I can not calculate the area of this hatch

[Giovannino60]

I can not calculate the area of this hatch, I also generated the outline, but I do not calculate the area, what can I do? Thank you 

Retini.dwg

[Cad64]

I think there's something wrong with that hatch pattern. If I delete the hatch and then create a new hatch, using the same hatch boundary lines, the Area will display in the Properties panel.

[XDSoft]

Mainly due to hatch boundary
1. Self-crossing
2. point too densely

......

 

It can be restored by re-establishing the boundary, then self-intersecting the boundary, thinning out the vertices, etc.

 

====================

 

[XDrX-PlugIn(145)] Fixed Hatch with area 0 (theswamp.org)

https://www.theswamp.org/index.php?topic=59461.0

 

 

(defun c:xdtb_hafix0 (/ ha ha1 ha-new has loop loops mp old-boundary progress re ss x)
  (defun _delete-old-boundary (loops)
    (mapcar
      '(lambda (loop)
	 (if (and
	       (setq ss (ssget "f" (xdrx-getpropertyvalue loop "vertices") '((0 . "*line,arc,ellipse,circle"))))
	       (ssdel loop ss)
	       (> (sslength ss) 0)
	     )
	   (progn
	     (mapcar
	       '(lambda (x)
		  (setq re (xdrx-geom-relation loop x t))
		  (if (or
			(= re XD:kTangent)
			(= re XD:kBoundary)
			(= re XD:kCoincident)
		      )
		    (xdrx-entity-delete x)
		  )
		)
	       (xdrx-ss->ents ss)
	     )
	   )
	 )
       )
      loops
    )
  )
  (if (and
	(setq ha (xdrx-ssget (xdrx-string-multilanguage "\n选择填充对象<退出>:" "\nSelect Hatch<Exit>:") '
			     ((0 . "hatch"))
		 )
	)
	(setq has (xdrx_hatch_get0area ha))
      )
    (progn
      (xdrx-begin)
      (xdrx-sysvar-push '("fitarc" 0))
      (xdrx-document-safezoom ha)
      (xdrx_statusbar_begin (xdrx-string-multilanguage "处理中..." "Procesing...") (length has))
      (setq progress 0)
      (mapcar
	'(lambda (x)
	   (xdrx_statusbar_setpos (setq progress (1+ progress)))
	   (if (setq mp (xdrx-hatch->mpolygon x))
	     (progn
	       (setq ha1 (xdrx-mpolygon->hatch mp))
	       (xdrx-entity-matchprop x ha1)
	       (setq ha x
		     ha-new (car (xdrx-ss-getsub ha1 '((0 . "hatch"))))
		     loops (xdrx-getpropertyvalue ha-new "assocobjids")
	       )
	       (if (setq old-boundary (xdrx-getpropertyvalue x "assocobjids"))
		 (progn
		   (xdrx-entity-delete old-boundary)
		 )
		 (progn
		   (_delete-old-boundary loops)
		 )
	       )
	       (xdrx-object-swapid ha ha-new)
	       (xdrx-entity-delete ha-new)
	     )
	   )
	 )
	has
      )
      (xdrx_statusbar_end)
      (xdrx-prompt (xdrx-string-formatex (xdrx-string-multilanguage "\n修复了 %d 个面积为0的填充."
								    "\nFixed %d Hatchs with area 0."
					 ) (length has)
		   )
      )
      (xdrx-sysvar-pop)
      (xdrx-end)
    )
  )
  (princ)
)

 

=============================

 

The code above , using XDRX - API,
Before trying the forum code, please download and install XDRX - API

 

xdcad/XDrx-API: Autolisp development library written in ObjectARX (github.com)

https://github.com/xdcad/XDrx-API

 

Edited April 17 by XDSoft

[mhupp]

On 3/5/2023 at 12:23 PM, Cad64 said:

I think there's something wrong with that hatch pattern. If I delete the hatch and then create a new hatch, using the same hatch boundary lines, the Area will display in the Properties panel.

 

I bet the polyline is self intersecting. use the following to check.

https://forums.autodesk.com/t5/visual-lisp-autolisp-and-general/to-find-self-intersection-of-lwpolyline/m-p/6491654/highlight/true#M343734