Fem: Add method to rename pipeline VTK data arrays

src/Mod/Fem/App/FemPostPipeline.cpp

@@ -27,6 +27,7 @@
 #include <vtkAppendFilter.h>
 #include <vtkDataSetReader.h>
 #include <vtkImageData.h>
+#include <vtkPointData.h>
 #include <vtkRectilinearGrid.h>
 #include <vtkStructuredGrid.h>
 #include <vtkUnstructuredGrid.h>
@@ -46,8 +47,6 @@
 #endif
 
 #include <Base/Console.h>
-#include <cmath>
-#include <QString>
 
 #include "FemMesh.h"
 #include "FemMeshObject.h"
@@ -737,6 +736,38 @@ void FemPostPipeline::onDocumentRestored()
     }
 }
 
+void FemPostPipeline::renameArrays(const std::map<std::string, std::string>& names)
+{
+    std::vector<vtkSmartPointer<vtkDataSet>> fields;
+    auto data = Data.getValue();
+    if (!data) {
+        return;
+    }
+
+    if (auto dataSet = vtkDataSet::SafeDownCast(data)) {
+        fields.emplace_back(dataSet);
+    }
+    else if (auto blocks = vtkMultiBlockDataSet::SafeDownCast(data)) {
+        for (unsigned int i = 0; i < blocks->GetNumberOfBlocks(); ++i) {
+            if (auto dataSet = vtkDataSet::SafeDownCast(blocks->GetBlock(i))) {
+                fields.emplace_back(dataSet);
+            }
+        }
+    }
+
+    for (auto f : fields) {
+        auto pointData = f->GetPointData();
+        for (const auto& name : names) {
+            auto array = pointData->GetAbstractArray(name.first.c_str());
+            if (array) {
+                array->SetName(name.second.c_str());
+            }
+        }
+    }
+
+    Data.touch();
+}
+
 PyObject* FemPostPipeline::getPyObject()
 {
     if (PythonObject.is(Py::_None())) {

src/Mod/Fem/App/FemPostPipeline.h

@@ -98,6 +98,7 @@ public:
               Base::Unit unit,
               std::string& frame_type);
     void scale(double s);
+    void renameArrays(const std::map<std::string, std::string>& names);
 
     // load from results
     void load(FemResultObject* res);

src/Mod/Fem/App/FemPostPipelinePy.xml

@@ -66,5 +66,10 @@ Load a single result object or create a multiframe result by loading multiple re
                 <UserDocu>Check if this pipeline holds a given post-processing object</UserDocu>
             </Documentation>
         </Methode>
+        <Methode Name="renameArrays">
+            <Documentation>
+                <UserDocu>Change name of data arrays</UserDocu>
+            </Documentation>
+        </Methode>
     </PythonExport>
 </GenerateModel>

src/Mod/Fem/App/FemPostPipelinePyImp.cpp

@@ -285,6 +285,28 @@ PyObject* FemPostPipelinePy::holdsPostObject(PyObject* args)
     return Py_BuildValue("O", (ok ? Py_True : Py_False));
 }
 
+PyObject* FemPostPipelinePy::renameArrays(PyObject* args)
+{
+    PyObject* pyObj;
+    if (!PyArg_ParseTuple(args, "O!", &(PyDict_Type), &pyObj)) {
+        return nullptr;
+    }
+
+    Py::Dict pyNames {pyObj};
+    std::map<std::string, std::string> names {};
+    for (auto&& [key, value] : pyNames) {
+        if (!key.isString() || !value.isString()) {
+            PyErr_SetString(PyExc_TypeError, "Names must be string objects");
+            return nullptr;
+        }
+        names.emplace(key.as_string(), static_cast<Py::Object>(value).as_string());
+    }
+
+    getFemPostPipelinePtr()->renameArrays(names);
+
+    Py_Return;
+}
+
 PyObject* FemPostPipelinePy::getCustomAttributes(const char* /*attr*/) const
 {
     return nullptr;