Hi Sergey,
My pano is a plain image (as a map). I see that getlooktodistance get the spherical distance in degrees from 0 to 180 degree. I see that ATH and ATV are degrees too.
The polyline in a plain image is as a rute. I need to measure it for later to convert it to meters.
Perhaps I must set a reference maxime distance between two known points to 180 degree and then calculate the value from other angles.
Example:
180 degree it is equivalent to 500 meters, then 90 degree to 250 meters in the plain image.
I will test this idea. The final goal is to measure distances in meters from the values of ath, atv.
Thanks very much for your answer, I wait for your comments.