orthomosaic fail, no identifiable error

[majou]

Hi all,

I want to generate an orthomosaic photo, the process goes about 20% then suddenly end with no error or success message, the ortho tab is there but totally empty, also I export the ortho photo, it is just a blank space (expected but wanted to experiment it)

there is already a topic in the forum with same issue, the advice there doesn't seem to help me in this situation. (link https://www.agisoft.com/forum/index.php?topic=7324.0)

any ideas or suggestion that might help?

below are more details:
chunk is merged of 4 chuck, all cameras are there with the right path, textured model of the merged chuck also looks very good, area is also iside the bounding box frame. I tried using smaller area of the model but also had the same issue.


looking forward to hearing from you all!
thanks.

[Alexey Pasumansky]

Hello majou,

Can you provide the log related to the failed operation?

If there are sensible filenames in the log, please remove/replace them.

[majou]

Hi Alexy,

thankf for the prompt reply.

attached are the info requested (I hope they are what you looking for)

[Alexey Pasumansky]

Hello majou,

According to the provided screenshots the orthomosaic is 2x2 pixels.

Which parameters you are using in the Build Orthomosaic dialog? Maybe something wrong with the reconstruction resolution or with the referencing of the merged chunk?

[majou]

Hi Alexey

the thing is, the process is terminated at about 20% and it shows an "orthomosaic" in the chunk. but it it's a failure.
i use the default settings as in photo

[PROBERT1968]

What was your workflow like before reaching to Orthomosaic ?

[majou]

@PROBERT1968


I had 4 essential chuncks of which I did the following for each:
 - adding photo folder
- running photo alignment alignment to generate sparse cloud
- adding GCP markers, then updating model transform
- running "optimize camera locations"
- correcting GCP markers errors

of which resulted in having sparse cloud for each of the chuncks, perfectly aligned to each other
I then cleaned the sparse cloud for each chunck to have left with the parts I need in the "merged" chunk.
then I selected 4 chunck, merged them  , I hade the "merge markers" enabled. Can't remember if I had the "merge depth maps" enabled too or not.
I had a merged chunck of sparse clouds.
then I run generating mesh, then generating texture for the mesh model. of which now I try to generate Orthomosaic of but fail every time.

attached are the parameters for one of the essential chuncks, and the merged chunk.

[PROBERT1968]

If i were me ,  I would give a try with Dense Cloud rather than spare cloud.

I would just back it up this project and then do a experiment to play around and see if the Dense cloud gives you much quicker than the spare cloud .

For me to build orthomsoaic , I would use DEM ..  ( my co-worker told me that DEM would give you smoother than mesh )

I do not know of the processing time seem unreasonable to run that long like two hours or so...   Shouldn't they less than an hour ??

I work a lot of old aerial photos and when I processing them, I always get funny feeling if things go no right, I would just keep experiment until I get them right.....  just sayin'

I hope Alexey can provide you the answer to nail it down what is the problem.

[majou]

what difference would it make to have dense cloud? I do not understand how this related to generating an orthomosaic.
indeed the processing time is quiet long, in general about 10 hours.

I really hope some one would be able to help me with this!

[Alexey Pasumansky]

Hello majou,

Is the pixel size 144166 a default value suggested in Build Orthomosaic dialog? It means that single pixel of the produced raster would contain 144166 meters.

Maybe you can send PDF report from the merged chunk and screenshots of the Source values tab from the Reference pane with the model overview (from the Model view) with the visible estimated camera locations, markers and coordinate system axis to support@agisoft.com?

[dpitman]

Hi majou,

The pixel size caught my eye as well.  It's like there is a decimal point missing.  Below is the dialog for my last ortho for comparison.

[majou]

@Alexey
@dpitman


I have not set that value manually. since both of you seems to see it as an issue, can you please advice on how should I determine the best value to input manually? and what could possible made Metashape suggest it as a default value for this project?


also, on another hand since generating the orthophoto based on DEM seems to be the better practice, I am currently trying it. I face another issue.
when generating DEM based on "depth maps", it shows an error saying "Empty DEM", with no result of course.  I run it again based on "mesh" and it generates it successfully. (however, it is a small part of the model for experimenting purpose.
at this very moment I am running an ortho photo based on DEM that I now have. fingers crossed for a successful result. Metashape suggest the same value as before for the pixel size, I have added the decimal (for experimenting too). let us see how it ends!

ok guys, an othrophoto is generated but seems like I missed it up. please see attached.
well, at least we are moving forward with this.

eagerly waiting for your comments.
@alexey, I will send the email as requested.

[Alexey Pasumansky]

Hello majou,

I think there are referencing issues with the project or chunk.

"Empty DEM" message may appear if different cases, but usually they indicate some problems with the project. For example, if all the cameras are disabled, if the bounding box doesn't contain the area of interest and etc.

[majou]

Hi again,


this is solved!
the issue seems to be only the pixel size. I manually changed it to (0.00144166) instead of (144166).

thanks all for your notes. always helpful.

[PROBERT1968]

Good for you....

and I also learned something new !