Add Actor.HasScene and Script.HasScene

Useful in managed code to check the existence of the scene in hot paths
by avoiding expensive marshalling of the Scene object.

Source/Editor/Content/Proxy/PrefabProxy.cs

@@ -89,7 +89,7 @@ namespace FlaxEditor.Content
                 // Cleanup it after usage
                 Object.Destroy(actor, 20.0f);
             }
-            else if (actor.Scene != null)
+            else if (actor.HasScene)
             {
                 // Create prefab with identity transform so the actor instance on a level will have it customized
                 resetTransform = true;

Source/Editor/CustomEditors/Dedicated/ActorEditor.cs

@@ -291,7 +291,7 @@ namespace FlaxEditor.CustomEditors.Dedicated
             if (editor.ChildrenEditors.Count == 0 || (isRefEdited && editor is CollectionEditor))
                 result = CreateDiffNode(editor);
             bool isScriptEditorWithRefValue = editor is ScriptsEditor && editor.Values.HasReferenceValue;
-            bool isActorEditorInLevel = editor is ActorEditor && editor.Values[0] is Actor actor && actor.IsPrefabRoot && actor.Scene != null;
+            bool isActorEditorInLevel = editor is ActorEditor && editor.Values[0] is Actor actor && actor.IsPrefabRoot && actor.HasScene;
             for (int i = 0; i < editor.ChildrenEditors.Count; i++)
             {
                 var childEditor = editor.ChildrenEditors[i];

Source/Editor/Modules/PrefabsModule.cs

@@ -227,7 +227,7 @@ namespace FlaxEditor.Modules
 
             // When applying changes to prefab from actor in level ignore it's root transformation (see ActorEditor.ProcessDiff)
             var originalTransform = instance.LocalTransform;
-            if (instance.IsPrefabRoot && instance.Scene != null)
+            if (instance.IsPrefabRoot && instance.HasScene)
                 instance.LocalTransform = prefab.GetDefaultInstance().Transform;
 
             // Call backend

Source/Editor/SceneGraph/GUI/ActorTreeNode.cs

@@ -68,7 +68,7 @@ namespace FlaxEditor.SceneGraph.GUI
                 Visible = (actor.HideFlags & HideFlags.HideInHierarchy) == 0;
 
                 // Pick the correct id when inside a prefab window.
-                var id = actor.HasPrefabLink && actor.Scene == null ? actor.PrefabObjectID : actor.ID;
+                var id = actor.HasPrefabLink && !actor.HasScene ? actor.PrefabObjectID : actor.ID;
                 if (Editor.Instance.ProjectCache.IsExpandedActor(ref id))
                 {
                     Expand(true);
@@ -291,7 +291,7 @@ namespace FlaxEditor.SceneGraph.GUI
                         return Style.Current.ForegroundGrey;
                     }
 
-                    if (actor.Scene != null && Editor.Instance.StateMachine.IsPlayMode && actor.IsStatic)
+                    if (actor.HasScene && Editor.Instance.StateMachine.IsPlayMode && actor.IsStatic)
                     {
                         // Static
                         return color * 0.85f;
@@ -366,7 +366,7 @@ namespace FlaxEditor.SceneGraph.GUI
             if (!IsLayoutLocked && actor)
             {
                 // Pick the correct id when inside a prefab window.
-                var id = actor.HasPrefabLink && actor.Scene == null ? actor.PrefabObjectID : actor.ID;
+                var id = actor.HasPrefabLink && !actor.HasScene ? actor.PrefabObjectID : actor.ID;
                 Editor.Instance.ProjectCache.SetExpandedActor(ref id, IsExpanded);
             }
         }
@@ -640,8 +640,8 @@ namespace FlaxEditor.SceneGraph.GUI
         private bool ValidateDragScript(Script script)
         {
             // Reject dragging scripts not linked to scene (eg. from prefab) or in the opposite way
-            var thisHasScene = Actor.Scene != null;
-            var otherHasScene = script.Scene != null;
+            var thisHasScene = Actor.HasScene;
+            var otherHasScene = script.HasScene;
             if (thisHasScene != otherHasScene)
                 return false;
 

Source/Editor/SceneGraph/LocalSceneGraph.cs

@@ -91,7 +91,7 @@ namespace FlaxEditor.SceneGraph
         private void OnActorSpawned(Actor actor)
         {
             // Skip actors from game
-            if (actor.Scene != null)
+            if (actor.HasScene)
                 return;
 
             // Check if it has parent

Source/Engine/Level/Actor.h

@@ -382,6 +382,15 @@ public:
         return _isActiveInHierarchy != 0;
     }
 
+    /// <summary>
+    /// Gets value indicating if actor is in a scene.
+    /// </summary>
+    API_PROPERTY(Attributes="HideInEditor, NoSerialize")
+    FORCE_INLINE bool HasScene() const
+    {
+        return _scene != nullptr;
+    }
+
     /// <summary>
     /// Returns true if object is fully static on the scene, otherwise false.
     /// </summary>

Source/Engine/Scripting/Script.cs

@@ -17,6 +17,12 @@ namespace FlaxEngine
             }
         }
 
+        /// <summary>
+        /// Gets value indicating if the actor owning the script is in a scene.
+        /// </summary>
+        [HideInEditor, NoSerialize]
+        public bool HasScene => Actor?.HasScene ?? false; 
+
         /// <summary>
         /// Gets or sets the world space transformation of the actors owning this script.
         /// </summary>