Topic: Ellipse/Spline question

[V-Man]

Is there a way to explode an ellipse or spline?

[David Hall]

i dont think so

[V-Man]

That's what I thought. I tried everything and still no go.

[CAB]

What are you looking for after you explode the object? That is what new object type. Arcs? Lines?


http://www.theswamp.org/index.php?topic=1804.msg23108#msg23108

[V-Man]

Well the End result I want it to be a lwpolyline. I tried to Bpoly inside an ellipse or spline and the result is it creates a Region.. I then try to Bpoly inside an Region and the result is another Region. If I explode a Region the result goes back to the original item i.e. ellipse/spline.

[CAB]

See the link i just added to my previous post.

[V-Man]

Thanks I will check it out.

[CarlB]

To create a polyline rather than a region with the "boundary" command, change HPBOUND system variable to 1.

[CADaver]

To create a polyline rather than a region with the "boundary" command, change HPBOUND system variable to 1.

In R2002 that'll still force a region.

[T.Willey]

Here is a link to a web page that shows a way.

[LE]

or..... (for the ellipses) recreate them and set PELLIPSE = 1

[lispman21]

here is a little lisp routine to convert ellipses to lwpolylines, this also does elliptical arcs but it converts them to there full elliptical state and cannot figure out how to trim it back to the arc it was.  but this does do ellipses.



The Code:
 

Code: [Select]

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;                                                                         ;;
;;    AutoLisp Program                                                     ;;
;;    PROGRAM: existing ellipses to Plines.lsp                             ;;
;;    DATE: 4-19-06                                                        ;;
;;    File Location: C:\Program Files\Trane Company\Data Maintenance\SM    ;;
;;    BY: Jeremy Preston                                                   ;;
;;                                                                         ;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;



(defun e2p( /
old new   ;existent and new polyline
sav    ;store system variables
cen    ;center of ellipse
dep    ;axis end point deplacement (relative to cen)
p1 p2 ;first axis enpoints
p3 ;sec. axis endpoint
 ellObjs   ; added
 numObjs   ; added   
 count ; added   
   )

(setq ellObjs (ssget "x" '((0 . "ELLIPSE"))))
(if ellObjs
  (progn
  (setq numOjbs (sslength ellObjs)
 count 0
 )
  (while (> numOjbs count)
(setq old (cdr (assoc -1 (entget (ssname ellObjs count)))))


   (setq sav (mapcar 'getvar '("PELLIPSE" "OSMODE" "UCSICON"))
cen (cdr (assoc 10 (entget old)))
dep (cdr (assoc 11 (entget old))))
   (mapcar 'setvar '("PELLIPSE" "OSMODE" "UCSICON") '(1 0 0))
   (command "UCS" "e" old)
   (setq p1 (trans (list (+ (car cen) (car dep))
   (+ (cadr cen) (cadr dep))
   (+ (caddr cen) (caddr dep)))
0 1)
p2 (trans (list (- (car cen) (car dep))
   (- (cadr cen) (cadr dep))
   (- (caddr cen) (caddr dep)))
0 1)
p3 (trans (polar cen
(+ (/ PI 2.0) (angle p1 p2))
(* 0.5 (cdr (assoc 40 (entget old))) (distance p1 p2)))
0 1)
)
   (command "ellipse" p1 p2 p3)
   (command "_.chprop" old "" "la" "0" "")   
   (setq new (entget (entlast))
new (subst (cons 8 (cdr (assoc 8 (entget old)))) (assoc 8 new) new))
   (entmod new)
   (entdel old)
   (command "ucs" "p")
   (mapcar 'setvar '("PELLIPSE" "OSMODE" "UCSICON") sav)

(setq count (1+ count))
); while
  ); progn
  ); if
(princ)
   );; end of program

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defun 2d2lw()
  (prompt "\nChanging LW to 2D\n ")
  (setq count 0)
   (if(setq sset (ssget "X" ' ((0 . "POLYLINE"))))
     (command "convertpoly" "L" sset"")
   );; end of if

 );; end of program

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;


(defun 2d()

(e2p) 
(2d2lw)
);; end of program

(alert "Program automatically starts when you press ok")
(2d)

[T.Willey]

Thanks for sharing your code lispman21 (Jeremy?), and welcome to the swamp.

[CAB]

Humm, another?
Look like a revision of this code, no?
http://cadtutor.net/forum/viewtopic.php?p=8739#8739