VTK/VTK 6 Migration/Removal of Update

Removal of Pipeline Update Methods from vtkDataObject

VTK 6 introduces a number of backwards-incompatible changes. The reasons behind these changes are described in more detail here. One of these changes is the removal of all pipeline related methods from vtkDataObject. Here we discuss the following update methods and provide suggestions in updating existing code.

Update()

vtkDataObject::Update() was a convenience method that in turn called Update() on the algorithm that produced the given data object. Since the data object no longer has a reference to its producer, this function could not be maintained and was removed.

Example 1

<source lang="cpp"> vtkDataObject* dobj = someAlgorithm->GetOutput(); dobj->Update(); </source>

should become

<source lang="cpp"> someAlgorithm->Update(); </source>

Example 2

Replace:

<source lang="cpp"> vtkDataObject* dobj = aFilter->GetOutput(1); dobj->Update(); </source>

with:

<source lang="cpp"> aFilter->Update(1); </source>

UpdateInformation()

vtkDataObject::UpdateInformation() was a convenience method that in turn called UpdateInformation() on the algorithm that produced the given data object. Since the data object no longer has a reference to its producer, this function could not be maintained and was removed.

Example 1

Replace

<source lang="cpp"> vtkDataObject* dobj = aFilter->GetOutput(); dobj->UpdateInformation(); dobj->SetUpdateExtent(0 /*piece*/, 2 /*number of pieces*/); dobj->Update(); </source>

with

<source lang="cpp"> aFilter->UpdateInformation(); vtkStreamingDemandDrivenPipeline::SetUpdateExtent(

       aFilter->GetOutputInformation(0 /*port number*/),
       0 /*piece*/,
       2 /*number of pieces*/,
       0 /*number of ghost levels*/);

aFilter->Update(); </source>

PropagateUpdateExtent()

vtkDataObject::UpdateInformation() was a convenience method that in turn called UpdateInformation() on the executive of the algorithm that produced the given data object. Since the data object no longer has a reference to its producer, this function could not be maintained and was removed.

Example 1

Replace

<source lang="cpp"> vtkDataObject* dobj = aFilter->GetOutput(); dobj->UpdateInformation(); dobj->SetUpdateExtent(0 /*piece*/, 2 /*number of pieces*/); dobj->PropagateUpdateExtent(); </source>

with

<source lang="cpp"> aFilter->UpdateInformation(); aFilter->SetUpdateExtent(0 /*piece*/, 2 /*number of pieces*/, 0 /*ghost levels*/); aFilter->PropagateUpdateExtent (); </source>

TriggerAsynchronousUpdate()

This method was no longer being used and therefore was removed from VTK as of VTK 6.

UpdateData()

vtkDataObject::Update() was a convenience method that in turn called UpdateData() on the executive of the algorithm that produced the given data object. Since the data object no longer has a reference to its producer, this function could not be maintained and was removed.

Example 1

Replace

<source lang="cpp"> vtkDataObject* dobj = aFilter->GetOutput(); dobj->UpdateInformation(); dobj->SetUpdateExtent(0 /*piece*/, 2 /*number of pieces*/); dobj->PropagateUpdateExtent(); dobj->UpdateData(); </source> with

<source lang="cpp"> aFilter->UpdateInformation(); vtkStreamingDemandDrivenPipeline::SetUpdateExtent(

       aFilter->GetOutputInformation(0 /*port number*/),
       0 /*piece*/,
       2 /*number of pieces*/,
       0 /*number of ghost levels*/);

aFilter->Update(); </source>