Central spherical projection of vertically cropped image

[ChameleonScales]

Sure, anyways. I must say you helped me a great deal for my bigger problem. However, it’s getting more complicated than I thought so I just posted a new question, this time explaining the whole thing:

Straighten and center a cylindrical panorama on a sphere

I’ve tried for many hours to achieve this : I would like to make procedural vector transformations to project an image of a central cylindrical panorama onto a sphere… BUT: This panorama image may have any orientation (yaw, pitch, roll) and any vertical field of view with truncated angles that may not be the same above and below and the only known value is the horizontal field of view. The end goal is to have a sphere that you can rotate to straighten the panorama as well as a “vertical cent…