this is better, but its 2d, how do i convert Cartesian to polar in 3d?(!)
the equation at the bottom of this page makes no sense, i need three radians
to correctly Orient the cube, this gives me 2 and a length. pls good ppl of
thanks wes, the page you directed me is missing a formula to find the
zenith(?) angle (probably me missing the point).
i followed wikipedia on this, also switched from arctang to atan2. bu still
no good, i still thnk i am missing an angle.
basically i am after rotating a number of planes around a center. keeping
them looking in the same direction. if i need math to do it, so be it.
i would now lke to apply this to the formulas supplied by andrew b. in my
shatter experiments, were i cannot use the rotatexyz (which is Euler if im
here is an example of the effect with jit.gl.multiple
On 9/30/07, Wesley Smith wrote:
> What are you after, Euler angles or "3D polar coordinates" which are
> called Spherical coordinates?
Euler angles don't give you a unique orientation. Sometimes the
result can be ambiguous. For unambigues 3D orientations, you have to
use either axis-angle or quaternions.
That said, given a location and vector direction (velocity for
instance), you can derive an axis angle orientation. You take the
vector from the point you want to face to yor location. This forms a
triangle with your vector orientation. You then normalize both of
those vectors. Next, make a vector halfway between them by
subtracting one form the other and dividing in half. This will be
your axis. To find the angle, take the arcsine of the distance from
your orientation to your halfvector. I forget if you have to multiply
by 2 here or not, but that is the basic procedure.