[vtkusers] Re : User Interaction with MultiBlocDataSet with unstructured Grid

[R M]

Hello,

I have see that when using vtkCompositeDataGeometryFilter on the 
multiBlockDataSet of UnstructuredGrid, the return vtkPolyData contains twice the 
same points array.

I mean, When creating my tetra that I set in the 2 unstructtured grid, they 
share the same points array:
points array  [ (0,0,0), (1,2,3), (-1,-2,-4) ]

And when the CompositeDataGeometryFilter is executed, I get the points of the 
generated vtkPolyData and I have this:
points array:[ (0,0,0), (1,2,3), (-1,-2,-4), (0,0,0), (1,2,3), (-1,-2,-4)]

How can I do to only have the original points array in the generated polydata: [ 
(0,0,0), (1,2,3), (-1,-2,-4) ] ? Like this, I could move a point belonging to 
two different cells that are in two different blocks.

I have tried on the CompositeDataGeometryFilter but no change:
    info->Set(vtkAlgorithm::PRESERVES_DATASET(), 1);
    info->Set(vtkAlgorithm::PRESERVES_GEOMETRY(), 1);
    info->Set(vtkAlgorithm::PRESERVES_BOUNDS(), 1);
    info->Set(vtkAlgorithm::PRESERVES_TOPOLOGY(), 1);
    info->Set(vtkAlgorithm::PRESERVES_ATTRIBUTES(), 1);
    info->Set(vtkAlgorithm::PRESERVES_RANGES(), 1);


Any idea would be welcome.

Thank you.



________________________________
De : R M <mlokida at yahoo.fr>
À : vtkusers at vtk.org
Envoyé le : Jeu 11 août 2011, 19h 34min 48s
Objet : [vtkusers] User Interaction with MultiBlocDataSet with unstructured Grid


Hi,

I have a MultiBlockDataSet composed of severals unstructuredGrid (tetra, 
hexa,...). All The cells share the same points array and I have some blocks 
'cells of the data set that share the same points.
The idea is to move a point belonging to a cell of block 1 and to acell of block 
2. Like this, because points array is share.

But, to render the  multiblockdataset, I use a vtkCompositeDataGeometryFilter 
that give me a vtkPolyData.

Then I use  the http://www.vtk.org/Wiki/VTK/Examples/Cxx/Interaction/MoveAVertex 
example to select and move points.

The problem is that the points  have been duplicated and are now independant (no 
more use of the global points array). 


So, is there a way to preserve the points array information in order to well 
move points and preserve the topology ?

Thank you.
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