Cycle UCS and rotate view accordingly

[lecheconagujas]

Hi everyone.

I was wondering if there's a way to alphabetically cycle through named (user defined) UCSs, automatically doing PLAN -> Current UCS for each cycle (maybe even better if there's some alternative to PLAN that keeps the current zoom level instead of doing zoom extents)

[_gile]

Hi,

I'm not sure this reply to your request but you could use the _DVIEW command with the _Twist option.

Here's an example which rotates the current view of 45° (pi / 4 radians).

(defun c:twistview (/ a)
  (setq	a (angtos
	    (+ (getvar 'viewtwist) (* pi 0.25))
	    (getvar 'aunits)
	    16
	  )
  )
  (command-s "_.dview" "" "_twist" a "")
  (princ)
)

[marko_ribar]

I know this is probably what you already know, but still...

Have you tried UCSFOLLOW=1 ?

And I believe that it will automatically zoom Extents, which is what you wanted to avoid...

[lecheconagujas]

I didn't know about this so thank you. It certainly helps in dropping the step of using PLAN so it solves part of the problem, even though it does have the problem of zooming extents which I guess is unavoidable (but that's secondary anyways). My main concern here is having a fast way to cycle through each of my named UCSs in a dwg file so that I can avoid either selecting them from the dropdown (it seems the only way to have a dropdown is having the ViewCube on, which I prefer off when working in 2D) or via regular UCS command which requires too many key presses

[lecheconagujas]

Hi, thanks for the reply. I did consider _Twist but it poses a few inconvenients. I need to switch between UCS so that my ortho axes will change too. Also, I don't want to twist the view in fixed increments, I need these views to be user defined so that I can easily cycle through them, adding/deleting as I deem convenient. Maybe there's a way to twist the view according to the current UCS?

This would solve the problem of the zoom level changing every time I switch UCS and adjust the view accordingly

[_gile]

Maybe you could start from this:

(defun c:ucscycle (/ ucs lst rot)
  (while (setq ucs (tblnext "UCS" (null ucs)))
    (setq lst (cons (cdr (assoc 2 ucs)) lst))
  )
  (setq lst (reverse lst))
  (if (setq ucs (cadr (member (getvar 'ucsname) lst)))
    (command "_ucs" "_restore" ucs)
    (command "_ucs" "_restore" (car lst))
  )
  (setq	rot (angtos
	    (angle '(0 0) (trans '(1 0) 0 1 T))
	    (getvar 'aunits)
	    16
	  )
  )
  (command-s "_.dview" "" "_twist" rot "")
  (princ)
)

[_gile]

If you need to integrate WCS in the cycle:

(defun c:ucscycle (/ ucs lst)
  (while (setq ucs (tblnext "UCS" (null ucs)))
    (setq lst (cons (cdr (assoc 2 ucs)) lst))
  )
  (setq	lst (reverse lst)
	ucs (getvar 'ucsname)
  )
  (cond
    ((null (member ucs lst))
     (command-s "_.ucs" "_restore" (car lst))
    )
    ((null (setq ucs (cadr (member ucs lst))))
     (command-s "_.ucs" "_world")
    )
    (T (command-s "_.ucs" "_restore" ucs))
  )
  (command-s "_.dview"
	     ""
	     "_twist"
	     (angtos
	       (angle '(0 0) (trans '(1 0) 0 1 T))
	       (getvar 'aunits)
	       16
	     )
	     ""
  )
  (princ)
)

[lecheconagujas]

This works like a charm! Excuse me if I'm asking for too much but I'm a complete ignorant on autolisp, is there a way to have this work in both ways? That is, having UCSNEXT and UCSPREV

[_gile · Accepted solution]

Here're two commands UCSFWD and UCSBWD to cycle UCSs forward or backword.

(defun c:ucsfwd () (ucscycle T))

(defun c:ucsbwd () (ucscycle nil))

(defun ucscycle	(fwd / ucs lst)
  (while (setq ucs (tblnext "UCS" (null ucs)))
    (setq lst (cons (cdr (assoc 2 ucs)) lst))
  )
  (if fwd
    (setq lst (reverse lst))
  )
  (setq ucs (getvar 'ucsname))
  (cond
    ((null (member ucs lst))
     (command-s "_.ucs" "_restore" (car lst))
    )
    ((null (setq ucs (cadr (member ucs lst))))
     (command-s "_.ucs" "_world")
    )
    (T (command-s "_.ucs" "_restore" ucs))
  )
  (command-s "_.dview"
	     ""
	     "_twist"
	     (angtos
	       (angle '(0 0) (trans '(1 0) 0 1 T))
	       (getvar 'aunits)
	       16
	     )
	     ""
  )
  (princ)
)

[_gile · Accepted solution]

This one allows to choose the UCS in a little dialog.

(defun c:ucstwist (/ listbox lst ucs)
  
  (defun listbox (title keys / tmp file dcl_id choice)
  (setq	tmp  (vl-filename-mktemp "tmp.dcl")
	file (open tmp "w")
  )
  (write-line
    (strcat "ListBox:dialog{label=\"" title "\";")
    file
  )
  (write-line "spacer;:list_box{key=\"lst\";}spacer;ok_only;}" file)
  (close file)
  (setq dcl_id (load_dialog tmp))
  (if (not (new_dialog "ListBox" dcl_id))
    (exit)
  )
  (start_list "lst")
  (mapcar 'add_list keys)
  (end_list)
  (action_tile "lst" "(setq choice (nth (atoi $value) keys)) (done_dialog)")
  (start_dialog)
  (unload_dialog dcl_id)
  (vl-file-delete tmp)
  choice
)
  
  (while (setq ucs (tblnext "UCS" (null ucs)))
    (setq lst (cons (cdr (assoc 2 ucs)) lst))
  )
  (setq lst (cons "World" (cons "Previous" (reverse lst))))
  (if (setq ucs (listbox "UCS Twist" lst))
    (progn
      (cond
	((= ucs "World") (command-s "_.ucs" "_world"))
	((= ucs "Previous") (command-s "_.ucs" "_previous"))
	(T (command-s "_.ucs" "_restore" ucs))
      )
      (command-s "_.dview"
		 ""
		 "_twist"
		 (angtos
		   (angle '(0 0) (trans '(1 0) 0 1 T))
		   (getvar 'aunits)
		   16
		 )
		 ""
      )
    )
  )
  (princ)
)

[lecheconagujas]

Both of these are awesome. The one with the dialog box is more than I would have dared to ask for! Thanks a lot.