Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityCommon/MacroStabilityIo/FillEngineFromMacroStabilityWrapperInput.cs
===================================================================
diff -u -r3029 -r3042
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityCommon/MacroStabilityIo/FillEngineFromMacroStabilityWrapperInput.cs	(.../FillEngineFromMacroStabilityWrapperInput.cs)	(revision 3029)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityCommon/MacroStabilityIo/FillEngineFromMacroStabilityWrapperInput.cs	(.../FillEngineFromMacroStabilityWrapperInput.cs)	(revision 3042)
@@ -126,7 +126,7 @@
         private void TransferUpliftVanCalculationGrid(KernelUpliftVanCalculationGrid kernelSlipPlaneUpliftVan,
             SearchAreaConditions kernelSearchAreaConditions)
         {
-            // UpliftVanCalculationGrid.IsAuto = kernelSearchAreaConditions.AutoSearchArea;
+            // UpliftVanCalculationGrid.IsGridsAutomatic = kernelSearchAreaConditions.AutoSearchArea;
             UpliftVanCalculationGrid = new UpliftVanCalculationGrid
             {
                 LeftGridXCount = kernelSlipPlaneUpliftVan.LeftGrid.GridXNumber,
Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityInwards/UpliftVanGridCreator.cs
===================================================================
diff -u -r3041 -r3042
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityInwards/UpliftVanGridCreator.cs	(.../UpliftVanGridCreator.cs)	(revision 3041)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityInwards/UpliftVanGridCreator.cs	(.../UpliftVanGridCreator.cs)	(revision 3042)
@@ -38,8 +38,8 @@
         {
             var upliftVanCalculationGrid = new UpliftVanCalculationGrid()
             {
-                IsAuto = false,
-                TangentLineAutomaticAtBoundaries = false
+                IsGridsAutomatic = false,
+                IsTangentLinesAutomatic = false
             };
 
             // Define specified active (left) grid
@@ -100,6 +100,28 @@
         public static void DetermineTangentLines(UpliftVanCalculationGrid upliftVanCalculationGrid, SlipCircleDefinition slipCircleDefinition, 
             SoilProfile1D soilProfile1D, double minimumCircleDepth)
         {
+            switch (slipCircleDefinition.UpliftVanTangentLinesDefinition)
+            {
+                case TangentLinesDefinition.OnBoundaryLines:
+                    DetermineTangentLinesOnBoundaryLines(upliftVanCalculationGrid, slipCircleDefinition, soilProfile1D, minimumCircleDepth);
+                    break;
+                case TangentLinesDefinition.Specified:
+                    DetermineTangentLinesSpecified(upliftVanCalculationGrid, slipCircleDefinition, soilProfile1D, minimumCircleDepth);
+                    break;
+            }
+
+        }
+
+        private static void DetermineTangentLinesOnBoundaryLines(UpliftVanCalculationGrid upliftVanCalculationGrid, 
+            SlipCircleDefinition slipCircleDefinition, SoilProfile1D soilProfile1D, double minimumCircleDepth)
+        {
+            upliftVanCalculationGrid.IsTangentLinesAutomatic = false;
+            throw new NotImplementedException();
+        }
+
+        private static void DetermineTangentLinesSpecified(UpliftVanCalculationGrid upliftVanCalculationGrid,
+            SlipCircleDefinition slipCircleDefinition, SoilProfile1D soilProfile1D, double minimumCircleDepth)
+        {
             double topOfBottomLayer = soilProfile1D.Layers.Last().TopLevel;
             double surfaceLevel = soilProfile1D.Layers.First().TopLevel;
             double bottomTangentLines = topOfBottomLayer - slipCircleDefinition.UpliftVanTangentLinesDistance;
@@ -111,7 +133,8 @@
                 topTangentLines += slipCircleDefinition.UpliftVanTangentLinesDistance;
                 tangentLinesCount++;
             }
-            upliftVanCalculationGrid.TangentLineAutomaticAtBoundaries = true;
+
+            upliftVanCalculationGrid.IsTangentLinesAutomatic = true;
             upliftVanCalculationGrid.TangentLineCount = tangentLinesCount;
             upliftVanCalculationGrid.TangentLineZTop = topTangentLines;
             upliftVanCalculationGrid.TangentLineZBottom = bottomTangentLines;
Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityCommon/MacroStabilityIo/FillMacroStabilityWrapperInputFromEngine.cs
===================================================================
diff -u -r3029 -r3042
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityCommon/MacroStabilityIo/FillMacroStabilityWrapperInputFromEngine.cs	(.../FillMacroStabilityWrapperInputFromEngine.cs)	(revision 3029)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityCommon/MacroStabilityIo/FillMacroStabilityWrapperInputFromEngine.cs	(.../FillMacroStabilityWrapperInputFromEngine.cs)	(revision 3042)
@@ -288,7 +288,7 @@
             if (damUpliftVanCalculationGrid == null) throw new ArgumentNullException(nameof(damUpliftVanCalculationGrid));
             if (kernelUpliftVanCalculationGrid == null) throw new ArgumentNullException(nameof(kernelUpliftVanCalculationGrid));
             // if (kernelSearchAreaConditions == null) throw new ArgumentNullException(nameof(kernelSearchAreaConditions));
-            // damUpliftVanCalculationGrid.IsAuto = kernelSearchAreaConditions.AutoSearchArea;
+            // damUpliftVanCalculationGrid.IsGridsAutomatic = kernelSearchAreaConditions.AutoSearchArea;
 
             kernelUpliftVanCalculationGrid.LeftGrid = new CalculationGrid
             {
@@ -310,7 +310,7 @@
                 GridZBottom = damUpliftVanCalculationGrid.RightGridZBottom
             };
             
-            // kernelSearchAreaConditions.AutoTangentLines = damUpliftVanCalculationGrid.TangentLineAutomaticAtBoundaries;
+            // kernelSearchAreaConditions.AutoTangentLines = damUpliftVanCalculationGrid.IsTangentLinesAutomatic;
             kernelUpliftVanCalculationGrid.TangentLines = GetTangentLines(damUpliftVanCalculationGrid.TangentLineZBottom,
                  damUpliftVanCalculationGrid.TangentLineZTop,
                  damUpliftVanCalculationGrid.TangentLineCount)
Index: DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityCommon/UpliftVanCalculationGrid.cs
===================================================================
diff -u -r2030 -r3042
--- DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityCommon/UpliftVanCalculationGrid.cs	(.../UpliftVanCalculationGrid.cs)	(revision 2030)
+++ DamEngine/trunk/src/Deltares.DamEngine.Calculators/KernelWrappers/MacroStabilityCommon/UpliftVanCalculationGrid.cs	(.../UpliftVanCalculationGrid.cs)	(revision 3042)
@@ -24,9 +24,9 @@
     /// <summary>Parameters for the UpliftVan Macrostability kernel; used for IO</summary>
     public class UpliftVanCalculationGrid
     {
-        /// <summary>Gets or sets the IsAuto option.</summary>
-        /// <value>IsAuto.</value>
-        public bool IsAuto { get; set; }
+        /// <summary>Gets or sets the IsGridsAutomatic option.</summary>
+        /// <value>IsGridsAutomatic.</value>
+        public bool IsGridsAutomatic { get; set; }
         /// <summary>Gets or sets the left grid x left.</summary>
         /// <value>The left grid x left.</value>
         public double LeftGridXLeft { get; set; }
@@ -74,6 +74,6 @@
         public int TangentLineCount { get; set; }
         /// <summary>Gets or sets the tangent line setting automatic at boundaries.</summary>
         /// <value>The tangent line setting automatic at boundaries.</value>
-        public bool TangentLineAutomaticAtBoundaries { get; set; }
+        public bool IsTangentLinesAutomatic { get; set; }
     }
 }