Hi,

I am a bit confused by angles and rotation.

The manual says, the ranges of the angles are
pan: 0 .. 360
tilt: -90 .. +90
roll: 0 .. 360
(online manual, section ENTITY->pan, tilt, roll)
And it also says, that it is important to keep the angles within this ranges to avoid gimbal lock problems.
Fine, I want to avoid any problem - so I try to keep the angles within the given ranges.

But if I use engine functions (e.g. ang_add, ang_rotate, c_rotate), the ranges of the result angles are:
pan: -180 .. 180
tilt: -90 .. +90
roll: -180 .. 180

I am using GS 8.10 Extra edition.

Does anyone know why the engine functions don't stay in the ranges which are stated in the manual? Or did I get something wrong?

Gimbal lock happens at tilt = (+/-)90, at which changing pan and roll has the same effect.

In terms of ambiguities, the main concern is tilt. If, for example, your tilt gets to 180 and your roll gets to 180, even though the entity looks like it's oriented upright it'll tilt down when you want it to tilt up and it'll face away from targets when you try to face towards them.

In practice, keeping pan and roll between -180 .. 180 is just as "safe" as using 0 .. 360, but is slightly easier to maintain since you can take advantage of the ang() function to enforce it.

Jibb

Thanks Jibb - this information is quite helpful.
I was "fighting against" the ang... functions to stay within the ranges which were described in the manual