Topic: viewdir vs Direction property

[gile]

Is this a bug or am I doing something wrong ?

The two following expressions should return the same result, but when changing the view (using 3dorbit or a predefined view), it looks like the direction property doesn't update.

 

Code: [Select]

(mapcar '-
(trans (getvar "viewdir") 1 0)
(trans '(0 0 0) 1 0)
)

 

Code: [Select]

(vlax-get (vla-get-ActiveViewport
    (vla-get-ActiveDocument
      (vlax-get-acad-object)
    )
  )
  'Direction
)

[LE]

No idea if it is a bug or not, and you are right the call with vlisp function, won't provide the current viewdir as it does with the viewdir sysvar.

You can do a save and call your vlisp code and will see that it will return the same value or

Code: [Select]

(defun array-vbDouble  (vla-lst)
  (vlax-safeArray-fill
    (vlax-make-safeArray
      vlax-vbDouble
      (cons 0 (1- (length vla-lst))))
    vla-lst))

(vla-put-direction (vla-get-ActiveViewport
    (vla-get-ActiveDocument
      (vlax-get-acad-object)
    )
  ) (array-vbDouble (getvar "viewdir")))

Using the above will give you the same results next time you use:

Code: [Select]

(vlax-get (vla-get-ActiveViewport
    (vla-get-ActiveDocument
      (vlax-get-acad-object)
    )
  )
  'Direction
)


HTH

[Bryco]

I found in vba I could also delete the ActiveViewport
then get an updated viewpot, although it sounds wierd it is quicker than forcing a save on a large drawing.
Perhaps it will work in vla to.
ThisDrawing.ActiveViewport.Delete
Set vp = ThisDrawing.ActiveViewport

[gile]

Thanks for your replies.

The way given by Bryco seems to work fine. Doing :

Code: [Select]

(setq doc (vla-get-ActiveDocument
      (vlax-get-acad-object)
    )
  )
  (vla-delete (vla-get-ActiveViewport doc))
  (vlax-get (vla-get-ActiveViewport doc) 'Direction)
returns the right result.

However, I think it's quite obvious to have to delete the active viewport to update its Direction.

[ElpanovEvgeniy]

In addition, look my work with "viewdir" using entmod...

http://www.theswamp.org/index.php?topic=12382.msg153796#msg153796

[gile]

I found a more simple and faster way to get the 'viewdir' vector in WCS, using the trans function :

Code: [Select]

(trans '(0 0 1) 2 0 T)