Extract a block's contour

[bograd]

Is there any way to extract or trace a blocks contour ?

I want a fast solution so i don't have to draw tha contour manualy.

I attach a image to ilustrate my request.

 

I use AutoCAD 2002.

[ASMI]

This lisp program draw contour of selected objects. Type ECO to run. Written by VVA.

 

;;; ! *********************************************************
;;; !                  lib:IsPtInView                         *
;;; ! *********************************************************
;;; ! Проверяет находится ли точка в видовом экране           *
;;; ! Auguments: 'pt'  — Точка для анализа в МСК!!!           *
;;; ! Return   : T или nil если 'pt' в видовом экране или нет *
;;; ! *********************************************************
(defun lib:IsPtInView (pt / VCTR Y_Len SSZ X_Pix Y_Pix X_Len Lc Uc)
 (setq pt (trans pt 0 1))
 (setq	VCTR  (getvar "VIEWCTR")
Y_Len (getvar "VIEWSIZE")
SSZ   (getvar "SCREENSIZE")
X_Pix (car SSZ)
Y_Pix (cadr SSZ)
X_Len (* (/ X_Pix Y_Pix) Y_Len)
Lc    (polar VCTR (dtr 180.0) (* 0.5 X_Len))
Uc    (polar Lc 0.0 X_Len)
Lc    (polar Lc (dtr 270.0) (* 0.5 Y_Len))
Uc    (polar Uc (dtr 90.0) (* 0.5 Y_Len))
 )
 (if (and (> (car pt) (car Lc))
   (< (car pt) (car Uc))
   (> (cadr pt) (cadr Lc))
   (< (cadr pt) (cadr Uc))
     )
   T
   nil
 )
)
(defun DTR (a) (* pi (/ a 180.0)))
(defun RTD (a) (/ (* a 180.0) pi))
;; ! **********************************************************
;; !                             lib:Zoom2Lst                 *
;; ! **********************************************************
;; ! Function : Zoom границ списка точек                      *
;; ! Arguments: 'vlist' — Список точек в МСК!!!!              *
;; ! Зуммирует экран, чтобы все точки были видны              *
;; ! Returns  : t — было зуммирование nil — нет               *
;; ! **********************************************************
(defun lib:Zoom2Lst (vlist / bl tr Lst OS)
 (setq	Lst (lib:pt_extents vlist)
bl  (car Lst)
tr  (cadr Lst)
 )
 (if (not (and (lib:IsPtInView bl) (lib:IsPtInView tr)))
   (progn (setq OS (getvar "OSMODE"))
   (setvar "OSMODE" 0)
   (command "_.Zoom"
	    "_Window"
	    (trans bl 0 1)
	    (trans tr 0 1)
	    "_.Zoom"
	    "0.95x"
   )
   (setvar "OSMODE" OS)
   T
   )
   NIL
 )
)
;; ! ************************************************************
;; !           lib:pt_extents                                   *
;; ! ************************************************************
;; ! Function : Возвращает границы MIN, MAX X,Y,Z списка точек  *
;; ! Argument : 'vlist' — Список точек                          *
;; ! Returns  : Список точек (ЛевНижн ПравВерхн)                *
;; ! ************************************************************
(defun lib:pt_extents (vlist / tmp)
 (setq	tmp
 (mapcar
   '(lambda (x) (vl-remove-if 'null x))
   (mapcar
     '(lambda (what)
	(mapcar	'(lambda (x)
		   (nth what x)
		 )
		vlist
	)
      )
     '(0 1 2)
   )
 )
 ) ;_setq
 (list
   (mapcar
     '(lambda (x)
 (apply 'min x)
      )
     tmp
   )
   (mapcar '(lambda (x) (apply 'max x)) tmp)
 )
) ;_defun
;http://www.autocad.ru/cgi-bin/f1/board.cgi?t=30724Ed
;External contour of objects
(defun C:ECO (/	      *error* blk     obj     MinPt   MaxPt   hiden
      pt      pl      unnamed_block   isRus   tmp_blk adoc
      blks    lays    lay     oname   sel     csp     loc
      sc      ec      ret     DS      osm
     )
 (defun *error* (msg)
   (mapcar '(lambda (x)
       (vla-put-Visible x :vlax-true)
     )
    hiden
   )
   (vla-endundomark adoc)
   (if	(and tmp_blk
     (not
       (vlax-erased-p tmp_blk)
     )
     (vlax-write-enabled-p tmp_blk)
)
     (vla-Erase tmp_blk)
   )
   (if	osm
     (setvar "OSMODE" osm)
   )
   (foreach x loc (vla-put-lock x :vlax-true))
 )
 (vl-load-com)
 (setvar "CMDECHO" 0)
 (setq osm (getvar "OSMODE"))
 (if
   (zerop (getvar "WORLDUCS"))
    (progn
      (vl-cmdf "_.UCS" "")
      (vl-cmdf "_.Plan" "")
    )
 )
 (setq	isRus
 (= (getvar "SysCodePage") "ANSI_1251")
 )
 (setq	adoc
     (vla-get-ActiveDocument
       (vlax-get-acad-object)
     )
blks (vla-get-blocks adoc)
lays
     (vla-get-layers adoc)
 )
 (vla-startundomark adoc)
 (if isRus
   (princ "\nВыберите объекты для построения контура")
   (princ "\nSelect objects for making a contour")
 )
 (if (setq sel (ssget))
   (progn
     (setq sel
     (mapcar 'vlax-ename->vla-object
	     (vl-remove-if
	       'listp
	       (mapcar 'cadr (ssnamex sel))
	     )
     )
     )
     (setq csp
     (vla-objectidtoobject
       adoc
       (vla-get-ownerid (car sel))
     )
     )
     (setq unnamed_block
     (vla-add (vla-get-blocks adoc)
	      (vlax-3d-point '(0. 0. 0.))
	      "*U"
     )
     )
     (foreach x sel
(setq oname
	    (strcase (vla-get-objectname x))
      lay
	    (vla-item lays (vla-get-layer x))
)
(if (= (vla-get-lock lay) :vlax-true)
  (progn
    (vla-put-lock lay :vlax-false)
    (setq loc (cons lay loc))
  )
)
(cond
  ((member oname '("ACDBVIEWPORT" "ACDBATTRIBUTEDEFINITION"))
   nil
  )
  ((= oname "ACDBBLOCKREFERENCE")
   (vla-InsertBlock
     unnamed_block
     (vla-get-insertionpoint x)
     (vla-get-name x)
     (vla-get-xscalefactor x)
     (vla-get-yscalefactor x)
     (vla-get-zscalefactor x)
     (vla-get-rotation x)
   )
   (setq blk (cons x blk))
  )
  (t (setq obj (cons x obj)))
)
     ) ;_foreach
     (setq lay
     (vla-item lays (getvar "CLAYER"))
     )
     (if
(= (vla-get-lock lay) :vlax-true)
 (progn	(vla-put-lock lay :vlax-false)
	(setq loc (cons lay loc))
 )
     )
     (if obj
(progn
  (vla-copyobjects
    (vla-get-activedocument
      (vlax-get-acad-object)
    )
    (vlax-make-variant
      (vlax-safearray-fill
	(vlax-make-safearray
	  vlax-vbobject
	  (cons 0 (1- (length obj)))
	)
	obj
      )
    )
    unnamed_block
  )
)
     )
     (setq obj (append obj blk))
     (if obj
(progn
  (setq	tmp_blk	(vla-insertblock
		  csp
		  (vlax-3d-point '(0. 0. 0.))
		  (vla-get-name unnamed_block)
		  1.0
		  1.0
		  1.0
		  0.0
		)
  )
  (vla-GetBoundingBox tmp_blk 'MinPt 'MaxPt) ;_Границы блока
  (setq	MinPt (vlax-safearray->list MinPt)
	MaxPt (vlax-safearray->list MaxPt)
	DS    (max (distance MinPt (list (car MinPt) (cadr MaxPt)))
		   (distance MinPt (list (car MaxPt) (cadr MinPt)))
	      )
	DS    (* 0.2 DS)	;1/5
	DS    (max DS 10)
	MinPt (mapcar '- MinPt (list DS DS))
	MaxPt (mapcar '+ MaxPt (list DS DS))
  )
  (lib:Zoom2Lst (list MinPt MaxPt))
  (setq sset (ssget "_C" MinPt MaxPt))
  (if sset
    (progn
      (setvar "OSMODE" 0)
      (setq hiden (mapcar 'vlax-ename->vla-object
			  (vl-remove-if
			    'listp
			    (mapcar 'cadr (ssnamex sset))
			  )
		  )
	    hiden (vl-remove tmp_blk hiden)
      )
      (mapcar '(lambda (x) (vla-put-Visible x :vlax-false))
	      hiden
      )
      (setq pt (mapcar '+ MinPt (list (* 0.5 DS) (* 0.5 DS))))
      (vl-cmdf "_.RECTANG" (trans MinPt 0 1) (trans MaxPt 0 1))
      (setq pl (vlax-ename->vla-object (entlast)))
      (setq sc (1- (vla-get-count csp)))
      (if
	(VL-CATCH-ALL-ERROR-P
	  (VL-CATCH-ALL-APPLY
	    '(lambda ()
	       (vl-cmdf "_-BOUNDARY" (trans pt 0 1) "")
	       (while (> (getvar "CMDACTIVE") 0) (command ""))
	     )
	  )
	)
	 (if isRus
	   (princ "\nНе удалось построить контур")
	   (princ "\nIt was not possible to construct a contour")
	 )
      )
      (setq ec (vla-get-count csp))
      (while (< sc ec)
	(setq ret (append ret (list (vla-item csp sc)))
	      sc  (1+ sc)
	)
      )
      (setq ret (vl-remove pl ret))
      (mapcar '(lambda (x) (vla-Erase x) (vlax-release-object x))
	      (list pl tmp_blk)
      )
      (setq pl nil
	    tmp_blk nil
      )
      (setq
	ret (mapcar '(lambda (x / mipt)
		       (vla-GetBoundingBox x 'MiPt nil) ;_Границы блока
		       (setq MiPt (vlax-safearray->list MiPt))
		       (list MiPt x)
		     )
		    ret
	    )
      )
      (setq ret	(vl-sort ret
			 '(lambda (e1 e2)
			    (< (distance MinPt (car e1))
			       (distance MinPt (car e2))
			    )
			  )
		)
      )
      (setq pl	(nth 1 ret)
	    ret	(vl-remove pl ret)
      )
      (mapcar 'vla-erase (mapcar 'cadr ret))
      (mapcar '(lambda (x) (vla-put-Visible x :vlax-true))
	      hiden
      )
      (foreach x loc (vla-put-lock x :vlax-true))
      (if pl
	(progn
	  (initget "Yes No")
	  (if
	    (= (getkword (if isRus
			   "\nУдалять объекты? [Yes/No] <No> : "
			   "\nDelete objects? [Yes/No] <No> : "
			 )
	       )
	       "Yes"
	    )
	     (mapcar '(lambda (x)
			(if (vlax-write-enabled-p x)
			  (vla-Erase x)
			)
		      )
		     obj
	     )
	  )
	)
	(if isRus
	  (princ "\nНе удалось построить контур")
	  (princ "\nIt was not possible to construct a contour")
	)
      )
    )
  )
)
     )
     (VL-CATCH-ALL-APPLY
'(lambda ()
   (mapcar 'vlax-release-object
	   (list unnamed_block tmp_blk csp blks lays)
   )
 )
     )
   )
 ) ;_if not
 (foreach x loc (vla-put-lock x :vlax-true))
 (setvar "OSMODE" osm)
 (vla-endundomark adoc)
 (vlax-release-object adoc)
 (princ)
)
(if (= (getvar "SysCodePage") "ANSI_1251")
 (princ "\nНаберите в командной строке ECO")
 (princ "\nType ECO in command line")
)

[Norts]

that looks mighty impressive

[SLW210]

Looks like a silhouette of Garfield.

[fuccaro]

An other way: draw a rectangle around the block and use BPOLY. Click a point between the block and the rectangle. AutoCAD will create two polylines: the desired one and one other in the top of the rectangle. Delete the two rectangles and move the contour in the desired place:

Command: MOVE

Select objects: l

1 found

 

Select objects:

 

Specify base point or [Displacement] : ....

[bograd]

Thank you for your help.It looks exactly what i need.

Anyway, i can't seem to get it to work.

How exactly do i load and run this script ?

[bograd]

I managed to get it to work.

Thank you very much for the help.

[Guest Cadalist]

that looks like the command curve union in Rhinoceros.

 

curve boolean tools are very useful.

[bograd]

The script runs fine but i discovered a little glitch.

When i have a block which was scaled up or down (on any direction x, y or z)

the script cannot draw the contour.

In other cases, even though the block is not scaled i have to explode it a few times until the script can draw the contour.

 

Is there a solution for this ?

[dusko]

An other way: draw a rectangle around the block and use BPOLY. Click a point between the block and the rectangle. AutoCAD will create two polylines: the desired one and one other in the top of the rectangle. Delete the two rectangles and move the contour in the desired place:

Command: MOVE

Select objects: l

1 found

 

Select objects:

 

Specify base point or [Displacement] : ....

cool solution (didn't use BPOLY command till now)!

[Debalance]

There is a more advanced tool - TotalBoundary. Look at this:

 

 

Direct download from this link.