find coordinate of a point at desired distanse of a polyline!!

Hi.

By which combination of functions, I can get coordination of a point at desired distace from the start point of a polyline?

Hi Kasra

A suitable function would be

(vlax-curve-getPointAtDist <ename> <dist>)

where

is the enity name

length along the curve

vlax-curve-getPointAtDist will return nil if the specified length does not lie on the curve

Just a quick sample

(defun c:test ()

 (if
   (and
     (setq ename    (car (entsel)))
     (setq chainage (getreal "\nChainage"))
     (setq basepoint    (vlax-curve-getPointAtDist ename chainage)))

   (entmake (list (cons 0 "Point")(cons 10 basepoint)))
 )
 )

Hi Dear Jammie.

I'm so thankful for your help.

I have a question:

How it can identify the start point of polyline?

Hi Kasra

Your welcome

How it can identify the start point of polyline?

Would you like to insert a point at the start of the curve? If this is the case the distance at the startpoint would be 0

ok.

I appreciate with you for helping me.

Kasra,

Search the VLIDE help for vlax-curve*

Also check out the

AutoLISP Developers Guide
    > Appendixes
         > AutoLISP Function  Synopsis
              > Visual  LISP Extensions to AutoLISP
                   > Curve Measurement Functions

section in the VLIDE help.

Lee

^^^^^

sincere apologies for going offtopic

lee, is the swamp offline? i can't access the webpage

^^^^^

sincere apologies for going offtopic

 

lee, is the swamp offline? i can't access the webpage

You are actually the third person to ask me whether it be by PM, email etc... I should think it would be maintenance, but yes, it has been down certainly this afternoon. I'm sure Mark will get it back up soon - people need their daily Swamp fix.

You are actually the third person to ask me whether it be by PM, email etc... I should think it would be maintenance, but yes, it has been down certainly this afternoon. I'm sure Mark will get it back up soon - people need their daily Swamp fix.

Maybe it's in honor of Alan (not me) going on vacation.