>>>> T
> c(new) = a + |My * |Mz *|Rx ( PSI) * ( C* cos(PHI), C*sin(PHI), 0)
>> This is the equation I came up with. Again in short:
>> c (new) is a point on the surface of the cone.
> PHI is the angle between c-a and b-a or in your case 180 -104.5. deg (
> cone angle ).
> C is the length of c-a.
> PSI is the angle by which c' is rotated out of the xy plane.
> Rx is the rotation matrix around x given the angle PSI.
>
Sorry, there has been a mix-up.:
> Mz is the rotation matrix that moves (-B,0,0) to ( -sqrt(b'x^2
> +b'y^2), 0, b'z)
> My is the rotation matirx that moves it to (b'x,b'y,b'z)
My is the matrix that rotates ( -B, 0,0 ) to ...
Mz rotates ... to ( b'x,b'y,b'z)
Lothar.