topic Create a path array with 2 points of the object on the curve in AutoCAD Forum

Create a path array with 2 points of the object on the curve

ColinRuy — Tue, 12 Nov 2024 09:48:34 GMT

I work in the event industry so I have a lot of fencing to draw and I'm trying to make it as efficient as possible. I currently use a path array to generate my fencing quickly. It works great when its straight lines but as soon as there is a curve, I can't get my blocks to stay linked. (cfr. image )

Is there any solution to force 2 points of the block to stay on the path ? The closest solution I could get is to set the base point on the middle of the block so I can get the tangent but it's not perfect.

I hope I'm being clear, English is not my first language.

Re: Create a path array with 2 points of the object on the curve

vinodkl — Tue, 12 Nov 2024 14:09:23 GMT

Hello @ColinRuy

This should be possible using lisp. Please check this thread: https://forums.autodesk.com/t5/visual-lisp-autolisp-and-general/multiple-constraints-along-array-path/td-p/7096003

Re: Create a path array with 2 points of the object on the curve

Kent1Cooper — Tue, 12 Nov 2024 14:48:14 GMT

There was also another very similar topic very recently, either here or in the Customization Forum, but I haven't found the right combination of Search terms to locate it....

Re: Create a path array with 2 points of the object on the curve

leeminardi — Tue, 12 Nov 2024 17:24:41 GMT

I think the following should do what you want.

(defun C:BlocksOnSpline( / blockname delta d path osm endpar dToEnd n p1 p2) ; Adds blocks along a spline with the base point and a secnd point of the blocck also on the spline. ; The second point is specified as a distance along the x acis of the block from the base point. ; L. Minardi 11/12/2024 (command "ucs" "w") (setvar 'osmode 0) (setq blockname (getstring "\nEnter block name: ")) (setq delta (getreal "\nEnter distance to second point on x axis of block: " ) ) (setq d 0 path (car (entsel)) endpar (vlax-curve-getEndParam path) osm (getvar 'osmode) ) (setq dToEnd (vlax-curve-getDistAtParam path endpar) n (atoi (rtos (/ dToEnd delta) 2 2)) ) (setvar "cmdecho" 0) (setq p1 (vlax-curve-getPointAtParam path 0)) (repeat n (setq d (+ d delta)) (setq p2 (vlax-curve-getPointAtDist path d)) (command "-insert" blockname '(0 0 0) 1 1 0) (command "_align" "last" "" '(0 0 0) p1 '(1 0 0) p2 "" "n") (setq p1 p2) ) ; end repeat (setvar 'osmode osm) (setvar "cmdecho" 1) (princ) )

Do you need another parameter to specify the distance between the blocks?

Re: Create a path array with 2 points of the object on the curve

ВeekeeCZ — Wed, 13 Nov 2024 10:02:54 GMT

How about implementing the cord length...

https://forums.autodesk.com/t5/visual-lisp-autolisp-and-general/dividing-a-curve-equaly/m-p/10279075/highlight/true#M414635

Edit: Attached a version that creates a segmented curve by segments equally long. Then could be created dynarray (between dist should be a little bit longer, say by .0001)

Re: Create a path array with 2 points of the object on the curve

leeminardi — Thu, 14 Nov 2024 01:14:27 GMT

@ВeekeeCZ wrote:
How about implementing the cord length...

https://forums.autodesk.com/t5/visual-lisp-autolisp-and-general/dividing-a-curve-equaly/m-p/10279075/highlight/true#M414635

Edit: Attached a version that creates a segmented curve by segments equally long. Then could be created dynarray (between dist should be a little bit longer, say by .0001)

@ВeekeeCZ , It seems like extra work for the user to create the array of blocks in two steps. I got the following results referencing the segmented curve generated by your code and then used the ARRAY PATH.

Here's a second attempt using PSEGLENGTH but with a distance of 1.201 !

Re: Create a path array with 2 points of the object on the curve

ВeekeeCZ — Thu, 14 Nov 2024 08:39:12 GMT

Lee, you're not very versed with this command, are you?

I did not try to address this specific case — I just found that the original algorithm of the chord routine did not work very well for me, so I rewrote it to better suit my needs. If the OP finds it useful, it could be easily adjusted to this case.

Re: Create a path array with 2 points of the object on the curve

ColinRuy — Tue, 19 Nov 2024 14:13:18 GMT

Hey,

Thanks @leeminardi and @ВeekeeCZ , I use a mix of both your commands and it works great. First I divide the curb with Bee's command, then I use Lee's to put the blocks on the divided spline. Dividing the spline first seems to correct the slight error I had using only Lee's command.

Thank to you both !

Cheers.