Area of Multiple 2D solids

[bsimpson]

Hi,

I am trying to find the 2D area of multiple 2D solids in a drawing. How do I do this? The attached drawing shows the green 2D solids which I need a combined area of. 

example_cadtutorial.dwg

[BIGAL]

The only problem I had was there is 13428 objects. So no way of checking answer. A boundary around would be a good check will see if I have time.

 

; get area of solids 
; By AlanH May 2020 info@alanh.com.au


(defun c:testarea ( / tot co-ords co-ordsxy getcoords ss-pts2area)
; pline co-ords example
(defun getcoords (ent)
  (vlax-safearray->list
    (vlax-variant-value
      (vlax-get-property
    (vlax-ename->vla-object ent)
    "Coordinates"
      )
    )
  )
)

(defun ss-pts2area  (l)
(/ (apply (function +)
            (mapcar (function (lambda (x y)
                                (- (* (car x) (cadr y)) (* (car y) (cadr x)))))
                    (cons (last l) l)
                    l)) 
2.)
)

; convert now to xyz note solid reports a Z so 3 
(defun co-ords2xy ()
(setq co-ordsxy '())
(progn
(setq I 0)
(repeat (/ (length co-ords) 3)
(setq xy (list (nth i co-ords)(nth (+ I 1) co-ords)(nth (+ I 2) co-ords) ))
(setq co-ordsxy (cons xy co-ordsxy))
(setq I (+ I 3))
)
)
)

; program starts here
(vl-load-com)
(setq tot 0.0)
(if (/= (setq ss (ssget  (list (cons 0 "SOLID")))) nil)
(repeat (setq x (sslength ss))
(setq co-ords (getcoords (ssname ss (setq x (- x 1)))))
(co-ords2xy)
(setq tot (+ (abs (ss-pts2area co-ordsxy)) tot))
)
)
(Alert (strcat "Total is " (rtos tot 2 2)))
(princ)
)

 

[bsimpson]

Thanks works brilliantly, I tested it on approx. 1million solids and it gave the correct answer. 

[BIGAL]

No worries it should work for more than 3 point solids also.