To answer your question: my current project is a 2D platform game (side view). The idea is to zoom out so that the player can view the entire current level. The levels are rectangular in shape so I can easily calculate their size.
I may have found a clue: I have the impression that we must use trigonometry. I manage to get the desired result but if the size of the viewport changes, it no longer works. I imagine that you have to manage the vertical FOV and the horizontal FOV as parameters in the formulas but I don’t see how. I found some advice in the forum but apparently there has been a change in FOV management since version 5.2 so the formulas I found no longer work…