Allow vtkStructuredGridBase as input for the vtkUnstructuredGridWriter
requested to merge mennodeij1/vtk:use_vtkUnstructuredGridBase_in_vtkUnstructuredGridWriter into master
The vtkUnstructuredGridWriter is used in marshaling objects across MPI processes and needs to work with vtkMappedUnstructuredGrid in Catalyst scenarios. Therefore the writer has been adapted to allow the use of vtkUnstructuredGridBase input instead of the more specialized vtkUnstructuredGrid input.
In addition, vtkDataWriter has been adapted to only perform static_cast and ->GetPointer(0) on data arrays that are compatible. When using vtkMappedDataArray in Catalyst use case, invoking GetPointer(0) would result in a segfault.
Currently, this is working for our Catalyst adapter to send pieces of grid across process boundaries using the appropriate calls to vtkMultiProcessController.