just curious – could it be something else causing the problem?
Like literally in say 1980 (thirty+ years ago) you’d hear people say “if possible avoid a square root!”
That’s irrelevant today. Consider how many calculations Unity is doing all the time man ??! All the rotations and so on… every single frame… I mean … my goodness … it’s not even a compiled language, you’re using vast layers of interpreters, physics engines, and what not.
I use and I see used Atan2 constantly, in fairly high performance code (every sort of typical 3D game etc), eg…