Fix spawned in Editor actor RigidBody to never be static

Source/Editor/SceneGraph/Actors/RigidBodyNode.cs

@@ -0,0 +1,29 @@
+// Copyright (c) Wojciech Figat. All rights reserved.
+
+using FlaxEngine;
+
+namespace FlaxEditor.SceneGraph.Actors
+{
+    /// <summary>
+    /// Scene tree node for <see cref="RigidBody"/> actor type.
+    /// </summary>
+    [HideInEditor]
+    public sealed class RigidBodyNode : ActorNode
+    {
+        /// <inheritdoc />
+        public RigidBodyNode(Actor actor)
+        : base(actor)
+        {
+        }
+
+        /// <inheritdoc />
+        public override void PostSpawn()
+        {
+            base.PostSpawn();
+
+            if (HasPrefabLink)
+                return;
+            Actor.StaticFlags = StaticFlags.None;
+        }
+    }
+}

Source/Editor/SceneGraph/SceneGraphFactory.cs

@@ -74,6 +74,7 @@ namespace FlaxEditor.SceneGraph
             CustomNodesTypes.Add(typeof(NavMesh), typeof(ActorNode));
             CustomNodesTypes.Add(typeof(SpriteRender), typeof(SpriteRenderNode));
             CustomNodesTypes.Add(typeof(Joint), typeof(JointNode));
+            CustomNodesTypes.Add(typeof(RigidBody), typeof(RigidBodyNode));
         }
 
         /// <summary>