Support splatfacto training for metashape exports

[jb-ye]

test commands:

ns-process-data metashape --xml floorboard.xml --data floorboard/ --ply floorboard.ply --output-dir floorboard_nerfstudio/

[jb-ye]

@simonbethke Could you try this PR and see if it works? I manually tested your dataset, and it seems fine.

[simonbethke]

Yea, I will test it

[simonbethke]

Okay, i tested a little bit. The happy path works!!

The unhappy paths are rather bad. Not worse than the average quality but when taking that as benchmark it will stay bad forever :D

1. When the ply-file has not .ply extension a stacktrace is printed. As this case is handled and even has a message, it should not print the stacktrace
2. when providing a non-existing .ply file, it takes forever, then there are some Open3D warnings and in the end, it summarizes that it imported the non-existing file which is wrong.

[simonbethke]

I know handling unhappy paths is tideous and no fun. If you like, just ignore what I wrote about them.

[brentyi]

For the stack trace verbosity, maybe we can add ValueError to the try/except statement?

https://github.com/nerfstudio-project/nerfstudio/blob/41deed6a52a33996b34053eea58bdc54e714573f/nerfstudio/scripts/process_data.py#L531C1-L539C1

[jb-ye]

For the stack trace verbosity, maybe we can add ValueError to the try/except statement?

https://github.com/nerfstudio-project/nerfstudio/blob/41deed6a52a33996b34053eea58bdc54e714573f/nerfstudio/scripts/process_data.py#L531C1-L539C1

Yes, I sent out a new revision.

[brentyi]

Looks good to me, thanks @simonbethke @jb-ye!

[simonbethke]

Thank you both for your help!

[simonbethke]

Regarding this PR:
unfortunately there is still a gap. If I transform something in metashape, the data cannot be exported/imported to nerfstudio anymore. I think the reason for this is, that in the metashape xml, another transform appears that is not used in the nerfstudio importer. However, I already tried to get this working but I was not able to.
I have to provide sample data for that and it would be great if somebody could look into this :)

[jb-ye]

@simonbethke Could you start a new issue and provide sample data there?