diff --git a/assignment-client/src/Agent.cpp b/assignment-client/src/Agent.cpp
index 157154606f..d9109703cb 100644
--- a/assignment-client/src/Agent.cpp
+++ b/assignment-client/src/Agent.cpp
@@ -233,8 +233,8 @@ void Agent::setIsAvatar(bool isAvatar) {
         }
         
         if (_avatarBillboardTimer) {
-            _avatarIdentityTimer->stop();
-            delete _avatarIdentityTimer;
+            _avatarBillboardTimer->stop();
+            delete _avatarBillboardTimer;
             _avatarBillboardTimer = nullptr;
         }
     }
@@ -364,10 +364,15 @@ void Agent::processAgentAvatarAndAudio(float deltaTime) {
 }
 
 void Agent::aboutToFinish() {
-    _scriptEngine->stop();
+    setIsAvatar(false);// will stop timers for sending billboards and identity packets
+    if (_scriptEngine) {
+        _scriptEngine->stop();
+    }
 
-    _pingTimer->stop();
-    delete _pingTimer;
+    if (_pingTimer) {
+        _pingTimer->stop();
+        delete _pingTimer;
+    }
 
     // our entity tree is going to go away so tell that to the EntityScriptingInterface
     DependencyManager::get<EntityScriptingInterface>()->setEntityTree(NULL);
diff --git a/assignment-client/src/octree/OctreeInboundPacketProcessor.cpp b/assignment-client/src/octree/OctreeInboundPacketProcessor.cpp
index 4ae07042e8..cb94990037 100644
--- a/assignment-client/src/octree/OctreeInboundPacketProcessor.cpp
+++ b/assignment-client/src/octree/OctreeInboundPacketProcessor.cpp
@@ -238,7 +238,6 @@ int OctreeInboundPacketProcessor::sendNackPackets() {
         return 0;
     }
 
-    auto nackPacketList = NLPacketList::create(_myServer->getMyEditNackType());
     auto nodeList = DependencyManager::get<NodeList>();
     int packetsSent = 0;
 
@@ -272,18 +271,19 @@ int OctreeInboundPacketProcessor::sendNackPackets() {
 
         auto it = missingSequenceNumbers.constBegin();
 
-        while (it != missingSequenceNumbers.constEnd()) {
-            unsigned short int sequenceNumber = *it;
-            nackPacketList->writePrimitive(sequenceNumber);
-            ++it;
-        }
-        
-        
-        if (nackPacketList->getNumPackets()) {
+        if (it != missingSequenceNumbers.constEnd()) {
+            auto nackPacketList = NLPacketList::create(_myServer->getMyEditNackType());
+
+            while (it != missingSequenceNumbers.constEnd()) {
+                unsigned short int sequenceNumber = *it;
+                nackPacketList->writePrimitive(sequenceNumber);
+                ++it;
+            }
+
             qDebug() << "NACK Sent back to editor/client... destinationNode=" << nodeUUID;
-            
+
             packetsSent += nackPacketList->getNumPackets();
-            
+
             // send the list of nack packets
             nodeList->sendPacketList(std::move(nackPacketList), *destinationNode);
         }
diff --git a/examples/actionInspector.js b/examples/actionInspector.js
new file mode 100644
index 0000000000..934120ddf6
--- /dev/null
+++ b/examples/actionInspector.js
@@ -0,0 +1,146 @@
+//
+//  actionInspector.js
+//  examples
+//
+//  Created by Seth Alves on 2015-9-30.
+//  Copyright 2015 High Fidelity, Inc.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+
+Script.include("libraries/utils.js");
+
+
+var INSPECT_RADIUS = 10;
+var overlays = {};
+
+
+var toType = function(obj) {
+  return ({}).toString.call(obj).match(/\s([a-zA-Z]+)/)[1].toLowerCase()
+}
+
+
+function actionArgumentsToString(actionArguments) {
+    var result = "type: " + actionArguments["type"] + "\n";
+    for (var argumentName in actionArguments) {
+        if (actionArguments.hasOwnProperty(argumentName)) {
+            if (argumentName == "type") {
+                continue;
+            }
+            var arg = actionArguments[argumentName];
+            var argType = toType(arg);
+            var argString = arg;
+            if (argType == "object") {
+                if (Object.keys(arg).length == 3) {
+                    argString = vec3toStr(arg, 1);
+                }
+            } else if (argType == "number") {
+                argString = arg.toFixed(2);
+            }
+            result += argumentName + ": "
+                // + toType(arg) + " -- "
+                + argString + "\n";
+        }
+    }
+
+    return result;
+}
+
+
+function updateOverlay(entityID, actionText) {
+    var properties = Entities.getEntityProperties(entityID, ["position", "dimensions"]);
+    var position = Vec3.sum(properties.position, {x:0, y:properties.dimensions.y, z:0});
+    // print("position: " + vec3toStr(position) + " " + actionText);
+    if (entityID in overlays) {
+        var overlay = overlays[entityID];
+        Overlays.editOverlay(overlay, {
+            text: actionText,
+            position: position
+        });
+    } else {
+        var lines = actionText.split(/\r\n|\r|\n/);
+
+        var maxLineLength = lines[0].length;
+        for (var i = 1; i < lines.length; i++) {
+            if (lines[i].length > maxLineLength) {
+                maxLineLength = lines[i].length;
+            }
+        }
+
+        var textWidth = maxLineLength * 0.034; // XXX how to know this?
+        var textHeight = .5;
+        var numberOfLines = lines.length;
+        var textMargin = 0.05;
+        var lineHeight = (textHeight - (2 * textMargin)) / numberOfLines;
+
+        overlays[entityID] = Overlays.addOverlay("text3d", {
+            position: position,
+            dimensions: { x: textWidth, y: textHeight },
+            backgroundColor: { red: 0, green: 0, blue: 0},
+            color: { red: 255, green: 255, blue: 255},
+            topMargin: textMargin,
+            leftMargin: textMargin,
+            bottomMargin: textMargin,
+            rightMargin: textMargin,
+            text: actionText,
+            lineHeight: lineHeight,
+            alpha: 0.9,
+            backgroundAlpha: 0.9,
+            ignoreRayIntersection: true,
+            visible: true,
+            isFacingAvatar: true
+        });
+    }
+}
+
+
+function cleanup() {
+    for (var entityID in overlays) {
+        Overlays.deleteOverlay(overlays[entityID]);
+    }
+}
+
+
+Script.setInterval(function() {
+    var nearbyEntities = Entities.findEntities(MyAvatar.position, INSPECT_RADIUS);
+    for (var entityIndex = 0; entityIndex < nearbyEntities.length; entityIndex++) {
+        var entityID = nearbyEntities[entityIndex];
+        var actionIDs = Entities.getActionIDs(entityID);
+        var actionText = ""
+        for (var actionIndex = 0; actionIndex < actionIDs.length; actionIndex++) {
+            var actionID = actionIDs[actionIndex];
+            var actionArguments = Entities.getActionArguments(entityID, actionID);
+            var actionArgumentText = actionArgumentsToString(actionArguments);
+            if (actionArgumentText != "") {
+                actionText += "-----------------\n";
+                actionText += actionArgumentText;
+            }
+        }
+        if (actionText != "") {
+            updateOverlay(entityID, actionText);
+        }
+
+        // if an entity no longer has an action, remove its overlay
+        if (actionIDs.length == 0) {
+            if (entityID in overlays) {
+                Overlays.deleteOverlay(overlays[entityID]);
+                delete overlays[entityID];
+            }
+        }
+    }
+
+
+    // if an entity is too far away, remove its overlay
+    for (var entityID in overlays) {
+        var position = Entities.getEntityProperties(entityID, ["position"]).position;
+        if (Vec3.distance(position, MyAvatar.position) > INSPECT_RADIUS) {
+            Overlays.deleteOverlay(overlays[entityID]);
+            delete overlays[entityID];
+        }
+    }
+
+}, 100);
+
+
+Script.scriptEnding.connect(cleanup);
diff --git a/examples/controllers/handControllerGrab.js b/examples/controllers/handControllerGrab.js
index 388c042285..5705bd4498 100644
--- a/examples/controllers/handControllerGrab.js
+++ b/examples/controllers/handControllerGrab.js
@@ -66,6 +66,7 @@ var MSEC_PER_SEC = 1000.0;
 // these control how long an abandoned pointer line will hang around
 var startTime = Date.now();
 var LIFETIME = 10;
+var ACTION_LIFETIME = 10; // seconds
 
 // states for the state machine
 var STATE_OFF = 0;
@@ -81,14 +82,25 @@ var STATE_RELEASE = 8;
 var GRAB_USER_DATA_KEY = "grabKey";
 var GRABBABLE_DATA_KEY = "grabbableKey";
 
-// HACK -- until we have collision groups, don't allow held object to collide with avatar
-var AVATAR_COLLISIONS_MENU_ITEM = "Enable avatar collisions";
+function getTag() {
+    return "grab-" + MyAvatar.sessionUUID;
+}
 
-
-// HACK -- until we have collision groups, don't allow held object to collide with avatar
-var initialAvatarCollisionsMenu = Menu.isOptionChecked(AVATAR_COLLISIONS_MENU_ITEM);
-var currentAvatarCollisionsMenu = initialAvatarCollisionsMenu;
-var noCollisionsCount = 0; // how many hands want collisions disabled?
+function entityIsGrabbedByOther(entityID) {
+    var actionIDs = Entities.getActionIDs(entityID);
+    for (var actionIndex = 0; actionIndex < actionIDs.length; actionIndex++) {
+        var actionID = actionIDs[actionIndex];
+        var actionArguments = Entities.getActionArguments(entityID, actionID);
+        var tag = actionArguments["tag"];
+        if (tag == getTag()) {
+            continue;
+        }
+        if (tag.slice(0, 5) == "grab-") {
+            return true;
+        }
+    }
+    return false;
+}
 
 
 function MyController(hand, triggerAction) {
@@ -152,28 +164,6 @@ function MyController(hand, triggerAction) {
         }
     };
 
-    // HACK -- until we have collision groups, don't allow held object to collide with avatar
-    this.disableAvatarCollisions = function() {
-        noCollisionsCount += 1;
-        if (currentAvatarCollisionsMenu != false) {
-            currentAvatarCollisionsMenu = false;
-            Menu.setIsOptionChecked(AVATAR_COLLISIONS_MENU_ITEM, false);
-            MyAvatar.updateMotionBehaviorFromMenu();
-        }
-    }
-
-    // HACK -- until we have collision groups, don't allow held object to collide with avatar
-    this.revertAvatarCollisions = function() {
-        noCollisionsCount -= 1;
-        if (noCollisionsCount < 1) {
-            if (currentAvatarCollisionsMenu != initialAvatarCollisionsMenu) {
-                currentAvatarCollisionsMenu = initialAvatarCollisionsMenu;
-                Menu.setIsOptionChecked(AVATAR_COLLISIONS_MENU_ITEM, initialAvatarCollisionsMenu);
-                MyAvatar.updateMotionBehaviorFromMenu();
-            }
-        }
-    }
-
     this.lineOn = function(closePoint, farPoint, color) {
         // draw a line
         if (this.pointer === null) {
@@ -267,6 +257,10 @@ function MyController(hand, triggerAction) {
                 this.state = STATE_NEAR_GRABBING;
 
             } else {
+                if (entityIsGrabbedByOther(intersection.entityID)) {
+                    // don't allow two people to distance grab the same object
+                    return;
+                }
                 // the hand is far from the intersected object.  go into distance-holding mode
                 this.state = STATE_DISTANCE_HOLDING;
                 this.lineOn(pickRay.origin, Vec3.multiply(pickRay.direction, LINE_LENGTH), NO_INTERSECT_COLOR);
@@ -306,9 +300,6 @@ function MyController(hand, triggerAction) {
 
     this.distanceHolding = function() {
 
-        // HACK -- until we have collision groups, don't allow held object to collide with avatar
-        this.disableAvatarCollisions();
-
         var handControllerPosition = Controller.getSpatialControlPosition(this.palm);
         var handRotation = Quat.multiply(MyAvatar.orientation, Controller.getSpatialControlRawRotation(this.palm));
         var grabbedProperties = Entities.getEntityProperties(this.grabbedEntity, ["position", "rotation"]);
@@ -320,11 +311,14 @@ function MyController(hand, triggerAction) {
         this.handPreviousPosition = handControllerPosition;
         this.handPreviousRotation = handRotation;
 
+        this.actionID = NULL_ACTION_ID;
         this.actionID = Entities.addAction("spring", this.grabbedEntity, {
             targetPosition: this.currentObjectPosition,
             linearTimeScale: DISTANCE_HOLDING_ACTION_TIMEFRAME,
             targetRotation: this.currentObjectRotation,
-            angularTimeScale: DISTANCE_HOLDING_ACTION_TIMEFRAME
+            angularTimeScale: DISTANCE_HOLDING_ACTION_TIMEFRAME,
+            tag: getTag(),
+            lifetime: ACTION_LIFETIME
         });
         if (this.actionID === NULL_ACTION_ID) {
             this.actionID = null;
@@ -348,9 +342,6 @@ function MyController(hand, triggerAction) {
 
     this.continueDistanceHolding = function() {
         if (this.triggerSmoothedReleased()) {
-            // HACK -- until we have collision groups, don't allow held object to collide with avatar
-            this.revertAvatarCollisions();
-
             this.state = STATE_RELEASE;
             return;
         }
@@ -390,11 +381,11 @@ function MyController(hand, triggerAction) {
         var handMovementFromTurning = Vec3.subtract(Quat.multiply(avatarDeltaOrientation, handToAvatar), handToAvatar); 
         var objectMovementFromTurning = Vec3.subtract(Quat.multiply(avatarDeltaOrientation, objectToAvatar), objectToAvatar); 
         this.currentAvatarOrientation = currentOrientation;
-      
+
         // how far did hand move this timestep?
         var handMoved = Vec3.subtract(handControllerPosition, this.handPreviousPosition);
         this.handPreviousPosition = handControllerPosition;
-        
+
         //  magnify the hand movement but not the change from avatar movement & rotation
         handMoved = Vec3.subtract(handMoved, avatarDeltaPosition);
         handMoved = Vec3.subtract(handMoved, handMovementFromTurning);
@@ -424,19 +415,14 @@ function MyController(hand, triggerAction) {
             targetPosition: this.currentObjectPosition,
             linearTimeScale: DISTANCE_HOLDING_ACTION_TIMEFRAME,
             targetRotation: this.currentObjectRotation,
-            angularTimeScale: DISTANCE_HOLDING_ACTION_TIMEFRAME
+            angularTimeScale: DISTANCE_HOLDING_ACTION_TIMEFRAME,
+            lifetime: ACTION_LIFETIME
         });
     };
 
     this.nearGrabbing = function() {
 
-        // HACK -- until we have collision groups, don't allow held object to collide with avatar
-        this.disableAvatarCollisions();
-
         if (this.triggerSmoothedReleased()) {
-            // HACK -- until we have collision groups, don't allow held object to collide with avatar
-            this.revertAvatarCollisions();
-            
             this.state = STATE_RELEASE;
             return;
         }
@@ -457,11 +443,13 @@ function MyController(hand, triggerAction) {
         var offset = Vec3.subtract(currentObjectPosition, handPosition);
         var offsetPosition = Vec3.multiplyQbyV(Quat.inverse(Quat.multiply(handRotation, offsetRotation)), offset);
 
+        this.actionID = NULL_ACTION_ID;
         this.actionID = Entities.addAction("hold", this.grabbedEntity, {
             hand: this.hand === RIGHT_HAND ? "right" : "left",
             timeScale: NEAR_GRABBING_ACTION_TIMEFRAME,
             relativePosition: offsetPosition,
-            relativeRotation: offsetRotation
+            relativeRotation: offsetRotation,
+            lifetime: ACTION_LIFETIME
         });
         if (this.actionID === NULL_ACTION_ID) {
             this.actionID = null;
@@ -483,9 +471,6 @@ function MyController(hand, triggerAction) {
 
     this.continueNearGrabbing = function() {
         if (this.triggerSmoothedReleased()) {
-            // HACK -- until we have collision groups, don't allow held object to collide with avatar
-            this.revertAvatarCollisions();
-            
             this.state = STATE_RELEASE;
             return;
         }
@@ -495,7 +480,7 @@ function MyController(hand, triggerAction) {
         // object's actual held offset is an idea intended to make it easier to throw things:
         // Because we might catch something or transfer it between hands without a good idea 
         // of it's actual offset, let's try imparting a velocity which is at a fixed radius
-        // from the palm.  
+        // from the palm.
 
         var handControllerPosition = Controller.getSpatialControlPosition(this.tip);
         var now = Date.now();
@@ -507,6 +492,8 @@ function MyController(hand, triggerAction) {
         this.currentHandControllerTipPosition = handControllerPosition;
         this.currentObjectTime = now;
         Entities.callEntityMethod(this.grabbedEntity, "continueNearGrab");
+
+        Entities.updateAction(this.grabbedEntity, this.actionID, {lifetime: ACTION_LIFETIME});
     };
 
     this.nearGrabbingNonColliding = function() {
diff --git a/examples/grab.js b/examples/grab.js
index 05bcf128e2..43a5ed220b 100644
--- a/examples/grab.js
+++ b/examples/grab.js
@@ -13,7 +13,27 @@
 var MAX_SOLID_ANGLE = 0.01; // objects that appear smaller than this can't be grabbed
 var ZERO_VEC3 = {x: 0, y: 0, z: 0};
 var IDENTITY_QUAT = {x: 0, y: 0, z: 0, w: 0};
+var ACTION_LIFETIME = 120; // 2 minutes
 
+function getTag() {
+    return "grab-" + MyAvatar.sessionUUID;
+}
+
+function entityIsGrabbedByOther(entityID) {
+    var actionIDs = Entities.getActionIDs(entityID);
+    for (var actionIndex = 0; actionIndex < actionIDs.length; actionIndex++) {
+        var actionID = actionIDs[actionIndex];
+        var actionArguments = Entities.getActionArguments(entityID, actionID);
+        var tag = actionArguments["tag"];
+        if (tag == getTag()) {
+            continue;
+        }
+        if (tag.slice(0, 5) == "grab-") {
+            return true;
+        }
+    }
+    return false;
+}
 
 // helper function
 function mouseIntersectionWithPlane(pointOnPlane, planeNormal, event, maxDistance) {
@@ -288,7 +308,7 @@ Grabber.prototype.moveEvent = function(event) {
     }
     this.currentPosition = entityProperties.position;
 
-    var actionArgs = {};
+    var actionArgs = {tag: getTag(), lifetime: ACTION_LIFETIME};
 
     if (this.mode === "rotate") {
         var drag = mouse.getDrag();
@@ -303,7 +323,7 @@ Grabber.prototype.moveEvent = function(event) {
         // var qZero = entityProperties.rotation;
         //var qZero = this.lastRotation;
         this.lastRotation = Quat.multiply(deltaQ, this.lastRotation);
-        actionArgs = {targetRotation: this.lastRotation, angularTimeScale: 0.1};
+        actionArgs = {targetRotation: this.lastRotation, angularTimeScale: 0.1, tag: getTag(), lifetime: ACTION_LIFETIME};
     } else {
         var newPointOnPlane;
         if (this.mode === "verticalCylinder") {
@@ -327,13 +347,15 @@ Grabber.prototype.moveEvent = function(event) {
             }
         }
         this.targetPosition = Vec3.subtract(newPointOnPlane, this.offset);
-        actionArgs = {targetPosition: this.targetPosition, linearTimeScale: 0.1};
+        actionArgs = {targetPosition: this.targetPosition, linearTimeScale: 0.1, tag: getTag(), lifetime: ACTION_LIFETIME};
 
         beacon.updatePosition(this.targetPosition);
     }
 
     if (!this.actionID) {
-        this.actionID = Entities.addAction("spring", this.entityID, actionArgs);
+        if (!entityIsGrabbedByOther(this.entityID)) {
+            this.actionID = Entities.addAction("spring", this.entityID, actionArgs);
+        }
     } else {
         Entities.updateAction(this.entityID, this.actionID, actionArgs);
     }
diff --git a/examples/toys/basketball_hoop/createHoop.js b/examples/toys/basketball_hoop/createHoop.js
new file mode 100644
index 0000000000..3887e0b421
--- /dev/null
+++ b/examples/toys/basketball_hoop/createHoop.js
@@ -0,0 +1,43 @@
+//
+//  createHoop.js
+//  examples/entityScripts
+//
+//  Created by James B. Pollack on 9/29/2015
+//  Copyright 2015 High Fidelity, Inc.
+//
+//  This is a script that creates a persistent basketball hoop with a working collision hull.  Feel free to move it.
+//  Run basketball.js to make a basketball.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+/*global MyAvatar, Entities, AnimationCache, SoundCache, Scene, Camera, Overlays, HMD, AvatarList, AvatarManager, Controller, UndoStack, Window, Account, GlobalServices, Script, ScriptDiscoveryService, LODManager, Menu, Vec3, Quat, AudioDevice, Paths, Clipboard, Settings, XMLHttpRequest, randFloat, randInt */
+
+var hoopURL = "http://hifi-public.s3.amazonaws.com/models/basketball_hoop/basketball_hoop.fbx";
+var hoopCollisionHullURL = "http://hifi-public.s3.amazonaws.com/models/basketball_hoop/basketball_hoop_collision_hull.obj";
+
+var hoopStartPosition =
+    Vec3.sum(MyAvatar.position,
+        Vec3.multiplyQbyV(MyAvatar.orientation, {
+            x: 0,
+            y: 0.0,
+            z: -2
+        }));
+
+var hoop = Entities.addEntity({
+    type: "Model",
+    modelURL: hoopURL,
+    position: hoopStartPosition,
+    shapeType: 'compound',
+    gravity: {
+        x: 0,
+        y: -9.8,
+        z: 0
+    },
+    dimensions: {
+        x: 1.89,
+        y: 3.99,
+        z: 3.79
+    },
+    compoundShapeURL: hoopCollisionHullURL
+});
+
diff --git a/examples/utilities/tools/currentAPI.js b/examples/utilities/tools/currentAPI.js
index 30b24910f9..cb9f152794 100644
--- a/examples/utilities/tools/currentAPI.js
+++ b/examples/utilities/tools/currentAPI.js
@@ -10,22 +10,21 @@
 //
 
 var array = [];
-var buffer = "\n\n\n\n\n======= JS API list =======";
 function listKeys(string, object) {
-    if (string == "listKeys" || string == "array" || string == "buffer" || string == "i") {
+    if (string === "listKeys" || string === "array" || string === "buffer" || string === "i") {
         return;
     }
     
-    if (typeof(object) != "object") {
+    if (typeof(object) !== "object" || object === null) {
         array.push(string + " " + typeof(object));
         return;
     }
     
     var keys = Object.keys(object);
     for (var i = 0; i < keys.length; ++i) {
-        if (string == "") {
+        if (string === "") {
             listKeys(keys[i], object[keys[i]]);
-        } else {
+        } else if (keys[i] !== "parent") {
             listKeys(string + "." + keys[i], object[keys[i]]);
         }
     }
@@ -34,9 +33,10 @@ function listKeys(string, object) {
 listKeys("", this);
 array.sort();
 
+var buffer = "\n======= JS API list =======";
 for (var i = 0; i < array.length; ++i) {
-    buffer = buffer + "\n" + array[i];
+    buffer += "\n" + array[i];
 }
-buffer = buffer + "\n========= API END =========\n\n\n\n\n";
+buffer += "\n========= API END =========\n";
 
 print(buffer);
diff --git a/interface/resources/meshes/defaultAvatar_full/avatar-animation.json b/interface/resources/meshes/defaultAvatar_full/avatar-animation.json
index 72eefaf7e8..dceecddfe0 100644
--- a/interface/resources/meshes/defaultAvatar_full/avatar-animation.json
+++ b/interface/resources/meshes/defaultAvatar_full/avatar-animation.json
@@ -26,13 +26,14 @@
                         {
                             "jointName": "Neck",
                             "positionVar": "neckPosition",
-                            "rotationVar": "neckRotation"
+                            "rotationVar": "neckRotation",
+                            "typeVar": "headAndNeckType"
                         },
                         {
                             "jointName": "Head",
                             "positionVar": "headPosition",
                             "rotationVar": "headRotation",
-                            "typeVar": "headType"
+                            "typeVar": "headAndNeckType"
                         }
                     ]
                 },
diff --git a/interface/resources/qml/VrMenu.qml b/interface/resources/qml/VrMenu.qml
index ef7ae852d4..14a4a449fd 100644
--- a/interface/resources/qml/VrMenu.qml
+++ b/interface/resources/qml/VrMenu.qml
@@ -196,7 +196,6 @@ Hifi.VrMenu {
 
     function insertItem(menu, beforeItem, newMenuItem) {
         for (var i = 0; i < menu.items.length; ++i) {
-            console.log(menu.items[i]);
             if (menu.items[i] === beforeItem) {
                 return menu.insertItem(i, newMenuItem);
             }
diff --git a/interface/src/InterfaceActionFactory.cpp b/interface/src/InterfaceActionFactory.cpp
index dca1015ecc..2879c19eaa 100644
--- a/interface/src/InterfaceActionFactory.cpp
+++ b/interface/src/InterfaceActionFactory.cpp
@@ -43,6 +43,9 @@ EntityActionPointer InterfaceActionFactory::factory(EntityActionType type,
     if (action) {
         bool ok = action->updateArguments(arguments);
         if (ok) {
+            if (action->lifetimeIsOver()) {
+                return nullptr;
+            }
             return action;
         }
     }
@@ -63,5 +66,9 @@ EntityActionPointer InterfaceActionFactory::factoryBA(EntityItemPointer ownerEnt
     if (action) {
         action->deserialize(data);
     }
+    if (action->lifetimeIsOver()) {
+        return nullptr;
+    }
+
     return action;
 }
diff --git a/interface/src/avatar/AvatarActionHold.cpp b/interface/src/avatar/AvatarActionHold.cpp
index 4ecdb692ac..1fa50b79fd 100644
--- a/interface/src/avatar/AvatarActionHold.cpp
+++ b/interface/src/avatar/AvatarActionHold.cpp
@@ -84,6 +84,9 @@ void AvatarActionHold::updateActionWorker(float deltaTimeStep) {
 
 
 bool AvatarActionHold::updateArguments(QVariantMap arguments) {
+    if (!ObjectAction::updateArguments(arguments)) {
+        return false;
+    }
     bool ok = true;
     glm::vec3 relativePosition =
         EntityActionInterface::extractVec3Argument("hold", arguments, "relativePosition", ok, false);
@@ -134,7 +137,7 @@ bool AvatarActionHold::updateArguments(QVariantMap arguments) {
 
 
 QVariantMap AvatarActionHold::getArguments() {
-    QVariantMap arguments;
+    QVariantMap arguments = ObjectAction::getArguments();
     withReadLock([&]{
         if (!_mine) {
             arguments = ObjectActionSpring::getArguments();
diff --git a/interface/src/avatar/MyAvatar.cpp b/interface/src/avatar/MyAvatar.cpp
index 8f7af63a81..a57740a691 100644
--- a/interface/src/avatar/MyAvatar.cpp
+++ b/interface/src/avatar/MyAvatar.cpp
@@ -271,6 +271,25 @@ glm::mat4 MyAvatar::getSensorToWorldMatrix() const {
     return _sensorToWorldMatrix;
 }
 
+// returns true if pos is OUTSIDE of the vertical capsule
+// where the middle cylinder length is defined by capsuleLen and the radius by capsuleRad.
+static bool capsuleCheck(const glm::vec3& pos, float capsuleLen, float capsuleRad) {
+    const float halfCapsuleLen = capsuleLen / 2.0f;
+    if (fabs(pos.y) <= halfCapsuleLen) {
+        // cylinder check for middle capsule
+        glm::vec2 horizPos(pos.x, pos.z);
+        return glm::length(horizPos) > capsuleRad;
+    } else if (pos.y > halfCapsuleLen) {
+        glm::vec3 center(0.0f, halfCapsuleLen, 0.0f);
+        return glm::length(center - pos) > capsuleRad;
+    } else if (pos.y < halfCapsuleLen) {
+        glm::vec3 center(0.0f, -halfCapsuleLen, 0.0f);
+        return glm::length(center - pos) > capsuleRad;
+    } else {
+        return false;
+    }
+}
+
 // Pass a recent sample of the HMD to the avatar.
 // This can also update the avatar's position to follow the HMD
 // as it moves through the world.
@@ -289,11 +308,14 @@ void MyAvatar::updateFromHMDSensorMatrix(const glm::mat4& hmdSensorMatrix) {
     _hmdSensorOrientation = glm::quat_cast(hmdSensorMatrix);
 
     const float STRAIGHTING_LEAN_DURATION = 0.5f;  // seconds
-    const float STRAIGHTING_LEAN_THRESHOLD = 0.2f;  // meters
+
+    // define a vertical capsule
+    const float STRAIGHTING_LEAN_CAPSULE_RADIUS = 0.2f;  // meters
+    const float STRAIGHTING_LEAN_CAPSULE_LENGTH = 0.05f;  // length of the cylinder part of the capsule in meters.
 
     auto newBodySensorMatrix = deriveBodyFromHMDSensor();
     glm::vec3 diff = extractTranslation(newBodySensorMatrix) - extractTranslation(_bodySensorMatrix);
-    if (!_straightingLean && glm::length(diff) > STRAIGHTING_LEAN_THRESHOLD) {
+    if (!_straightingLean && capsuleCheck(diff, STRAIGHTING_LEAN_CAPSULE_LENGTH, STRAIGHTING_LEAN_CAPSULE_RADIUS)) {
 
         // begin homing toward derived body position.
         _straightingLean = true;
@@ -1854,13 +1876,39 @@ glm::mat4 MyAvatar::deriveBodyFromHMDSensor() const {
     const glm::quat hmdOrientation = getHMDSensorOrientation();
     const glm::quat hmdOrientationYawOnly = cancelOutRollAndPitch(hmdOrientation);
 
-    // In sensor space, figure out where the avatar body should be,
-    // by applying offsets from the avatar's neck & head joints.
-    vec3 localEyes = _skeletonModel.getDefaultEyeModelPosition();
-    vec3 localNeck(0.0f, 0.48f, 0.0f);  // start with some kind of guess if the skeletonModel is not loaded yet.
-    _skeletonModel.getLocalNeckPosition(localNeck);
+    const glm::vec3 DEFAULT_RIGHT_EYE_POS(-0.3f, 1.6f, 0.0f);
+    const glm::vec3 DEFAULT_LEFT_EYE_POS(0.3f, 1.6f, 0.0f);
+    const glm::vec3 DEFAULT_NECK_POS(0.0f, 1.5f, 0.0f);
+    const glm::vec3 DEFAULT_HIPS_POS(0.0f, 1.0f, 0.0f);
+
+    vec3 localEyes, localNeck;
+    if (!_debugDrawSkeleton) {
+        const glm::quat rotY180 = glm::angleAxis((float)PI, glm::vec3(0.0f, 1.0f, 0.0f));
+        localEyes = rotY180 * (((DEFAULT_RIGHT_EYE_POS + DEFAULT_LEFT_EYE_POS) / 2.0f) - DEFAULT_HIPS_POS);
+        localNeck = rotY180 * (DEFAULT_NECK_POS - DEFAULT_HIPS_POS);
+    } else {
+        // TODO: At the moment MyAvatar does not have access to the rig, which has the skeleton, which has the bind poses.
+        // for now use the _debugDrawSkeleton, which is initialized with the same FBX model as the rig.
+
+        // TODO: cache these indices.
+        int rightEyeIndex = _debugDrawSkeleton->nameToJointIndex("RightEye");
+        int leftEyeIndex = _debugDrawSkeleton->nameToJointIndex("LeftEye");
+        int neckIndex = _debugDrawSkeleton->nameToJointIndex("Neck");
+        int hipsIndex = _debugDrawSkeleton->nameToJointIndex("Hips");
+
+        glm::vec3 absRightEyePos = rightEyeIndex != -1 ? _debugDrawSkeleton->getAbsoluteBindPose(rightEyeIndex).trans : DEFAULT_RIGHT_EYE_POS;
+        glm::vec3 absLeftEyePos = leftEyeIndex != -1 ? _debugDrawSkeleton->getAbsoluteBindPose(leftEyeIndex).trans : DEFAULT_LEFT_EYE_POS;
+        glm::vec3 absNeckPos = neckIndex != -1 ? _debugDrawSkeleton->getAbsoluteBindPose(neckIndex).trans : DEFAULT_NECK_POS;
+        glm::vec3 absHipsPos = neckIndex != -1 ? _debugDrawSkeleton->getAbsoluteBindPose(hipsIndex).trans : DEFAULT_HIPS_POS;
+
+        const glm::quat rotY180 = glm::angleAxis((float)PI, glm::vec3(0.0f, 1.0f, 0.0f));
+        localEyes = rotY180 * (((absRightEyePos + absLeftEyePos) / 2.0f) - absHipsPos);
+        localNeck = rotY180 * (absNeckPos - absHipsPos);
+    }
 
     // apply simplistic head/neck model
+    // figure out where the avatar body should be by applying offsets from the avatar's neck & head joints.
+
     // eyeToNeck offset is relative full HMD orientation.
     // while neckToRoot offset is only relative to HMDs yaw.
     glm::vec3 eyeToNeck = hmdOrientation * (localNeck - localEyes);
diff --git a/libraries/animation/src/AnimInverseKinematics.cpp b/libraries/animation/src/AnimInverseKinematics.cpp
index de226092f1..c0adba0ad6 100644
--- a/libraries/animation/src/AnimInverseKinematics.cpp
+++ b/libraries/animation/src/AnimInverseKinematics.cpp
@@ -89,7 +89,7 @@ static int findRootJointInSkeleton(AnimSkeleton::ConstPointer skeleton, int inde
     return rootIndex;
 }
 
-void AnimInverseKinematics::computeTargets(const AnimVariantMap& animVars, std::vector<IKTarget>& targets) {
+void AnimInverseKinematics::computeTargets(const AnimVariantMap& animVars, std::vector<IKTarget>& targets, const AnimPoseVec& underPoses) {
     // build a list of valid targets from _targetVarVec and animVars
     _maxTargetIndex = -1;
     bool removeUnfoundJoints = false;
@@ -107,7 +107,7 @@ void AnimInverseKinematics::computeTargets(const AnimVariantMap& animVars, std::
             }
         } else {
             IKTarget target;
-            AnimPose defaultPose = _skeleton->getAbsolutePose(targetVar.jointIndex, _relativePoses);
+            AnimPose defaultPose = _skeleton->getAbsolutePose(targetVar.jointIndex, underPoses);
             target.pose.trans = animVars.lookup(targetVar.positionVar, defaultPose.trans);
             target.pose.rot = animVars.lookup(targetVar.rotationVar, defaultPose.rot);
             target.setType(animVars.lookup(targetVar.typeVar, QString("")));
@@ -154,7 +154,6 @@ void AnimInverseKinematics::solveWithCyclicCoordinateDescent(const std::vector<I
     do {
         int lowestMovedIndex = _relativePoses.size();
         for (auto& target: targets) {
-            int tipIndex = target.index;
             if (target.type == IKTarget::Type::RotationOnly) {
                 // the final rotation will be enforced after the iterations
                 continue;
@@ -162,6 +161,7 @@ void AnimInverseKinematics::solveWithCyclicCoordinateDescent(const std::vector<I
             AnimPose targetPose = target.pose;
 
             // cache tip absolute transform
+            int tipIndex = target.index;
             glm::vec3 tipPosition = absolutePoses[tipIndex].trans;
             glm::quat tipRotation = absolutePoses[tipIndex].rot;
 
@@ -288,6 +288,17 @@ void AnimInverseKinematics::solveWithCyclicCoordinateDescent(const std::vector<I
         }
     } while (numLoops < MAX_IK_LOOPS);
 
+    /* KEEP: example code for measuring endeffector error of IK solution
+    for (uint32_t i = 0; i < targets.size(); ++i) {
+        auto& target = targets[i];
+        if (target.type == IKTarget::Type::RotationOnly) {
+            continue;
+        }
+        glm::vec3 tipPosition = absolutePoses[target.index].trans;
+        std::cout << i << " IK error = " << glm::distance(tipPosition, target.pose.trans) << std::endl;  // adebug
+    }
+    */
+
     // finally set the relative rotation of each tip to agree with absolute target rotation
     for (auto& target: targets) {
         int tipIndex = target.index;
@@ -312,25 +323,8 @@ void AnimInverseKinematics::solveWithCyclicCoordinateDescent(const std::vector<I
 
 //virtual
 const AnimPoseVec& AnimInverseKinematics::evaluate(const AnimVariantMap& animVars, float dt, AnimNode::Triggers& triggersOut) {
-    if (!_relativePoses.empty()) {
-        // build a list of targets from _targetVarVec
-        std::vector<IKTarget> targets;
-        computeTargets(animVars, targets);
-    
-        if (targets.empty()) {
-            // no IK targets but still need to enforce constraints
-            std::map<int, RotationConstraint*>::iterator constraintItr = _constraints.begin();
-            while (constraintItr != _constraints.end()) {
-                int index = constraintItr->first;
-                glm::quat rotation = _relativePoses[index].rot;
-                constraintItr->second->apply(rotation);
-                _relativePoses[index].rot = rotation;
-                ++constraintItr;
-            }
-        } else {
-            solveWithCyclicCoordinateDescent(targets);
-        }
-    }
+    // don't call this function, call overlay() instead
+    assert(false);
     return _relativePoses;
 }
 
@@ -356,7 +350,27 @@ const AnimPoseVec& AnimInverseKinematics::overlay(const AnimVariantMap& animVars
             }
         }
     }
-    return evaluate(animVars, dt, triggersOut);
+
+    if (!_relativePoses.empty()) {
+        // build a list of targets from _targetVarVec
+        std::vector<IKTarget> targets;
+        computeTargets(animVars, targets, underPoses);
+    
+        if (targets.empty()) {
+            // no IK targets but still need to enforce constraints
+            std::map<int, RotationConstraint*>::iterator constraintItr = _constraints.begin();
+            while (constraintItr != _constraints.end()) {
+                int index = constraintItr->first;
+                glm::quat rotation = _relativePoses[index].rot;
+                constraintItr->second->apply(rotation);
+                _relativePoses[index].rot = rotation;
+                ++constraintItr;
+            }
+        } else {
+            solveWithCyclicCoordinateDescent(targets);
+        }
+    }
+    return _relativePoses;
 }
 
 RotationConstraint* AnimInverseKinematics::getConstraint(int index) {
diff --git a/libraries/animation/src/AnimInverseKinematics.h b/libraries/animation/src/AnimInverseKinematics.h
index 121b35bd9d..2eb0d9b08e 100644
--- a/libraries/animation/src/AnimInverseKinematics.h
+++ b/libraries/animation/src/AnimInverseKinematics.h
@@ -50,7 +50,7 @@ protected:
         void setType(const QString& typeVar) { type = ((typeVar == "RotationOnly") ?  Type::RotationOnly : Type::RotationAndPosition); }
     };
 
-    void computeTargets(const AnimVariantMap& animVars, std::vector<IKTarget>& targets);
+    void computeTargets(const AnimVariantMap& animVars, std::vector<IKTarget>& targets, const AnimPoseVec& underPoses);
     void solveWithCyclicCoordinateDescent(const std::vector<IKTarget>& targets);
     virtual void setSkeletonInternal(AnimSkeleton::ConstPointer skeleton);
 
diff --git a/libraries/animation/src/AnimVariant.h b/libraries/animation/src/AnimVariant.h
index 700a8b4121..cb886cd369 100644
--- a/libraries/animation/src/AnimVariant.h
+++ b/libraries/animation/src/AnimVariant.h
@@ -184,6 +184,8 @@ public:
             case AnimVariant::Type::String:
                 qCDebug(animation) << "    " << pair.first << "=" << pair.second.getString();
                 break;
+            default:
+                assert("AnimVariant::Type" == "valid");
             }
         }
     }
diff --git a/libraries/animation/src/Rig.cpp b/libraries/animation/src/Rig.cpp
index 0022749d51..5dc81fecfe 100644
--- a/libraries/animation/src/Rig.cpp
+++ b/libraries/animation/src/Rig.cpp
@@ -1026,12 +1026,21 @@ static void computeHeadNeckAnimVars(AnimSkeleton::ConstPointer skeleton, const A
     const glm::quat hmdOrientation = hmdPose.rot * rotY180;  // rotY180 will make z forward not -z
 
     // TODO: cache jointIndices
+    int rightEyeIndex = skeleton->nameToJointIndex("RightEye");
+    int leftEyeIndex = skeleton->nameToJointIndex("LeftEye");
+    int headIndex = skeleton->nameToJointIndex("Head");
+    int neckIndex = skeleton->nameToJointIndex("Neck");
+
+    const glm::vec3 DEFAULT_RIGHT_EYE_POS(-0.3f, 1.6f, 0.0f);
+    const glm::vec3 DEFAULT_LEFT_EYE_POS(0.3f, 1.6f, 0.0f);
+    const glm::vec3 DEFAULT_HEAD_POS(0.0f, 1.55f, 0.0f);
+    const glm::vec3 DEFAULT_NECK_POS(0.0f, 1.5f, 0.0f);
 
     // Use absolute bindPose positions just in case the relBindPose have rotations we don't expect.
-    glm::vec3 absRightEyePos = skeleton->getAbsoluteBindPose(skeleton->nameToJointIndex("RightEye")).trans;
-    glm::vec3 absLeftEyePos = skeleton->getAbsoluteBindPose(skeleton->nameToJointIndex("LeftEye")).trans;
-    glm::vec3 absHeadPos = skeleton->getAbsoluteBindPose(skeleton->nameToJointIndex("Head")).trans;
-    glm::vec3 absNeckPos = skeleton->getAbsoluteBindPose(skeleton->nameToJointIndex("Neck")).trans;
+    glm::vec3 absRightEyePos = rightEyeIndex != -1 ? skeleton->getAbsoluteBindPose(rightEyeIndex).trans : DEFAULT_RIGHT_EYE_POS;
+    glm::vec3 absLeftEyePos = leftEyeIndex != -1 ? skeleton->getAbsoluteBindPose(leftEyeIndex).trans : DEFAULT_LEFT_EYE_POS;
+    glm::vec3 absHeadPos = headIndex != -1 ? skeleton->getAbsoluteBindPose(headIndex).trans : DEFAULT_HEAD_POS;
+    glm::vec3 absNeckPos = neckIndex != -1 ? skeleton->getAbsoluteBindPose(neckIndex).trans : DEFAULT_NECK_POS;
 
     glm::vec3 absCenterEyePos = (absRightEyePos + absLeftEyePos) / 2.0f;
     glm::vec3 eyeOffset = absCenterEyePos - absHeadPos;
@@ -1079,7 +1088,7 @@ void Rig::updateNeckJoint(int index, const HeadParameters& params) {
 
                 _animVars.set("headPosition", headPos);
                 _animVars.set("headRotation", headRot);
-                _animVars.set("headType", QString("RotationAndPosition"));
+                _animVars.set("headAndNeckType", QString("RotationAndPosition"));
                 _animVars.set("neckPosition", neckPos);
                 _animVars.set("neckRotation", neckRot);
 
@@ -1092,7 +1101,7 @@ void Rig::updateNeckJoint(int index, const HeadParameters& params) {
 
                 _animVars.unset("headPosition");
                 _animVars.set("headRotation", realLocalHeadOrientation);
-                _animVars.set("headType", QString("RotationOnly"));
+                _animVars.set("headAndNeckType", QString("RotationOnly"));
                 _animVars.unset("neckPosition");
                 _animVars.unset("neckRotation");
             }
diff --git a/libraries/avatars/src/AvatarData.cpp b/libraries/avatars/src/AvatarData.cpp
index 3bd147d398..f64504d662 100644
--- a/libraries/avatars/src/AvatarData.cpp
+++ b/libraries/avatars/src/AvatarData.cpp
@@ -966,7 +966,8 @@ bool AvatarData::hasIdentityChangedAfterParsing(NLPacket& packet) {
 QByteArray AvatarData::identityByteArray() {
     QByteArray identityData;
     QDataStream identityStream(&identityData, QIODevice::Append);
-    const QUrl& urlToSend = (_skeletonModelURL == AvatarData::defaultFullAvatarModelUrl()) ? QUrl("") : _skeletonModelURL;
+    QUrl emptyURL("");
+    const QUrl& urlToSend = (_skeletonModelURL == AvatarData::defaultFullAvatarModelUrl()) ? emptyURL : _skeletonModelURL;
 
     identityStream << QUuid() << _faceModelURL << urlToSend << _attachmentData << _displayName;
 
diff --git a/libraries/entities/src/EntityActionInterface.h b/libraries/entities/src/EntityActionInterface.h
index a4f1c8ea15..e61019c98c 100644
--- a/libraries/entities/src/EntityActionInterface.h
+++ b/libraries/entities/src/EntityActionInterface.h
@@ -46,6 +46,8 @@ public:
     static EntityActionType actionTypeFromString(QString actionTypeString);
     static QString actionTypeToString(EntityActionType actionType);
 
+    virtual bool lifetimeIsOver() { return false; }
+
 protected:
     virtual glm::vec3 getPosition() = 0;
     virtual void setPosition(glm::vec3 position) = 0;
diff --git a/libraries/networking/src/NLPacketList.cpp b/libraries/networking/src/NLPacketList.cpp
index 3b115c558b..318fb037a1 100644
--- a/libraries/networking/src/NLPacketList.cpp
+++ b/libraries/networking/src/NLPacketList.cpp
@@ -23,7 +23,8 @@ std::unique_ptr<NLPacketList> NLPacketList::create(PacketType packetType, QByteA
 }
 
 std::unique_ptr<NLPacketList> NLPacketList::fromPacketList(std::unique_ptr<PacketList> packetList) {
-    auto nlPacketList = std::unique_ptr<NLPacketList>(new NLPacketList(std::move(*packetList.release())));    nlPacketList->open(ReadOnly);
+    auto nlPacketList = std::unique_ptr<NLPacketList>(new NLPacketList(std::move(*packetList.release())));
+    nlPacketList->open(ReadOnly);
     return nlPacketList;
 }
 
diff --git a/libraries/networking/src/SentPacketHistory.cpp b/libraries/networking/src/SentPacketHistory.cpp
index c6eec8eb63..fbb7eff41a 100644
--- a/libraries/networking/src/SentPacketHistory.cpp
+++ b/libraries/networking/src/SentPacketHistory.cpp
@@ -35,6 +35,7 @@ void SentPacketHistory::packetSent(uint16_t sequenceNumber, const NLPacket& pack
     }
     _newestSequenceNumber = sequenceNumber;
 
+    QWriteLocker locker(&_packetsLock);
     _sentPackets.insert(NLPacket::createCopy(packet));
 }
 
@@ -48,6 +49,11 @@ const NLPacket* SentPacketHistory::getPacket(uint16_t sequenceNumber) const {
     if (seqDiff < 0) {
         seqDiff += UINT16_RANGE;
     }
-
-    return _sentPackets.get(seqDiff)->get();
+    
+    QReadLocker locker(&_packetsLock);
+    auto packet = _sentPackets.get(seqDiff);
+    if (packet) {
+        return packet->get();
+    }
+    return nullptr;
 }
diff --git a/libraries/networking/src/SentPacketHistory.h b/libraries/networking/src/SentPacketHistory.h
index 1808e0020b..72150658e3 100644
--- a/libraries/networking/src/SentPacketHistory.h
+++ b/libraries/networking/src/SentPacketHistory.h
@@ -12,7 +12,9 @@
 #define hifi_SentPacketHistory_h
 
 #include <stdint.h>
-#include <qbytearray.h>
+
+#include <QtCore/QByteArray>
+#include <QtCore/QReadWriteLock>
 
 #include "NLPacket.h"
 #include "RingBufferHistory.h"
@@ -29,6 +31,7 @@ public:
     const NLPacket* getPacket(uint16_t sequenceNumber) const;
 
 private:
+    mutable QReadWriteLock _packetsLock { QReadWriteLock::Recursive };
     RingBufferHistory<std::unique_ptr<NLPacket>> _sentPackets;    // circular buffer
 
     uint16_t _newestSequenceNumber;
diff --git a/libraries/networking/src/ThreadedAssignment.cpp b/libraries/networking/src/ThreadedAssignment.cpp
index 5f0db9412c..0422c03297 100644
--- a/libraries/networking/src/ThreadedAssignment.cpp
+++ b/libraries/networking/src/ThreadedAssignment.cpp
@@ -49,7 +49,8 @@ void ThreadedAssignment::setFinished(bool isFinished) {
             }
 
             if (_statsTimer) {
-                _statsTimer->stop();
+                _statsTimer->deleteLater();
+                _statsTimer = nullptr;
             }
 
             // call our virtual aboutToFinish method - this gives the ThreadedAssignment subclass a chance to cleanup
@@ -105,7 +106,7 @@ void ThreadedAssignment::sendStatsPacket() {
 void ThreadedAssignment::startSendingStats() {
     // send the stats packet every 1s
     if (!_statsTimer) {
-        _statsTimer = new QTimer();
+        _statsTimer = new QTimer;
         connect(_statsTimer, &QTimer::timeout, this, &ThreadedAssignment::sendStatsPacket);
     }
     
diff --git a/libraries/networking/src/udt/CongestionControl.cpp b/libraries/networking/src/udt/CongestionControl.cpp
index ea46d60acb..c1feae3911 100644
--- a/libraries/networking/src/udt/CongestionControl.cpp
+++ b/libraries/networking/src/udt/CongestionControl.cpp
@@ -161,13 +161,16 @@ void DefaultCC::onLoss(SequenceNumber rangeStart, SequenceNumber rangeEnd) {
         
         _lastDecreaseMaxSeq = _sendCurrSeqNum;
         
-        // avoid synchronous rate decrease across connections using randomization
-        std::random_device rd;
-        std::mt19937 generator(rd());
-        std::uniform_int_distribution<> distribution(1, _avgNAKNum);
-        
-        _randomDecreaseThreshold = distribution(generator);
-        
+        if (_avgNAKNum < 1) {
+            _randomDecreaseThreshold = 1;
+        } else {
+            // avoid synchronous rate decrease across connections using randomization
+            std::random_device rd;
+            std::mt19937 generator(rd());
+            std::uniform_int_distribution<> distribution(1, std::max(1, _avgNAKNum));
+
+            _randomDecreaseThreshold = distribution(generator);
+        }
     } else if ((_decreaseCount++ < MAX_DECREASES_PER_CONGESTION_EPOCH) && ((++_nakCount % _randomDecreaseThreshold) == 0)) {
         // there have been fewer than MAX_DECREASES_PER_CONGESTION_EPOCH AND this NAK matches the random count at which we
         // decided we would decrease the packet send period
diff --git a/libraries/networking/src/udt/Connection.cpp b/libraries/networking/src/udt/Connection.cpp
index 1bda840a6c..e8b22f6ab8 100644
--- a/libraries/networking/src/udt/Connection.cpp
+++ b/libraries/networking/src/udt/Connection.cpp
@@ -32,7 +32,7 @@ Connection::Connection(Socket* parentSocket, HifiSockAddr destination, std::uniq
     _destination(destination),
     _congestionControl(move(congestionControl))
 {
-    Q_ASSERT_X(socket, "Connection::Connection", "Must be called with a valid Socket*");
+    Q_ASSERT_X(parentSocket, "Connection::Connection", "Must be called with a valid Socket*");
     
     Q_ASSERT_X(_congestionControl, "Connection::Connection", "Must be called with a valid CongestionControl object");
     _congestionControl->init();
diff --git a/libraries/networking/src/udt/PacketList.h b/libraries/networking/src/udt/PacketList.h
index ae783dabe3..7978e77ad7 100644
--- a/libraries/networking/src/udt/PacketList.h
+++ b/libraries/networking/src/udt/PacketList.h
@@ -28,7 +28,8 @@ class Packet;
 class PacketList : public QIODevice {
     Q_OBJECT
 public:
-    static std::unique_ptr<PacketList> create(PacketType packetType, QByteArray extendedHeader = QByteArray(), bool isReliable = false, bool isOrdered = false);
+    static std::unique_ptr<PacketList> create(PacketType packetType, QByteArray extendedHeader = QByteArray(),
+                                              bool isReliable = false, bool isOrdered = false);
     static std::unique_ptr<PacketList> fromReceivedPackets(std::list<std::unique_ptr<Packet>>&& packets);
     
     bool isReliable() const { return _isReliable; }
diff --git a/libraries/octree/src/OctreeEditPacketSender.cpp b/libraries/octree/src/OctreeEditPacketSender.cpp
index 1be271cbdd..495effc825 100644
--- a/libraries/octree/src/OctreeEditPacketSender.cpp
+++ b/libraries/octree/src/OctreeEditPacketSender.cpp
@@ -346,6 +346,7 @@ void OctreeEditPacketSender::processNackPacket(NLPacket& packet, SharedNodePoint
     if (_sentPacketHistories.count(sendingNode->getUUID()) == 0) {
         return;
     }
+    
     const SentPacketHistory& sentPacketHistory = _sentPacketHistories[sendingNode->getUUID()];
 
     // read sequence numbers and queue packets for resend
diff --git a/libraries/physics/src/ObjectAction.cpp b/libraries/physics/src/ObjectAction.cpp
index 5205e08c62..82395c21cf 100644
--- a/libraries/physics/src/ObjectAction.cpp
+++ b/libraries/physics/src/ObjectAction.cpp
@@ -30,6 +30,18 @@ void ObjectAction::updateAction(btCollisionWorld* collisionWorld, btScalar delta
         dynamicsWorld->removeAction(this);
         return;
     }
+
+    if (_expires > 0) {
+        quint64 now = usecTimestampNow();
+        if (now > _expires) {
+            EntityItemPointer ownerEntity = _ownerEntity.lock();
+            _active = false;
+            if (ownerEntity) {
+                ownerEntity->removeAction(nullptr, getID());
+            }
+        }
+    }
+
     if (!_active) {
         return;
     }
@@ -37,6 +49,40 @@ void ObjectAction::updateAction(btCollisionWorld* collisionWorld, btScalar delta
     updateActionWorker(deltaTimeStep);
 }
 
+bool ObjectAction::updateArguments(QVariantMap arguments) {
+    bool lifetimeSet = true;
+    float lifetime = EntityActionInterface::extractFloatArgument("action", arguments, "lifetime", lifetimeSet, false);
+    if (lifetimeSet) {
+        quint64 now = usecTimestampNow();
+        _expires = now + (quint64)(lifetime * USECS_PER_SECOND);
+    } else {
+        _expires = 0;
+    }
+
+    bool tagSet = true;
+    QString tag = EntityActionInterface::extractStringArgument("action", arguments, "tag", tagSet, false);
+    if (tagSet) {
+        _tag = tag;
+    } else {
+        tag = "";
+    }
+
+    return true;
+}
+
+QVariantMap ObjectAction::getArguments() {
+    QVariantMap arguments;
+    if (_expires == 0) {
+        arguments["lifetime"] = 0.0f;
+    } else {
+        quint64 now = usecTimestampNow();
+        arguments["lifetime"] = (float)(_expires - now) / (float)USECS_PER_SECOND;
+    }
+    arguments["tag"] = _tag;
+    return arguments;
+}
+
+
 void ObjectAction::debugDraw(btIDebugDraw* debugDrawer) {
 }
 
@@ -136,3 +182,14 @@ void ObjectAction::activateBody() {
     }
 }
 
+bool ObjectAction::lifetimeIsOver() {
+    if (_expires == 0) {
+        return false;
+    }
+
+    quint64 now = usecTimestampNow();
+    if (now >= _expires) {
+        return true;
+    }
+    return false;
+}
diff --git a/libraries/physics/src/ObjectAction.h b/libraries/physics/src/ObjectAction.h
index 4d91d0dbb1..5c29ac9892 100644
--- a/libraries/physics/src/ObjectAction.h
+++ b/libraries/physics/src/ObjectAction.h
@@ -33,8 +33,8 @@ public:
     virtual EntityItemWeakPointer getOwnerEntity() const { return _ownerEntity; }
     virtual void setOwnerEntity(const EntityItemPointer ownerEntity) { _ownerEntity = ownerEntity; }
 
-    virtual bool updateArguments(QVariantMap arguments) = 0;
-    virtual QVariantMap getArguments() = 0;
+    virtual bool updateArguments(QVariantMap arguments);
+    virtual QVariantMap getArguments();
 
     // this is called from updateAction and should be overridden by subclasses
     virtual void updateActionWorker(float deltaTimeStep) = 0;
@@ -46,6 +46,8 @@ public:
     virtual QByteArray serialize() const = 0;
     virtual void deserialize(QByteArray serializedArguments) = 0;
 
+    virtual bool lifetimeIsOver();
+
 protected:
 
     virtual btRigidBody* getRigidBody();
@@ -59,11 +61,11 @@ protected:
     virtual void setAngularVelocity(glm::vec3 angularVelocity);
     virtual void activateBody();
 
-private:
-
-protected:
     bool _active;
     EntityItemWeakPointer _ownerEntity;
+
+    quint64 _expires; // in seconds since epoch
+    QString _tag;
 };
 
 #endif // hifi_ObjectAction_h
diff --git a/libraries/physics/src/ObjectActionOffset.cpp b/libraries/physics/src/ObjectActionOffset.cpp
index 2c1b391ba5..448ec34689 100644
--- a/libraries/physics/src/ObjectActionOffset.cpp
+++ b/libraries/physics/src/ObjectActionOffset.cpp
@@ -80,6 +80,9 @@ void ObjectActionOffset::updateActionWorker(btScalar deltaTimeStep) {
 
 
 bool ObjectActionOffset::updateArguments(QVariantMap arguments) {
+    if (!ObjectAction::updateArguments(arguments)) {
+        return false;
+    }
     bool ok = true;
     glm::vec3 pointToOffsetFrom =
         EntityActionInterface::extractVec3Argument("offset action", arguments, "pointToOffsetFrom", ok, true);
@@ -90,7 +93,7 @@ bool ObjectActionOffset::updateArguments(QVariantMap arguments) {
     ok = true;
     float linearTimeScale =
         EntityActionInterface::extractFloatArgument("offset action", arguments, "linearTimeScale", ok, false);
-    if (!ok) { 
+    if (!ok) {
         linearTimeScale = _linearTimeScale;
     }
 
@@ -119,7 +122,7 @@ bool ObjectActionOffset::updateArguments(QVariantMap arguments) {
 }
 
 QVariantMap ObjectActionOffset::getArguments() {
-    QVariantMap arguments;
+    QVariantMap arguments = ObjectAction::getArguments();
     withReadLock([&] {
         arguments["pointToOffsetFrom"] = glmToQMap(_pointToOffsetFrom);
         arguments["linearTimeScale"] = _linearTimeScale;
@@ -140,6 +143,9 @@ QByteArray ObjectActionOffset::serialize() const {
     dataStream << _linearTimeScale;
     dataStream << _positionalTargetSet;
 
+    dataStream << _expires;
+    dataStream << _tag;
+
     return ba;
 }
 
@@ -165,5 +171,8 @@ void ObjectActionOffset::deserialize(QByteArray serializedArguments) {
     dataStream >> _linearTimeScale;
     dataStream >> _positionalTargetSet;
 
+    dataStream >> _expires;
+    dataStream >> _tag;
+
     _active = true;
 }
diff --git a/libraries/physics/src/ObjectActionSpring.cpp b/libraries/physics/src/ObjectActionSpring.cpp
index d163933299..7d0bab5143 100644
--- a/libraries/physics/src/ObjectActionSpring.cpp
+++ b/libraries/physics/src/ObjectActionSpring.cpp
@@ -109,6 +109,9 @@ void ObjectActionSpring::updateActionWorker(btScalar deltaTimeStep) {
 const float MIN_TIMESCALE = 0.1f;
 
 bool ObjectActionSpring::updateArguments(QVariantMap arguments) {
+    if (!ObjectAction::updateArguments(arguments)) {
+        return false;
+    }
     // targets are required, spring-constants are optional
     bool ok = true;
     glm::vec3 positionalTarget =
@@ -155,7 +158,7 @@ bool ObjectActionSpring::updateArguments(QVariantMap arguments) {
 }
 
 QVariantMap ObjectActionSpring::getArguments() {
-    QVariantMap arguments;
+    QVariantMap arguments = ObjectAction::getArguments();
     withReadLock([&] {
         arguments["linearTimeScale"] = _linearTimeScale;
         arguments["targetPosition"] = glmToQMap(_positionalTarget);
@@ -182,6 +185,9 @@ QByteArray ObjectActionSpring::serialize() const {
     dataStream << _angularTimeScale;
     dataStream << _rotationalTargetSet;
 
+    dataStream << _expires;
+    dataStream << _tag;
+
     return serializedActionArguments;
 }
 
@@ -210,5 +216,8 @@ void ObjectActionSpring::deserialize(QByteArray serializedArguments) {
     dataStream >> _angularTimeScale;
     dataStream >> _rotationalTargetSet;
 
+    dataStream >> _expires;
+    dataStream >> _tag;
+
     _active = true;
 }