CCW euler angles to CW euler angles

CCW euler angles to CW euler angles

Hi,

Can anyone tell me how to transform counter clockwise euler angles to
clockwise euler angles?

regards,
Rune Laursen

CCW euler angles to CW euler angles

Rene

> Hi,

> Can anyone tell me how to transform counter clockwise euler angles to
> clockwise euler angles?

CCW euler angles to CW euler angles

Ok, I didn't explain the problem well enough. I am using a headtracker which
returns it's viewing direction in 3 euler angles. One of the angles is in
the range -90 to 90 and the other two is in the range -180 to 180. The
angles are measured counter clockwise. I have a function that converts these
angles to a counter clockwise rotation matrix. I need a clockwise rotation
matrix, so I figured that the euler angles would have to be converted to
clockwise before converting them to a rotation matrix. Is that the wrong
approach?

> isn't it 360deg-(your angle) ?

> Rene

> > Hi,

> > Can anyone tell me how to transform counter clockwise euler angles to
> > clockwise euler angles?

CCW euler angles to CW euler angles

> Ok, I didn't explain the problem well enough. I am using a headtracker which
> returns it's viewing direction in 3 euler angles. One of the angles is in
> the range -90 to 90 and the other two is in the range -180 to 180. The
> angles are measured counter clockwise.

That doesn't make sense without a definition what side these 3 clocks
are supposed to be facing.  Remember that a clock's hand will appear
to rotate CCW if you're looking at the back of the clock.

Quote:> I have a function that converts these angles to a counter clockwise
> rotation matrix. I need a clockwise rotation matrix, so I figured
> that the euler angles would have to be converted to clockwise before
> converting them to a rotation matrix. Is that the wrong approach?

This description still doesn't make much sense, I think.  There is no
such thing as a clockwise rotation matrix.

To convert any triplet of Euler angles into a rotation matrix, you
have to know *exactly* how these Euler angles are defined, so you can
reflect that knowledge by chosing the right axis direction vectors in
the formula:

M := R(axis1,angle1)*R(axis2,angle2)*R(axis3,angle3)

CCW vs. CW rotation can be implemented in this setup by flipping
either the sign of the angle, or the direction of the axis direction
vector.
--

Even if all the snow were burnt, ashes would remain.

I would like to convert 3 euler angles that I'm using to define the
orientation
of a 3d mesh object to an axis/angle representation, so I can call
glRotate(angle, axis)
to rotate the 3d object without suffering from this gimbol lock
thingy-mcbob.
Can anyone here tell how to do this ?
I'm using the right-handed coord. system like OpenGL's.

Thanks,
--Rick

10. Euler angles