[vtkusers] vtkImageReslice zoomed performance - no clipping?

[Henning Meyer]

Hi David,

thank you for your explanation.
I still can't help but get the impression something is odd there.
When I call
m_reslice->SetOutputExtent(0,100,0,100,0,0);
I get a nice square clipped area, which seems to be scaled up in my QVTKWidget.

And when I start to use
m_reslice->SetResliceAxes(myTransform);
this clipped area will move inside (even outside) my QVTKWidget.

So - what is going on here? Can I help to solve this issue?

Henning

Btw: When I never call SetOutputExtent, I get an OutputExtent of:
-2147483648 ,2147483647 ,-2147483648 ,2147483647 ,-2147483648 ,2147483647


2010/6/24 David Gobbi <david.gobbi at gmail.com>:
> Hi Henning,
>
> The vtkImageReslice filter will clip the image if you call
> SetOutputExtent(), or if you don't set the OutputExtent, then clipping
> is done according the UpdateExtent set by the pipeline.  So those are
> the only ways to change the clipping: either set it manually with
> SetOutputExtent, or fiddle with the downstream filters to change the
> UpdateExtent.
>
> I've wanted to write an easier-to-use alternative to vtkImageReslice
> for a very long time (there really isn't any way to make
> vtkImageReslice "smarter" without breaking backwards compatibility in
> one way or another).
>
>   David
>
>
> On Thu, Jun 24, 2010 at 9:13 AM, Henning Meyer <tutmann at gmail.com> wrote:
>> Hi!
>>
>> When using vtkImageReslice, I get very low performance, once I zoom
>> into an image. It seems, that vtkImageReslice is rendering a huge
>> virtual image, and is clipping after that, is that true? Could it be
>> changed to be clipped before? Also I found, the clipping is not always
>> correct, as sometimes with certain transforms the output image gets
>> clipped inside the render window.
>> Is there anything I could do here?
>>
>> Thank you,
>>
>> Henning
>> _______________________________________________
>> Powered by www.kitware.com
>>
>> Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html
>>
>> Please keep messages on-topic and check the VTK FAQ at: http://www.vtk.org/Wiki/VTK_FAQ
>>
>> Follow this link to subscribe/unsubscribe:
>> http://www.vtk.org/mailman/listinfo/vtkusers
>>
>