[Paraview] Need help with UpdateExtents and RequestedExtents

[Mike Jackson]

On Mon, Jul 6, 2009 at 8:18 AM, Mike Jackson<mike.jackson at bluequartz.net> wrote:
> Awesome. That did the trick. Just a few outstanding issues left and
> this plugin will be nicely updated. Again, thanks for the info.
>
> Mike Jackson
>
> On Sun, Jul 5, 2009 at 8:08 PM, Burlen<burlen.loring at gmail.com> wrote:
>>
>>>  How do I tell the pipeline that the user is requesting a smaller
>>> sub-volume? Are there some special variables I can use? or something
>>> along those lines?
>>
>> Set WHOLE_EXTENT to your desired subset during in RequestInformation. Honor
>> UPDATE_EXTENT in your RequestData pass. It will all work out.
>>
>> RequestInformation runs every time after user clicks apply in ParaView so
>> what ever values they choose will be passed into the pipeline each time.
>>
>>
>> Mike Jackson wrote:
>>>
>>> I am trying to update a previous ParaView plugin and I am running into
>>> some trouble with the UpdateExtents and RequestedExtents. My problem
>>> is that when my plugin runs the RequestInformation iI read from the
>>> file to extract the origin, spacing and extent information. I then set
>>> them into the pipeline as such:
>>>
>>> outInfo->Set( vtkDataObject::ORIGIN(), origin, 3 );
>>> outInfo->Set( vtkDataObject::SPACING(), this->CurrentScalingFactor, 3 );
>>> outInfo->Set( vtkStreamingDemandDrivenPipeline::WHOLE_EXTENT(),
>>> this->PixelActual, 6 );
>>>
>>> That all seems to work fine. My plugin loads up a custom gui to allow
>>> the user to select a sub-volume to actually render as the volume is
>>> quite large and can not be rendered in 32 bit clients or even some 64
>>> bit clients for that matter.
>>>
>>> So I have the Custom plugin GUI talking to my custom reader so that
>>> values entered into the GUI are available during the RequestData()
>>> method of my reader class. Now here is the fun:
>>>
>>>  This code:
>>>
>>> vtkInformation* outInfo = outputVector->GetInformationObject(0);
>>> vtkImageData* output =
>>> vtkImageData::SafeDownCast(outInfo->Get(vtkDataObject::DATA_OBJECT()));
>>> vtkTypeInt32 updateExtent[6];
>>> if (outInfo->Has(vtkStreamingDemandDrivenPipeline::UPDATE_EXTENT()))
>>> {
>>> // Get the requested data extent.
>>> updateExtent[0] =
>>> (outInfo->Get(vtkStreamingDemandDrivenPipeline::UPDATE_EXTENT()))[0];
>>> updateExtent[1] =
>>> (outInfo->Get(vtkStreamingDemandDrivenPipeline::UPDATE_EXTENT()))[1];
>>> updateExtent[2] =
>>> (outInfo->Get(vtkStreamingDemandDrivenPipeline::UPDATE_EXTENT()))[2];
>>> updateExtent[3] =
>>> (outInfo->Get(vtkStreamingDemandDrivenPipeline::UPDATE_EXTENT()))[3];
>>> updateExtent[4] =
>>> (outInfo->Get(vtkStreamingDemandDrivenPipeline::UPDATE_EXTENT()))[4];
>>> updateExtent[5] =
>>> (outInfo->Get(vtkStreamingDemandDrivenPipeline::UPDATE_EXTENT()))[5];
>>> }
>>>
>>> will always return the entire volume space which I guess I can
>>> understand as that is what I put into those values during the
>>> RequestInformation. I was merrily just using the values that get
>>> pushed into my class via the custom GUI text fields. These values will
>>> differ from the UPDATE_EXTENT. I setup the output with the smaller
>>> extents and now my "RequestData()" is executed at least twice. I have
>>> seen this before and have no idea what I do to solve it.'
>>>
>>>  How do I tell the pipeline that the user is requesting a smaller
>>> sub-volume? Are there some special variables I can use? or something
>>> along those lines?
>>>
>>>
>>>   Also during the copying of the data from the file into the
>>> vtkImageData object I get any number of errors:
>>>
>>> Warning: In /Users/Shared/OpenSource/vtk-5.4.2/Filtering/vtkDataSet.cxx,
>>> line 414
>>> vtkImageData (0x353d380): Point array RoboMet Voxels with 1
>>> components, has 0 tuples but there are only -208926896 points
>>>
>>> Here are some stats about what I am trying to produce:
>>>
>>> MicronVOI: 46979.1 47526.7 48347.6 49080.1 492 495.2
>>> MicronActual: 46979.1 48525.1 48347.6 50078.9 490 510
>>> Requested Extent: 0 7440 0 8330 490 510
>>> PixelActual: 0 7440 0 8330 490 510
>>> PixelVOI: 0 2631 0 3520 0 3
>>> dims: 2632 3521 4
>>>
>>> All that seems correct and the data seems to copy from the file into
>>> the array but then I get the error above and ParaView will just crash.
>>>
>>> This is all with PV CVS, OS X intel 10.5.7, Xcode 3.1.3 tooling, cmake
>>> 2.6.4 and GCC 4.2 compiler.
>>>
>>>
>>> Any help is appreciated.
>>> Mike Jackson
>>> BlueQuartz Software  | www.bluequartz.net
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>>
>>
>