[Core] Adding possibility to customize the skin variable in `Calculat…

…eNodalDistanceToSkinProcess` when considered

docs/pages/Kratos/Processes/Calculation/calculate_nodal_distance_to_skin_process.md

@@ -72,7 +72,8 @@ The selected lambda function is then applied to calculate the distances for all
     "skin_model_part"           : "",
     "distance_database"         : "nodal_historical",
     "save_max_distance_in_skin" : false,
-    "distance_variable"         : "DISTANCE"
+    "distance_variable"         : "DISTANCE",
+    "skin_distance_variable"    : "DISTANCE"
 }
 ```
 
@@ -89,4 +90,7 @@ This flag indicating whether historical variable is enabled or otherwise non-his
 This flag indicates if the distance is going to be saved in the skin. By default is false, if activated will save the maximum distance in the found skin geometry and set the flag `VISITED`. This also deactivate shared memory parallelization.
 
 ##### `distance_variable`
-Denotes the variable for applying the process, with `DISTANCE` set as the default value.
+Denotes the variable for applying the process, with `DISTANCE` set as the default value.
+
+##### `skin_distance_variable`
+Denotes the variable sved into the skin if `save_max_distance_in_skin` is active, with `DISTANCE` set as the default value.

kratos/processes/calculate_nodal_distance_to_skin_process.cpp

@@ -79,6 +79,7 @@ CalculateNodalDistanceToSkinProcess::CalculateNodalDistanceToSkinProcess(
 
     // Assign distance variable
     mpDistanceVariable = &KratosComponents<Variable<double>>::Get(ThisParameters["distance_variable"].GetString());
+    mpSkinDistanceVariable = &KratosComponents<Variable<double>>::Get(ThisParameters["skin_distance_variable"].GetString());
 
     // Check it is serial
     KRATOS_ERROR_IF(mrVolumeModelPart.IsDistributed()) << "Distributed computation still not supported. Please update implementation as soon as MPI search is merged. See https://github.com/KratosMultiphysics/Kratos/pull/11719" << std::endl;
@@ -108,12 +109,13 @@ void CalculateNodalDistanceToSkinProcess::Execute()
 
     const std::function<void(ModelPart::NodesContainerType& rNodes, GeometricalObjectsBins& rBins)> distance_lambda_historical_save_skin = [this, &p_variable_retriever](ModelPart::NodesContainerType& rNodes, GeometricalObjectsBins& rBins) {
         const auto& r_variable = *mpDistanceVariable;
+        const auto& r_skin_variable = *mpSkinDistanceVariable;
         for (Node& rNode: rNodes) {
             auto result = rBins.SearchNearest(rNode);
             const double value = result.GetDistance();
             auto p_result = result.Get().get();
-            if (p_result->GetValue(r_variable) < value) {
-                p_result->SetValue(r_variable, value);
+            if (p_result->GetValue(r_skin_variable) < value) {
+                p_result->SetValue(r_skin_variable, value);
                 p_result->Set(VISITED);
             }
             p_variable_retriever->GetValue(rNode, r_variable) = value;
@@ -160,7 +162,8 @@ const Parameters CalculateNodalDistanceToSkinProcess::GetDefaultParameters() con
         "skin_model_part"           : "",
         "distance_database"         : "nodal_historical",
         "save_max_distance_in_skin" : false,
-        "distance_variable"         : "DISTANCE"
+        "distance_variable"         : "DISTANCE",
+        "skin_distance_variable"    : "DISTANCE"
     })");
     return default_parameters;
 }

kratos/processes/calculate_nodal_distance_to_skin_process.h

@@ -189,6 +189,9 @@ class KRATOS_API(KRATOS_CORE) CalculateNodalDistanceToSkinProcess
     /// Pointer to the distance variable.
     const Variable<double>* mpDistanceVariable = &DISTANCE;
 
+    /// Pointer to the skin saved distance variable.
+    const Variable<double>* mpSkinDistanceVariable = &DISTANCE;
+
     /// This flag is used in order to check if the values are historical
     bool mHistoricalValue = true;