<div>Hi, </div><div><br></div><div>Hope you can help. I have some code running in parallel, that by other means I have constructed nprocs worth of vtkRectilinearGrids, one per process. Each of which is a valid nprocs-worth of the whole serial mesh, I've check this and I am happy with that i.e. it's partitioned properly and nothing is missing. I need the following information to process my data in parallel:</div>
<div><br></div><div>1) I would like the local -> global cell mapping between the local rgrid and the corresponding global single mesh.</div><div>2) I would like to know which cells are on processor boundaries for parallel exchange purposes.</div>
<div>3) I would like all the double arrays per processor to be "expanded" by the amount of (1 level of) ghost cells such that I can properly do the computations I want with the ability to exchange only those additional cells given the local to global mapping.</div>
<div><br></div><div>I have tried from the examples to use the following code, which I call on every process, each of which has it's own local rgrid as I said. I do the following:</div><div><br></div><div><span class="Apple-tab-span" style="white-space:pre"> </span> vtkSmartPointer<vtkDistributedDataFilter> dd = vtkSmartPointer<vtkDistributedDataFilter>::New();</div>
<div><span class="Apple-tab-span" style="white-space:pre"> </span></div><div><span class="Apple-tab-span" style="white-space:pre"> </span> dd->SetInput(rgrid);</div><div><span class="Apple-tab-span" style="white-space:pre"> </span> </div>
<div><span class="Apple-tab-span" style="white-space:pre"> </span> dd->SetController(getVtkController());</div><div><span class="Apple-tab-span" style="white-space:pre"> </span></div><div><span class="Apple-tab-span" style="white-space:pre"> </span> dd->SetBoundaryModeToSplitBoundaryCells(); </div>
<div><span class="Apple-tab-span" style="white-space:pre"> </span> //dd->SetBoundaryModeToAssignToOneRegion();</div><div><span class="Apple-tab-span" style="white-space:pre"> </span> //dd->SetBoundaryModeToAssignToAllIntersectingRegions();</div>
<div><span class="Apple-tab-span" style="white-space:pre"> </span> dd->UseMinimalMemoryOff();</div><div><span class="Apple-tab-span" style="white-space:pre"> </span> dd->Update();</div><div><span class="Apple-tab-span" style="white-space:pre"> </span></div>
<div><span class="Apple-tab-span" style="white-space:pre"> </span> vtkPieceScalars *ps = vtkPieceScalars::New();</div><div><span class="Apple-tab-span" style="white-space:pre"> </span> ps->SetInputConnection(dd->GetOutputPort());</div>
<div><span class="Apple-tab-span" style="white-space:pre"> </span> ps->SetScalarModeToCellData();</div><div><span class="Apple-tab-span" style="white-space:pre"> </span></div><div><span class="Apple-tab-span" style="white-space:pre"> </span> vtkDataSetSurfaceFilter *dss = vtkDataSetSurfaceFilter::New();</div>
<div><span class="Apple-tab-span" style="white-space:pre"> </span> dss->SetInputConnection(ps->GetOutputPort());</div><div><br></div><div>The dd object works fine and writing its contents out on each processor gives nprocs worth of meshes, each of which look slightly different to the way I've partitioned them up, but sum to the same serial mesh so I am happy with that working correctly. But I can't for the life of me figure out how to obtain local to global cell mappings, allocate ghost cells, or work out how to exchange data given the above partition info and comms....</div>
<div><br></div><div>Note I have not provided any additional information to "dd" regarding global cells as per the doxy notes so I assume it went away and computed it. I can't figure out how to extract it however. I also have no idea how to modify each local processor rgrid to include the ghost cells for that processor. Finally given that info, I could exchange between processors to write to each local processors ghost cells the corresponding "real" cell data from the neighbouring meshes and continue the code.</div>
<div><br></div><div>Any help really appreciated!</div><div><br>Cheers,</div><div>Andy</div><div><br></div>