;; | ---------------------------------------------------------------------------
;; | PL_3d?
;; | ---------------------------------------------------------------------------
;; | Function : Checks if a polyline is 3D or not
;; | Argument : 'ename' - Polyline or Line entity name
;; | Returns  : T if the polyline is 3D, else nil
;; | Updated  : February 9, 1999
;; | e-mail   : rakesh.rao@4d-technologies.com 
;; | Web      : www.4d-technologies.com
;; | ---------------------------------------------------------------------------


(defun PL_3d?( ename / en entl 3d flag )

(setq
	entl (entget ename)
	en   (LI_item 0 entl)
	3d   nil
)
(cond
	((member en (list "POLYLINE" "LWPOLYLINE"))
		(setq flag (LI_item 70 entl))
		(if (zerop (logand flag 8))
			(setq 3d nil)
			(setq 3d T)
		)
	)
	((= en "LINE")
		(if (and
				(zerop (caddr (LI_item 10 entl)))
				(zerop (caddr (LI_item 11 entl)))
			)
			(setq 3d nil)
			(setq 3d T)
		)
	)
	(T
		(alert (strcat "Error : Entity passed to PL_3d? '" en "'is not a Line or Polyline."))
		(exit)
	)
)
3d
)