[Visualpython-users] Rotated frame relative coordinates

[Ron A. <rr...@ro...>]

I want to add a vector in world relative coordinates to objects in a 
rotated frame.  It first needs to be translated to frame coordinates.

I can do this for single axis, but when the frame rotation involves 
rotation of more than one axis, I can't seem to get it correct.


It would be nice to have these three functions ...


     # The current world_space_function.

     def frame_to_world_pos(pos, frame):
         """ Frame position in world space coordinates. """
         x_axis = norm(frame.axis)
         z_axis = norm(cross(frame.axis, frame.up))
         y_axis = norm(cross(z_axis, x_axis))
         return frame.pos+pos.x*x_axis+pos.y*y_axis+pos.z*z_axis


     def world_to_frame_pos(pos, frame):
         """ World position in frame space coordinates. """
         ???
         return frame_pos


     def frame_to_frame_pos(pos, frame1, frame2):
         """ Frame position in other frame space coordinates. """
         wpos = frame_to_world_pos(pos, frame1)
         return world_to_frame_pos(wpos, frame2)


Is there an easy way to move objects from frame to frame and keep their 
orientation relative to world space?


Thanks, Ron