diff --git a/CADability.Forms/PaintToOpenGL.cs b/CADability.Forms/PaintToOpenGL.cs
index 95bc5a88..445d898b 100644
--- a/CADability.Forms/PaintToOpenGL.cs
+++ b/CADability.Forms/PaintToOpenGL.cs
@@ -67,7 +67,7 @@ struct state
         IntPtr deviceContext = IntPtr.Zero, renderContext = IntPtr.Zero;
         IntPtr controlHandle = IntPtr.Zero;
         Graphics graphics = null;
-        byte accumBits = 0, colorBits = 32, depthBits = 16, stencilBits = 0;
+        byte accumBits = 0, colorBits = 32, depthBits = 16;
         static IntPtr MainRenderContext = IntPtr.Zero;
         static IntPtr LastRenderContext = IntPtr.Zero;
         private static List<System.Drawing.Bitmap> bitmapList = null;
diff --git a/CADability/BSpline2D.cs b/CADability/BSpline2D.cs
index 40848ef5..53382255 100644
--- a/CADability/BSpline2D.cs
+++ b/CADability/BSpline2D.cs
@@ -55,7 +55,6 @@ public class BSpline2D : GeneralCurve2D, ISerializable, IDeserializationCallback
         //private GeoVector2D[] interdir; // Richtungen an den Stützpunkten
         //private double[] interparam; // Parameterwerte an den Stützpunkten
         //private GeoPoint2D[] tringulation; // Dreiecks-Zwischenpunkte (einer weniger als interpol)
-        private bool extendIsValid; // schon berechnet?
         private double parameterEpsilon; // ein epsilon, welches sich auf den Parameter bezieht. Abbruch für Iterationen
         private double distanceEpsilon; // ein epsilon, welches sich auf die Ausdehnung bezieht. Abbruch für Iterationen
         WeakReference<ExplicitPCurve2D> explicitPCurve2D;
@@ -67,7 +66,6 @@ private void InvalidateCache()
             //interdir = null;
             //interparam = null;
             //tringulation = null;
-            extendIsValid = false;
             nubs = null;
             nurbs = null;
             explicitPCurve2D = null;
@@ -277,9 +275,7 @@ private void MakeFlat()
         //            }
         //#endif
         //        }
-#if DEBUG
-        private static int maxTriangleCount = 0;
-#endif
+
         private bool FindInflectionPoint(double su, GeoPoint2D pl, GeoVector2D dir1l, GeoVector2D dir2l, double eu, GeoPoint2D pr, GeoVector2D dir1r, GeoVector2D dir2r, out double par)
         {
             GeoPoint2D pm;
diff --git a/CADability/ConstructAction.cs b/CADability/ConstructAction.cs
index ee4d2166..2866f028 100644
--- a/CADability/ConstructAction.cs
+++ b/CADability/ConstructAction.cs
@@ -7137,7 +7137,7 @@ protected void Finish()
          * in der Callback Methode ausführen. Dann kann man immer noch Escape drücken, wenns zu lange dauart (Vervielfältigen, Schraffur)
          */
         Thread backgroundTask;
-        bool finishedBackgroundTask, syncCallBack;
+        bool finishedBackgroundTask;
         Delegate CallbackOnDone;
         private void StartThread(object pars)
         {   // das läuft im background thread
@@ -7165,7 +7165,6 @@ protected void StartBackgroundTask(Delegate MethodToInvoke, Delegate CallbackOnD
         {
             //System.Diagnostics.Trace.WriteLine("StartBackgroundTask");
             backgroundTask = new Thread(new ParameterizedThreadStart(StartThread));
-            syncCallBack = true;
             backgroundTask.Start(new object[] { MethodToInvoke, CallbackOnDone, invokeParameters });
             //System.Diagnostics.Trace.WriteLine("StartBackgroundTask-Done");
         }
@@ -7196,8 +7195,8 @@ protected void WaitForBackgroundTask()
                 bool stop = false;
                 lock (this)
                 {   // sind wir schon über den kritischen Punkt in der Ausführung, d.h. ist die Berechnung schon fertig
-                    if (finishedBackgroundTask) stop = true;
-                    else syncCallBack = false;
+                    if (finishedBackgroundTask) 
+                        stop = true;
                 }
                 if (stop)
                 {   // hier abbrechen, da wir schon über den kritischen Punkt sind und syncCallBack nicht mehr rechtzeitig gesetzt werden konnte
diff --git a/CADability/Edge.cs b/CADability/Edge.cs
index 70ea9974..e8c479d1 100644
--- a/CADability/Edge.cs
+++ b/CADability/Edge.cs
@@ -220,7 +220,6 @@ public class Edge : ISerializable, IGeoObjectOwner, IDeserializationCallback, IC
         private Vertex v1, v2;
         private bool oriented; // obsolete, if false (forwardOnPrimaryFace, forwardOnSecondaryFace) have not yet been calculated
         enum EdgeKind { unknown, sameSurface, tangential, sharp }
-        private EdgeKind edgeKind = EdgeKind.unknown;
         internal BRepOperation.EdgeInfo edgeInfo; // only used for BRepOperation
         // TODO: überprüfen, ob isPartOf und startAtOriginal, endAtOriginal noch gebraucht wird (evtl. zu einem Objekt machen)
         // TODO: ist owner nicht immer primaryFace?
@@ -818,7 +817,6 @@ public override int GetHashCode()
         }
         internal Edge()
         {
-            edgeKind = EdgeKind.unknown;
             hashCode = hashCodeCounter++; // 
 #if DEBUG
             if (hashCode == 1214)
@@ -1761,7 +1759,6 @@ internal void SetPrimary(Face primaryFace, ICurve2D curveOnPrimaryFace, bool for
             this.curveOnPrimaryFace = curveOnPrimaryFace;
             this.forwardOnPrimaryFace = forwardOnPrimaryFace;
             oriented = true;
-            edgeKind = EdgeKind.unknown;
         }
         internal void SetPrimary(Face fc, bool forward)
         {
@@ -1770,7 +1767,6 @@ internal void SetPrimary(Face fc, bool forward)
             if (!forward) curveOnPrimaryFace.Reverse();
             forwardOnPrimaryFace = forward;
             oriented = true;
-            edgeKind = EdgeKind.unknown;
         }
         internal void SetSecondary(Face fc, bool forward)
         {
@@ -1779,7 +1775,6 @@ internal void SetSecondary(Face fc, bool forward)
             if (!forward) curveOnSecondaryFace.Reverse();
             forwardOnSecondaryFace = forward;
             oriented = true;
-            edgeKind = EdgeKind.unknown;
         }
         internal void UpdateInterpolatedDualSurfaceCurve()
         {
diff --git a/CADability/Extensions.cs b/CADability/Extensions.cs
index eb029dba..62ff9546 100644
--- a/CADability/Extensions.cs
+++ b/CADability/Extensions.cs
@@ -81,13 +81,11 @@ void IEnumerator.Reset()
     public class LookedUpEnumerable<T> : IEnumerable<T>, IEnumerator<T>, IEnumerator
     {
         IEnumerable<T> toEnumerate;
-        int currentIndex;
         IEnumerator<T> currentEnumerator;
         Dictionary<T, T> lookUp;
         public LookedUpEnumerable(IEnumerable<T> enumerable, Dictionary<T, T> lookUp)
         {
             toEnumerate = enumerable;
-            currentIndex = 0;
             currentEnumerator = null;
             this.lookUp = lookUp;
             currentEnumerator = enumerable.GetEnumerator();
diff --git a/CADability/Face.cs b/CADability/Face.cs
index c1b23741..2e08f4a1 100644
--- a/CADability/Face.cs
+++ b/CADability/Face.cs
@@ -6737,7 +6737,6 @@ private void TryAssureTriangles(double precision)
                 }
             }
         }
-        static int maxtime = 0;
         internal void AssureTriangles(double precision)
         {
             lock (lockTriangulationRecalc)
diff --git a/CADability/GeoVectorProperty.cs b/CADability/GeoVectorProperty.cs
index 3e342e52..e64f7254 100644
--- a/CADability/GeoVectorProperty.cs
+++ b/CADability/GeoVectorProperty.cs
@@ -83,7 +83,6 @@ private enum DisplayCoordinateSystem { local, absolute, both };
         private Plane drawingPlane; // spiegelt die aktuelle drawingplane wieder
         private bool displayZComponent; // true: z-Wert darstellen, false: nur x,y-Werte darstellen
         private bool alwaysAbsoluteCoordinateSystem; // immer im basoluten Koordinatensystem darstellen
-        private bool alwaysZComponent; // immer z-Wert darstellen
 
         /// <summary>
         /// Delegate definition for the <see cref="SelectionChangedEvent"/>
@@ -134,7 +133,6 @@ private void InitFormat(IFrame frame)
                 displayZComponent = true;
             }
             alwaysAbsoluteCoordinateSystem = false;
-            alwaysZComponent = false;
             displayMode = (DisplayMode)frame.GetIntSetting("Formatting.Vector.Mode", 0);
             numberFormatInfo = (NumberFormatInfo)CultureInfo.CurrentCulture.NumberFormat.Clone();
             int decsym = Settings.GlobalSettings.GetIntValue("Formatting.Decimal", 0); // Systemeinstellung | Punkt | Komma
diff --git a/CADability/IntegerProperty.cs b/CADability/IntegerProperty.cs
index c4641772..cfb342a8 100644
--- a/CADability/IntegerProperty.cs
+++ b/CADability/IntegerProperty.cs
@@ -18,7 +18,6 @@ public class IntegerProperty : EditableProperty<int>, ISerializable, ISettingCha
         private string text;
         private bool readOnly;
         private bool IsSetting;
-        private bool settingChanged;
         private bool highlight;
         private int minValue; // Grenzen für die Eingabe
         private int maxValue;
@@ -51,7 +50,6 @@ private void Initialize(object ObjectWithInt, string PropertyName, string resour
                 }
             }
             IntChanged();
-            settingChanged = false;
         }
         public IntegerProperty(object ObjectWithInt, string PropertyName, string resourceId)
         {
@@ -169,7 +167,6 @@ public void SetInt(int d)
         {
             if (d == internalValue)
                 return;
-            settingChanged = true;
             internalValue = d;
             if (SetIntEvent != null)
             {
diff --git a/CADability/MultipleChoiceProperty.cs b/CADability/MultipleChoiceProperty.cs
index 7622df79..fcd8cdce 100644
--- a/CADability/MultipleChoiceProperty.cs
+++ b/CADability/MultipleChoiceProperty.cs
@@ -27,7 +27,6 @@ public class MultipleChoiceProperty : PropertyEntryImpl
         //protected ImageList images; // die ImageList (kann fehlen)
         protected string selectedText; // der ausgewählte Text
         protected string unselectedText; // der Text, wenn nichts ausgewählt ist (wenn null, dann ganz leer)
-        private bool popup;
         /// <value>
         /// Back reference to any user item. Not used by the MultipleChoiceProperty object itself.
         /// </value>
@@ -59,7 +58,6 @@ public MultipleChoiceProperty(string resourceId, int InitialSelection)
         /// </summary>
         public MultipleChoiceProperty()
         {
-            popup = true;
         }
         //private int ImageIndex(int Index)
         //{
diff --git a/CADability/NameProperty.cs b/CADability/NameProperty.cs
index 163c8dbb..a1bacb8d 100644
--- a/CADability/NameProperty.cs
+++ b/CADability/NameProperty.cs
@@ -12,17 +12,15 @@ public class NameProperty : IShowPropertyImpl
     {
         private object ObjectWithName;
         private PropertyInfo TheProperty;
-        private bool IsSetting;
 
         public NameProperty(object ObjectWithName, string PropertyName, string resourceId)
         {
-            IsSetting = false;
             this.ObjectWithName = ObjectWithName;
             base.resourceId = resourceId;
             TheProperty = ObjectWithName.GetType().GetProperty(PropertyName);
             if (TheProperty == null) TheProperty = ObjectWithName.GetType().BaseType.GetProperty(PropertyName); // besser rekursiv
         }
-        
+
         private void SetName(string s)
         {
             MethodInfo mi = TheProperty.GetSetMethod();
@@ -30,13 +28,13 @@ private void SetName(string s)
             prm[0] = s;
             try
             {
-                IsSetting = true;
                 mi.Invoke(ObjectWithName, prm);
             }
             finally
             {
-                IsSetting = false;
+
             }
+
         }
         private string GetName()
         {
diff --git a/CADability/ParallelHelper.cs b/CADability/ParallelHelper.cs
index b4e03442..094328d2 100644
--- a/CADability/ParallelHelper.cs
+++ b/CADability/ParallelHelper.cs
@@ -8,8 +8,8 @@ namespace CADability
     public class ParallelHelper
     {
 #if DEBUG
-        private static string lmfa = ""; // to have an object to lock access to maxFailedAttempts
-        static int maxFailedAttempts = 0;
+        //private static string lmfa = ""; // to have an object to lock access to maxFailedAttempts
+        //static int maxFailedAttempts = 0;
         static HashSet<string> debug = new HashSet<string>();
 #endif
         class LockMultiple : IDisposable
diff --git a/CADability/ProjectedModel.cs b/CADability/ProjectedModel.cs
index 498f58c6..d685bee6 100644
--- a/CADability/ProjectedModel.cs
+++ b/CADability/ProjectedModel.cs
@@ -65,7 +65,6 @@ public enum Kind { HardEdge, SoftEdge, ContourEdge }
     [Serializable]
     public class ProjectedModel : ISerializable, IDeserializationCallback, IJsonSerialize
     {
-        static bool DoBackgroundPaint = false; // immer false, keine Hidden lines mehr!
         #region Konzept:
         /*	Konzept zum ProjectedModel:
          * Die Klasse ProjectedModel hält einen QuadTree, der die Objekte für die 2D Darstellung enthält.