topic Re: Find Intersection point automatically in Visual LISP, AutoLISP and General Customization Forum

Find Intersection point automatically

Anonymous — Thu, 08 Oct 2020 13:52:58 GMT

Hello,

I have a lot of line which have to cut a single line. I need to know all intersection point location. How can I find it easily? Can I do it with a single command?

Thanks in advance.

Re: Find Intersection point automatically

Patchy — Thu, 08 Oct 2020 13:56:01 GMT

https://www.cadstudio.cz/en/download.asp?file=IntLines

Then use Dataextraction.

How many lines do you have? ☺

Re: Find Intersection point automatically

Anonymous — Thu, 08 Oct 2020 13:59:38 GMT

Thank you for your reply. I have almost 100 intersection points. I have to find out every intersection points locations.

Re: Find Intersection point automatically

Patchy — Thu, 08 Oct 2020 14:01:14 GMT

Upload the example, let's see if it can be done ☺

Please upload 2007 version ☺

Re: Find Intersection point automatically

pendean — Thu, 08 Oct 2020 14:02:00 GMT

How do you think these 100 points should be presented to you? explain your expectations or wishes in more detail, if needed, fake something visual in your file to show us.

Re: Find Intersection point automatically

Anonymous — Thu, 08 Oct 2020 14:07:45 GMT

Here it is sir.

Re: Find Intersection point automatically

Anonymous — Thu, 08 Oct 2020 14:10:35 GMT

Yes, I have uploaded a sample drawing file, Kindly see the drawing.

I have to find out the location where red line cuts the white line.

Re: Find Intersection point automatically

Patchy — Thu, 08 Oct 2020 14:19:17 GMT

You want the coordinates or dimensions?

Re: Find Intersection point automatically

Anonymous — Thu, 08 Oct 2020 14:25:48 GMT

Sir, the red line midpoint would be (x,y) = (0,0), if I want find out the coordinate. or it would be dimension form the red line mid point.

Re: Find Intersection point automatically

Anonymous — Thu, 08 Oct 2020 14:27:02 GMT

actually, I need the distance from the red line mid point to intersection point

Re: Find Intersection point automatically

hak_vz — Thu, 08 Oct 2020 14:30:23 GMT

(defun c:intersections nil(intersections)) (defun intersections ( / e eo ss i getintersections mappend mklist flatten pointlist3d io int all) (defun getintersections (obj1 obj2 / var) ; from RonJonP (setq var (vlax-variant-value (vla-intersectwith obj1 obj2 1))) (if (< 0 (vlax-safearray-get-u-bound var 1)) (vlax-safearray->list var) ) ;_ end of if ) ;_ end of defun (defun mappend (fn lst) ; Peter Norvig ?? ; Append the results of calling fn on each element of list. ; Like mapcon, but uses append instead of nconc." ; One thing to notice is that fn must return a list, otherwise, it will go wrong. ; usage: (mappend '(lambda (x) (list x (* x x))) '(1 2 3)) (apply 'append (mapcar fn lst)) ) ;_ end of defun (defun mklist (x) ; If x is a list return it, otherwise return the list of x (if (listp x) x (list x) ) ;_ end of if ) ;_ end of defun (defun flatten (expr) ; Get rid of imbedded lists (to one level only)." (mappend 'mklist expr) ) ;_ end of defun (defun pointlist3d (lst / ret) ; converts one dimensional list (vector) to list of 3d points (while lst (setq ret (cons (list (car lst) (cadr lst) (caddr lst)) ret) lst (cdddr lst) ) ;_ end of setq ) ;_ end of while (reverse ret) ) ;_ end of defun (while (not e )(setq e (car (entsel "\nSelect base object > ")))) (setq eo (vlax-ename->vla-object e)) (princ "\nSelect intersection objects >") (setq ss (ssget) i 0) (repeat (sslength ss) (setq io (vlax-ename->vla-object (ssname ss i))) (setq int (pointlist3d(flatten(getintersections eo io)))) (if (and int)(setq all (cons int all))) (setq i (+ i 1)) ) all )

Try this.

Re: Find Intersection point automatically

Anonymous — Thu, 08 Oct 2020 14:34:52 GMT

Thanks a lot. But I am sorry sir, I don't know how to input this. I know programming, but don't know about autocad coding. Please help me sir

Re: Find Intersection point automatically

Patchy — Thu, 08 Oct 2020 14:40:06 GMT

Maybe like this.

Re: Find Intersection point automatically

Anonymous — Thu, 08 Oct 2020 14:41:37 GMT

WOW! How you do it? 😄

Re: Find Intersection point automatically

Patchy — Thu, 08 Oct 2020 14:44:13 GMT

Most of the autolisp I used were from here:

http://www.lee-mac.com/index.html

Re: Find Intersection point automatically

Anonymous — Thu, 08 Oct 2020 14:47:33 GMT

OK sir. Thank you. But could you please tell me how you do that? How you find out all coordinate points?

Re: Find Intersection point automatically

hak_vz — Thu, 08 Oct 2020 14:53:00 GMT

Save this code to a file with extension .lsp i.e. intersections.lsp. Load it into AUTOCAD though menus

tools-> load application -> select wile name

or by using command APPLOAD

When loaded type command INTERSTECTIONS to console and follow what it asks.

For your sample when origin is set to 0,0 you will receive a list:

Re: Find Intersection point automatically

hak_vz — Thu, 08 Oct 2020 14:57:13 GMT

@Patchyhas something that is probably easier for you to use since you don't know how to use lisp code, and you didn't elaborated how you want your intersection list to be represented.

Re: Find Intersection point automatically

Anonymous — Thu, 08 Oct 2020 15:01:45 GMT

Sir, I successfully load the app. After that I cannot do what it wants. It is asking for base objects.

Re: Find Intersection point automatically

Anonymous — Thu, 08 Oct 2020 15:04:17 GMT

Yes sir. @Patchy sir's solution is enough for my work. I need this type of output. I would like to request @Patchy sir, how he do it?