This AutoLISP routine, DIVPL, divides a polyline, including arc segments, into points at a specified interval. It then exports the X, Y, Z coordinates of these points to a temporary tab-delimited text file and automatically opens the file.

divpl.lsp

(defun c:DIVPL ( / ss ent obj len interval counter param pt output_file file_path temp_path )
  (vl-load-com) ; Load Visual LISP functions

  ;; Get the path to the user's temporary directory
  (setq temp_path (getenv "TEMP"))
  ;; Use MILLISECS for a unique temporary file name
  (setq file_path (strcat temp_path "\\polyline_points_" (itoa (getvar "MILLISECS")) ".txt"))

  ;; --- Check for existing selection ---
  (setq ss (ssget "_I")) ; Get implicit selection set (already selected objects)

  (if (and ss (= (sslength ss) 1)) ; If exactly one object is pre-selected
      (setq ent (ssname ss 0)) ; Get the ename of the selected object
      (setq ent (car (entsel "\nSelect a polyline to divide (or press Enter if already selected): "))) ; Else, prompt user to select
  )

  (if (and ent (eq "LWPOLYLINE" (cdr (assoc 0 (entget ent)))))
    (progn
      (setq obj (vlax-ename->vla-object ent))

      ;; --- Set default interval to 50 ---
      (setq interval (getreal (strcat "\nEnter division interval (default: 50): <50>")))
      (if (null interval)
          (setq interval 50.0) ; If user presses Enter, use default 50
      )

      (if (and (<= 0.0 interval) (/= 0.0 interval))
        (progn
          ;; Open the file for writing
          (setq output_file (open file_path "w"))

          (if output_file
            (progn
              (setq len (vlax-curve-getDistAtParam obj (vlax-curve-getEndParam obj)))
              (setq counter 0)

              ;; Loop through points and write to file
              (while (<= (* counter interval) len)
                (setq param (vlax-curve-getParamAtDist obj (* counter interval)))
                (setq pt (vlax-curve-getPointAtParam obj param))

                ;; Write coordinates to the file, separated by tabs
                (write-line (strcat (rtos (car pt) 2 8) "\t" (rtos (cadr pt) 2 8) "\t" (rtos (caddr pt) 2 8)) output_file)

                ;; Create a point object in AutoCAD (optional, can be removed)
                (entmake (list '(0 . "POINT") (cons 10 pt)))

                (setq counter (1+ counter))
              )
              ;; Close the file
              (close output_file)
              (princ (strcat "\nCoordinates saved to temporary file: " file_path))

              ;; Open the file using the default application
              (startapp "EXPLORER" file_path)
            )
            (princ (strcat "\nError: Could not open file for writing: " file_path))
          )
        )
        (princ "\nInvalid interval. Please enter a positive number.")
      )
    )
    (princ "\nNo polyline selected or selected object is not a polyline.")
  )
  (princ) ; Suppress last value
)

AutoCAD LISP: Polyline Division & Coordinate Export

This AutoLISP routine, DIVPL, divides a polyline, including arc segments, into points at a specified interval. It then exports the X, Y, Z coordinates of these points to a temporary tab-delimited text file and automatically opens the file.

Features

• Polyline Selection: Uses a pre-selected polyline if one is present. Otherwise, it prompts the user to select.
• Default Interval: Sets a default division interval of 50 units. Users can accept the default or input a custom value.
• Coordinate Export: Writes X, Y, Z coordinates to a text file.
• Tab Delimited: Coordinates are separated by tabs.
• Temporary File: Creates a uniquely named file in the user's temporary directory.
• Auto-Open: Opens the generated text file using the system's default application.
• Optional Point Creation: Creates AutoCAD point entities at each division point (can be removed from the code).

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How to Use

1. Save: Save the code to a .lsp file (e.g., divpl_smart.lsp).
2. Load: In AutoCAD, type APPLOAD, navigate to and load the .lsp file.
3. Run: Type DIVPL in the command line.
   • Select a polyline or ensure one is pre-selected.
   • Enter the division interval, or press Enter for the default (50).