diff --git a/wh-engine/actor.lisp b/wh-engine/actor.lisp
index 9354fb3..2dccec8 100644
--- a/wh-engine/actor.lisp
+++ b/wh-engine/actor.lisp
@@ -15,6 +15,7 @@
    (scene :documentation "The scene containing this actor."
           :reader scene
           :type pointer
+          :initarg :scene
           :initform nil)
    (tags :documentation "This actor's tags."
          :reader tags
@@ -87,6 +88,12 @@
   "Whether or not this actor and all its parents are active."
   (and [this active-p] (not [this :slot blocked-p])))
 
+(defmethod apply-to-tree ((this actor) fun)
+  (funcall fun this)
+  (loop for child-ptr in [this children]
+        when (typep child-ptr 'weak-pointer)
+          do [(weak-pointer-value child-ptr) (apply-to-tree fun)]))
+
 (defmethod print-object ((this actor) stream)
   (print-unreadable-object (this stream :type t :identity t)
     (prin1 [this :slot id] stream)
diff --git a/wh-engine/main.lisp b/wh-engine/main.lisp
index d8aaa90..bb45251 100644
--- a/wh-engine/main.lisp
+++ b/wh-engine/main.lisp
@@ -98,6 +98,20 @@
   "Get a scene by its ID."
   (find-if (lambda (scene) (eq [scene id] scene-id)) *world-scenes*))
 
+(defun attach-actor-to-world (actor scene)
+  "Properly attach actor and its descendents to scene, and initialize them."
+  ;; attach actors to scene
+  (apply-to-tree actor (lambda (a)
+                         (setf [a :slot scene] nil)
+                         [scene (add-actor a)]))
+  ;; (resume) -> automatically resumes children
+  [actor (resume)]
+  ;; FIXME make (activate) call itself recursively on children
+  (apply-to-tree actor (lambda (a)
+                         (when [a tree-active-p]
+                               [a (activate)])))
+  )
+
 (defvar *view-width* 384
   "View-space width in pixels.")
 (defvar *view-height* 256
@@ -122,7 +136,7 @@
 
     (setf test-actor (make-instance 'actor
                                     :name "Actor"))
-    [test-scene (add-actor test-actor)]
+    ;; [test-scene (add-actor test-actor)]
 
     (setf test-drawable (make-instance 'drawable-test))
     [test-actor (add-component test-drawable)]
@@ -132,7 +146,7 @@
                                       :location (vec2 0.5 0.5)
                                       :rotation (coerce (/ pi 4) 'single-float)
                                       :z-layer -1))
-    [test-scene (add-actor test-actor-2)]
+    ;; [test-scene (add-actor test-actor-2)]
 
     [test-actor-2 (add-component (make-instance 'drawable-test
                                                 :colour (vec4 0.0 1.0 0.0 1.0)))
@@ -142,7 +156,7 @@
                                      :name "Child Actor"
                                      :location (vec2 0 0.5)
                                      :z-layer -2))
-    [test-scene (add-actor child-actor)]
+    ;; [test-scene (add-actor child-actor)]
     [test-actor-2 (add-child child-actor)]
 
     [child-actor (add-component (make-instance 'drawable-test
@@ -154,7 +168,7 @@
                                           :location (vec2 0 1)
                                           :scale (vec2 0.25 0.25)
                                           :z-layer 1))
-    [test-scene (add-actor grandchild-actor)]
+    ;; [test-scene (add-actor grandchild-actor)]
     [child-actor (add-child grandchild-actor)]
 
     [grandchild-actor (add-component (make-instance 'drawable-test
@@ -163,11 +177,15 @@
 
     (setf camera-actor (make-instance 'actor
                                       :name "Camera"))
-    [test-scene (add-actor camera-actor)]
+    ;; [test-scene (add-actor camera-actor)]
 
     (setf camera-view (make-instance 'view))
     [camera-actor (add-component camera-view)]
 
+    (attach-actor-to-world test-actor test-scene)
+    (attach-actor-to-world test-actor-2 test-scene)
+    (attach-actor-to-world camera-actor test-scene)
+
     test-scene))
 
 (defun run ()