Add NoUndo attribute for properties without undo usage

Source/Editor/Surface/NodeFactory.cs

@@ -28,6 +28,7 @@ namespace FlaxEditor.Surface
             typeof(RangeAttribute),
             typeof(SpaceAttribute),
             typeof(NoAnimateAttribute),
+            typeof(NoUndoAttribute),
         };
 
         /// <summary>

Source/Editor/Utilities/ObjectSnapshot.cs

@@ -48,7 +48,8 @@ namespace FlaxEditor.Utilities
         private static readonly Type[] AttributesIgnoreList =
         {
             typeof(NonSerializedAttribute),
-            typeof(NoSerializeAttribute)
+            typeof(NoSerializeAttribute),
+            typeof(NoUndoAttribute),
         };
 
         private static void GetEntries(MemberInfoPath.Entry member, Stack<MemberInfoPath.Entry> membersPath, List<TypeEntry> result, List<object> values, Stack<object> refStack, ScriptType memberType, object memberValue)

Source/Engine/Scripting/Attributes/Editor/NoUndoAttribute.cs

@@ -0,0 +1,15 @@
+// Copyright (c) 2012-2021 Wojciech Figat. All rights reserved.
+
+using System;
+
+namespace FlaxEngine
+{
+    /// <summary>
+    /// Makes a property to not use undo/redo when modifying it in Editor.
+    /// </summary>
+    [Serializable]
+    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Property)]
+    public sealed class NoUndoAttribute : Attribute
+    {
+    }
+}