Hello,
It's difficult for me to discribe this in English. I try it. Pan and roll are not the same. This is only in the special case, in wich tilt is 90 or -90. The engine rotates the entity first to its pan angle and then relativ from its pan angle to its tilt angle. And now relative from its tilt and pan angle to its roll angle. If you don't understand this, you have to wait for another memeber...

Sincerely yours
Jupp