Measure...vlax-curve-getPointAtDist...how to do this?

Good morning,

I want to put a "gradation" on a curve (pline, spline, line) - see the attached drawing. And i have no idea how to do it, or if it's possible to do it. "Gradation" is always perpendicular on the curve.L1, L2, D - given values. Any idea? Measure? Vlax-curve-getPointAtDist?

measure.dwg

Regarding the programmatically approach, for sure it can be done. Along the function that you already proposed you will need to look also for the second derivative on insertion point in order to get the local tangent, and therefore the perpendicular on curve.

Regards,

Mircea

For the second derivative, which function to use?

To list the second derivative on a curve at a given location should use vlax-curve-getSecondDeriv.

I suggest you to check in help the vlax-curve-* functions family.

Regards,

Mircea

Sorry Mircea, I don't think the SecondDeriv is needed. This may help::

(setq tg (vlax-curve-getFirstDeriv entity param)) will give you the direction of the tangent to curve at param. So the perpendicular direction is (atan (cadr tg) (car tg)) + or - pi/2.

Stefan, you are entirely right; I stand corrected. Sorry for inconvenience.

Regards,

Mircea

This may get you started , although that I did not get what you wanted specifically .

Consider this just as an example .

(defun c:TesT (/ ss p2 l d n)
 ;;; Tharwat 21. Feb. 2012 ;;;
 (if (and
       (setq ss (entsel "\n Select a Poly :"))
       (member (cdr (assoc 0 (entget (car ss))))
               '("LINE" "SPLINE" "LWPOLYLINE" "POLYLINE")
       )
       (setq p2 (1+ (fix (vlax-curve-getendparam (car ss)))))
       (setq l (vlax-curve-getdistatparam (car ss) (- p2 1)))
       (setq d (getdist "\n Specify the distance between points :"))
       (setq n d)
     )
   (progn
     (entmake
       (list '(0 . "POINT")
             (cons 10 (vlax-curve-getpointatparam (car ss) 0))
       )
     )
     (repeat
       (fix (/ l d))
        (setq pt (vlax-curve-getpointatdist (car ss) d))
        (entmake (list '(0 . "POINT") (cons 10 pt)))
        (setq d (+ n d))
     )
   )
   (princ)
 )
 (princ)
)

I want to compare 2 strings, what function to use?

(= (cdr (assoc 0 (entget (car(entsel))))) "line") , i select a line and is not working... shoul i use equal, or eq...?

You should use it like this ..

and = and eq functions are the same in this case .

(eq (cdr (assoc 0 (entget (car(entsel))))) [color=blue][b]"LINE"[/b][/color])

Or this ...

(= (cdr (assoc 0 (entget (car(entsel))))) [color=blue][b]"LINE"[/b][/color])

But all of these are not a good way of programming .

because if you selected nothing , error would take a place .

how to determine start point and endpoint for a spline?

how to determine start point and endpoint for a spline?

(if (and
     (setq sp (car (entsel "\n Select Spline :")))
     (eq (cdr (assoc 0 (entget sp))) "SPLINE")
   )
 (progn
   (princ (vlax-curve-getStartPoint sp))
   (princ (vlax-curve-getendPoint sp))
 )
 (princ "\n Nothing selected or it is not a Spline ** ")
)

Thanks! I'm still sleeping...

Thanks! I'm still sleeping...

You're welcome .

Wake up and study the simple codes that we have just provided for you , and do not hesitate to ask for any clarification .

Regards.

This is what i'm working on... sorry, not in English, but many of you will understand how is working... in fact are 3 codes in one... for different situation... many parts of the code is not necessary, is for my way of working... so i will show you guys my "masterpiece" ...still in working, not finished...

Regards!

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defun c:taluz (/ Ldata )
;;;;;;;;;;;;;;;;; UNDO COMPLET
 (defun *error* (msg) 
   (and uFlag (vla-EndUndoMark aDoc)) 
   (and msg (or (wcmatch (strcase msg) "*BREAK,*CANCEL*,*EXIT*") 
                (princ (strcat "\n** Error: " msg " **")))) 
   (princ)) 
(setq aDoc (vla-get-ActiveDocument (vlax-get-acad-object))) 
(setq uFlag (not (vla-StartUndoMark aDoc)))
;;;;;;;;;;;;;;;;;;;;
(setq _LastEnt_ (entlast)) ;Selectie obiecte pt manipulare   
(setvar 'cmdecho 0)  
(defun rtd (r) (* 180.0(/ r pi)))
 (setq
   pol        (car (entsel "\nSelecteaza  Polilinia: "))
   dist1    (getdist "\nDistanta intre borduri: ")
   l1  (getdist "\nLatime start: ")
   l2  (getdist "\nLatime sfarsit: ")
   lungpol (vlax-curve-getDistAtParam pol (vlax-curve-getEndParam pol)) ;lungime polilinie
   nrbord  (fix (/ lungpol dist1))
   dist (/ lungpol nrbord)
   dif (- l1 l2)
 )
(repeat    (setq i nrbord)
 (setq    Ldata (cons
       (list
         (setq    pt (vlax-curve-getpointatdist
                pol
                (* (setq i (- i 1.0)) dist)
              )
         )

         (setq l (/ (+ l2 (* dif (/ i nrbord)))))
         (setq    ang
            (+ (* 1.0 pi)
               (atan (cadr    (vlax-curve-getFirstDeriv
                     pol
                     (vlax-curve-getParamAtPoint pol pt)
                   )
                 )
                 (car (vlax-curve-getFirstDeriv
                    pol
                    (vlax-curve-getParamAtPoint pol pt)
                      )
                 )
               )
            )
         )
           ;;;;;;;;;;;;;;;
         (setq    ptm (vlax-curve-getpointatdist
                 pol
                 (+ (* 0.5 dist) (* i dist))
               )
         )
         (setq lm (/ l 2))
         (setq    angm
            (+ (* 1.0 pi)
               (atan (cadr    (vlax-curve-getFirstDeriv
                     pol
                     (vlax-curve-getParamAtPoint pol ptm)
                   )
                 )
                 (car (vlax-curve-getFirstDeriv
                    pol
                    (vlax-curve-getParamAtPoint pol ptm)
                      )
                 )
               )
            )
         )
       )
       Ldata
         )
 )
)
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(if (not (tblsearch "BLOCK" "bordura"))
(PROGN 
(entmake '((0 . "BLOCK") (100 . "AcDbEntity") (67 . 0) (8 . "0") (100 . "AcDbBlockReference") (2 . "bordura") (10 0 0 0) (70 . 0)))
(entmakex (append (list (cons 0 "LINE") (cons 100 "AcDbEntity") (cons 67 0) (cons 8 "contur") (cons 100 "AcDbLine")
(append '(10 0 0 0))(list 11 0 1 0))))
(entmake '((0 . "ENDBLK") (100 . "AcDbBlockEnd") (8 . "0")))))
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(setq i nrbord)  
(repeat    nrbord
 (command "-insert" "bordura"
             (car (nth (setq i (1- i)) Ldata));punct
             (cadr (nth i Ldata));scala x
             (cadr (nth i Ldata));scala y
              (rtd (caddr (nth i Ldata)));unghi
 )
 )
(setq i (- nrbord 0))
 (repeat i
   (command "-insert" "bordura"
             (car (cdddr(nth (setq i (1- i)) Ldata)));punct
             (cadr (cdddr(nth i Ldata)));scala x
             (cadr (cdddr(nth i Ldata)));scala y
              (rtd (caddr (cdddr(nth i Ldata))));unghi
 )
 
)

;inserare primul bloc - la capatul poliliniei
(setq tipentitate (cdr (assoc 0 (entget pol))))  
(if (= (cdr (assoc 0 (entget pol))) "LINE") 
(setq p1 (cdr (assoc 11 (entget pol)))))
;;;;;;;;;;; 
(if (or(= (cdr (assoc 0 (entget pol))) "SPLINE")
      (= (cdr (assoc 0 (entget pol))) "LWPOLYLINE"))
(setq p1 (vlax-curve-getEndPoint pol)))

(setq par1 (vlax-curve-getParamAtPoint pol p1))
(setq ang1(atan (cadr (vlax-curve-getFirstDeriv pol (vlax-curve-getParamAtPoint pol p1)))
               (car (vlax-curve-getFirstDeriv pol (vlax-curve-getParamAtPoint pol p1))))) 
(command "-insert" "bordura" p1 l1 "" (rtd(+ ang1 pi)))

 
(setq Ltest    Ldata) 
(*error* nil) ;pentru anulare completa - undo tot ce a fost desenat


;; Selectie obiecte pt manipulare
 (setq ss (ssadd))
 (if (setq en (entnext _LastEnt_)) 
   (while en 
     (setq ss (ssadd en ss) 
           en (entnext en) 
     )
   )
 ) 
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(command "_.select" ss "") 
(princ) 
);end defun c:

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defun c:taluzr (/ Ldata )
;;;;;;;;;;;;;;;;; UNDO COMPLET
 (defun *error* (msg) 
   (and uFlag (vla-EndUndoMark aDoc)) 
   (and msg (or (wcmatch (strcase msg) "*BREAK,*CANCEL*,*EXIT*") 
                (princ (strcat "\n** Error: " msg " **")))) 
   (princ)) 
(setq aDoc (vla-get-ActiveDocument (vlax-get-acad-object))) 
(setq uFlag (not (vla-StartUndoMark aDoc)))
;;;;;;;;;;;;;;;;;;;;
(setq _LastEnt_ (entlast)) ;Selectie obiecte pt manipulare   
(setvar 'cmdecho 0)  
(defun rtd (r) (* 180.0(/ r pi)))
 (setq
   pol        (car (entsel "\nSelecteaza  Polilinia: "))
   dist1    (getdist "\nDistanta intre borduri: ")
   l1  (getdist "\nLatime start: ")
   l2  (getdist "\nLatime sfarsit: ")
   lungpol (vlax-curve-getDistAtParam pol (vlax-curve-getEndParam pol)) ;lungime polilinie
   nrbord  (fix (/ lungpol dist1))
   dist (/ lungpol nrbord)
   dif (- l1 l2)
 )
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(repeat    (setq i nrbord)
 (setq    Ldata (cons
       (list
         (setq    pt (vlax-curve-getpointatdist
                pol
                (* (setq i (- i 1.0)) dist)
              )
         )

         (setq l (/ (+ l2 (* dif (/ i nrbord)))))
         (setq    ang
            (+ (* 1.0 pi)
               (atan (cadr    (vlax-curve-getFirstDeriv
                     pol
                     (vlax-curve-getParamAtPoint pol pt)
                   )
                 )
                 (car (vlax-curve-getFirstDeriv
                    pol
                    (vlax-curve-getParamAtPoint pol pt)
                      )
                 )
               )
            )
         )
           ;;;;;;;;;;;;;;;
         (setq    ptm (vlax-curve-getpointatdist
                 pol
                 (+ (* 0.5 dist) (* i dist))
               )
         )
         (setq lm (/ l 2))
         (setq    angm
            (+ (* 1.0 pi)
               (atan (cadr    (vlax-curve-getFirstDeriv
                     pol
                     (vlax-curve-getParamAtPoint pol ptm)
                   )
                 )
                 (car (vlax-curve-getFirstDeriv
                    pol
                    (vlax-curve-getParamAtPoint pol ptm)
                      )
                 )
               )
            )
         )
       )
       Ldata
         )
 )
)
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(if (not (tblsearch "BLOCK" "bordurar"))
(PROGN 
(entmake '((0 . "BLOCK") (100 . "AcDbEntity") (67 . 0) (8 . "0") (100 . "AcDbBlockReference") (2 . "bordurar") (10 0 0 0) (70 . 0)))
(entmakex (append (list (cons 0 "LINE") (cons 100 "AcDbEntity") (cons 67 0) (cons 8 "contur") (cons 100 "AcDbLine")
(append '(10 0 0 0))(list 11 0 -1 0))))
(entmake '((0 . "ENDBLK") (100 . "AcDbBlockEnd") (8 . "0")))))
 
(setq i nrbord)  
(repeat    nrbord
 (command "-insert" "bordurar"
             (car (nth (setq i (1- i)) Ldata));punct
             (cadr (nth i Ldata));scala x
             (cadr (nth i Ldata));scala y
              (rtd (caddr (nth i Ldata)));unghi
 )
 )
(setq i (- nrbord 0))
 (repeat i
   (command "-insert" "bordurar"
             (car (cdddr(nth (setq i (1- i)) Ldata)));punct
             (cadr (cdddr(nth i Ldata)));scala x
             (cadr (cdddr(nth i Ldata)));scala y
              (rtd (caddr (cdddr(nth i Ldata))));unghi
 )
 
)

;inserare primul bloc - la capatul poliliniei
(setq tipentitate (cdr (assoc 0 (entget pol))))  
(if (= (cdr (assoc 0 (entget pol))) "LINE") 
(setq p1 (cdr (assoc 11 (entget pol)))))
;;;;;;;;;;;
 
(if (or(= (cdr (assoc 0 (entget pol))) "SPLINE")
      (= (cdr (assoc 0 (entget pol))) "LWPOLYLINE"))
(setq p1 (vlax-curve-getEndPoint pol)))

(setq par1 (vlax-curve-getParamAtPoint pol p1))
(setq ang1(atan (cadr (vlax-curve-getFirstDeriv pol (vlax-curve-getParamAtPoint pol p1)))
               (car (vlax-curve-getFirstDeriv pol (vlax-curve-getParamAtPoint pol p1))))) 
(command "-insert" "bordurar" p1 l1 "" (rtd(+ ang1 pi)))

 
(setq Ltest        Ldata) 
(princ)

(*error* nil) ;pentru anulare completa - undo tot ce a fost desenat


;; Selectie obiecte pt manipulare
 (setq ss (ssadd))
 (if (setq en (entnext _LastEnt_)) 
   (while en 
     (setq ss (ssadd en ss) 
           en (entnext en) 
     )
   )
 ) 
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(command "_.select" ss "") 
 
);end defun c:

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;

(defun c:bordura (/ Ldata )  
;;;;;;;;;;;;;;;;; UNDO COMPLET
 (defun *error* (msg) 
   (and uFlag (vla-EndUndoMark aDoc)) 
   (and msg (or (wcmatch (strcase msg) "*BREAK,*CANCEL*,*EXIT*") 
                (princ (strcat "\n** Error: " msg " **")))) 
   (princ)) 
(setq aDoc (vla-get-ActiveDocument (vlax-get-acad-object))) 
(setq uFlag (not (vla-StartUndoMark aDoc)))
;;;;;;;;;;;;;;;;;;;;

(setq _LastEnt_ (entlast)) ;Selectie obiecte pt manipulare 
 
(setvar 'cmdecho 0)  
(defun rtd (r) (* 180.0(/ r pi)))
 (setq
   pol        (car (entsel "\nSelecteaza  Polilinia: "))
   dist1    (getdist "\nDistanta intre borduri: ")
   l1  (getdist "\nLatime start: ")
   l2  (getdist "\nLatime sfarsit: ")
   lungpol (vlax-curve-getDistAtParam pol (vlax-curve-getEndParam pol)) ;lungime polilinie
   nrbord  (fix (/ lungpol dist1))
   dist (/ lungpol nrbord)
   dif (- l1 l2)
 )
;;;;;;;;;;;;;;;;;;;;;
(repeat    (setq i nrbord)
 (setq    Ldata (cons
       (list
         (setq    pt (vlax-curve-getpointatdist
                pol
                (* (setq i (- i 1.0)) dist)
              )
         )

         (setq l (/ (+ l2 (* dif (/ i nrbord)))))
         (setq    ang
            (+ (* 1.0 pi)
               (atan (cadr    (vlax-curve-getFirstDeriv
                     pol
                     (vlax-curve-getParamAtPoint pol pt)
                   )
                 )
                 (car (vlax-curve-getFirstDeriv
                    pol
                    (vlax-curve-getParamAtPoint pol pt)
                      )
                 )
               )
            )
         )
       
       )
       Ldata
         )
 )
)
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(if (not (tblsearch "BLOCK" "bordura"))
(PROGN 
(entmake '((0 . "BLOCK") (100 . "AcDbEntity") (67 . 0) (8 . "0") (100 . "AcDbBlockReference") (2 . "bordura") (10 0 0 0) (70 . 0)))
(entmakex (append (list (cons 0 "LINE") (cons 100 "AcDbEntity") (cons 67 0) (cons 8 "contur") (cons 100 "AcDbLine")
(append '(10 0 0 0))(list 11 0 1 0))))
(entmake '((0 . "ENDBLK") (100 . "AcDbBlockEnd") (8 . "0")))))
 
(setq i nrbord)  
(repeat    nrbord
 (command "-insert" "bordura"
             (car (nth (setq i (1- i)) Ldata));punct
             (cadr (nth i Ldata));scala x
             (cadr (nth i Ldata));scala y
              (rtd (caddr (nth i Ldata)));unghi
 )
 )

;inserare primul bloc - la capatul poliliniei
(setq tipentitate (cdr (assoc 0 (entget pol))))  
(if (= (cdr (assoc 0 (entget pol))) "LINE") 
(setq p1 (cdr (assoc 11 (entget pol)))))
;;;;;;;;;;;
 
(if (or(= (cdr (assoc 0 (entget pol))) "SPLINE")
      (= (cdr (assoc 0 (entget pol))) "LWPOLYLINE"))
(setq p1 (vlax-curve-getEndPoint pol)))

(setq par1 (vlax-curve-getParamAtPoint pol p1))
(setq ang1(atan (cadr (vlax-curve-getFirstDeriv pol (vlax-curve-getParamAtPoint pol p1)))
               (car (vlax-curve-getFirstDeriv pol (vlax-curve-getParamAtPoint pol p1))))) 
(command "-insert" "bordura" p1 l1 "" (rtd(+ ang1 pi)))


 
(setq Ltest        Ldata) 
(princ)

(*error* nil) ;pentru anulare completa - undo tot ce a fost desenat

  ;; Selectie obiecte pt manipulare
 (setq ss (ssadd))
 (if (setq en (entnext _LastEnt_)) 
   (while en 
     (setq ss (ssadd en ss) 
           en (entnext en) 
     )
   )
 ) 
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
(command "_.select" ss "") 
);end defun c:

Wish you best of luck buddy .