Optimize ViewportRubberBandSelector

#3151

Source/Editor/SceneGraph/ActorNode.cs

@@ -188,25 +188,28 @@ namespace FlaxEditor.SceneGraph
         /// <returns>An array of ActorNodes</returns>
         public ActorNode[] GetAllChildActorNodes()
         {
-            // Check itself
-            if (ChildNodes == null || ChildNodes.Count == 0)
-                return [];
-
-            // Check deeper
             var nodes = new List<ActorNode>();
-            for (int i = 0; i < ChildNodes.Count; i++)
+            GetAllChildActorNodes(nodes);
+            return nodes.ToArray();
+        }
+        
+        /// <summary>
+        /// Get all nested actor nodes under this actor node.
+        /// </summary>
+        /// <param name="nodes">The output list to fill with results.</param>
+        public void GetAllChildActorNodes(List<ActorNode> nodes)
+        {
+            var children = ChildNodes;
+            if (children == null)
+                return;
+            for (int i = 0; i < children.Count; i++)
             {
-                if (ChildNodes[i] is ActorNode node)
+                if (children[i] is ActorNode node)
                 {
                     nodes.Add(node);
-                    var childNodes = node.GetAllChildActorNodes();
-                    if (childNodes.Length > 0)
-                    {
-                        nodes.AddRange(childNodes);
-                    }
+                    node.GetAllChildActorNodes(nodes);
                 }
             }
-            return nodes.ToArray();
         }
 
         /// <summary>

Source/Editor/SceneGraph/Actors/StaticModelNode.cs

@@ -24,6 +24,9 @@ namespace FlaxEditor.SceneGraph.Actors
     public sealed class StaticModelNode : ActorNode
     {
         private Dictionary<IntPtr, Mesh.Vertex[]> _vertices;
+        private Vector3[] _selectionPoints;
+        private Transform _selectionPointsTransform;
+        private Model _selectionPointsModel;
 
         /// <inheritdoc />
         public StaticModelNode(Actor actor)
@@ -31,6 +34,16 @@ namespace FlaxEditor.SceneGraph.Actors
         {
         }
 
+        /// <inheritdoc />
+        public override void OnDispose()
+        {
+            _vertices = null;
+            _selectionPoints = null;
+            _selectionPointsModel = null;
+
+            base.OnDispose();
+        }
+
         /// <inheritdoc />
         public override bool OnVertexSnap(ref Ray ray, Real hitDistance, out Vector3 result)
         {
@@ -91,25 +104,40 @@ namespace FlaxEditor.SceneGraph.Actors
         /// <inheritdoc />
         public override Vector3[] GetActorSelectionPoints()
         {
-            if (Actor is not StaticModel sm || !sm.Model)
-                return base.GetActorSelectionPoints();
-
-            // Check collision proxy points for more accurate selection.
-            var vecPoints = new List<Vector3>();
-            var m = sm.Model.LODs[0];
-            foreach (var mesh in m.Meshes)
+            if (Actor is StaticModel sm && sm.Model)
             {
-                var points = mesh.GetCollisionProxyPoints();
-                foreach (var point in points)
+                // Try to use cache
+                var model = sm.Model;
+                var transform = Actor.Transform;
+                if (_selectionPoints != null && 
+                    _selectionPointsTransform == transform && 
+                    _selectionPointsModel == model)
+                    return _selectionPoints;
+                Profiler.BeginEvent("GetActorSelectionPoints");
+
+                // Check collision proxy points for more accurate selection
+                var vecPoints = new List<Vector3>();
+                var m = model.LODs[0];
+                foreach (var mesh in m.Meshes)
                 {
-                    vecPoints.Add(Actor.Transform.LocalToWorld(point));
+                    var points = mesh.GetCollisionProxyPoints();
+                    vecPoints.EnsureCapacity(vecPoints.Count + points.Length);
+                    for (int i = 0; i < points.Length; i++)
+                    {
+                        vecPoints.Add(transform.LocalToWorld(points[i]));
+                    }
+                }
+
+                Profiler.EndEvent();
+                if (vecPoints.Count != 0)
+                {
+                    _selectionPoints = vecPoints.ToArray();
+                    _selectionPointsTransform = transform;
+                    _selectionPointsModel = model;
+                    return _selectionPoints;
                 }
             }
-            
-            // Fall back to base actor editor box if no points from collision proxy.
-            if (vecPoints.Count == 0)
-                return base.GetActorSelectionPoints();
-            return vecPoints.ToArray();
+            return base.GetActorSelectionPoints();
         }
 
         private void OnAddMeshCollider(EditorWindow window)