Mixing horizontal pictures and vertical
« on: June 01, 2014, 03:03:20 PM »
Hi,

Still testing Photoscan inside out with my multicopter.

I had a good success taking 200 horizonal pictures of a dam in the South of France and assembling them with PS.

I have a problem though, horizontal surfaces are perfectly detailed, but vertical are not so good.

So I went back there to the dam and took about 50 vertical pictures of both sides.
I then added those pictures to the directory where i have horizontal pictures, and re-runned the full process.

That totally messed up my results, portion of the sky integrating into the dam textture,  in short, no go :-)

I could not find any tutorial related to mixing both horizontal and vertical textures. Is there any ?

Thank you

Philippe
« Last Edit: June 01, 2014, 04:34:52 PM by frejus »

chadfx

  • Full Member
  • ***
  • Posts: 205
    • View Profile
Re: Dam in 3D - Mixing horizontal pictures and vertical
« Reply #1 on: June 01, 2014, 03:28:15 PM »
I think Photoscan should correctly interpret the photo orientation as long as your camera is passing it along in the EXIF metadata; and thus allow you to mix orientations in a project. Do the vertical photos appear vertical in the photos window in Photoscan? You might try rotating them manually in Photoscan (the middle two tools at the top of the Photos panel) if they are not already vertical.

Cheers, -Chad

James

  • Hero Member
  • *****
  • Posts: 736
    • View Profile
Re: Dam in 3D - Mixing horizontal pictures and vertical
« Reply #2 on: June 01, 2014, 04:10:52 PM »
I assumed you meant the 'horizontal' photos are pointing down and the 'vertical' photos are looking across at the dam. In that case they will include sky in the shot, which you could try masking out.

It might also be that the change in angle between 'horizontal' and 'vertical' orientation is too extreme for photoscan to detect matching features between both sets, so you may need some oblique images to tie the two sets together.

chadfx

  • Full Member
  • ***
  • Posts: 205
    • View Profile
Re: Dam in 3D - Mixing horizontal pictures and vertical
« Reply #3 on: June 01, 2014, 04:31:56 PM »
Ah yes, you are likely correct James, that makes much more sense. I did a couple of multicopter tests (including a church) and photographed with multiple angle settings on the camera mount, emulating the same process for objects I would normally photograph on the ground or in a studio setup.

frejus

  • Newbie
  • *
  • Posts: 6
    • View Profile
Re: Dam in 3D - Mixing horizontal pictures and vertical
« Reply #4 on: June 01, 2014, 04:33:07 PM »
Fine, will try that, thank you guys  ;)
« Last Edit: June 01, 2014, 04:35:07 PM by frejus »

frejus

  • Newbie
  • *
  • Posts: 6
    • View Profile
Re: Dam in 3D - Mixing horizontal pictures and vertical
« Reply #5 on: June 02, 2014, 07:51:46 AM »
Guys  ;)

I do not have many batteries and the dam i am modelizing is not so close from home so i'd rather make it fine from the start.

What angle do you think would suit the best to both show vertical details but also suit photoscan calculation ?

chadfx

  • Full Member
  • ***
  • Posts: 205
    • View Profile
Re: Dam in 3D - Mixing horizontal pictures and vertical
« Reply #6 on: June 02, 2014, 08:43:25 AM »
I don't know if your camera angles are exactly horizontal and vertical (ie. 90 degrees from each other), but I would think a 45 degree angle would split the difference between the two sets of images and help Photoscan find the correlation between them. I believe the general guidance is that any particular point should be visible in at least three photos (and in your case, between the two sets of images).

chadfx

  • Full Member
  • ***
  • Posts: 205
    • View Profile
Re: Dam in 3D - Mixing horizontal pictures and vertical
« Reply #7 on: June 02, 2014, 09:13:32 AM »
Hi Frejus,

I thought I would send a pic of the project I did (also in the South of France, nobody to bother me while shooting in this remote area!). It is probably more photos than I needed, but at least it shows the variety of angles I captured with the multicopter. It was mainly an experiment to see what I could capture with a basic DJI Phantom and Canon point and shoot camera, and it generally worked well. I didn't have a lot of control over the shooting, as it was using an intervalometer and I didn't always have a great FPV view...so I just sort of flew it around as systematically as I could.

I used a bunch of batteries for the flights, which were not too expensive by purchasing 3rd party batteries from here (they have a warehouse in the UK in addition to others):
http://www.hobbyking.com/hobbyking/store/index.asp

They were about a third of the price of the DJI batteries...which meant a lot more flying time for the money.

Good luck and I hope you are able to get it to work out, it would be great to see the results!

Cheers, -Chad

James

  • Hero Member
  • *****
  • Posts: 736
    • View Profile
Re: Dam in 3D - Mixing horizontal pictures and vertical
« Reply #8 on: June 02, 2014, 11:41:39 AM »
I would agree with that, but my only experience of using UAV is for building facades (they never seem interested in roofs?) so we only ever have the camera facing forward anyway.

Marcel

  • Sr. Member
  • ****
  • Posts: 309
    • View Profile
Re: Dam in 3D - Mixing horizontal pictures and vertical
« Reply #9 on: June 02, 2014, 02:47:43 PM »
If I understand correctly your two sets (horizontal and vertical) were shot on different days? It could also be that the lighting is too different for the images to match.

We have been mixing images in portrait and landscape in the past without problem (if Photoscan can pinpoint the camera position with millimeter accuracy then the camera orientation should be no problem).

HyperFox

  • Newbie
  • *
  • Posts: 18
    • View Profile
Re: Dam in 3D - Mixing horizontal pictures and vertical
« Reply #10 on: June 02, 2014, 04:24:14 PM »
I would recommend one set of imagery taken with nadir dircetion and two other sets wit a 60 and 45 or 30 degreee camera tilt. Additionally photos from the ground. Then you'll have enough tie points for a correct photo alignment.

James

  • Hero Member
  • *****
  • Posts: 736
    • View Profile
Re: Dam in 3D - Mixing horizontal pictures and vertical
« Reply #11 on: June 02, 2014, 04:43:04 PM »
I thought I would send a pic of the project I did (also in the South of France, nobody to bother me while shooting in this remote area!).

On the subject of scanning old buildings in the South of France... I did this just for fun while I was at Digital Heritage conference last year in Marseilles, so it is one of the few I can actually share publicly!

I did not use a UAV for it as they had conveniently built in >100 multilevel vantage points all the way around! http://en.wikipedia.org/wiki/La_Vieille_Charit%C3%A9

The camera was more or less directed straight forwards, but using an ultrawide angle (10mm on a Nikon D90) I was able to look across and down at the same time :)

Just another possibility, although ultrawides do obviously bring other problems.

chadfx

  • Full Member
  • ***
  • Posts: 205
    • View Profile
Re: Dam in 3D - Mixing horizontal pictures and vertical
« Reply #12 on: June 02, 2014, 04:56:48 PM »
<sigh> There is always some vehincle parked in front of these historical buildings...even in 3D.  ;-)

How was that conference, BTW? Anything interesting?

James

  • Hero Member
  • *****
  • Posts: 736
    • View Profile
Re: Dam in 3D - Mixing horizontal pictures and vertical
« Reply #13 on: June 02, 2014, 05:17:40 PM »
Hehe, I left them in because I was impressed that PhotoScan had modelled them so well!

It seemed like a bit of a PhotoScan frenzy, everyone seemed to be demonstrating things that were doing with it (although few mentioned it by name in the presentations).

A few people were demonstrating things they had done using alternative software/techniques which was interesting but mostly I thought they should be better off using PhotoScan too!

I did seek out the laser scanning/photogrammetry/3d technologies talks so it's no surprise that that's what I found...

The conference overall was pretty big with three huge buildings booked up in the city for a week with always 3 or 4 things running in parallel, and the food was amazing :)

Shame I was there on my own for most of it, and too shy to mingle/network very effectively!