[vtk-developers] Understanding vtkMultiGroupDataGroupFilter

[Bill McGrory]

Trying to get new pipeline set up for a multiblock dataset.
Following the suggestions of Berk, from previous thread, I'm now using a
vtkStructuredGridAlgorithm as a source to create a vtkStructuredGrid


I'm feeding the output ports of the algorithm into a
vtkMultiGroupDataGroupFilter in order to create a vtkMultiGroupData
which contains only vtkStructuredGrid's

my pipeline is below.

The problem as this is implemented is this:

When vtkCompositeDataPipeline::ExecuteDataObjectForBlock is called,
vtkMultiGroupDataGroupFilter::ExecuteData has yet to be called.
However, that is where the vtkMultiGroupDataSet has the children loaded.
This means that there are no datasets in the multigroupdataset, so the
request for a block data object fails, and a simple polydata object is
passed down the pipeline. At this point, the vtkStructuredGridOutline
filter fails, because, it does a check to make sure the input port is
correctly set to vtkStructuredGrid, and it's set to the dummy
vtkPolyData.

Is this a bug, or am I still trying to do something that's not
supported?

Regards, Bill



MyStructuredGridAlgorithm *sgridsrc0 = MyStructuredGridAlgorithm::New();
MyStructuredGridAlgorithm *sgridsrc1 = MyStructuredGridAlgorithm::New();
  
sgridsrc0->myoffset = 0.;
sgridsrc1->myoffset = 3.;

vtkMultiGroupDataGroupFilter *mbFilter =
vtkMultiGroupDataGroupFilter::New();

mbFilter->SetInputConnection(0,sgridsrc0->GetOutputPort(0));
mbFilter->AddInputConnection(0,sgridsrc1->GetOutputPort(0)); 

vtkStructuredGridOutlineFilter *outlineFilter =
vtkStructuredGridOutlineFilter::New();

outlineFilter->SetInputConnection(0, mbFilter->GetOutputPort(0));

vtkMultiGroupDataGeometryFilter *mgdgFilter =
vtkMultiGroupDataGeometryFilter::New();
mgdgFilter->SetInputConnection(0, outlineFilter->GetOutputPort(0));

vtkPolyDataMapper* mapper = vtkPolyDataMapper::New();
mapper->SetInputConnection(0, mgdgFilter->GetOutputPort(0));



-- 
Dr. William D. McGrory    AeroSoft, Inc.
mcgrory at aerosft.com       Suite 1275
(540) 557-1904            1872 Pratt Drive
(540) 557-1919 (FAX)      Blacksburg, VA 24060