Recursive roof from polylines

[ilya346445]

Hi,
I am new to lisp but I have experience with other programming languages.
I am trying to create roof meshes from a number of polylines, there are thousands, so I am trying to write a simple script to get the job done.

here is what I have so far

(defun roofmaker( / sset item ctr)
 
(while
 
    (setq sset (ssget))
 
    (setq ctr 0)

    (repeat (sslength sset)
 
        (setq item (sset ctr))
 
        (command "_.roofconvert" item "" "n" )
 
        (setq ctr (1+ ctr))
 
    );repeat
 
);while
 
  (princ)
 
);defun
 
(princ)

Because I can't apply the roofconvert command to a set of polylines I have go through the selected set one object at a time and run that command.
Right now I am getting an error, I am guessing it something to do with the selection list but I am not sure.

[Opie]

Adjust this line

(setq item (sset ctr))

to include the ssname function

(setq item (ssname sset ctr))

[BlackBox]

Firstly, welcome to AUGI!


Couple of things....

In order for your LISP to register as a Command (something you can enter at the Command line, etc.), your Defun statement's Symbol requires a "C:" prefix (not case sensitive).

What error are you receiving specifically? That's usually helpful in offering advice.

As I do not have any architectural software to look up for myself, you might consider this adaptation (untested):

(defun c:RoofMaker (/ ss i)
  (princ "\rROOFMAKER ")
  (if (setq ss (ssget "_:L" '((0 . "*POLYLINE"))))
    (repeat (setq i (sslength ss))
      (command "_.roofconvert" (ssname ss (setq i (1- i))) "" "n")
    )
    (prompt "\n** Nothing selected ** ")
  )
  (princ)
)

Lastly, if you already possess development experience with other languages, consider looking into your application's available API's as most (not all) support a COM, and .NET API.

Hope this Helps (HTH)

[ilya346445]

Thanks, RenderMan
that did the trick.
definitely, extracting each object from the list was the culprit. I was not sure how lisp stores objects in a list or how it retrieves them.
Don't really deal a lot with autocad, just needed to get this one problem solved quickly for a project I'm working on - Autocad had the roof generator I needed,
otherwise it would have needed to write a much larger script to calculate roof slopes and 3d intersections and etc. in another environment.

[BlackBox]

Thanks, RenderMan
that did the trick.

You're welcome; I'm happy to help.

definitely, extracting each object from the list was the culprit. I was not sure how lisp stores objects in a list or how it retrieves them.
Don't really deal a lot with autocad, just needed to get this one problem solved quickly for a project I'm working on - Autocad had the roof generator I needed,
otherwise it would have needed to write a much larger script to calculate roof slopes and 3d intersections and etc. in another environment.

When dealing with LISP, major tasks often involve iteration of Selection Sets, or Lists (sometimes of Lists)... Repeat will give you the best performance when dealing with AutoLISP Lists, and for iterating Visual LISP Collection Objects (i.e., DocumentCollection, ActiveSelectionsSet, etc.), then Vlax-For is the ticket.

Again, not sure of the languages you're familiar with, but AutoCAD supports both .NET (C#,F#,VB.NET) API, and ObjectARX (C++ for AutoCAD) API... Even though I'm progressively doing more and more .NET development (verticals such as Civil 3D are somewhat forcing that), LISP is still the quickest bang for the buck in my work.

Let us know if we can help out with anything else - Cheers!