;; | ----------------------------------------------------------------------------
;; | MI_3PUcs
;; | ----------------------------------------------------------------------------
;; | Function : Create a new User coordinate system using the 3 Point option
;; | Argument :
;; |            'pt1' - First point (origin) of the UCS
;; |            'pt2' - Second point (on X-axis) of the UCS
;; |            'pt3' - Third point (defining XY plane) of the UCS
;; |            If 'pt3' is nil, the third point will be assumed along the
;; |            X axis starting from the first point as the origin
;; | Action   : Create a new 3 Point UCS if the distance between the points
;; |            are non-zero
;; | Updated  : July 19, 1999
;; | e-mail   : rakesh.rao@4d-technologies.com 
;; | Web      : www.4d-technologies.com
;; | ----------------------------------------------------------------------------


(defun MI_3PUcs( pt1 pt2 pt3 / Done OS )

(setq
	Done nil
	OS (getvar "OSMODE")
)

(setvar "OSMODE" 0)
(if (not pt3)
	(setq pt3 (polar pt1 (+ (angle pt1 pt2) #pb2) 10.0))
)

(if (and
		(> (distance pt1 pt2) 0.001)
		(> (distance pt1 pt3) 0.001)
		(> (distance pt2 pt3) 0.001)
	)
	(progn
		(command "._Ucs" "_3Point" pt1 pt2 pt3)
		(setq Done T)
	)
)
(setvar "OSMODE" OS)
Done
)