Map cell data arrays through vtkmContour.

Accelerators/Vtkm/Testing/Cxx/TestVTKMMarchingCubes.cxx

@@ -15,6 +15,7 @@
 //=============================================================================
 #include "vtkActor.h"
 #include "vtkCellData.h"
+#include "vtkCountVertices.h"
 #include "vtkmContour.h"
 #include "vtkElevationFilter.h"
 #include "vtkImageData.h"
@@ -70,12 +71,29 @@ int RunVTKPipeline(T *t, int argc, char* argv[])
     retVal = vtkRegressionTester::PASSED;
     }
 
-  if (!cubes->GetOutput()->GetPointData()->GetNormals())
+  vtkDataSet *output = cubes->GetOutput();
+
+  if (!output->GetPointData()->GetNormals())
   {
     std::cerr << "Output normals not set.\n";
     return EXIT_FAILURE;
   }
 
+  vtkDataArray *cellvar = output->GetCellData()->GetArray("Vertex Count");
+  if (!cellvar)
+  {
+    std::cerr << "Cell data missing.\n";
+    return EXIT_FAILURE;
+  }
+
+  if (cellvar->GetNumberOfTuples() != output->GetNumberOfCells())
+  {
+    std::cerr << "Mapped cell field does not match number of output cells.\n"
+              << "Expected: " << output->GetNumberOfCells() << " Actual: "
+              << cellvar->GetNumberOfTuples() << "\n";
+    return EXIT_FAILURE;
+  }
+
   return (!retVal);
 }
 
@@ -96,6 +114,9 @@ int TestVTKMMarchingCubes(int argc, char* argv[])
   elevation->SetLowPoint(-1.75, 0.0, 1.0);
   elevation->SetHighPoint(0.75, 0.0, 1.0);
 
+  vtkNew<vtkCountVertices> countVerts;
+  countVerts->SetInputConnection(elevation->GetOutputPort());
+
   //run the pipeline
-  return RunVTKPipeline(elevation.GetPointer(),argc,argv);
+  return RunVTKPipeline(countVerts.GetPointer(),argc,argv);
 }

Accelerators/Vtkm/vtkmContour.cxx

@@ -15,6 +15,7 @@
 //=============================================================================
 #include "vtkmContour.h"
 
+#include "vtkCellData.h"
 #include "vtkDataSet.h"
 #include "vtkInformation.h"
 #include "vtkInformationVector.h"
@@ -83,9 +84,9 @@ int vtkmContour::RequestData(vtkInformation* request,
     filter.SetIsoValue(i, this->GetValue(i));
   }
 
-
   // convert the input dataset to a vtkm::cont::DataSet
-  vtkm::cont::DataSet in = tovtkm::Convert(input);
+  vtkm::cont::DataSet in = tovtkm::Convert(input,
+                                           tovtkm::FieldsFlag::PointsAndCells);
 
   // we need to map the given property to the data set
   int association = this->GetInputArrayAssociation(0, inputVector);
@@ -108,7 +109,6 @@ int vtkmContour::RequestData(vtkInformation* request,
     vtkWarningMacro(<< "Will not be able to use VTKm field type is unknown");
   }
 
-
   vtkm::filter::ResultDataSet result;
   bool convertedDataSet = false;
   if (dataSetValid && fieldValid)
@@ -123,30 +123,19 @@ int vtkmContour::RequestData(vtkInformation* request,
       return this->Superclass::RequestData(request, inputVector, outputVector);
     }
 
-    // convert other scalar arrays
-    if (this->GetComputeScalars())
+    vtkm::Id numFields = static_cast<vtkm::Id>(in.GetNumberOfFields());
+    for (vtkm::Id fieldIdx = 0; fieldIdx < numFields; ++fieldIdx)
     {
-      vtkPointData* pd = input->GetPointData();
-      for (vtkIdType i = 0; i < pd->GetNumberOfArrays(); i++)
+      const vtkm::cont::Field &field = in.GetField(fieldIdx);
+      try
+      {
+        filter.MapFieldOntoOutput(result, field, policy);
+      }
+      catch (vtkm::cont::Error &e)
       {
-        vtkDataArray* array = pd->GetArray(i);
-        if (array == NULL)
-        {
-          continue;
-        }
-
-        vtkm::cont::Field pfield =
-            tovtkm::Convert(array, vtkDataObject::FIELD_ASSOCIATION_POINTS);
-        try
-        {
-          filter.MapFieldOntoOutput(result, pfield, policy);
-        }
-        catch (vtkm::cont::Error&)
-        { // nothing to do for now
-          vtkWarningMacro(<< "Unable to use VTKm to convert field( "
-                          << array->GetName() << " ) to the MarchingCubes"
-                          << "output.");
-        }
+        vtkWarningMacro(<< "Unable to use VTKm to convert point field( "
+                        << field.GetName() << " ) to the MarchingCubes"
+                        << " output: " << e.what());
       }
     }
 
@@ -162,6 +151,11 @@ int vtkmContour::RequestData(vtkInformation* request,
 
   }
 
+  if (this->ComputeScalars)
+  {
+    output->GetPointData()->SetActiveScalars(inputArray->GetName());
+  }
+
   if (this->ComputeNormals)
   {
     output->GetPointData()->SetActiveAttribute(