[Paraview] Image filters & extent

[Bryn Lloyd]

The same thing happens with the vtkImageConstantPad filter.

I wrote a GUI and ServerManager xml file and added the plugin to  
paraview. The output outline is shown correctly, but the extent and  
dimensions displayed in the Information tab are incorrect -> they are  
are the same as for the input image, even though I set a larger output  
extent in the vtkImageConstantPad filter.

Additionally, the data array looses it's name (I think this happens  
with all image filters, which is not compatible with paraview as far  
as I can tell).

Has any body got a solution or any advice? Thanks!


--Bryn








On Mar 9, 2009, at 12:36 PM, Bryn Lloyd wrote:

> Another problem I get with the "partial solution" of setting the  
> update extent in the output, is that the update extent is sent  
> through the pipeline to the input. But it is too big for the input:
>
> ERROR: In /Users/brynlloyd/pack/ParaView-CVS/VTK/Filtering/ 
> vtkStreamingDemandDrivenPipeline.cxx, line 818
> vtkCompositeDataPipeline (0x2183b5b0): The update extent specified  
> in the information for output port 0 on algorithm  
> vtkImageDataSource(0x2183b670) is 0 11 0 11 0 11, which is outside  
> the whole extent 0 9 0 9 0 9.
>
>
>
> On Mar 9, 2009, at 12:27 PM, Bryn Lloyd wrote:
>
>> Hi,
>>
>> I have been having trouble with writing image filter plugins. If  
>> the extent of the output image is larger than the input image  
>> extent, I get all sorts of problems.
>>
>> I have tried using various parent classes, including  
>> vtkImageAlgorithm. Currently I am using vtkDataSetAlgorithm (I  
>> thought it would not try to be as "clever" as the  
>> vtkImageAlgorithm, but it seems to be the same thing).
>>
>>
>> 1. The full extent is not visualized:
>> by setting the the extent of the output in RequestData I managed to  
>> get the visualization right:
>>
>> outInfo->Set( vtkStreamingDemandDrivenPipeline::WHOLE_EXTENT(),  
>> DataExtent, 6 );
>> outInfo->Set( vtkStreamingDemandDrivenPipeline::UPDATE_EXTENT(),  
>> DataExtent, 6 );
>>
>>
>> 2. Unfortunately, even with the addition above, the information  
>> (extent, dimensions etc.) are not shown correctly in the  
>> "Information tab" in paraview. Strangely enough, if I change a  
>> parameter of the filter and call Apply a second time, the values in  
>> the information tab are suddenly correct.
>>
>>
>> What I want is really a simple way to generate an output image with  
>> different size/extent than the input image, without having all this  
>> trouble setting pipeline information. Is there a way?
>>
>> Thanks
>> Bryn
>>
>>
>>
>>
>>