diff --git a/src/java/com/threerings/jme/model/Model.java b/src/java/com/threerings/jme/model/Model.java
index cfc4168c..d11dd6a9 100644
--- a/src/java/com/threerings/jme/model/Model.java
+++ b/src/java/com/threerings/jme/model/Model.java
@@ -794,7 +794,8 @@ public class Model extends ModelNode
                 getWorldTranslation(), getWorldScale(), worldBound);
             
         } else {
-            super.updateGeometricState(_accum, initiator);
+            super.updateGeometricState(_shouldAccumulate ? _accum : time,
+                initiator);
             _accum = 0f;
         }
     }
@@ -847,7 +848,9 @@ public class Model extends ModelNode
         // initialize the controllers
         for (Object ctrl : getControllers()) {
             if (ctrl instanceof ModelController) {
-                ((ModelController)ctrl).init(this);
+                ModelController mctrl = (ModelController)ctrl;
+                mctrl.init(this);
+                _shouldAccumulate |= mctrl.shouldAccumulate();
             }
         }
     }
@@ -1004,6 +1007,9 @@ public class Model extends ModelNode
     /** The amount of update time accumulated while outside of view frustum. */
     protected float _accum;
     
+    /** Whether or not we should accumulate update time while out of view. */
+    protected boolean _shouldAccumulate;
+    
     /** The child node that contains the model's emissions in world space. */
     protected Node _emissionNode;
     
diff --git a/src/java/com/threerings/jme/model/ModelController.java b/src/java/com/threerings/jme/model/ModelController.java
index f129c7f7..e3d8b18d 100644
--- a/src/java/com/threerings/jme/model/ModelController.java
+++ b/src/java/com/threerings/jme/model/ModelController.java
@@ -84,6 +84,16 @@ public abstract class ModelController extends Controller
         }
     }
     
+    /**
+     * Determines whether the controller updates should include time
+     * accumulated while the model was out of sight.  Accumulating will
+     * be turned off only if all controllers are non-accumulating.
+     */
+    public boolean shouldAccumulate ()
+    {
+        return true;
+    }
+    
     /**
      * Creates or populates and returns a clone of this object using the given
      * clone properties.
diff --git a/src/java/com/threerings/jme/model/ModelNode.java b/src/java/com/threerings/jme/model/ModelNode.java
index 9af6b79e..10478582 100644
--- a/src/java/com/threerings/jme/model/ModelNode.java
+++ b/src/java/com/threerings/jme/model/ModelNode.java
@@ -107,9 +107,8 @@ public class ModelNode extends Node
     @Override // documentation inherited
     public void updateWorldBound ()
     {
-        // if the node is culled, there are no mesh descendants and thus no
-        // bounds
-        if (cullMode != CULL_ALWAYS) {
+        // don't bother updating if we know there are no visible descendants
+        if (_hasVisibleDescendants) {
             super.updateWorldBound();
         }
     }
@@ -171,6 +170,7 @@ public class ModelNode extends Node
                     ((ModelSpatial)child).putClone(null, properties));
             }
         }
+        mstore._hasVisibleDescendants = _hasVisibleDescendants;
         return mstore;
     }
     
@@ -327,16 +327,15 @@ public class ModelNode extends Node
      */
     protected boolean cullInvisibleNodes ()
     {
-        boolean hasVisibleDescendants = false;
         for (int ii = 0, nn = getQuantity(); ii < nn; ii++) {
             Spatial child = getChild(ii);
             if (!(child instanceof ModelNode) ||
                 ((ModelNode)child).cullInvisibleNodes()) {
-                hasVisibleDescendants = true;
+                _hasVisibleDescendants = true;
             }
         }
-        setCullMode(hasVisibleDescendants ? CULL_INHERIT : CULL_ALWAYS);
-        return hasVisibleDescendants;
+        setCullMode(_hasVisibleDescendants ? CULL_INHERIT : CULL_ALWAYS);
+        return _hasVisibleDescendants;
     }
     
     /**
@@ -403,5 +402,8 @@ public class ModelNode extends Node
     protected Matrix4f _localTransform = new Matrix4f(),
         _modelTransform = new Matrix4f();
 
+    /** Whether or not this node has mesh descendants. */
+    protected boolean _hasVisibleDescendants;
+    
     private static final long serialVersionUID = 1;
 }