Topic: Align Polyline to Polyline

[chvnprasad]

How to align one polyline to another polyline.both polylines are different number of verices. If i select source polyline and target polyline,source polyline should be align(coincide) with target poly line

[irneb]

How should they align? Simply the picked vectors to be co-linear? Or should the one also scale such that the picked vectors are the same length and / or start & end points? Are both always on the same UCS? Should something else than the picked vectors be used for alignment, say vectors closest to each other? What about curved vectors, should these be ignored?

[alanjt]

Would this be essential to using Rotate by Reference?

eg.

Code: [Select]

Command: r
ROTATE
Current positive angle in UCS:  ANGDIR=counterclockwise  ANGBASE=0d

Select objects: Specify opposite corner: 1 found

Select objects:

Specify base point:
Specify rotation angle or [Copy/Reference] <0d>: r

[irneb]

Or simply using the Align command? E.g.:

Code - Auto/Visual Lisp: [Select]

1. (vl-load-com)
2.  
3. (defun c:AlignPoly (/ SelPoly p1 p2 en1 en2 p3 p4)
4.   (defun SelPoly ( msg / p )
5.     (while (and (setq p (entsel msg)) (not (eq (cdr (assoc 0 (entget (car p)))) "LWPOLYLINE")))
6.       (princ "That's not a polyline, try again.\n"))
7.     p)
8.  
9.   (if (setq p1 (SelPoly "Pick Polyline to rotate/move/scale <Exit>: "))
10.     (setq p1 (fix (vlax-curve-getParamAtPoint (setq en1 (car p1)) (vlax-curve-getClosestPointTo en1 (cadr p1)))))
11.     (exit))
12.   (if (setq p2 (SelPoly "Pick target Polyline <Exit>: "))
13.     (setq p2 (fix (vlax-curve-getParamAtPoint (setq en2 (car p2)) (vlax-curve-getClosestPointTo en2 (cadr p2)))))
14.     (exit))
15.   (command "._ZOOM" "_Object" en1 en2 "")
16.   (setq p3 (vlax-curve-getPointAtParam en1 (1+ p1))
17.         p4 (vlax-curve-getPointAtParam en2 (1+ p2)))
18.   (grdraw (setq p1 (vlax-curve-getPointAtParam en1 p1))
19.           (setq p2 (vlax-curve-getPointAtParam en2 p2))
20.           2 1)
21.   (grdraw p3 p4 2 1)
22.   (initget "Swap Continue")
23.   (if (eq (getkword "Is this corect? [Swap/Continue] <Continue>: ") "Swap")
24.     (progn (redraw) (command "._ALIGN" en1 "" p3 p2 p1 p4 ""))
25.     (progn (redraw) (command "._ALIGN" en1 "" p1 p2 p3 p4 "")))
26.   (princ))

[ribarm]

Irneb, I think command ALIGN has some sort of bug when calling from inside routine...
I suggest that you use (arxload "geom3d.arx") and call (align) sub-function shown in this example :

http://www.theswamp.org/index.php?topic=41382.msg464959#msg464959

M.R.

[irneb]

I don't know ... for me on Vanilla 2012 it seems to work fine.

[alanjt]

Oh yeah, Align. drrr