From 54e5e6895df80a44aeee9b281dabd1ac7faab042 Mon Sep 17 00:00:00 2001
From: Wojtek Figat <wojtek@figat.pl>
Date: Sun, 19 Apr 2026 10:22:35 +0200
Subject: [PATCH] Fix material instance parameters order in editor to match
 from base material

---
 Source/Editor/Surface/SurfaceParameter.cs     |  6 +++++
 Source/Editor/Surface/SurfaceUtils.cs         | 25 +++++++++++++------
 .../Engine/Graphics/Materials/MaterialInfo.cs |  9 +++++++
 3 files changed, 32 insertions(+), 8 deletions(-)

diff --git a/Source/Editor/Surface/SurfaceParameter.cs b/Source/Editor/Surface/SurfaceParameter.cs
index c76cb058e..be69f69b2 100644
--- a/Source/Editor/Surface/SurfaceParameter.cs
+++ b/Source/Editor/Surface/SurfaceParameter.cs
@@ -48,5 +48,11 @@ namespace FlaxEditor.Surface
         /// </summary>
         [NoSerialize, HideInEditor]
         public readonly SurfaceMeta Meta = new SurfaceMeta();
+
+        /// <inheritdoc />
+        public override string ToString()
+        {
+            return $"{Type} {Name} = {Value?.ToString() ?? "null"}";
+        }
     }
 }
diff --git a/Source/Editor/Surface/SurfaceUtils.cs b/Source/Editor/Surface/SurfaceUtils.cs
index 60cd714c4..638d8338c 100644
--- a/Source/Editor/Surface/SurfaceUtils.cs
+++ b/Source/Editor/Surface/SurfaceUtils.cs
@@ -21,6 +21,7 @@ namespace FlaxEditor.Surface
         {
             public GraphParameter Parameter;
             public bool IsPublic;
+            public int Index;
             public Type Type;
             public object Tag;
             public Attribute[] Attributes;
@@ -31,15 +32,16 @@ namespace FlaxEditor.Surface
             public HeaderAttribute Header;
             public string DisplayName;
 
-            public GraphParameterData(GraphParameter parameter, object tag = null)
-            : this(parameter, null, parameter.IsPublic, parameter.Type, SurfaceMeta.GetAttributes(parameter), tag)
+            public GraphParameterData(GraphParameter parameter, int index, object tag = null)
+            : this(parameter, index, null, parameter.IsPublic, parameter.Type, SurfaceMeta.GetAttributes(parameter), tag)
             {
             }
 
-            public GraphParameterData(GraphParameter parameter, string name, bool isPublic, Type type, Attribute[] attributes, object tag)
+            public GraphParameterData(GraphParameter parameter, int index, string name, bool isPublic, Type type, Attribute[] attributes, object tag)
             {
                 Parameter = parameter;
                 IsPublic = isPublic;
+                Index = index;
                 Type = type;
                 Tag = tag;
                 Attributes = attributes;
@@ -74,8 +76,14 @@ namespace FlaxEditor.Surface
                 if (Editor.Instance.Options.Options.General.ScriptMembersOrder == GeneralOptions.MembersOrder.Alphabetical)
                     return string.Compare(x.DisplayName, y.DisplayName, StringComparison.InvariantCulture);
 
-                // Keep same order
-                return 0;
+                // Keep same order (from input indices)
+                return x.Index - y.Index;
+            }
+
+            /// <inheritdoc />
+            public override string ToString()
+            {
+                return $"{Type} {DisplayName}";
             }
         }
 
@@ -206,6 +214,7 @@ namespace FlaxEditor.Surface
                 Profiler.EndEvent();
             }
 
+            int index = 0;
             foreach (var parameter in parameters)
             {
                 var parameterId = parameter.ParameterID;
@@ -229,7 +238,7 @@ namespace FlaxEditor.Surface
                     surfaceParameters.Add(surfaceParameter);
                 }
                 var attributes = surfaceParameter?.Meta.GetAttributes() ?? FlaxEngine.Utils.GetEmptyArray<Attribute>();
-                data[i] = new GraphParameterData(null, parameter.Name, parameter.IsPublic, ToType(parameter.ParameterType), attributes, parameter);
+                data[i] = new GraphParameterData(null, index++, parameter.Name, parameter.IsPublic, ToType(parameter.ParameterType), attributes, parameter);
                 i++;
             }
             Array.Sort(data, GraphParameterData.Compare);
@@ -243,7 +252,7 @@ namespace FlaxEditor.Surface
             int i = 0;
             foreach (var parameter in parameters)
             {
-                data[i] = new GraphParameterData(parameter.EmitterParameter, parameter);
+                data[i] = new GraphParameterData(parameter.EmitterParameter, i, parameter);
                 i++;
             }
             Array.Sort(data, GraphParameterData.Compare);
@@ -257,7 +266,7 @@ namespace FlaxEditor.Surface
             int i = 0;
             foreach (var parameter in parameters)
             {
-                data[i] = new GraphParameterData(parameter);
+                data[i] = new GraphParameterData(parameter, i);
                 i++;
             }
             Array.Sort(data, GraphParameterData.Compare);
diff --git a/Source/Engine/Graphics/Materials/MaterialInfo.cs b/Source/Engine/Graphics/Materials/MaterialInfo.cs
index a8ff82665..4ff56ea63 100644
--- a/Source/Engine/Graphics/Materials/MaterialInfo.cs
+++ b/Source/Engine/Graphics/Materials/MaterialInfo.cs
@@ -97,4 +97,13 @@ namespace FlaxEngine
             }
         }
     }
+
+    partial class MaterialParameter
+    {
+        /// <inheritdoc />
+        public override string ToString()
+        {
+            return $"{ParameterType} {Name} = {Value?.ToString() ?? "null"}";
+        }
+    }
 }