[vtkusers] Extent Problem

rywchiu rywchiu at interchange.ubc.ca
Thu Jun 9 17:08:01 EDT 2005

Hi Tom,

Thanks for your quick reply! But I am actually using 4 separate renderers (all within one window, and thus sharing one interactor). Sorry about the confusion, perhaps I should have been more concise in my email. 

Here is my problem in more detail: 
When I change the the size or move the planes on my widget, I can see the corresponding images change in the other renderers. When simply moving the planes, I don't run into any problems. It's only when expanding/shrinking the plane that causes errors. When I expand the plane on the widget, the size of its corresponding image does not change, but instead it sort of shifts around in its renderer, displaying only the portion of the image in its original extent.  If I shrink the image, I receive the following errors:

"ERROR: In \Vtk\Common\vtkDataObject.cxx, line 524
vtkImageData (09C98AE8): Update extent does not lie within whole extent

ERROR: In \Vtk\Common\vtkDataObject.cxx, line 531
vtkImageData (09C98AE8): Update extent is: 0, 127, 0, 31, 0, 0

ERROR: In \Vtk\Common\vtkDataObject.cxx, line 538
vtkImageData (09C98AE8): Whole extent is: 0, 127, 0, 15, 0, 0

Is this an extent-related issue? Or would it still be the camera? Any suggestions?

Thanks for your input!

-----Original Message-----

> Date: Thu Jun 09 13:38:55 PDT 2005
> From: "tom fogal" <tfogal at apollo.sr.unh.edu>
> Subject: Re: [vtkusers] Extent Problem
> To: 
>  <16950896.1118347166371.JavaMail.myubc2 at portal9.itservices.ubc.ca>rywchiu writes:
> >Hi,
> >
> >I've implemented an ImagePlaneWidget in one window, and am trying to display the 3 planes of the widget in 3 other separate windows. When I change the size of the planes in the wid
> >get (e.g. zoom in/out), it does not correctly update size of the corresponding image in the other window.  I've looked at some suggestions from the mailing list, but I'm still gett
> >ing the problem. 
> <snip>
> i'm not sure on the specifics, but i imagine zooming / rotating / etc
> only modifies the /camera/ of that particular interactor. therefore the
> other windows (which, presumably, use different interactors) would have
> no way of knowing that you zoomed / did some other operation (as the
> data are not modified, only the camera for that particular window).
> in short, i dont think zooming will modify the 'Extent' of your data;
> if they fall outside the viewing area they would probably be clipped at
> the mapping stage, i think.
> if you want a zoom in one window to change the viewpoint in another,
> you can hook up some controls to that windows' input method[s] and in
> those control methods you can propagate the appropriate calls to other
> windows. i have never done this, but have heard about it being done
> many times on the mailing list so I imagine it shouldnt be too hard to
> figure out.
> HTH,
> -tom

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