Polyline inside block coordinate

[jan_ek]

Hello, how to get coordinates of a polyline on a layer eg "Boundary" inside a block . I would like the coordinates to be in the global system.

I found some code but it returns coordinates relative to the base point of the block

https://forums.augi.com/showthread.php?83935-Creating-a-list-Polyline-vertices

Edited October 25, 2019 by jan_ek

[BIGAL]

If you can get the co-ords and the insbase point of the block, then current insertion point you can work out a offset to add to the vertices.

[Tharwat]

You can use the command: NCOPY then retrieve the coordinate of the derived polyline from the block. 

[jan_ek]

Unfortunately, the AutoCad substitute does not have this function

"Unable to recognize command "NCOPY". This error can occur when the command is not supported for the active license."

[Tharwat]

The NCOPY command is included with the Express Tools and apparently you don't have them installed with your AutoCAD version.

[jan_ek]

Sorry I didn't write at first, I use bricscad

[Tharwat]

The following routine should print the coordinates of all polylines that on layer "Boundary" in the selected block to the command line.

NOTE: Be sure to have all your layers unlocked.

(defun c:Test (/ sel lst pts)
  ;;	Tharwat - 26.Oct.2019	;;
  (and (setq sel (car (entsel "\nSelect a Block :")))
       (or (= (cdr (assoc 0 (entget sel))) "INSERT")
           (alert "Selected object is not a block <!>")
       )
       (setq lst (vlax-invoke (vlax-ename->vla-object sel) 'Explode))
       (mapcar
         '(lambda (obj)
            (and (= (vla-get-objectname obj) "AcDbPolyline")
                 (= (vla-get-layer obj) "Boundary")
                 (setq
                   pts (cons (mapcar 'cdr
                                     (vl-remove-if-not
                                       '(lambda (p) (= (car p) 10))
                                       (entget (vlax-vla-object->ename obj))
                                     )
                             )
                             pts
                       )
                 )
            )
          )
         lst
       )
       (mapcar 'vla-delete lst)
  )
  (if pts
    (princ pts)
    (princ)
  )
) (vl-load-com)

 

[Lee Mac]

For what it's worth, it is not necessary to perform a nested copy of the polyline, nor explode the block reference in order to ascertain the polyline vertex coordinates with respect to the block reference - instead, you can transform the polyline vertices obtained from the block definition using the position, scale, rotation & orientation of the block reference. This is a very similar question to that posed in this thread.

 

To offer an example, consider the following code:

(defun c:test ( / ent enx lst ocs )
    (while
        (progn (setvar 'errno 0) (setq ent (car (entsel "\nSelect block: ")))
            (cond
                (   (= 7 (getvar 'errno))
                    (princ "\nMissed, try again.")
                )
                (   (null ent)
                    nil
                )
                (   (/= "INSERT" (cdr (assoc 0 (setq enx (entget ent)))))
                    (princ "\nThe selected object is not a block.")
                )
                (   (null (setq lst (blockreferencepolylinevertices ent)))
                    (princ "\nThe selected block does not contain a 2D polyline on the Boundary layer.")
                )
                (   (progn
                        (setq ocs (cdr (assoc 210 enx)))
                        (entmake
                            (append
                                (list
                                   '(000 . "LWPOLYLINE")
                                   '(100 . "AcDbEntity")
                                   '(100 . "AcDbPolyline")
                                    (cons 090 (length lst))
                                   '(070 . 0)
                                    (cons 038 (cadddr (assoc 010 enx)))
                                    (cons 210 ocs)
                                )
                                (mapcar '(lambda ( p ) (cons 10 (trans p 0 ocs))) lst)
                            )
                        )
                    )
                    nil
                )
                (   (princ "\nUnable to recreated nested polyline."))
            )
        )
    )
    (princ)
)

(defun blockreferencepolylinevertices ( ref / elv ent enx lst ocs )
   (setq ent (tblobjname "block" (cdr (assoc 2 (entget ref)))))
   (while
       (and
           (null lst)
           (setq ent (entnext ent))
           (setq enx (entget  ent))
       )
       (if
           (and
               (= "LWPOLYLINE" (cdr (assoc 0 enx)))
               (= "BOUNDARY" (strcase (cdr (assoc 8 enx))))
           )
           (setq elv (cdr (assoc 038 enx))
                 ocs (cdr (assoc 210 enx))
                 lst
               (mapcar
                  '(lambda ( v )
                       (trans (list (cadr v) (caddr v) elv) ocs 0)
                   )
                   (vl-remove-if-not '(lambda ( x ) (= 10 (car x))) enx)
               )
           )
       )
   )
   (if lst
       (apply
           (function
               (lambda ( mat vec )
                   (mapcar
                       (function
                           (lambda ( vtx )
                               (mapcar '+ (mxv mat vtx) vec)
                           )
                       )
                       lst
                   )
               )
           )
           (refgeom ref)
       )
   )
)

;; RefGeom (gile)
;; Returns a list whose first item is a 3x3 transformation matrix and
;; second item the object insertion point in its parent (xref, block or space)

(defun refgeom ( ent / ang enx mat ocs )
    (setq enx (entget ent)
          ang (cdr (assoc 050 enx))
          ocs (cdr (assoc 210 enx))
    )
    (list
        (setq mat
            (mxm
                (mapcar '(lambda ( v ) (trans v 0 ocs t))
                   '(
                        (1.0 0.0 0.0)
                        (0.0 1.0 0.0)
                        (0.0 0.0 1.0)
                    )
                )
                (mxm
                    (list
                        (list (cos ang) (- (sin ang)) 0.0)
                        (list (sin ang) (cos ang)     0.0)
                       '(0.0 0.0 1.0)
                    )
                    (list
                        (list (cdr (assoc 41 enx)) 0.0 0.0)
                        (list 0.0 (cdr (assoc 42 enx)) 0.0)
                        (list 0.0 0.0 (cdr (assoc 43 enx)))
                    )
                )
            )
        )
        (mapcar '- (trans (cdr (assoc 10 enx)) ocs 0)
            (mxv mat (cdr (assoc 10 (tblsearch "block" (cdr (assoc 2 enx))))))
        )
    )
)

;; Matrix Transpose  -  Doug Wilson
;; Args: m - nxn matrix

(defun trp ( m )
    (apply 'mapcar (cons 'list m))
)

;; Matrix x Matrix  -  Vladimir Nesterovsky
;; Args: m,n - nxn matrices

(defun mxm ( m n )
    ((lambda ( a ) (mapcar '(lambda ( r ) (mxv a r)) m)) (trp n))
)

;; Matrix x Vector  -  Vladimir Nesterovsky
;; Args: m - nxn matrix, v - vector in R^n

(defun mxv ( m v )
    (mapcar '(lambda ( r ) (apply '+ (mapcar '* r v))) m)
)

(princ)

 

Edited October 26, 2019 by Lee Mac

[Wan]

Hi Mr. Lee,

Thank you for the above code. Is there any code to create layers for these blocks automatically just after I created them?