[uup]

In most game engines, constructing the rotation matrix is trivial. Something like Quaternion.Euler(0, 45, 0). The ultimate position / rotation of any given object in a game is usually a compound transform computed via matrix multiplication anyway, e.g. a model view projection matrix. I'm not sure it's the best way, but that's just how most game engines work.

[jacobolus]

If your game engine is using quaternions as a canonical internal representation for rotations, it is already following my advice from above.

(Game engine developers are smart people and have lots of practical experience with the benefits of avoiding angle measures, as do developers of computer vision, computer graphics, robotics, physical simulations, aerospace flight control, GIS, etc. etc. tools.)

[uup]

Yea, I see. I originally interpreted your comment as being about game developers, but you were actually talking about game engine developers. In which case, we agree :)