Calculation of Visibility Not Working

[lalafreguete]

Good afternoon, Dr. Dietrich.
I am wondering if you could give some enlightenment on this issue I have been facing when using the script for refraction correction.
When I run it for my dataset, the function for visibility calculation returns a empty array, but regardless that, I still can get the calculation of corrected depth.
For another dataset, the output corrected point cloud show some points without the correction calculation. I am trying to figure out why is that, but not success so far. I did check the target points' coordinates and camera coordinates, as well, and they seem ok.
Would you possibly have some idea of the cause for it?

Thank you.