CHECK ELEVATIONS OF SELECTED OBJECTS

[etilley327KA]

I have a lisp that I'm using but ran into an issue. I'm currently collecting a group of objects including (lines, 2d polylines, arcs) and use "change" command to change all the elevations to zero. However, recently I ran into an instance were some of the objects weren't changed. Does someone know how I could create a check to alert me if any of the objects are not at zero elevation?

[Kent1Cooper]

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@etilley327KA wrote:

.... some of the objects weren't changed. ....

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Post a small drawing with some objects that are not changed, and the AutoLisp routine.

[pendean]

Share that LISP here along with the problem DWG that contains " some of the objects weren't changed" please.

[etilley327KA]

Heres part of it. I believe the problem came because one of the 2d polyline had two different start and end z elevations.

(setq A (ssget '((8 . "AP-BUILDING LINE,AP-EASEMENT,AP-BOUNDARY"))))

       (setq Sline (entsel "\nSelect Source property line: "))

       (command "_.CHANGE" Sline "" "_P" "_E" "0" "")

       (setq Sline (car Sline))

       (setq Dline (car (nentsel "\nSelect Destination property line: ")))

     (command "_.CHANGE" Dline "" "_P" "_E" "0" "")

       (setq

          1stS (vlax-curve-getStartPoint Sline)

          2ndS (vlax-curve-getEndPoint Sline))

       (setq

          1stD (vlax-curve-getStartPoint Dline)

          2ndD (vlax-curve-getEndPoint Dline))

   (command "_.copybase" "0,0" A "")

   (command "_.pasteclip" "0,0")

   (command "_.align" A "" 1stS 1stD 2ndS 2ndD "" "")

[etilley327KA]

Woops forgot this part.

(command "_.CHANGE" A "" "_P" "_E" "0" "")

[Kent1Cooper]

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@etilley327KA wrote:

....

       (setq Sline (entsel "\nSelect Source property line: "))

       (command "_.CHANGE" Sline "" "_P" "_E" "0" "")

       (setq Sline (car Sline))

       (setq Dline (car (nentsel "\nSelect Destination property line: ")))

     (command "_.CHANGE" Dline "" "_P" "_E" "0" "")

....

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Red:  For me, CHANGE doesn't accept the return of (entsel) [a list of entity and pick point].  Shouldn't the blue line be moved up above the CHANGE command line, so that CHANGE is given an entity, not a list?

Magenta:  Is it even possible to change the elevation of a nested object?  You could pick a top-level object with (nentsel), and it should work, but I expect it would fail if that property line is part of an Xref or something.

[etilley327KA]

You are correct I guess I had those flipped and yes, I'm also running into the problem of the nested object not working when a xref line is selected. I'm trying to figure out how to differentiate wither the DLINE is nested object or a regular line and run the change command accordingly. However, I still run in to the issue of ensuring all the objects variable "A", at the end are at zero, even if the start and end Z are different, or to alert the user if it is so.

[Kent1Cooper]

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@etilley327KA wrote:

.... I'm trying to figure out how to differentiate wither the DLINE is nested object or a regular line and run the change command accordingly. ....

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The return of (nentsel) adds some stuff not returned by (entsel), including at the end a list of what entities the object is nested in.  So its last item is that list, rather than the list you get from (entsel) of the coordinates of the point at which you picked it.  The last thing in the return of each is a list, but what's in them differs.  So you can, for example, compare:

(type (car (last (entsel))))

returns

REAL

[the X coordinate of the pick point], whereas

(type (car (last (nentsel))))

returns

ENAME

[Kent1Cooper · Accepted solution]

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@etilley327KA wrote:

.... I still run in to the issue of ensuring all the objects variable "A", at the end are at zero, even if the start and end Z are different, or to alert the user if it is so.

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The CHANGE command gives you a notification:

Cannot change elevation of objects with differing Z coordinates.

but unfortunately, it's only informational, and doesn't cause an error that could be detected to trigger alerting the user with something more obvious.

You could go plowing through the selection, and check everything's bounding box for non-zero Z values, either before or after doing the CHANGE command.

[etilley327KA]

Thanks for the help, but something is going wrong in my "if" I believe. What am I missing?

(defun c:test ()

(setq a (nentsel "\nSelect Destination property line: "))

(if

  (= "REAL" (type (car (last a))))

  (progn

    (setq a (car a))

    (command "_.CHANGE" a "" "_P" "_E" "0" "")

  )

  (setq a (car a))

)

)

[ВeekeeCZ]

You can simply test the length of the return list. If it's 2, it's a basic entity. If 4, it's nested.

(if (setq s (nentsel))
  (if (= (length s) 2)
    (basic ent) ; the same return as from entsel
    (nested))
  (nothing selected))

[etilley327KA]

Thank you

[etilley327KA]

Im still trying to figure out how to see if any of the objects have an elevation higher than zero. I came up with this, but it isnt quite working. Is there a way to make this work and check if any of the return list are above zero?

(defun c:TEST (/ a e i ob obelev)

(setq a (ssget))

(repeat (setq i (sslength a))

  (setq e (ssname a (setq i (1- i))))

  (setq ob (cons (Cdr (assoc 10 (entget e))) ob))

  (setq obelev (cons (cddr ob) obelev)))

  (princ obelev)

)

[ВeekeeCZ]

Don't you want rather use a different way to flatten objects? Possibly move to the second suggestion from HERE 

[Kent1Cooper]

That's not a Text string.  Try:

(= 'REAL (type (car (last a))))

[Kent1Cooper]

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@etilley327KA wrote:

Im still trying to figure out how to see if any of the objects have an elevation higher than zero. ....

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Is that really what you want to know?  Those that do, but have a constant elevation [higher or lower], get taken to zero by your CHANGE command, so they should not be a problem.  Don't you really want to know whether any objects have varying elevation, no matter where the elevations may be relative to zero?  Those are the ones for which CHANGE can't fix the elevation.

[etilley327KA]

Does the "MOVE" command have any issues with varying elevations? Yes you are correct, its the varying elevations that are causing the problem.

[Sea-Haven]

There is a lot of suggestions but what does "Flatten" do ?

With objects like pline with different z you may have to walk along the pline resetting vertices to z=0, maybe same with Lines. Where 10 may have a z=0 but 11 is another value. Note also LWPOLYLINE and POLYLINE are 2 different types of pline.

A 2d LWPOLYLINE can have an "Elevation" variable set rather than Z 

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