[vtkusers] How to transfer data through vtkInformation

[Mathieu Westphal]

Hello

I have implemented my own data reader, which inherit vtkPolyDataAlgotihm.

This reader need parameter to read data

The vtkPolyDataMapper, connected to the reader output port, know which 
mode he have to use, so i would like to create/modify a vtkInformation 
in the vtkPolyDataMapper with a key named "myKeys" of length 3.

And then in the reader, read this key and make the appropriate read.

But anyway i tried, i've never found my keys in the information i get in 
the reader.

in Reader :

int vtkHDF5Reader::RequestData(vtkInformation* info2,
                                        vtkInformationVector**,
                                        vtkInformationVector* outputVector)
{
   vtkInformation* info = outputVector->GetInformationObject(0);
   info->PrintKeys(std::cout,vtkIndent(0));
   return 1;
}

in main :

  // Create a point cloud
   vtkSmartPointer<Reader> pointSource =
     vtkSmartPointer<Reader>::New();


   vtkSmartPointer<vtkPolyDataMapper> pointsMapper =
     vtkSmartPointer<vtkPolyDataMapper>::New();
   pointsMapper->SetInputConnection(pointSource->GetOutputPort());

  // access the info (presently none stored)
   vtkInformation* info = pointsMapper->GetInputPortInformation(0);

   // add one attribute, a double vector
   const char *name = "myKey";
   const char *location = "MyClass"; //
   const int length = 3;
   vtkInformationDoubleVectorKey *key = new 
vtkInformationDoubleVectorKey(name,
                                                                          location,
                                                                          length);


     double values[] = {0.1, 0.2, 0.3};
     info->Set(key, values[0], values[1],values[2]);
     info->PrintKeys(std::cout,vtkIndent(0));
     pointSource->Update();


And the output i get :

PORT_REQUIREMENTS_FILLED: 1
INPUT_REQUIRED_DATA_TYPE: vtkPolyData
myKey: 0.1 0.2 0.3


PRODUCER: vtkStreamingDemandDrivenPipeline(0x9092e0) port 0
UPDATE_NUMBER_OF_PIECES: 1
MAXIMUM_NUMBER_OF_PIECES: 1
DATA_OBJECT: vtkPolyData(0x90e1e0)
CONSUMERS: vtkStreamingDemandDrivenPipeline(0x90c790) port 0
UPDATE_NUMBER_OF_GHOST_LEVELS: 0
UPDATE_PIECE_NUMBER: 0
UPDATE_EXTENT_INITIALIZED: 0


So the keys have nothin in common, i guess i dont modify or read the 
right information.

Could someone help me?

Mathieu