Measure a polyline with a block and stop after inserting first block.

[Dayananda]

I want to insert a block at a given distance from a start end of a polyline.

Pl. can somebody give me a code.

[mhupp]

Need a little more information or a sample drawing.

Must have just read title

 

Assumes start end of poly are same distance.  Easy enough using vlax-curve-getpointatdist. error check to see if distance is less than 1/2 the distance of the polyline. or the start block would be past the end block on the polyline.

;;----------------------------------------------------------------------------;;
;; INSERT BLOCK AT DISTANCE FROM ENDPOINTS ON POLYLINE
(defun C:foo (/ dist poly Spt Ept)
  (vl-load-com)
  (setvar 'cmdecho 0)
  (setq dist (getdist "\nDistance from ends of poyline: "))
  (setq poly (vlax-ename->vla-object (car (entsel "\nSelect Polyline: "))))
  (if (< dist (/ (vla-get-length poly) 2))
    (progn
      (setq Spt (vlax-curve-getpointatdist poly dist))
      (command "_.Insert" blockname "_non" Spt "" "" "")
      (setq Ept (vlax-curve-getpointatdist poly (- (vla-get-length poly) dist)))
      (command "_.Insert" blockname "_non" Ept "" "" "")
    )
    (prompt "\nDistance is to large")
  )
  (setvar 'cmdecho 1)
  (princ)
)

 

Edited July 24, 2022 by mhupp
cmdecho and princ

[Steven P]

Along the polyline? Look at chainage LISPS, there are some that will place a block there and I think will have a repeat or while loop as it iterates along the line, maybe all you need is to take that out to get the first distance.