Bowl/banana effect in photogrammetry

[blue-simonA]

I am new to photogrammetry and trying to create a 3D model in Meshroom of a supermarket rooftop - photovoltaics project. I have 261 photos from drone DJI Air 3 (FC8282), focal length 6.72mm/24mm with GPS coordinates in metadata. After reconstruction using simple photogrammetry pipeline I get a model that is warped like a bowl. It's best seen with camera positions.


I have two questions:

1. Is it possible to correct the effect with existing photos using Meshroom parameters?
2. How to avoid it in the future, if it is a fault of methodology in taking photos?

[beaki]

this is only a hack: there is a cache directory, by default in the /tmp if you have not changed it. In this directory you can find the positions and the pose of the cameras here MeshroomCache/StructureFromMotion/<latest_run_folder>/cameras.sfm
you could change the camera position (center and rotation) making sure they are in one perfect plane and use the fixed camera positions as input for the following nodes.

[natowi]

Could be caused by lens distortion. You could try to calibrate your camera and use the values from the calibration in the CameraInit node.