As someone who played a lot of OpenDroneMap, I think that will be influenced by how the collection of photos was taken, if photographing looking down directly (

As someone who played a lot of OpenDroneMap, I think that will be influenced by how the collection of photos was taken, if photographing looking down directly (nadir), there won't be much information to be derived from the bottom of the bridge and the software will make a best guess with the data they were given. ODM recommends flying in two patterns, separated by 20° with a 5° forward-facing camera to avoid some of the effects of photographing with the nadir, but this doubles the time of the survey. https://docs.opendronemap.org/tutorials/ https://docs.opendronemap.org/tutorials/