fix north arrow

[htls69]

i need help making my north arrow rotate with the viewport if anyone can help me that would be awesome

[jmartt · Accepted solution]

I've made a button that uses this LISP file.

I didn't write this. It was probably Sam Lucido.

(defun c:rn()
  (setq tw(entget(car(entsel" Select a Viewport:"))))
  (setq new (cdr (assoc 0 tw)))
(cond
                ((= new "VIEWPORT")(setq rt(cdr(assoc 51 tw))))
((= new "LWPOLYLINE")(setq temp (entget(cdr (assoc 330 tw))))(setq rt(cdr(assoc 51 temp))))
             )
  (setq en(car(entsel" Select North Arrow: ")))
  (setq elist(entget en))
  (setq elist(subst (cons 50 rt)(assoc 50 elist) elist))
  (entmod elist)
  (princ)
)

[augusto.goncalves]

Can you provide more details on your request? It seems that you have a custom arrow (not a built in), am I right?

[htls69]

yes I have a custom arrow that I brought in to one of the existing arrows so that I could adjust it and change it but now it will not rotate with the viewport so I was hoping that somebody might be able to make it rotate with the association to the viewport

[augusto.goncalves]

To keep an AutoCAD entity from rotating with the view, you'll need to override (in C++) or overrule (in .NET) the ViewportDraw behavior to maintain the entity position regarding the view direction.

There is a basic implementation for this in C++ at http://adndevblog.typepad.com/autocad/2012/06/how-to-control-an-entity-viewportdraw-so-that-it-alway...

Is that the direction that you need?

[htls69]

I just want it to work like the built in ones but with my north arrow

[htls69]

Like one in the custom north arrows in the layout elements

[augusto.goncalves]

The built-in AutoCAD arrow is not on the drawing, but a different type of image...

If you need yours on the drawing, then you need to manipulate it, at least that's my understanding...

[htls69]

yes i know i was trying to just edit one of the stock north arrows to make it work just like one of the built it arrows and could not get the block to associate the new north arrow that i put in the block to work like the built in one

[redtransitconsultants]

I have modified the stock north arrows before and I will tell you they are setup with dynamic blocks and must contain the exact same parameters set in the stock ones with the exact same names. Open a stock one and get into the block editor on it to view the dynamic parameters. It can be done...