Coordinate Frame conversion of coordinates

 From:  bemfarmer
5000.5 In reply to 5000.4 
Thank you Michael.
Should have enough now to finish a catenary curve script hanging from two points in 3D, even with different z values, with
gravity in the -y direction. There is plenty of code on the internet.
Yes, the new x-axis "rotates" about the new y-axis, to "zero out" the z values.

EDITED: 12 Mar 2012 by BEMFARMER