Fix topology bug with uniform grid filter (#1319)

We know the field name so we will grab the topology that way.

src/libs/ascent/runtimes/flow_filters/ascent_runtime_vtkh_filters.cpp

@@ -3361,26 +3361,25 @@ VTKHUniformGrid::execute()
     }
     std::shared_ptr<VTKHCollection> collection = data_object->as_vtkh_collection();
 
-    bool throw_error = false;
-    std::string topo_name = detail::resolve_topology(params(),
-                                                     this->name(),
-                                                     collection,
-                                                     throw_error);
-    if(topo_name == "")
+    std::string field = params()["field"].as_string();
+    if(!collection->has_field(field))
     {
+      bool throw_error = false;
+      detail::field_error(field, this->name(), collection, throw_error);
       // this creates a data object with an invalid soource
       set_output<DataObject>(new DataObject());
       return;
     }
 
+
+    std::string topo_name = collection->field_topology(field);
     vtkh::DataSet &data = collection->dataset_by_topology(topo_name);
 
     vtkm::Bounds d_bounds = data.GetGlobalBounds();
     vtkm::Float64 x_extents = d_bounds.X.Length() + 1; //add one b/c we are
     vtkm::Float64 y_extents = d_bounds.Y.Length() + 1; //setting num points
     vtkm::Float64 z_extents = d_bounds.Z.Length() + 1; //(not cells) in each dim
 
-    std::string field = params()["field"].as_string();
     vtkm::Float64 invalid_value = 0.0;
 
     using Vec3f = vtkm::Vec<vtkm::Float64,3>;