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Author Topic: reset selected cameras removes tie points  (Read 711 times)

Faulty_geo

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reset selected cameras removes tie points
« on: April 08, 2021, 07:08:33 AM »
Hi,

This might sound like a stupid comment, but after performing a camera alignment, if I select the cameras, right-click, and choose "reset select "reset camera alignment" all of my tie points are removed. It used to be that when I chose this option, I would keep the tie points and could align the selected cameras again. This cut down a ton of reprocessing time because I already had the tie points.

I'm not sure if this is a version issue, but I recently updated to 1.7.2.

Is there a workaround, where I can make adjustments to the model parameters/gcps/whatever, reset the alignment (but keep tie points), and then realign the cameras? I like to make several chunks and try out different things, and if I have to start from scratch every time, it takes a really long time.

JMR

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Re: reset selected cameras removes tie points
« Reply #1 on: April 08, 2021, 01:06:16 PM »
Tie points are matched feature points. If you reset some cameras alignment, the tie points will be removed form the 3D scene as the cameras are no longer located in the 3D scene. However key points are still on your photos so you can use align selected cameras to bring them back to the 3D scene hopefully in a better location. It should take but just seconds to re-align cameras that where reset.

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cbnewham

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Re: reset selected cameras removes tie points
« Reply #2 on: April 08, 2021, 05:16:07 PM »
Do you mean the tie points are removed for all cameras?

If so, that doesn't sound right. You should be able to reset one camera or a group of cameras. I do that all the time.


Alexey Pasumansky

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Re: reset selected cameras removes tie points
« Reply #3 on: April 09, 2021, 01:52:17 PM »
Hello Faulty_geo,

Please specify, if you are resetting the alignment for all the cameras at once? If so, then it is expected to have the 3D tie points discarded in the Model view, however, the tie point projections in such case should be still there in the project and you should be able to select all cameras and use Align Selected Cameras command.
Best regards,
Alexey Pasumansky,
Agisoft LLC

Faulty_geo

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Re: reset selected cameras removes tie points
« Reply #4 on: April 11, 2021, 11:34:29 PM »
Hi all,

Sorry I took so long to get back, I was trying to figure out why this problem only seemed to happen sometimes.

I think the missing tie point problem occurs when I have the "film camera with fiducials" box checked in camera calibration. After the initial alignment, I had set some of the camera parameters (f) but didn't have any of the fiducials placed. I'm guessing that caused things to glitch when I tried to realign the cameras without fiducial information.

I originally went down this path because I had problems with cameras not aligning in my original project (one where I had placed fiducials). l need to spend a little bit of time trying to figure that out first before I ask more questions.

I think this problem (missing tie points) is due to missing fiducial information.

Alexey Pasumansky

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Re: reset selected cameras removes tie points
« Reply #5 on: April 13, 2021, 01:55:24 AM »
Hello Faulty_geo,

Can you provide the steps that we can follow to reproduce the issue? Like add photos, set "scanned images" option, align photos and etc.
Best regards,
Alexey Pasumansky,
Agisoft LLC

Faulty_geo

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Re: reset selected cameras removes tie points
« Reply #6 on: April 18, 2021, 03:12:15 AM »
Hi Alexey,

I'm having problems now aligning any project with "film camera with fiducials" checked. I've started a new project to try and remove some of the variables. This problem only occurs when I have the "film camera with fiducials" checked in camera calibration, but works fine when I just go straight to alignment (see attached image) without any camera calibration information and without checking the box.

These are my steps:

1) load photos into project (these are high-res scanned air photos)
2) import masks (I saved them from the old project)
3) in the Camera calibration window:
     select all camera groups, select "film camera with fiducials"
   
This is where the problems start (second chunk in attachment image). I did a third trial by also including the following steps (third chunk in attached image):

    merge all calibration groups
     add fiducial locations and focal length
     fix "f" parameter
4) add fiducials to photos (these were exported from the original agisoft project that was malfunctioning. A colleague wrote a python script, but they all seem to have imported fine)
5) align photos
     accuracy high
     generic selection
     60,000 key points, 10,000 tie points
     ignore stationary points

The processing takes a reasonable amount of time given the size and number of photos. All things appear to work until the end- when it says 0 of the cameras have aligned. What weird is it says I have points in the reference frame when I click on the project, but none of them display since none of the cameras are aligned. (see attached image)

This is all very strange because I've run a gazillion of these types of models before, with the same photos even, and only now and hitting this problem.

The attachment shows three chunks, labeled with the differences. The only one that works doesn't have any camera calibration information (first chunk in attached image).

Let me know if you have any ideas. I'm using v1.7.2