I give up. After much trying and searching, I have to say I was unable to achieve the following task, for which I must call for your wise advice.
In my current Unity 5 application (using C#), there is a procedurally generated object (therefore with variable shape) to which the camera should be aligned when players hit a given key. By aligned, please understand it making the width of the screen parallel to the longest part of the object. The idea is represented in the following picture, where in black one can see the irregular object, in yellow is the bounding box.
In other words, it means that I want the camera to be rotated so to align to the longest side of the object's bounding box. I tried that. Still, I was unable to properly calculate the correct angles so to rotate the camera in a way that the horizontal axis of the screen becomes parallel to the width of the objects' bounding box.
Any help would be much appreciated.