Shortest polyline between two flanges

February 8

Hello everyone,
I am looking for a way to automatically connect necks or flanges with a flexible pipe of a given size, or at least a polyline with a given fillet radius.
For flexible pipes size=radius
DWG attached for clarification

Flexible ducts.dwg

February 8

Here you go.

(defun c:Wrap (/ int sel ent obj)
  ;;----------------------------------------------------;;
  ;;	Author : Tharwat Al Choufi			;;
  ;; website: https://autolispprograms.wordpress.com	;;
  ;;----------------------------------------------------;;
  (and (or (tblsearch "LAYER" "MF_Flexo")
           (alert "Please create a layer name < MF_Flexo > in prior to process.!")
           )
       (princ "\nSelect center 'polyline' of Flexible duct : ")
       (setq int -1 sel (ssget "_:L" '((0 . "LWPOLYLINE"))))
       (while (setq int (1+ int) ent (ssname sel int))
         (setq obj (vlax-ename->vla-object ent))
         (mapcar (function (lambda (v / o)
                             (setq o (car (vlax-invoke obj 'Offset v)))
                             (vla-put-layer o "MF_Flexo")
                             (vla-put-linetype o "ByLayer")
                             (vla-put-Color o 256)
                           )
                 )
                 '(79.5 -79.5)
         )
       )
  )
  (princ)
) (vl-load-com)

February 8

Hey, that's a fun problem to try to solve.

I got part of the solution.

- Command DFT (for Draw Flexible Tube)

- Select point 1

- Select point 2

- Select point 3

... as shown on the picture

;;	https://www.cadtutor.net/forum/topic/79564-shortest-polyline-between-two-flanges/

;; @file  

(defun r2d (r / ) 
	(/ (* r 180.0) pi)
)

(defun d2r (d / ) 
	(* (/ d 180.0) pi)
)

;; midpoint of 2 given points
(defun mid ( pt1 pt2 / )
  (mapcar '(lambda (x y) (+ (* 0.5 x) (* 0.5 y)))
  pt1
  pt2
  )
)

(defun drawLWPoly (lst cls)
 (entmakex (append (list (cons 0 "LWPOLYLINE")
                         (cons 100 "AcDbEntity")
                         (cons 100 "AcDbPolyline")
                         (cons 90 (length lst))
                         (cons 70 cls))
                   (mapcar (function (lambda (p) (cons 10 p))) lst))))
				   
(defun drawLine (p1 p2)
 (entmakex (list (cons 0 "LINE")
                 (cons 10 p1)
                 (cons 11 p2))))


;; command DFT, for Draw Flexible Tube
(defun c:DFT ( / p1 p2 pm p3 duct_diam ang1 ang2 kink1 kink2 pl1 pl2 pl3 fillet1 fillet2)

	(setq p1 (getpoint "\nPoint 1 (right edge of the base): "))
	(setq p2 (getpoint p1 "\nPoint 2 (left edge of the base): "))
	(setq pm (mid p1 p2))
	(setq duct_diam (distance p1 p2))
	;; read angle.  minus 90°, that's the angle of the first vertex of the duct
	(setq ang1 (- (angle p1 p2) (d2r 90.0)))	
	(princ (r2d ang1))
	
	(princ "\nDuct diameter: ")
	(princ duct_diam)
	(princ " - angle: ")
	(princ (r2d ang1))
	
	(setq p3 (getpoint "\nPoint 3: (middle of the top): "))
	
	;; step 1, we need a point perpendicular to p1-p2, length = distance p1-p2
	(setq kink1 (polar pm ang1 duct_diam))
	;; dito for endpoint.  I assume the top is always horizontal
	(setq kink2 (polar p3 (d2r -90.0) duct_diam))
	
	;; We draw 3 lines. 
	(setq pl1 (drawLine pm kink1))
	(setq pl2 (drawLine kink1 kink2))
	(setq pl3 (drawLine kink2 p3))

	;; now fillet 
	(setvar "FILLETRAD" duct_diam)
	(command "_.fillet" pl2 pl1)
	(setq fillet1 (entlast))
	(command "_.fillet" pl2 pl3)
	(setq fillet2 (entlast))
	
	(princ)
	
)

February 8

2 hours ago, Tharwat said:

Here you go.

(defun c:Wrap (/ int sel ent obj)
  ;;----------------------------------------------------;;
  ;;	Author : Tharwat Al Choufi			;;
  ;; website: https://autolispprograms.wordpress.com	;;
  ;;----------------------------------------------------;;
  (and (or (tblsearch "LAYER" "MF_Flexo")
           (alert "Please create a layer name < MF_Flexo > in prior to process.!")
           )
       (princ "\nSelect center 'polyline' of Flexible duct : ")
       (setq int -1 sel (ssget "_:L" '((0 . "LWPOLYLINE"))))
       (while (setq int (1+ int) ent (ssname sel int))
         (setq obj (vlax-ename->vla-object ent))
         (mapcar (function (lambda (v / o)
                             (setq o (car (vlax-invoke obj 'Offset v)))
                             (vla-put-layer o "MF_Flexo")
                             (vla-put-linetype o "ByLayer")
                             (vla-put-Color o 256)
                           )
                 )
                 '(79.5 -79.5)
         )
       )
  )
  (princ)
) (vl-load-com)

Perfect, effective wrapping code. Much, much better than what I actually use.
But my goal is to draw a centreline (polyline) to connect necks or flanges much more efficiently without using auxiliary lines.
Especially when the flanges are rotated against the ortho system.

February 8

My code draws the center line.

Tharwat's code wraps it.

My code should just polyline edit -> join them

February 8

11 minutes ago, Emmanuel Delay said:

My code draws the center line.

Tharwat's code wraps it.

My code should just polyline edit -> join them

Great I see
Thank you for your code.
It works fine but it is very sensitive to the order of the points as you can see in the attachments and I never know what order to choose to get the right result
And in case number 8, the line created is not perpendicular.

Flexible ducts.dwg

February 8

Yeah, as your example showed, my code assumed a vertical ending.
I'll adapt it for different angles.

And yes, it asks for an order of points. First right edge, then left edge.

Right and left are defined as: point 1 is right, point 2 is left.

Take a line p1-p2. Now that angle based of the line, turn it 90° clockwise. In that angle the duct will go away from the base

Edited February 8 by Emmanuel Delay

February 9

If you can get used of the Right-Left definition, then use this. It now does any angle

(again: line from right to left, add 90 ° clockwise, that's the direction of the tube/duct)

EDIT:

- Oh yes, and I join the lines and arcs to 1 polyline.

- And I set it to the right layer, color, linetype and lt scale

Then you can use Tharwat's code to make the wrapping

(vl-load-com) 

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; https://www.cadtutor.net/forum/topic/32405-looking-for-the-join-polyline-lisp-that-is-in-this-forum/?do=findComment&comment=261544
;; Polyline Edit, Join 

(defun c:pj ( / pe ss )
 (setq pe (getvar 'PEDITACCEPT))
 (setvar 'PEDITACCEPT 1)
 (if (setq ss (ssget "_:L" '((0 . "ARC,LINE,LWPOLYLINE"))))
   (command "_.pedit" "_M" ss "" "_J" "" "")
 )
 (setvar 'PEDITACCEPT pe)
 (princ)
)

;; SS is a ssget selection (could be made with ssadd of course) of "ARC,LINE,LWPOLYLINE"...
;;
(defun pj (ss  / pe )
	;; (setq ss (ssget "_:L" '((0 . "ARC,LINE,LWPOLYLINE"))))
	(setq pe (getvar 'PEDITACCEPT))
	(setvar 'PEDITACCEPT 1)
	(if ss
		(command "_.pedit" "_M" ss "" "_J" "" "")
	)
	(setvar 'PEDITACCEPT pe)
	(entlast)		;; return the newly made polyline object
)


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

;; @file  

(defun r2d (r / ) 
	(/ (* r 180.0) pi)
)

(defun d2r (d / ) 
	(* (/ d 180.0) pi)
)

;; midpoint of 2 given points
(defun mid ( pt1 pt2 / )
  (mapcar '(lambda (x y) (+ (* 0.5 x) (* 0.5 y)))
  pt1
  pt2
  )
)

(defun drawLWPoly (lst cls)
 (entmakex (append (list (cons 0 "LWPOLYLINE")
                         (cons 100 "AcDbEntity")
                         (cons 100 "AcDbPolyline")
                         (cons 90 (length lst))
                         (cons 70 cls))
                   (mapcar (function (lambda (p) (cons 10 p))) lst))))
				   
(defun drawLine (p1 p2)
 (entmakex (list (cons 0 "LINE")
                 (cons 10 p1)
                 (cons 11 p2))))


;; command DFT, for Draw Flexible Tube
(defun c:DFT ( / p1 p2 pm p3 p4 p5 duct_diam ang1 ang2 kink1 kink2 pl1 pl2 pl3 fillet1 fillet2 duct)

	(setq p1 (getpoint "\nPoint 1 (right edge of the base): "))
	(setq p2 (getpoint p1 "\nPoint 2 (left edge of the base): "))
	(setq pm (mid p1 p2))
	(setq duct_diam (distance p1 p2))
	;; read angle.  minus 90°, that's the angle of the first vertex of the duct
	(setq ang1 (- (angle p1 p2) (d2r 90.0)))	
	(princ (r2d ang1))
	
	(princ "\nDuct diameter: ")
	(princ duct_diam)
	(princ " - angle: ")
	(princ (r2d ang1))
	
	
	(setq p4 (getpoint "\nPoint 4: (right edge of the end): "))
	(setq p5 (getpoint "\nPoint 5: (left edge of the end): "))
	(setq p3 (mid p4 p5))
	(setq ang2 (- (angle p4 p5) (d2r 90.0)))	

	;;(setq p3 (getpoint "\nPoint 3: (middle of the top): "))
	
	;; step 1, we need a point perpendicular to p1-p2, length = distance p1-p2
	(setq kink1 (polar pm ang1 duct_diam))
	;; dito for endpoint.  I assume the top is always horizontal
	(setq kink2 (polar p3 ang2 duct_diam))
	
	;; We draw 3 lines. 
	(setq pl1 (drawLine pm kink1))
	(setq pl2 (drawLine kink1 kink2))
	(setq pl3 (drawLine kink2 p3))

	;; now fillet 
	(setvar "FILLETRAD" duct_diam)
	(command "_.fillet" pl2 pl1)
	(setq fillet1 (entlast))
	(command "_.fillet" pl2 pl3)
	(setq fillet2 (entlast))
	
	;; Now we'll join these lines and arcs to 1 polyline.  We first put them in a ss selection
	(setq duct (ssadd))
	(ssadd pl1 		duct)
	(ssadd fillet1 	duct)
	(ssadd pl2 		duct)
	(ssadd fillet2 	duct)
	(ssadd pl3 		duct)
	
	(setq duct (pj duct))
	
	;; linetype and scale
	(setq obj (vlax-ename->vla-object duct))	
	(vla-put-layer obj "MF_Flexo")
	(vla-put-color obj 7)		;; 7 = white
	(vla-put-linetype obj "TRACKS")
	(vla-put-linetypescale obj 320)

	(princ)
	
)

Edited February 9 by Emmanuel Delay

February 9

4 hours ago, Emmanuel Delay said:

If you can get used of the Right-Left definition, then use this. It now does any angle

(again: line from right to left, add 90 ° clockwise, that's the direction of the tube/duct)

EDIT:

- Oh yes, and I join the lines and arcs to 1 polyline.

- And I set it to the right layer, color, linetype and lt scale

Then you can use Tharwat's code to make the wrapping

(vl-load-com) 

;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
;; https://www.cadtutor.net/forum/topic/32405-looking-for-the-join-polyline-lisp-that-is-in-this-forum/?do=findComment&comment=261544
;; Polyline Edit, Join 

(defun c:pj ( / pe ss )
 (setq pe (getvar 'PEDITACCEPT))
 (setvar 'PEDITACCEPT 1)
 (if (setq ss (ssget "_:L" '((0 . "ARC,LINE,LWPOLYLINE"))))
   (command "_.pedit" "_M" ss "" "_J" "" "")
 )
 (setvar 'PEDITACCEPT pe)
 (princ)
)

;; SS is a ssget selection (could be made with ssadd of course) of "ARC,LINE,LWPOLYLINE"...
;;
(defun pj (ss  / pe )
	;; (setq ss (ssget "_:L" '((0 . "ARC,LINE,LWPOLYLINE"))))
	(setq pe (getvar 'PEDITACCEPT))
	(setvar 'PEDITACCEPT 1)
	(if ss
		(command "_.pedit" "_M" ss "" "_J" "" "")
	)
	(setvar 'PEDITACCEPT pe)
	(entlast)		;; return the newly made polyline object
)


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

;; @file  

(defun r2d (r / ) 
	(/ (* r 180.0) pi)
)

(defun d2r (d / ) 
	(* (/ d 180.0) pi)
)

;; midpoint of 2 given points
(defun mid ( pt1 pt2 / )
  (mapcar '(lambda (x y) (+ (* 0.5 x) (* 0.5 y)))
  pt1
  pt2
  )
)

(defun drawLWPoly (lst cls)
 (entmakex (append (list (cons 0 "LWPOLYLINE")
                         (cons 100 "AcDbEntity")
                         (cons 100 "AcDbPolyline")
                         (cons 90 (length lst))
                         (cons 70 cls))
                   (mapcar (function (lambda (p) (cons 10 p))) lst))))
				   
(defun drawLine (p1 p2)
 (entmakex (list (cons 0 "LINE")
                 (cons 10 p1)
                 (cons 11 p2))))


;; command DFT, for Draw Flexible Tube
(defun c:DFT ( / p1 p2 pm p3 p4 p5 duct_diam ang1 ang2 kink1 kink2 pl1 pl2 pl3 fillet1 fillet2 duct)

	(setq p1 (getpoint "\nPoint 1 (right edge of the base): "))
	(setq p2 (getpoint p1 "\nPoint 2 (left edge of the base): "))
	(setq pm (mid p1 p2))
	(setq duct_diam (distance p1 p2))
	;; read angle.  minus 90°, that's the angle of the first vertex of the duct
	(setq ang1 (- (angle p1 p2) (d2r 90.0)))	
	(princ (r2d ang1))
	
	(princ "\nDuct diameter: ")
	(princ duct_diam)
	(princ " - angle: ")
	(princ (r2d ang1))
	
	
	(setq p4 (getpoint "\nPoint 4: (right edge of the end): "))
	(setq p5 (getpoint "\nPoint 5: (left edge of the end): "))
	(setq p3 (mid p4 p5))
	(setq ang2 (- (angle p4 p5) (d2r 90.0)))	

	;;(setq p3 (getpoint "\nPoint 3: (middle of the top): "))
	
	;; step 1, we need a point perpendicular to p1-p2, length = distance p1-p2
	(setq kink1 (polar pm ang1 duct_diam))
	;; dito for endpoint.  I assume the top is always horizontal
	(setq kink2 (polar p3 ang2 duct_diam))
	
	;; We draw 3 lines. 
	(setq pl1 (drawLine pm kink1))
	(setq pl2 (drawLine kink1 kink2))
	(setq pl3 (drawLine kink2 p3))

	;; now fillet 
	(setvar "FILLETRAD" duct_diam)
	(command "_.fillet" pl2 pl1)
	(setq fillet1 (entlast))
	(command "_.fillet" pl2 pl3)
	(setq fillet2 (entlast))
	
	;; Now we'll join these lines and arcs to 1 polyline.  We first put them in a ss selection
	(setq duct (ssadd))
	(ssadd pl1 		duct)
	(ssadd fillet1 	duct)
	(ssadd pl2 		duct)
	(ssadd fillet2 	duct)
	(ssadd pl3 		duct)
	
	(setq duct (pj duct))
	
	;; linetype and scale
	(setq obj (vlax-ename->vla-object duct))	
	(vla-put-layer obj "MF_Flexo")
	(vla-put-color obj 7)		;; 7 = white
	(vla-put-linetype obj "TRACKS")
	(vla-put-linetypescale obj 320)

	(princ)
	
)

Great,
It works exactly as expected.

I don't want to be ungrateful, but couldn't it be made more efficient by not entering points, but selecting a line (flange), calculating the centre of the line, the length of the line (duct_diam), then the normal vector to the line and the coordinates of the point lying on the normal duct_diam away, (there will be 2 points on each side :)), the same for the other flange and then find out which normals intersect and that will indicate the direction of drawing the axis of the pipe.
It would be 2 clicks instead of 4

Of course, I don't want to waste your time, and the code you already sent me will save me a lot of time anyway.

Thank you very much

February 9

Right now the flanges are not lines.

They're blocks.

So it's selecting a vertex of the polyline inside a block

I'll need to extend this code I wrote a while ago. It will takes some time

February 9

8 minutes ago, Emmanuel Delay said:

Right now the flanges are not lines.

They're blocks.

So it's selecting a vertex of the polyline inside a block

I'll need to extend this code I wrote a while ago. It will takes some time

Yes, you're right.
That would be my next question, how to select part of the polyline and also inside the block

February 9

Yep nentsel will find a pline in a block. Then can work out which segment, then in turn 90 angle and midpoint. (cadr (nentsel)) is pick point.

(entget (car (nentsel)))
Select entity: ((-1 . <Entity name: 62ba0840>) (0 . "LWPOLYLINE")

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Shortest polyline between two flanges

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