怎么求两条样条曲线或是求样条曲线与直线的交点?

zcg319

我从CAD帮助文件中看到:可以用 ill 函数来求两直线的交点,可是如果是求两条样条曲线或是求样条曲线与直线的交点该怎么办呢?

陈伯雄

alin

I remember Long Long Zai pasted this routine months ago, probably it might help you.[br];;-----------------------------------------------
;; CDNC5-02.LSP
;; Bill Kramer
;; Find all intersections between objects in
;; the selection set SS.
;; Process - Create drawing with intersecting lines and lwpolylines.
;;           Load function set
;;           Run command function INTLINES
;;           Intersections are marked with POINT objects on current layer
(defun C:INTLINES (/ SSL ;length of SS
   PTS ;returning list
   AOBJ1 ;Object 1
   AOBJ2 ;Object 2
   N1 ;Loop counter
   N2 ;Loop counter
   IPTS ;intersects
   A N NN HOLDOSMODE
  )
  (vl-load-com)
  (command "_.UNDO" "_GROUP")
  (setq HOLDOSMODE (getvar "OSMODE"))
  (setvar "OSMODE" 0)
  (setq SS (ssget '((0 . "*LINE,ARC,CIRCLE,ELLIPSE"))))
  (setq N1  0 ;index for outer loop
SSL (sslength SS)
  ) ; Outer loop, first through second to last
  (while (< N1 (1- SSL)) ; Get object 1, convert to VLA object type
    (setq AOBJ1 (ssname SS N1)
  AOBJ1 (vlax-ename->vla-object AOBJ1)
  N2 (1+ N1)
    ) ;index for inner loop
;;; Inner loop, go through remaining objects
    (while (< N2 SSL) ; Get object 2, convert to VLA object
      (setq AOBJ2 (ssname SS N2)
    AOBJ2 (vlax-ename->vla-object AOBJ2)
;;;Find intersections of Objects
    IPTS  (vla-intersectwith
    AOBJ1
    AOBJ2
    0
  ) ; variant result
    IPTS  (vlax-variant-value IPTS)
      )
;;;Variant array has values?
      (if (> (vlax-safearray-get-u-bound IPTS 1) 0)
(progn ;array holds values, convert it
  (setq IPTS ;to a list.
(vlax-safearray->list IPTS)
  )
;;;Loop through list constructing points
  (while (> (length IPTS) 0)
    (setq PTS  (cons (list (car IPTS)
   (cadr IPTS)
   (caddr IPTS)
     )
     PTS
       )
  IPTS (cdddr IPTS)
    )
  )
)
      )
      (setq N2 (1+ N2))
    ) ;inner loop end
    (setq N1 (1+ N1))
  ) ;outer loop end
  (print PTS)
  (setvar "OSMODE" HOLDOSMODE)
  (command "_.UNDO" "_END")
  (princ)
)

龙龙仔

http://www.mjtd.com/bbs/dispbbs.asp?boardID=3&RootID=9982&ID=9993

http://www.mjtd.com/bbs/dispbbs.asp?boardID=3&RootID=12521&ID=12698