Topic: Convert pline segment to pline with arcs

[dgpuertas]

Anyone knows code to convert a polyline by segment to a polyline with arcs and delete vertex?

[ribarm]

Green one I can convert to simplified arced LWPOLYLINE, but red one which happen to be your case I can't... All I could think of is that you should find the way to overdraw with command PLINE and perhaps do it manually (automation I don't know how to achieve) - so this is challenge...

Look in attached *.DWG to see what I am talking about...
Regards...

[xdcad]

Anyone knows code to convert a polyline by segment to a polyline with arcs and delete vertex?

There is no DWG picture,
I don’t know if your lines are already LWPOLYLINE.
You have to do this job in two steps
1. First fit those polylines into arcs
2. The arc is combined with other LINEs to generate LWPOLYLINE

[xdcad]

Code - Auto/Visual Lisp: [Select]

1. ;|
2. Function name: XD::Pnts:InOtherPnts
3. Calling format: (XD::Pnts:InOtherPnts pts1 pts2)
4. Parameter description: pts1 ---------- point table
5. pts2 ---------- Point table
6. Return value: point list or nil
7. Function introduction: Get the points of point table 1 in point table 2
8. Function source: original
9. Function author:
10. Applicable versions: XDRX API
11. Last updated: 2016-11-21
12. |;
13. (defun XD::Pnts:InOtherPnts (pts1 pts2)
14.    (vl-remove nil
15.               (mapcar '(lambda (x)
16.                          (if (xd::pnt:isinside x pts2)
17.                            x
18.                            nil
19.                          )
20.                        )
21.                       pts1
22.               )
23.    )
24. )
25. (defun c:tt ()
26.   (while
27.     (and (setq
28.            e (car
29.                (xdrx-entsel
30.                  "\nPick the polyline to be processed into an arc<Exit>:"
31.                  '((0 . "*polyline"))
32.                )
33.              )
34.          )
35.          (setq p1 (getpoint "\nPolyline range lower left point <exit>:"))
36.          (setq
37.            p2 (getcorner p1 "\nPolyline range upper right point <exit>:")
38.          )
39.     )
40.      (progn
41.        (setq ln        (xdge::constructor "kLineSeg3d" p1 p2)
42.              ;;Construct LINE's AcGe geometric object
43.              box       (xdrx-entity-box ln)
44.              ;;Entity bounding box
45.              verts     (xdrx-getpropertyvalue e "vertices")
46.              ;;Polyline vertex table
47.              inPnts    (XD::Pnts:InOtherPnts verts box)
48.              ; Get the points of the point table verts in the point table box
49.              startPt   (car inpnts)
50.              endPt     (last inpnts)
51.              sInx      (xdrx-getpropertyvalue e "NearIndex" startPt)
52.              ;The index value of the polyline closest to the starting point of the polyline
53.              prand     (nth (fix (/ (length inpnts) 2.0)) inpnts)
54.              ;; Randomly pick a point in the polyline
55.              arc       (xd::pnts:fitarc inpnts)
56.              ;; The point table fits the circle
57.              cen       (car arc)
58.              r         (cadr arc)
59.              gcirc     (xdge::constructor "kCircArc2d" cen r)
60.              ; Constructs an AcGe geometric object with a specified center radius
61.              midPt     (xdge::getpropertyvalue gcirc "closestPointTo" prand)
62.              ; find the closest point and get the third point
63.              garc      (xdge::constructor "kCircArc2d" startPt midPt endPt)
64.              ; The starting point, the middle point, and the end point construct a circular arc geometric object.
65.              bulge     (xdge::getpropertyvalue garc "bulge")
66.              ; calculate Bulge
67.              otherPnts (reverse (cdr (reverse (cdr inpnts))))
68.              ; Remove the starting point and end point from the polyline, and delete the remaining points
69.        )
70.        (mapcar '(lambda (x) (xdrx-setpropertyvalue e "removeVertexAt" x))
71.                otherpnts
72.        );;Remove excess points of polyline
73.        (xdrx-setpropertyvalue e "bulgeat" (list sInx bulge))
74.        ;;Set the bulge of the starting index point and generate arc segments
75.      )
76.   )
77.   (princ)
78. )

=============

The above LISP code uses the XDRX-API, which can be downloaded from https://github.com/xdcad/XDrx-API and is updated at any time.

The XDRX API encapsulates AcDb, AcEd, AcGe, AcBr... C++ library, using C++ methods to develop LISP programs.Thousands of Lisp functions are available.
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[BIGAL]

The line segments do not look like a proposed arc is tangential, that is my question. If so then the end points of the 2 straights will move. Adopting one of the mid points as a control.

[xdcad]

Green one I can convert to simplified arced LWPOLYLINE, but red one which happen to be your case I can't... All I could think of is that you should find the way to overdraw with command PLINE and perhaps do it manually (automation I don't know how to achieve) - so this is challenge...

Look in attached *.DWG to see what I am talking about...
Regards...

another version:

Code - Auto/Visual Lisp: [Select]

1. (defun xd::pline:fitarc (e sInx eInx / i inx inpnts pnt startpt
2.                          endpt arc cen r gcirc midpt garc bulge otherpnts)
3.   (mapcar 'set '(sInx eInx) (vl-sort (list sInx eInx) '<))
4.   (setq i 0
5.         inx sInx
6.         inpnts nil
7.   )
8.   (repeat (1+ (- eInx sInx))
9.     (setq inx (+ sInx i))
10.     (setq pnt    (xdrx-getpropertyvalue e "PointAt" inx)
11.           inpnts (cons pnt inpnts)
12.           i      (1+ i)
13.     )
14.   )
15.   (setq inpnts  (reverse inpnts)
16.         startPt (xdrx-getpropertyvalue e "PointAt" sInx)
17.         endPt   (xdrx-getpropertyvalue e "PointAt" eInx)
18.         prand     (nth (fix (/ (length inpnts) 2.0)) inpnts)
19.         ;; Randomly pick a point in the polyline
20.                 arc       (xd::pnts:fitarc inpnts)
21.         ;; The point table fits the circle
22.                 cen       (car arc)
23.                 r         (cadr arc)
24.                 gcirc     (xdge::constructor "kCircArc2d" cen r)
25.         ; Constructs an AcGe geometric object with a specified center radius
26.                 midPt     (xdge::getpropertyvalue gcirc "closestPointTo" prand)
27.         ; find the closest point and get the third point
28.                 garc      (xdge::constructor "kCircArc2d" startPt midPt endPt)
29.         ; The starting point, the middle point, and the end point construct a circular arc geometric object.
30.                 bulge     (xdge::getpropertyvalue garc "bulge")
31.         ; calculate Bulge
32.                 otherPnts (reverse (cdr (reverse (cdr inpnts))))
33.         ; Remove the starting point and end point from the polyline, and delete the remaining points
34.   )
35.   (xdrx-object-release garc gcirc);;free Ge Object Memory
36.   (list sInx eInx bulge otherPnts)
37. )
38. (defun c:tt ()
39.   (if
40.     (and (xdrx-sysvar-push '("osmode" 512))
41.          (setq
42.            e (car
43.                (xdrx-entsel
44.                  "\nPick the polyline to be processed into an arc<Exit>:"
45.                  '((0 . "*polyline"))
46.                )
47.              )
48.          )
49.     )
50.      (progn
51.        (xdrx-begin)
52.        (while
53.          (and
54.            (xdrx-entity-redraw e 1)
55.            (setq p1 (getpoint "\nClick near the starting Point<exit>:"))
56.            (setq inx1 (xdrx-getpropertyvalue e "nearindex" p1))
57.            (setq
58.              p2 (getpoint p1 "\nClick near the ending Point <exit>:")
59.            )
60.            (setq inx2 (xdrx-getpropertyvalue e "nearindex" p2))
61.          )
62.           (setq fitinfo   (XD::PLINE:FITARC e inx1 inx2)
63.                 bulge     (nth 2 fitinfo)
64.                 otherpnts (nth 3 fitinfo)
65.                 sInx      (nth 0 fitinfo)
66.           )
67.           (mapcar
68.             '(lambda (x) (xdrx-setpropertyvalue e "removeVertexAt" x))
69.             otherpnts
70.           )
71.           ;;Remove excess points of polyline
72.           (xdrx-setpropertyvalue e "bulgeat" (list sInx bulge))
73.           ;;Set the bulge of the starting index point and generate arc segments
74.        )
75.        (xdrx-end)
76.      )
77.   )
78.   (xdrx-entity-redraw e t)
79.   (xdrx-sysvar-pop)
80.   (princ)
81. )

=============

The above LISP code uses the XDRX-API, which can be downloaded from https://github.com/xdcad/XDrx-API and is updated at any time.

The XDRX API encapsulates AcDb, AcEd, AcGe, AcBr... C++ library, using C++ methods to develop LISP programs.Thousands of Lisp functions are available.
Modify message

[xdcad]

The line segments do not look like a proposed arc is tangential, that is my question. If so then the end points of the 2 straights will move. Adopting one of the mid points as a control.

After fitting the arc, and add the FILLET code

[xdcad]

The line segments do not look like a proposed arc is tangential, that is my question. If so then the end points of the 2 straights will move. Adopting one of the mid points as a control.

Actually,
In actual work, there is a small probability that random fold lines like the original poster will appear.

Generally, it is as shown in the figure below. For some reasons, the arc segment becomes many small segments. Such a figure can be fitted with an accuracy of 99.999%, which means there is no need to deal with tangency. Condition

The following picture can also be processed fully automatically

[xdcad]

For some 3D industrial software to generate DWG drawings, arcs may change into polylines.
The following code automatically selects multiple items for batch processing.

Code - Auto/Visual Lisp: [Select]

1. (defun c:tt ()
2.   (defun _fitarc (e pts / startpt endpt   prand arc cen r
3.                           gcirc   midpt   garc    bulge   otherpnts
4.                  )
5.     (setq startPt   (car pts)
6.           endPt     (last pts)
7.           prand     (nth (fix (/ (length pts) 2.0)) pts)
8.           ;; Randomly pick a point in the polyline
9.           arc       (xd::pnts:fitarc pts)
10.           ;; The point table fits the circle
11.           cen       (car arc)
12.           r         (cadr arc)
13.           gcirc     (xdge::constructor "kCircArc2d" cen r)
14.           ; Constructs an AcGe geometric object with a specified center radius
15.           midPt     (xdge::getpropertyvalue gcirc "closestPointTo" prand)
16.           ; find the closest point and get the third point
17.           garc      (xdge::constructor "kCircArc2d" startPt midPt endPt)
18.           ; The starting point, the middle point, and the end point construct a circular arc geometric object.
19.           bulge     (xdge::getpropertyvalue garc "bulge")
20.           ; calculate Bulge
21.           otherPnts (reverse (cdr (reverse (cdr pts))))
22.           ; Remove the starting point and end point from the polyline, and delete the remaining points
23.     )
24.     (xdrx-object-release garc gcirc)
25.     ;;free Ge Object Memory
26.     (list bulge otherPnts)
27.   )
28.   (defun _process (e / numverts inx pts set len pnt info bulge otherpnts)
29.     (xdrx-prompt "\nPolyLine " index " :")
30.     (xdrx-prompt
31.       (xdrx-string-format       "\n  Before Area: %.4f"
32.         (xdrx-getpropertyvalue e "area")
33.       )
34.     )
35.     (setq index (1+ index))
36.     (setq numVerts (xdrx-getpropertyvalue e "numverts"))
37.     (setq inx 0
38.           pts nil
39.     )
40.     (repeat (1- numverts)
41.       (setq seg (xdrx-getpropertyvalue e "segat" inx)
42.       ;|The AcGe geometry object of the segment starting at the specified
43.         index value position, which may be: kLineSeg3d or kCircArc3d|;
44.             len (xdrx-getpropertyvalue seg "length")
45.             pnt (xdrx-getpropertyvalue e "pointat" inx)
46.       )
47.       (xdrx-object-release seg)
48.       (if (< len tol)
49.         (progn
50.           (if (not pts)
51.             (setq sInx inx)
52.           )
53.           (setq pts (cons pnt pts))
54.         )
55.         (progn
56.           (if (> (length pts) 3)
57.             (progn
58.               (setq pts
59.                      (reverse
60.                        (cons (xdrx-getpropertyvalue e "pointat" inx)
61.                              pts
62.                        )
63.                      )
64.               )
65.               (setq info      (_fitarc e pts)
66.                     bulge     (car info)
67.                     otherpnts (cadr info)
68.               )
69.               (mapcar
70.                 '(lambda (x)
71.                    (xdrx-setpropertyvalue e "removeVertexAt" x)
72.                  )
73.                 otherpnts
74.               )
75.               ;;Remove excess points of polyline
76.               (xdrx-setpropertyvalue e "bulgeat" (list sInx bulge))
77.               (xdrx-prompt
78.                 (xdrx-string-format
79.                   "\n  After  Area: %.4f"
80.                   (xdrx-getpropertyvalue e "area")
81.                 )
82.                 "\n========================"
83.               )
84.               (setq pts nil)
85.             )
86.           )
87.         )
88.       )
89.       (setq inx (1+ inx))
90.     )
91.     (princ)
92.   )
93.   ;;Main =====================================
94.   (if (not #tol)
95.     (setq #tol 10.0)
96.   )
97.   (setq index 1)
98.   (if (and
99.         (or (setq
100.               tol (getreal
101.                     (xdrx-prompt "\nEnter tolerance value<" #tol ">:" t)
102.                   )
103.             )
104.             (setq tol #tol)
105.         )
106.         (setq ss (xdrx-ssget
107.                    "\nSelect polylines to Process <Exit>:"
108.                    '((0 . "*polyline"))
109.                  )
110.         )
111.       )
112.     (progn
113.       (xdrx-begin)
114.       (setq #tol tol)
115.       (xdrx-prompt "\n========================")
116.       (mapcar '(lambda (x)
117.                  (_process x)
118.                )
119.               (xdrx-pickset->ents ss)
120.       )
121.       (xdrx-entity-redraw ss 1)
122.       (xdrx-end)
123.     )
124.   )
125.   (princ)
126. )

=============

The above LISP code uses the XDRX-API, which can be downloaded from https://github.com/xdcad/XDrx-API and is updated at any time.

The XDRX API encapsulates AcDb, AcEd, AcGe, AcBr... C++ library, using C++ methods to develop LISP programs.Thousands of Lisp functions are available.
Modify message