Major contours vs minor contours - Polylines

[TASC1]

Hi all,

I was provided this large dwg file converted from lidar (1.8 Gb) of a large area (500 hectares).

The only issue is they didn't distinguish between major and minor contours.
The major contours are at 1 metre intervals.
The minor contours are at 0.25 metre intervals.

Is there a lisp routine which can scan the z values that do not have (0.25, 0.5, 0.75) and find only those with #.0 - EG 92.0, 93.0, etc....?

This is so I can identify the major contours and change the layer to major contours, and separate them from the minor contours?

[Steven P]

are you able to post a sample or part of the drawing. I suspect that the contours will be LWpolylines and then you should be able to identify their elevations through LISP and put on a suitable layer

[BIGAL]

Like Steven this is just a start pick 1 pline, really need a dwg to see what your contour objects are.

 

(defun c:test ( / lay ent elev)
(setq lay "major contour")
(while (setq ent (entget (car (entsel "\npick a contour "))))
  (setq elev (cdr (assoc 38 ent)))
   (if (= (- elev (fix elev)) 0.0)(entmod (subst (cons 8 lay) (assoc 8 ent) ent)))
)
(princ)
)

 

Edited September 3 by BIGAL

[TASC1]

On 9/3/2024 at 7:55 AM, Steven P said:

are you able to post a sample or part of the drawing. I suspect that the contours will be LWpolylines and then you should be able to identify their elevations through LISP and put on a suitable layer

Hi I thought of that after reading through earlier posts in the forum but they aren't LWPolylines.
Someone posted a LISP routine for LWPolylines.

[TASC1]

On 9/3/2024 at 10:07 AM, BIGAL said:

Like Steven this is just a start pick 1 pline, really need a dwg to see what your contour objects are.

 

(defun c:test ( / lay ent elev)
(setq lay "major contour")
(while (setq ent (entget (car (entsel "\npick a contour "))))
  (setq elev (cdr (assoc 38 ent)))
   (if (= (- elev (fix elev)) 0.0)(entmod (subst (cons 8 lay) (assoc 8 ent) ent)))
)
(princ)
)

 

The contour file is 1.8 Gb, and the lines are not LWPolylines, but Polylines.
As you can imagine there are 1000's of contour lines over a 500 hectare site so going through them one by one to find the ones that don't have a Z value ending in 0.25, 0.5, 0.75 takes time.
I'm only trying to pick the contours that are 1m intervals so I can change their layer to Major Contours and leave the rest as Minor Contours.

Below is only a small fraction of what I need to process.

Edited September 5 by TASC1
Additional information

[SLW210]

Still need a sample drawing not an image.

 

Did you LIST the PLINES? If you just select the pline and Properties, it shows as Polyline if it's a LWPolyline.

 

From LIST...

 

LWPOLYLINE  Layer: "03_material_list"
                            Space: Model space
                   Handle = 2fb
              Open
    Constant width     0'-0"
              area   264.07 square in. (1.8338 square ft.)
            length   4'-3 23/32"

          at point  X=7'-5 9/16"  Y=1'-6 29/32"  Z=    0'-0"
          at point  X=5'-10 23/32"  Y=1'-6 29/32"  Z=    0'-0"
          at point  X=5'-10 23/32"  Y=0'-4 29/32"  Z=    0'-0"
          at point  X=7'-5 9/16"  Y=0'-4 29/32"  Z=    0'-0"

 

Same pline in Properties...

 

 

[BIGAL]

Like SLW210, a 3dpoly will appear as a POLYLINE.

 

Entities in set: 1
---------- Polyline -----------------------------------------------

Location:  X=   -5901.2092  Y=   18451.3999  Z=   10.0000

Location:  X=   -5638.1762  Y=   22906.5219  Z=   10.0000

Location:  X=   -2531.0985  Y=   22577.7306  Z=   10.0000

 

Again use wblock and just save a small part of your dwg and post.
 

[SLW210]

I don't use meters very much, but.

 

Maybe this...

 

;;; Place polylines by Z value, whole numbers on Major Contour all else on Minor Contour.                                |
;;;                                                                                                                      |
;;; https://www.cadtutor.net/forum/topic/90707-major-contours-vs-minor-contours-polylines/?do=findComment&comment=650651 |
;;;                                                                                                                      |
;;; By SLW210 (Steve Wilson)                                                                                             |
;;;                                                                                                                      |
;;; Works on AutoCAD 2000i                                                                                               |
;;;                                                                                                                      |
;;; September 6th, 2024                                                                                                  |
;;;______________________________________________________________________________________________________________________|

(defun c:PBZ ()
  (c:PolylinesByZ)
)

(defun c:PolylinesByZ (/ ss i ent layer color z pt)
  ;; Select all polylines in the drawing
  (setq ss (ssget "X" '((0 . "LWPOLYLINE"))))
  
  (if (null ss)
    (progn
      (princ "\nNo polylines found in the drawing.")
      (exit)
    )
  )

  ;; Loop through polylines
  (setq i 0)
  (repeat (sslength ss)
    (setq ent (ssname ss i))
    (setq i (1+ i))

    ;; Get the polyline's Z value
    (setq pt (cdr (assoc 10 (entget ent))))
    (setq z (if pt (vlax-get (vlax-ename->vla-object ent) 'Elevation) 0))

    ;; Determine layer based on Z value
    (if (and (numberp z) (zerop (rem z 1)))
      (progn
        (setq layer "Major Contour")
        
      )
      (progn
        (setq layer "Minor Contour")
        
      )
    )

    ;; Check if layer exists, otherwise create it
    (if (not (tblsearch "LAYER" layer))
      (progn
        (entmake
          (list
            (cons 0 "LAYER")
            (cons 2 layer)
            (cons 70 0)
            
          )
        )
      )
    )

    ;; Change the polyline's layer
    (entmod (subst (cons 8 layer) (assoc 8 (entget ent)) (entget ent)))
    (entupd ent)
  )
  
  (princ "\nPolylines sorted by Z value.")
  (princ)
)

 

[BIGAL]

@SLW210 TASC1 has shown the objects are an object of type "POLYLINE" not a "LWPOLYLINE" so 3d object rather than a 2d object. There is no Elevation in a "POLYLINE" but there are Z values. So check object type and use Elevation or Z. Ps ssget *POLYLINE & (vlax-get obj 'objectname)

 

3dpoly (0 . "POLYLINE")(100 . "AcDb3dPolyline")

2D Polyline (0 . "LWPOLYLINE")(100 . "AcDbPolyline")(38 . 20.0) ; elevation is dxf 38 

 

 

Really need a sample dwg to check properly what object is.

Edited September 6 by BIGAL

[SLW210]

The OP has disappeared and I am not going to continue a guessing game.

 

Just offered up something I already had the basis of and adjusted it a little for the OP.