Looks like my problem was an amateur mistake - causing integer division
on a float value, which when dealing with values that range between -1 &
1 is fairly debilitating!
I'm now getting the right values, but in the wrong places, using the
LLQuaternion(F32 x, F32 y, F32 z, F32 w);
constructor. I presume this must just be because whilst SL uses E/W as
+ve/-ve x axis & N/S as +ve/-ve y axis I must be assuming something else
for my magnetometer/accelerometer.
SL looking North - {0.0, 0.0, 0.7, 0.7}
magnetometer pointing North - {0.0, 0.0, 0.0, 1.0}
SL looking East - {0.0, 0.0, 0.0, 1.0}
magnetometer pointing North - {0.7, 0.0, 0.0, 0.7}
SL looking South - {0.0, 0.0, -0.7, 0.7}
magnetometer pointing South - {-1.0, 0.0, 0.0, 0.0}
SL looking West - {0.0, 0.0, 1.0, 0.0}
magnetometer pointing West - {-0.7, 0.0, 0.0, 0.7}
Whilst I'm at it, llquaternion.h has some confusing comments in it...
(look at the order of parameters in declaration & comment closely!)
const LLQuaternion& setEulerAngles(F32 roll, F32 pitch, F32 yaw); //
Sets Quaternion to euler2quat(pitch, yaw, roll)
Regards,
CJ Davies
On 31/07/12 16:14, Nexii Malthus wrote:
> Hey Folks,
>
> The C++ codebase doesn't have much to do with LSL, so llEuler2Rot won't
> exactly help.
>
> What you are looking for CJ are the helper functions for quaternions,
> maybe this one will help:
>
> const LLQuaternion& setEulerAngles(F32 roll, F32 pitch, F32 yaw);
>
> (form llquaternion
> <https://bitbucket.org/lindenlab/viewer-release/src/24c6da14256c/indra/llmath/llquaternion.h#cl-83>)
>
> - Nexii
>
> On Tue, Jul 31, 2012 at 1:38 PM, Sophira Crystal <sl-...@theblob.org
> <mailto:sl-...@theblob.org>> wrote:
>
> Hi,
>
> To follow up on this...
>
> The easiest way to do what you want is to make a vector made up of
> <roll, bearing, pitch> in degrees, multiply the vector by DEG_TO_RAD,
> and then put it through llEuler2Rot. You should then have a good
> rotation that you can pass to a function that needs it.
>
> Hope this helps!
>
> - Sophie.
>
> On Tue, Jul 31, 2012 at 1:29 PM, Sophira Crystal <sl-...@theblob.org
> <mailto:sl-...@theblob.org>> wrote:
> > Hi,
> >
> > You don't convert degrees to quaternions directly. You convert
> vectors
> > to rotations (which are quarternions), and you do that with the
> > llEuler2Rot function.
> >
> > As for the rest of your query, you might find
> > http://wiki.secondlife.com/wiki/Rotation helpful - I don't know much
> > about rotations, but I bet the answer you want is probably in there
> > somewhere.
> >
> > I hope my reply's been helpful, even though I personally don't
> know much...
> >
> > - Sophie.
> >
> > On Tue, Jul 31, 2012 at 11:54 AM, CJ Davies
> <cjohndav...@gmail.com <mailto:cjohndav...@gmail.com>> wrote:
> >> I've been struggling with this for 2 days now & am no closer to
> working
> >> it out (despite investigating all sorts of examples online,
> including
> >> the SL wiki).
> >>
> >> I have a accelerometer/magnetometer that tells me orientation via
> >> compass bearing, pitch & roll. All of these are in degrees which can
> >> easily be converted to radians via foo*DEG_TO_RAD. I want to
> plug these
> >> values into llcoordframe methods to control where the camera
> points. All
> >> of the llcoordframe stuff works in quaternions & I can't for the
> life of
> >> me convert properly.
> >>
> >> I've just tried following this approach -->
> >>
>
> http://www.euclideanspace.com/maths/geometry/rotations/conversions/eulerToQuaternion/index.htm
> >>
> >> But this results in output like this --> http://paste2.org/p/2089138
> >>
> >> Note how the calculated w/x/y/z values change drastically with tiny
> >> changes in the bearing/pitch/roll, eg between lines 43 & 50 (the
> >> accelerometer/magnetometer was motionless on the desk at the time!).
> >>
> >> Any help greatly appreciated.
> >>
> >> Regards,
> >> CJ Davies
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