Cylindrical UAV Mapping (or Unwrap)

[Photo]

Hello everyone,

I would be very happy if someone could help me. I've been trying to unwrap the reveal of a bridge for days. Unfortunately without success.
My model needs to stay georeferenced, so I'm not allowed to rotate the model (need scale). I have attached a few screenshots. could someone tell me the best way to do this or where can I put my markers so that I can do it correctly. Thanks in advance.

Cheers
Photo

[Kiesel]

Hallo photo,

According to the Metashape help:

Metashape allows using one of the following projection types: Geographic, Planar or Cylindrical

Metashape can unroll cylinders only.
Your brigde looks more like a three-part basket arch so you have three cylindrical parts. If you can manage to split it in three parts (2 with the same smaller radius and one with a bigger radius in the middle part) it should be possible to get orthomosaics of them and mount them afterwards.

Another possibility is to do it in CloudCompare with "Unfolding a cloud along a polyline"
http://www.cloudcompare.org/doc/wiki/index.php?title=Extract_Sections#Unfolding_a_cloud_along_a_polyline
and then reimport it in Metashape and make the orthomosaic out of it.

Hope it helps

Kiesel