Hybrid parallel

[SLW210]

Yes, GP_'s need Express Tools AFAIK.

 

As I posted, It still is off from yours on some corners.

 

It also creates lines and splines, though easy enough to make them polylines.

[PGia]

2 hours ago, SLW210 said:

Yes, GP_'s need Express Tools AFAIK.

 

As I posted, It still is off from yours on some corners.

 

It also creates lines and splines, though easy enough to make them polylines.

 

Yes
I already said my method wasn't perfect.

That's why, besides Lisp, I wanted to know if there was a better method than mine.
And the result GP_'s Lisp achieves corresponds very well with what I understand to be a correct axis.

The only drawback might be using this code in AutoCAD 2000.

But I suppose I can avoid that in AutoCAD 2015.

[GP_]

On 10/27/2025 at 12:31 PM, SLW210 said:

Command: CPL

Cannot invoke (command) from *error* without prior call to (*push-error-using-command*).
Converting (command) calls to (command-s) is recommended.

 

 

3 hours ago, SLW210 said:

It also creates lines and splines, though easy enough to make them polylines.

 

Normally the final result is a polyline, maybe you don't have ExpressTools loaded, try:

(or acet-flatn (load "FLATTENSUP.LSP"))

[SLW210]

1 hour ago, GP_ said:

 

 

Normally the final result is a polyline, maybe you don't have ExpressTools loaded, try:

(or acet-flatn (load "FLATTENSUP.LSP"))

 

Yes, I added 

(acet-load-expresstools)

 

Answered by me.

 

Gian's (as well as the other LISPs) still want to cut some corners short, etc. IMHO. 

 

@mhupp's actually does some of the corners better, though "off" in other places.

 

I believe Civil 3D has something to do this, but it may not be much better.

 

If I get more time I'm still going to work on improving mine.

 

 

[GP_]

 

14 minutes ago, SLW210 said:

 

Yes, I added 

(acet-load-expresstools)

 

Answered by me.

 

It's true... sorry 

 

 

14 minutes ago, SLW210 said:

I believe Civil 3D has something to do this, but it may not be much better.

 

I'm curious to see if there are any differences.

[SLW210]

 

If I get any time at home, I'll do some testing in AutoCAD 2000i.

[GLAVCVS]

 

Calculating an axis using angle bisectors

a) Attempt number 1 (it was my first impulse, but I came up with a better one later)
Advantages:
- Pure LISP: doesn't depend on Express Tools,
- It's faster

Disadvantages:
- The result isn't as good as @GP_'s  "c:CPL"

- It only accepts LWPOLYLINES and ignores arcs

 

Basically, the approach is to obtain angle bisectors on each polyline, extend them to the other reference polyline, and use their midpoints.

The result is acceptably good, but not as accurate as c:CPL.

 

 

(defun c:creAxis (/ e e1 e2 l1 l2 lr p p0 p1 p2 px pm abis lii pmi pfi pi1 pi2 pf1 pf2 dameInters+Prox ordena)
  (defun dameInters+Prox (p0 a lp / p1 px pt1 pt2 dmin d pf)
    (setq pt1 (polar p0 a 1e8) pt2 (polar p0 (+ a PI) 1e8))
    (foreach p lp
      (if p1
        (if (setq px (inters pt1 pt2 p1 p))
	  (if dmin (if (< (setq d (distance px p0)) dmin) (setq dmin d pf px)) (setq dmin (distance px p0) pf px))
        )
      )
      (setq p1 p)
    )
    pf
  )

  (defun ordena (pr lp / d dmin ps lr)
    (while lp
      (foreach p lp
	(if dmin
	  (if (< (setq d (distance p pr)) dmin)
	    (setq dmin d ps p)
	  )
	  (setq	dmin (distance p pr) ps p)
	)
      )
      (setq dmin nil pr ps lp (vl-remove ps lp) lr (append lr (list ps)))
    )	
  )
  (if (and (setq e1 (car (entsel "\nSelect first LWPOLYLINE..."))) (= (cdr (assoc 0 (setq l1 (entget e1)))) "LWPOLYLINE") (not (redraw e1 3)))
    (if (and (setq e2 (car (entsel "\nSelect second LWPOLYLINE..."))) (= (cdr (assoc 0 (setq l2 (entget e2)))) "LWPOLYLINE") (not (redraw e2 3)))
      (progn
	(setq lp1 (reverse (foreach l l1 (if (= (car l) 10) (setq lr (cons (cdr l) lr)) lr))) lr nil;
	      lp2 (reverse (foreach l l2 (if (= (car l) 10) (setq lr (cons (cdr l) lr)) lr))) lr nil;
	)
	(if (< (distance (setq pi1 (cdr (assoc 10 l1))) (setq pi2 (cdr (assoc 10 l2)))) (distance pi1 (setq pf2 (cdr (assoc 10 (reverse l2))))))
	  (setq pmi (mapcar '(lambda (a b) (/ (+ a b) 2.0)) pi1 pi2)
		pfi (mapcar '(lambda (a b) (/ (+ a b) 2.0)) (setq pf1 (cdr (assoc 10 (reverse l1)))) pf2)
	  )
	  (setq pmi (mapcar '(lambda (a b) (/ (+ a b) 2.0)) pi1 pf2)
		pfi (mapcar '(lambda (a b) (/ (+ a b) 2.0)) (cdr (assoc 10 (reverse l1))) pi2)
	  )
	)
	(redraw e1 4)
	(redraw e2 4)
	(foreach l l1
	  (if (= (car l) 10)
	    (if p1
	      (if p2
		(setq abis (+ (/ (+ (angle p1 p2) (angle p2 (cdr l))) 2) (/ PI 2.)) x (princ)
		      px (dameInters+Prox p2 abis lp2)
		      lr nil
		      pm (if px (mapcar '(lambda (a b) (/ (+ a b) 2.0)) p2 px))
		      lii (if px (append lii (list pm)) lii)
		      p1 p2 p2 (cdr l)
		)
		(setq p2 (cdr l))
	      )
	      (setq p1 (cdr l))
	    )
	  )
	)
	(setq p1 nil p2 nil lr nil)
	(foreach l l2
	  (if (= (car l) 10)
	    (if p1
	      (if p2
		(setq abis (+ (/ (+ (angle p1 p2) (angle p2 (cdr l))) 2.) (/ PI 2.))
		      px (dameInters+Prox p2 abis lp1);
		      pm (if px (mapcar '(lambda (a b) (/ (+ a b) 2.0)) p2 px) (princ) )
		      lii (if px (append lii (list pm)) lii);
		      p1 p2 p2 (cdr l)
		)
		(setq p2 (cdr l))
	      )
	      (setq p1 (cdr l))
	    )
	  )
	)
	(setq lii (append (list pmi) (ordena pmi lii) (list pfi)))
      )
    )
  )
  (entmake (append '((0 . "LWPOLYLINE") (100 . "AcDbEntity") (67 . 0) (8 . "0") (100 . "AcDbPolyline") (70 . 0) (60 . 0)) (list (cons 90 (length lii))) (mapcar '(lambda (a) (cons 10 a)) lii)))
  (princ)
)

 

 

PS: It seems to work well, but I haven't tested it extensively.

As I said at the beginning, there's a better approach, using angle bisectors, which I'll publish later.

 

Edited 3 hours ago by GLAVCVS