;|***************************************************************************|;
;| hLx: Nonlineer Helix                                                      |;
;|      M. Şahin Güvercin (ProhibiT) - www.cizimokulu.com - 07.02.2014       |;
;|---------------------------------------------------------------------------|;
(defun c:hLx (/ Hei KoT L n Obj pT0 pTs PvT sLp sTe)
  (setvar "cmdecho" 0) (command "undo" "group") (vl-load-com)
  (setq Obj (vlax-ename->vla-object (car (entsel "\nSelect 3DPolyline: ")))
Hei (getreal "\nHeight: ")
sLp (/ Hei (vlax-get-property Obj 'Length))
pTs (vlax-safearray->list
              (variant-value (vlax-get-property Obj 'Coordinates)))
sTe (nth 2 pTs) L (length pTs) n -3)
  (while (< (setq n (+ n 3)) L)
    (setq PvT (list (nth n pTs) (nth (1+ n) pTs) (nth (+ 2 n) pTs))
  KoT (+ sTe (* sLp (vlax-curve-getDistAtPoint Obj PvT)))
          pT0 (append pT0 (list (nth n pTs) (nth (1+ n) pTs) KoT))))
  (setq PvT (vlax-vla-object->ename Obj) n -3)
  (while (/= "SEQEND"
             (cdr (assoc 0 (entget (setq n (+ n 3) PvT (entnext PvT))))))
    (setq PvT (entget PvT)
          PvT (subst
                (cons 10 (list (nth n pT0) (nth (1+ n) pTs) (nth (+ n 2) pT0)))
                (assoc 10 PvT) PvT) Pvt (entmod PvT)
          Pvt (entupd (cdr (assoc -1 PvT)))))
  (command "_.undo" "e") (princ))