not so simple problem

Lothar Esser esser at chop.swmed.edu
Tue May 23 10:40:28 EST 2000


>
>
>
> 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.






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