changed to use attribute to add items to the content context menu, this also allows users to add their own items to the CM

Source/Editor/Content/Proxy/AnimationGraphFunctionProxy.cs

@@ -11,14 +11,12 @@ namespace FlaxEditor.Content
     /// A <see cref="AnimationGraphFunction"/> asset proxy object.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.BinaryAssetProxy" />
+    [ContentContextMenu("New/Animation/Animation Graph Function")]
     public class AnimationGraphFunctionProxy : BinaryAssetProxy
     {
         /// <inheritdoc />
         public override string Name => "Animation Graph Function";
 
-        /// <inheritdoc />
-        public override string CategoryName => "Animation";
-
         /// <inheritdoc />
         public override EditorWindow Open(Editor editor, ContentItem item)
         {

Source/Editor/Content/Proxy/AnimationGraphProxy.cs

@@ -11,13 +11,11 @@ namespace FlaxEditor.Content
     /// A <see cref="AnimationGraph"/> asset proxy object.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.BinaryAssetProxy" />
+    [ContentContextMenu("New/Animation/Animation Graph")]
     public class AnimationGraphProxy : BinaryAssetProxy
     {
         /// <inheritdoc />
         public override string Name => "Animation Graph";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Animation";
 
         /// <inheritdoc />
         public override EditorWindow Open(Editor editor, ContentItem item)

Source/Editor/Content/Proxy/AnimationProxy.cs

@@ -14,13 +14,11 @@ namespace FlaxEditor.Content
     /// A <see cref="Animation"/> asset proxy object.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.BinaryAssetProxy" />
+    [ContentContextMenu("New/Animation/Animation")]
     public class AnimationProxy : BinaryAssetProxy
     {
         /// <inheritdoc />
         public override string Name => "Animation";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Animation";
 
         /// <inheritdoc />
         public override bool CanReimport(ContentItem item)

Source/Editor/Content/Proxy/AssetProxy.cs

@@ -22,11 +22,6 @@ namespace FlaxEditor.Content
         /// </summary>
         public abstract string TypeName { get; }
 
-        /// <summary>
-        ///  The category name used to sort in context menus
-        /// </summary>
-        public abstract string CategoryName { get; }
-
         /// <summary>
         /// Checks if this proxy supports the given asset type id at the given path.
         /// </summary>

Source/Editor/Content/Proxy/AudioClipProxy.cs

@@ -62,9 +62,6 @@ namespace FlaxEditor.Content
 
         /// <inheritdoc />
         public override string Name => "Audio Clip";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Audio";
 
         /// <inheritdoc />
         public override bool CanReimport(ContentItem item)

Source/Editor/Content/Proxy/CSharpScriptProxy.cs

@@ -12,6 +12,7 @@ namespace FlaxEditor.Content
     /// Context proxy object for C# script files.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.CSharpScriptProxy" />
+    [ContentContextMenu("New/C# Script")]
     public class CSharpScriptProxy : ScriptProxy
     {
         /// <summary>

Source/Editor/Content/Proxy/CollisionDataProxy.cs

@@ -38,13 +38,11 @@ namespace FlaxEditor.Content
     /// A <see cref="CollisionData"/> asset proxy object.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.BinaryAssetProxy" />
+    [ContentContextMenu("New/Physics/Collision Data")]
     class CollisionDataProxy : BinaryAssetProxy
     {
         /// <inheritdoc />
         public override string Name => "Collision Data";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Physics";
 
         /// <inheritdoc />
         public override EditorWindow Open(Editor editor, ContentItem item)

Source/Editor/Content/Proxy/CppProxy.cs

@@ -75,6 +75,7 @@ namespace FlaxEditor.Content
     /// Context proxy object for C++ script files.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.CSharpScriptProxy" />
+    [ContentContextMenu("New/C++/C++ Script")]
     public class CppScriptProxy : CppProxy
     {
         /// <inheritdoc />
@@ -98,6 +99,7 @@ namespace FlaxEditor.Content
     /// Context proxy object for C++ Json Asset files.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.CSharpScriptProxy" />
+    [ContentContextMenu("New/C++/C++ Function Library")]
     public class CppStaticClassProxy : CppProxy
     {
         /// <inheritdoc />
@@ -115,6 +117,7 @@ namespace FlaxEditor.Content
     /// Context proxy object for C++ Json Asset files.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.CSharpScriptProxy" />
+    [ContentContextMenu("New/C++/C++ Json Asset")]
     public class CppAssetProxy : CppProxy
     {
         /// <inheritdoc />

Source/Editor/Content/Proxy/CubeTextureProxy.cs

@@ -20,9 +20,6 @@ namespace FlaxEditor.Content
 
         /// <inheritdoc />
         public override string Name => "Cube Texture";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Texture";
 
         /// <inheritdoc />
         public override bool CanReimport(ContentItem item)

Source/Editor/Content/Proxy/FontProxy.cs

@@ -17,9 +17,6 @@ namespace FlaxEditor.Content
     {
         /// <inheritdoc />
         public override string Name => "Font";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Font";
 
         /// <inheritdoc />
         public override bool CanReimport(ContentItem item)

Source/Editor/Content/Proxy/GameplayGlobalsProxy.cs

@@ -11,13 +11,11 @@ namespace FlaxEditor.Content
     /// A <see cref="GameplayGlobals"/> asset proxy object.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.BinaryAssetProxy" />
+    [ContentContextMenu("New/Gameplay Globals")]
     public class GameplayGlobalsProxy : BinaryAssetProxy
     {
         /// <inheritdoc />
         public override string Name => "Gameplay Globals";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Globals";
 
         /// <inheritdoc />
         public override EditorWindow Open(Editor editor, ContentItem item)

Source/Editor/Content/Proxy/IESProfileProxy.cs

@@ -20,9 +20,6 @@ namespace FlaxEditor.Content
 
         /// <inheritdoc />
         public override string Name => "IES Profile";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Lighting";
 
         /// <inheritdoc />
         public override bool CanReimport(ContentItem item)

Source/Editor/Content/Proxy/JsonAssetProxy.cs

@@ -22,6 +22,7 @@ namespace FlaxEditor.Content
     /// Json assets proxy.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.JsonAssetBaseProxy" />
+    [ContentContextMenu("New/Json Asset")]
     public abstract class JsonAssetProxy : JsonAssetBaseProxy
     {
         /// <summary>
@@ -31,9 +32,6 @@ namespace FlaxEditor.Content
 
         /// <inheritdoc />
         public override string Name => "Json Asset";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Json Asset";
 
         /// <inheritdoc />
         public override string FileExtension => Extension;
@@ -168,20 +166,6 @@ namespace FlaxEditor.Content
         /// <inheritdoc />
         public override string Name { get; } = Utilities.Utils.GetPropertyNameUI(typeof(T).Name);
 
-        private string _categoryName;
-
-        /// <inheritdoc />
-        public override string CategoryName => _categoryName;
-
-        /// <summary>
-        /// Sets the category name
-        /// </summary>
-        /// <param name="name">This is the category name</param>
-        public void SetCategoryName(string name)
-        {
-            _categoryName = name;
-        }
-
         /// <inheritdoc />
         public override bool CanCreate(ContentFolder targetLocation)
         {

Source/Editor/Content/Proxy/MaterialFunctionProxy.cs

@@ -11,13 +11,11 @@ namespace FlaxEditor.Content
     /// A <see cref="MaterialFunction"/> asset proxy object.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.BinaryAssetProxy" />
+    [ContentContextMenu("New/Material/Material Function")]
     public class MaterialFunctionProxy : BinaryAssetProxy
     {
         /// <inheritdoc />
         public override string Name => "Material Function";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Material";
 
         /// <inheritdoc />
         public override EditorWindow Open(Editor editor, ContentItem item)

Source/Editor/Content/Proxy/MaterialInstanceProxy.cs

@@ -14,15 +14,13 @@ namespace FlaxEditor.Content
     /// A <see cref="MaterialInstance"/> asset proxy object.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.BinaryAssetProxy" />
+    [ContentContextMenu("New/Material/Material Instance")]
     public class MaterialInstanceProxy : BinaryAssetProxy
     {
         private MaterialPreview _preview;
 
         /// <inheritdoc />
         public override string Name => "Material Instance";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Material";
 
         /// <inheritdoc />
         public override EditorWindow Open(Editor editor, ContentItem item)

Source/Editor/Content/Proxy/MaterialProxy.cs

@@ -15,15 +15,13 @@ namespace FlaxEditor.Content
     /// A <see cref="Material"/> asset proxy object.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.BinaryAssetProxy" />
+    [ContentContextMenu("New/Material/Material")]
     public class MaterialProxy : BinaryAssetProxy
     {
         private MaterialPreview _preview;
 
         /// <inheritdoc />
         public override string Name => "Material";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Material";
 
         /// <inheritdoc />
         public override EditorWindow Open(Editor editor, ContentItem item)

Source/Editor/Content/Proxy/ModelProxy.cs

@@ -21,9 +21,6 @@ namespace FlaxEditor.Content
 
         /// <inheritdoc />
         public override string Name => "Model";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Model";
 
         /// <inheritdoc />
         public override bool CanReimport(ContentItem item)

Source/Editor/Content/Proxy/ParticleEmitterFunctionProxy.cs

@@ -11,13 +11,11 @@ namespace FlaxEditor.Content
     /// A <see cref="ParticleEmitterFunction"/> asset proxy object.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.BinaryAssetProxy" />
+    [ContentContextMenu("New/Particles/Particle Emitter Function")]
     public class ParticleEmitterFunctionProxy : BinaryAssetProxy
     {
         /// <inheritdoc />
         public override string Name => "Particle Emitter Function";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Particles";
 
         /// <inheritdoc />
         public override EditorWindow Open(Editor editor, ContentItem item)

Source/Editor/Content/Proxy/ParticleEmitterProxy.cs

@@ -15,6 +15,7 @@ namespace FlaxEditor.Content
     /// A <see cref="ParticleEmitter"/> asset proxy object.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.BinaryAssetProxy" />
+    [ContentContextMenu("New/Particles/Particle Emitter")]
     public class ParticleEmitterProxy : BinaryAssetProxy
     {
         private ParticleEmitterPreview _preview;
@@ -22,9 +23,6 @@ namespace FlaxEditor.Content
 
         /// <inheritdoc />
         public override string Name => "Particle Emitter";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Particles";
 
         /// <inheritdoc />
         public override EditorWindow Open(Editor editor, ContentItem item)

Source/Editor/Content/Proxy/ParticleSystemProxy.cs

@@ -39,6 +39,7 @@ namespace FlaxEditor.Content
     /// A <see cref="ParticleSystem"/> asset proxy object.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.BinaryAssetProxy" />
+    [ContentContextMenu("New/Particles/Particle System")]
     public class ParticleSystemProxy : BinaryAssetProxy
     {
         private ParticleSystemPreview _preview;
@@ -46,9 +47,6 @@ namespace FlaxEditor.Content
 
         /// <inheritdoc />
         public override string Name => "Particle System";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Particles";
 
         /// <inheritdoc />
         public override EditorWindow Open(Editor editor, ContentItem item)

Source/Editor/Content/Proxy/PrefabProxy.cs

@@ -15,6 +15,7 @@ namespace FlaxEditor.Content
     /// Content proxy for <see cref="PrefabItem"/>.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.JsonAssetBaseProxy" />
+    [ContentContextMenu("New/Prefab")]
     public sealed class PrefabProxy : JsonAssetBaseProxy
     {
         private PrefabPreview _preview;
@@ -31,9 +32,6 @@ namespace FlaxEditor.Content
 
         /// <inheritdoc />
         public override string Name => "Prefab";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Prefab";
 
         /// <inheritdoc />
         public override string FileExtension => Extension;

Source/Editor/Content/Proxy/PreviewsCacheProxy.cs

@@ -15,9 +15,6 @@ namespace FlaxEditor.Content
     {
         /// <inheritdoc />
         public override string Name => "Previews Cache";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Previews Cache";
 
         /// <inheritdoc />
         public override EditorWindow Open(Editor editor, ContentItem item)

Source/Editor/Content/Proxy/SceneAnimationProxy.cs

@@ -40,9 +40,6 @@ namespace FlaxEditor.Content
     {
         /// <inheritdoc />
         public override string Name => "Scene Animation";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Animation";
 
         /// <inheritdoc />
         public override EditorWindow Open(Editor editor, ContentItem item)

Source/Editor/Content/Proxy/SceneProxy.cs

@@ -10,6 +10,7 @@ namespace FlaxEditor.Content
     /// Content proxy for <see cref="SceneItem"/>.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.JsonAssetBaseProxy" />
+    [ContentContextMenu("New/Scene")]
     public sealed class SceneProxy : JsonAssetBaseProxy
     {
         /// <summary>
@@ -19,9 +20,6 @@ namespace FlaxEditor.Content
 
         /// <inheritdoc />
         public override string Name => "Scene";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Scene";
 
         /// <inheritdoc />
         public override string FileExtension => Extension;

Source/Editor/Content/Proxy/SettingsProxy.cs

@@ -11,6 +11,7 @@ namespace FlaxEditor.Content
     /// Content proxy for json settings assets (e.g <see cref="GameSettings"/> or <see cref="TimeSettings"/>).
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.JsonAssetProxy" />
+    [ContentContextMenu("New/Settings")]
     public class SettingsProxy : JsonAssetProxy
     {
         private readonly Type _type;
@@ -20,9 +21,6 @@ namespace FlaxEditor.Content
         /// Gets the settings type.
         /// </summary>
         public Type Type => _type;
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Settings";
 
         /// <summary>
         /// Initializes a new instance of the <see cref="SettingsProxy"/> class.

Source/Editor/Content/Proxy/ShaderProxy.cs

@@ -14,9 +14,6 @@ namespace FlaxEditor.Content
     {
         /// <inheritdoc />
         public override string Name => "Shader";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Shader";
 
         /// <inheritdoc />
         public override bool CanReimport(ContentItem item)

Source/Editor/Content/Proxy/SkeletonMaskProxy.cs

@@ -11,13 +11,11 @@ namespace FlaxEditor.Content
     /// A <see cref="SkeletonMask"/> asset proxy object.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.BinaryAssetProxy" />
+    [ContentContextMenu("New/Animation/Skeleton Mask")]
     public class SkeletonMaskProxy : BinaryAssetProxy
     {
         /// <inheritdoc />
         public override string Name => "Skeleton Mask";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Animation";
 
         /// <inheritdoc />
         public override EditorWindow Open(Editor editor, ContentItem item)

Source/Editor/Content/Proxy/SkinnedModelProxy.cs

@@ -20,9 +20,6 @@ namespace FlaxEditor.Content
 
         /// <inheritdoc />
         public override string Name => "Skinned Model";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Model";
 
         /// <inheritdoc />
         public override bool CanReimport(ContentItem item)

Source/Editor/Content/Proxy/SpriteAtlasProxy.cs

@@ -20,9 +20,6 @@ namespace FlaxEditor.Content
 
         /// <inheritdoc />
         public override string Name => "Sprite Atlas";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Sprites";
 
         /// <inheritdoc />
         public override bool CanReimport(ContentItem item)

Source/Editor/Content/Proxy/TextureProxy.cs

@@ -20,9 +20,6 @@ namespace FlaxEditor.Content
 
         /// <inheritdoc />
         public override string Name => "Texture";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Texture";
 
         /// <inheritdoc />
         public override bool CanReimport(ContentItem item)

Source/Editor/Content/Proxy/VisualScriptProxy.cs

@@ -15,6 +15,7 @@ namespace FlaxEditor.Content
     /// A <see cref="VisualScript"/> asset proxy object.
     /// </summary>
     /// <seealso cref="FlaxEditor.Content.BinaryAssetProxy" />
+    [ContentContextMenu("New/Visual Script")]
     public class VisualScriptProxy : BinaryAssetProxy, IScriptTypesContainer
     {
         internal VisualScriptProxy()
@@ -24,9 +25,6 @@ namespace FlaxEditor.Content
 
         /// <inheritdoc />
         public override string Name => "Visual Script";
-        
-        /// <inheritdoc />
-        public override string CategoryName => "Scripting";
 
         /// <inheritdoc />
         public override EditorWindow Open(Editor editor, ContentItem item)

Source/Editor/Modules/ContentDatabaseModule.cs

@@ -927,9 +927,7 @@ namespace FlaxEditor.Modules
             Proxy.Add(new VisualScriptProxy());
             Proxy.Add(new LocalizedStringTableProxy());
             Proxy.Add(new FileProxy());
-            var pm = new SpawnableJsonAssetProxy<PhysicalMaterial>();
+            Proxy.Add(new SpawnableJsonAssetProxy<PhysicalMaterial>());
-            pm.SetCategoryName("Physics");
-            Proxy.Add(pm);
 
             // Settings
             Proxy.Add(new SettingsProxy(typeof(GameSettings), Editor.Instance.Icons.GameSettings128));

Source/Editor/Windows/ContentWindow.ContextMenu.cs

@@ -1,6 +1,7 @@
 // Copyright (c) 2012-2022 Wojciech Figat. All rights reserved.
 
 using System;
+using System.CodeDom;
 using System.Collections.Generic;
 using System.Linq;
 using FlaxEditor.Content;
@@ -152,64 +153,78 @@ namespace FlaxEditor.Windows
             {
                 cm.AddButton("New folder", NewFolder);
             }
-
+            
-            // categorize the asset proxies according to their category name
+            // loop through each proxy and user defined json type and add them to the context menu
-            Dictionary<string, List<AssetProxy>> categorizedProxyList = new Dictionary<string, List<AssetProxy>>();
+            foreach (var type in Editor.CodeEditing.All.Get())
-            for (int i = 0; i < Editor.ContentDatabase.Proxy.Count; i++)
             {
-                var p = Editor.ContentDatabase.Proxy[i];
+                if (type.IsAbstract || !type.HasAttribute(typeof(ContentContextMenuAttribute), true))
+                    continue;
+                
+                ContentContextMenuAttribute attribute = null;
+                foreach (var typeAttribute in type.GetAttributes(true))
+                {
+                    if (typeAttribute is ContentContextMenuAttribute contentContextMenuAttribute)
+                    {
+                        attribute = contentContextMenuAttribute;
+                        break;
+                    }
+                }
+
+                ContentProxy p;
+                if (type.Type.IsSubclassOf(typeof(ContentProxy)))
+                {
+                    p = Editor.ContentDatabase.Proxy.Find(T => T.GetType() == type.Type);
+                }
+                else
+                {
+                    // user can use attribute to put their own assets into the content context menu
+                    var generic = typeof(SpawnableJsonAssetProxy<>).MakeGenericType(type.Type);
+                    var instance = Activator.CreateInstance(generic);
+                    dynamic obj = instance;
+                    p = obj as AssetProxy;
+                }
+                
+                if (p == null)
+                    continue;
+                
+                // create menus
                 if (p.CanCreate(folder))
                 {
-                    if (p is AssetProxy ap)
+                    var splitPath = attribute.Path.Split('/');
+                    ContextMenuChildMenu childCM = null;
+                    bool mainCM = true;
+                    for (int i = 0; i < splitPath?.Length; i++)
                     {
-                        if (categorizedProxyList.ContainsKey(ap.CategoryName))
+                        if (i == splitPath.Length - 1)
                         {
-                            categorizedProxyList.TryGetValue(ap.CategoryName, out var apList);
+                            if (mainCM)
-                            apList?.Add(ap);
+                            {
+                                cm.AddButton(splitPath[i].Trim(), () => NewItem(p));
+                                mainCM = false;
+                            }
+                            else
+                            {
+                                childCM?.ContextMenu.AddButton(splitPath[i].Trim(), () => NewItem(p));
+                                childCM.ContextMenu.AutoSort = true;
+                            }
                         }
                         else
                         {
-                            categorizedProxyList.Add(ap.CategoryName, new List<AssetProxy>() {ap});
+                            if (mainCM)
+                            {
+                                childCM = cm.GetOrAddChildMenu(splitPath[i].Trim());
+                                mainCM = false;
+                            }
+                            else
+                            {
+                                childCM = childCM?.ContextMenu.GetOrAddChildMenu(splitPath[i].Trim());
+                            }
+                            childCM.ContextMenu.AutoSort = true;
                         }
                     }
                 }
             }
             
-            c = cm.AddChildMenu("New");
-            c.ContextMenu.Tag = item;
-            c.ContextMenu.AutoSort = true;
-            int newItems = 0;
-            for (int i = 0; i < Editor.ContentDatabase.Proxy.Count; i++)
-            {
-                var p = Editor.ContentDatabase.Proxy[i];
-                if (p.CanCreate(folder))
-                {
-                    if (p is AssetProxy ap && categorizedProxyList.TryGetValue(ap.CategoryName, out var apList))
-                    {
-                        if (apList.Contains(ap))
-                        {
-                            if (apList.Count > 1)
-                            {
-                                var childMenu = c.ContextMenu.GetOrAddChildMenu(ap.CategoryName);
-                                childMenu.ContextMenu.AutoSort = true;
-                                childMenu.ContextMenu.AddButton(p.Name, () => NewItem(p));
-                            }
-                            else
-                            {
-                                c.ContextMenu.AddButton(p.Name, () => NewItem(p));
-                            }
-                        }
-                    }
-                    else
-                    {
-                        c.ContextMenu.AddButton(p.Name, () => NewItem(p));
-                    }
-
-                    newItems++;
-                }
-            }
-            c.Enabled = newItems > 0;
-
             if (folder.CanHaveAssets)
             {
                 cm.AddButton("Import file", () =>

Source/Engine/Physics/PhysicalMaterial.h

@@ -8,7 +8,7 @@
 /// <summary>
 /// Physical materials are used to define the response of a physical object when interacting dynamically with the world.
 /// </summary>
-API_CLASS() class FLAXENGINE_API PhysicalMaterial final : public ISerializable
+API_CLASS(Attributes = "ContentContextMenu(\"New/Physics/Physical Material\")") class FLAXENGINE_API PhysicalMaterial final : public ISerializable
 {
     API_AUTO_SERIALIZATION();
     DECLARE_SCRIPTING_TYPE_MINIMAL(PhysicalMaterial);

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

@@ -0,0 +1,26 @@
+using System;
+
+namespace FlaxEngine
+{
+    /// <summary>
+    /// This attribute is used to show content items that can be created in the content browser context menu. Separate the subcontext menus with a /. 
+    /// </summary>
+    [Serializable]
+    [AttributeUsage(AttributeTargets.Class)]
+    public class ContentContextMenuAttribute : Attribute
+    {
+        /// <summary>
+        /// The path to be used in the context menu
+        /// </summary>
+        public string Path;
+
+        /// <summary>
+        /// Initializes a new instance of the  <see cref="ContentContextMenuAttribute"/> class.
+        /// </summary>
+        /// <param name="path">The path to use to create the context menu</param>
+        public ContentContextMenuAttribute(string path)
+        {
+            Path = path;
+        }
+    }
+}