[vtkusers] ImageViewer2 extent problem

[David Borland]

Sebastien, thanks for your help.  I've been using release 4.4, but I 
tried switching to the latest nightly build so I could incorporate your 
change.  However, this led to some issues with a couple of other 
libraries I'm using that are based on 4.4, so I'm stuck with that for now. 

Unfortunately, this also means that I cannot take advantage of the 
SetSliceOrientation functionality.  I want to view 3 orthogonal slices 
of my data.  What is the best way to go about doing this?  I tried using 
vtkImagePermute, but am getting errors in vtkopenglimageactor when I try 
this

Perhaps I should just replicate the code that does the image slicing 
from the newest version of vtkImageViewer2?  Any help would be 
appreciated.  Thanks,

David

Sebastien BARRE wrote:

> At 9/9/2005 05:06 PM, David Borland wrote:
>
>> Thanks.  That did the trick.  Need to make sure UpdateInformaton is 
>> called on the input image also.
>>
>> David
>>
>> Mark Wyszomierski wrote:
>>
>>> I had this problem too, vtkImageViewer2 is just a wrapper around a 
>>> few classes that put it all together, the one you need to alter is 
>>> the underlying image actor object. So get it, call 
>>> SetDisplayExtent() with the new image dimensions on the image actor, 
>>> and reset your camera. This worked for me. Goodluck,
>>>
>>> Mark
>>
>
> David, Mark
>
> Thanks for the feedback. As Mark stated, vtkImageViewer2 is a wrapper 
> around a few classes. Calling SetDisplayExtent can do the trick, but 
> you have to be careful about it, since you have to set the display 
> extent correctly depending on the Slice and SliceOrientation 
> parameters of the viewer (I added SliceOrientation recently). This is 
> done automatically for you (as well as resetting the camera) each time 
> you change the Input of the viewer, but of course, most of the time 
> the input of this class is likely to remain the same, i.e. connected 
> to the output of a filter, or an image reader. When the input of this 
> filter is changed, an error message is displayed since the current 
> display extent is probably outside the new whole extent. That's what 
> you saw David.
>
> To make your life easier, I moved the UpdateDisplayExtent method from 
> the protected to the public section of the class. Everytime you change 
> the input of a filter upstream in the pipeline, you can simply call 
> this method, which will set the display extent properly and try to set 
> a reasonable camera clipping range (you may still have to call 
> ResetCamera on the Renderer to center the image afterwards, since 
> there was probably no reason to force it in UpdateDisplayExtent).
>