diff --git a/assignment-client/src/AssignmentAction.cpp b/assignment-client/src/AssignmentAction.cpp
index 6cb3c06312..8b5650ee42 100644
--- a/assignment-client/src/AssignmentAction.cpp
+++ b/assignment-client/src/AssignmentAction.cpp
@@ -13,9 +13,8 @@
 
 #include "AssignmentAction.h"
 
-AssignmentAction::AssignmentAction(EntityActionType type, QUuid id, EntityItemPointer ownerEntity) :
-    _id(id),
-    _type(type),
+AssignmentAction::AssignmentAction(EntityActionType type, const QUuid& id, EntityItemPointer ownerEntity) :
+    EntityActionInterface(type, id),
     _data(QByteArray()),
     _active(false),
     _ownerEntity(ownerEntity) {
@@ -28,7 +27,7 @@ void AssignmentAction::removeFromSimulation(EntitySimulation* simulation) const
     simulation->removeAction(_id);
 }
 
-QByteArray AssignmentAction::serialize() {
+QByteArray AssignmentAction::serialize() const {
     return _data;
 }
 
diff --git a/assignment-client/src/AssignmentAction.h b/assignment-client/src/AssignmentAction.h
index cd72c1f277..23720bd465 100644
--- a/assignment-client/src/AssignmentAction.h
+++ b/assignment-client/src/AssignmentAction.h
@@ -21,23 +21,19 @@
 
 class AssignmentAction : public EntityActionInterface {
 public:
-    AssignmentAction(EntityActionType type, QUuid id, EntityItemPointer ownerEntity);
+    AssignmentAction(EntityActionType type, const QUuid& id, EntityItemPointer ownerEntity);
     virtual ~AssignmentAction();
 
-    const QUuid& getID() const { return _id; }
-    virtual EntityActionType getType() { return _type; }
     virtual void removeFromSimulation(EntitySimulation* simulation) const;
     virtual EntityItemWeakPointer getOwnerEntity() const { return _ownerEntity; }
     virtual void setOwnerEntity(const EntityItemPointer ownerEntity) { _ownerEntity = ownerEntity; }
     virtual bool updateArguments(QVariantMap arguments);
     virtual QVariantMap getArguments();
 
-    virtual QByteArray serialize();
+    virtual QByteArray serialize() const;
     virtual void deserialize(QByteArray serializedArguments);
 
 private:
-    QUuid _id;
-    EntityActionType _type;
     QByteArray _data;
 
 protected:
diff --git a/assignment-client/src/AssignmentActionFactory.cpp b/assignment-client/src/AssignmentActionFactory.cpp
index ba2692c611..e1c5d3adff 100644
--- a/assignment-client/src/AssignmentActionFactory.cpp
+++ b/assignment-client/src/AssignmentActionFactory.cpp
@@ -12,14 +12,14 @@
 #include "AssignmentActionFactory.h"
 
 
-EntityActionPointer assignmentActionFactory(EntityActionType type, QUuid id, EntityItemPointer ownerEntity) {
+EntityActionPointer assignmentActionFactory(EntityActionType type, const QUuid& id, EntityItemPointer ownerEntity) {
     return (EntityActionPointer) new AssignmentAction(type, id, ownerEntity);
 }
 
 
 EntityActionPointer AssignmentActionFactory::factory(EntitySimulation* simulation,
                                                      EntityActionType type,
-                                                     QUuid id,
+                                                     const QUuid& id,
                                                      EntityItemPointer ownerEntity,
                                                      QVariantMap arguments) {
     EntityActionPointer action = assignmentActionFactory(type, id, ownerEntity);
diff --git a/assignment-client/src/AssignmentActionFactory.h b/assignment-client/src/AssignmentActionFactory.h
index f71d22c0dd..41245dac68 100644
--- a/assignment-client/src/AssignmentActionFactory.h
+++ b/assignment-client/src/AssignmentActionFactory.h
@@ -21,7 +21,7 @@ public:
     virtual ~AssignmentActionFactory() { }
     virtual EntityActionPointer factory(EntitySimulation* simulation,
                                         EntityActionType type,
-                                        QUuid id,
+                                        const QUuid& id,
                                         EntityItemPointer ownerEntity,
                                         QVariantMap arguments);
     virtual EntityActionPointer factoryBA(EntitySimulation* simulation,
diff --git a/cmake/externals/oglplus/CMakeLists.txt b/cmake/externals/oglplus/CMakeLists.txt
index a0b91739f6..43730129a0 100644
--- a/cmake/externals/oglplus/CMakeLists.txt
+++ b/cmake/externals/oglplus/CMakeLists.txt
@@ -4,8 +4,8 @@ string(TOUPPER ${EXTERNAL_NAME} EXTERNAL_NAME_UPPER)
 include(ExternalProject)
 ExternalProject_Add(
     ${EXTERNAL_NAME}
-    GIT_REPOSITORY https://github.com/matus-chochlik/oglplus.git
-    GIT_TAG a2681383928b1166f176512cbe0f95e96fe68d08
+    URL http://iweb.dl.sourceforge.net/project/oglplus/oglplus-0.63.x/oglplus-0.63.0.zip
+    URL_MD5 de984ab245b185b45c87415c0e052135
     CONFIGURE_COMMAND ""
     BUILD_COMMAND ""
     INSTALL_COMMAND ""
diff --git a/examples/defaultScripts.js b/examples/defaultScripts.js
index fb76b62dbe..922047b90c 100644
--- a/examples/defaultScripts.js
+++ b/examples/defaultScripts.js
@@ -12,7 +12,6 @@ Script.load("progress.js");
 Script.load("edit.js");
 Script.load("selectAudioDevice.js");
 Script.load("inspect.js");
-Script.load("lobby.js");
 Script.load("notifications.js");
 Script.load("users.js");
 Script.load("grab.js");
diff --git a/examples/example/games/make-dummy.js b/examples/example/games/make-dummy.js
new file mode 100644
index 0000000000..068a8b7f9a
--- /dev/null
+++ b/examples/example/games/make-dummy.js
@@ -0,0 +1,70 @@
+//
+//  make-dummy.js
+//  examples
+//
+//  Created by Seth Alves on 2015-6-10
+//  Copyright 2015 High Fidelity, Inc.
+//
+//  Makes a boxing-dummy that responds to collisions.
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+//
+"use strict";
+/*jslint vars: true*/
+var Overlays, Entities, Controller, Script, MyAvatar, Vec3; // Referenced globals provided by High Fidelity.
+
+var HIFI_PUBLIC_BUCKET = "http://s3.amazonaws.com/hifi-public/";
+
+var rezButton = Overlays.addOverlay("image", {
+    x: 100,
+    y: 350,
+    width: 32,
+    height: 32,
+    imageURL: HIFI_PUBLIC_BUCKET + "images/close.png",
+    color: {
+        red: 255,
+        green: 255,
+        blue: 255
+    },
+    alpha: 1
+});
+
+
+function mousePressEvent(event) {
+    var clickedOverlay = Overlays.getOverlayAtPoint({
+        x: event.x,
+        y: event.y
+    });
+
+    if (clickedOverlay === rezButton) {
+        var boxId;
+
+        var position = Vec3.sum(MyAvatar.position, {x: 1.0, y: 0.4, z: 0.0});
+        boxId = Entities.addEntity({
+            type: "Box",
+            name: "dummy",
+            position: position,
+            dimensions: {x: 0.3, y: 0.7, z: 0.3},
+            gravity: {x: 0.0, y: -3.0, z: 0.0},
+            damping: 0.2,
+            collisionsWillMove: true
+        });
+
+        var pointToOffsetFrom = Vec3.sum(position, {x: 0.0, y: 2.0, z: 0.0});
+        Entities.addAction("offset", boxId, {pointToOffsetFrom: pointToOffsetFrom,
+                                             linearDistance: 2.0,
+                                             // linearTimeScale: 0.005
+                                             linearTimeScale: 0.1
+                                            });
+    }
+}
+
+
+function scriptEnding() {
+    Overlays.deleteOverlay(rezButton);
+}
+
+Controller.mousePressEvent.connect(mousePressEvent);
+Script.scriptEnding.connect(scriptEnding);
diff --git a/examples/example/games/sword.js b/examples/example/games/sword.js
new file mode 100644
index 0000000000..66503b62aa
--- /dev/null
+++ b/examples/example/games/sword.js
@@ -0,0 +1,269 @@
+//  stick.js
+//  examples
+//
+//  Created by Seth Alves on 2015-6-10
+//  Copyright 2015 High Fidelity, Inc.
+//
+//  Allow avatar to hold a stick
+//
+//  Distributed under the Apache License, Version 2.0.
+//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
+//
+"use strict";
+/*jslint vars: true*/
+var Script, Entities, MyAvatar, Window, Overlays, Controller, Vec3, Quat, print, ToolBar; // Referenced globals provided by High Fidelity.
+Script.include(["../../libraries/toolBars.js"]);
+
+var hand = "right";
+var nullActionID = "00000000-0000-0000-0000-000000000000";
+var controllerID;
+var controllerActive;
+var stickID = null;
+var actionID = nullActionID;
+var targetIDs = [];
+var dimensions = { x: 0.3, y: 0.1, z: 2.0 };
+var AWAY_ORIENTATION =  Quat.fromPitchYawRollDegrees(-90, 0, 0);
+var BUTTON_SIZE = 32;
+
+var stickModel = "https://hifi-public.s3.amazonaws.com/eric/models/stick.fbx";
+var swordModel = "https://hifi-public.s3.amazonaws.com/ozan/props/sword/sword.fbx";
+var whichModel = "sword";
+var attachmentOffset, MOUSE_CONTROLLER_OFFSET = {x: 0.5, y: 0.4, z: 0.0}; // A fudge when using mouse rather than hand-controller, to hit yourself less often.
+
+var toolBar = new ToolBar(0, 0, ToolBar.vertical, "highfidelity.sword.toolbar", function () {
+    return {x: 100, y: 380};
+});
+
+var SWORD_IMAGE = "http://s3.amazonaws.com/hifi-public/images/billiardsReticle.png";  // Toggle between brandishing/sheathing sword (creating if necessary)
+var TARGET_IMAGE = "http://s3.amazonaws.com/hifi-public/images/puck.png"; // Create a target dummy
+var CLEANUP_IMAGE = "http://s3.amazonaws.com/hifi-public/images/delete.png"; // Remove sword and all target dummies.f
+var swordButton = toolBar.addOverlay("image", {
+    width: BUTTON_SIZE,
+    height: BUTTON_SIZE,
+    imageURL: SWORD_IMAGE,
+    alpha: 1
+});
+var targetButton = toolBar.addOverlay("image", {
+    width: BUTTON_SIZE,
+    height: BUTTON_SIZE,
+    imageURL: TARGET_IMAGE,
+    alpha: 1
+});
+var cleanupButton = toolBar.addOverlay("image", {
+    width: BUTTON_SIZE,
+    height: BUTTON_SIZE,
+    imageURL: CLEANUP_IMAGE,
+    alpha: 1
+});
+
+var flasher;
+function clearFlash() {
+    if (!flasher) {
+        return;
+    }
+    Script.clearTimeout(flasher.timer);
+    Overlays.deleteOverlay(flasher.overlay);
+    flasher = null;
+}
+function flash(color) {
+    clearFlash();
+    flasher = {};
+    flasher.overlay = Overlays.addOverlay("text", {
+        backgroundColor: color,
+        backgroundAlpha: 0.7,
+        width: Window.innerWidth,
+        height: Window.innerHeight
+    });
+    flasher.timer = Script.setTimeout(clearFlash, 500);
+}
+
+
+var health = 100;
+var display;
+var isAway = false;
+function updateDisplay() {
+    var text = health.toString();
+    if (!display) {
+        health = 100;
+        display = Overlays.addOverlay("text", {
+            text: text,
+            font: { size: 20 },
+            color: {red: 0, green: 255, blue: 0},
+            backgroundColor: {red: 100, green: 100, blue: 100}, // Why doesn't this and the next work?
+            backgroundAlpha: 0.9,
+            x: Window.innerWidth - 50,
+            y: 50
+        });
+    } else {
+        Overlays.editOverlay(display, {text: text});
+    }
+}
+function removeDisplay() {
+    if (display) {
+        Overlays.deleteOverlay(display);
+        display = null;
+    }
+}
+
+function cleanUp(leaveButtons) {
+    attachmentOffset = {x: 0, y: 0, z: 0};
+    if (stickID) {
+        Entities.deleteAction(stickID, actionID);
+        Entities.deleteEntity(stickID);
+        stickID = null;
+        actionID = null;
+    }
+    targetIDs.forEach(function (id) {
+        Entities.deleteAction(id.entity, id.action);
+        Entities.deleteEntity(id.entity);
+    });
+    targetIDs = [];
+    removeDisplay();
+    if (!leaveButtons) {
+        toolBar.cleanup();
+    }
+}
+
+function computeEnergy(collision, entityID) {
+    var id = entityID || collision.idA || collision.idB;
+    var entity = id && Entities.getEntityProperties(id);
+    var mass = entity ? (entity.density * entity.dimensions.x * entity.dimensions.y * entity.dimensions.z) : 1;
+    var linearVelocityChange = Vec3.length(collision.velocityChange);
+    var energy = 0.5 * mass * linearVelocityChange * linearVelocityChange;
+    return Math.min(Math.max(1.0, Math.round(energy)), 20);
+}
+function gotHit(collision) {
+    if (isAway) { return; }
+    var energy = computeEnergy(collision);
+    health -= energy;
+    flash({red: 255, green: 0, blue: 0});
+    updateDisplay();
+}
+function scoreHit(idA, idB, collision) {
+    if (isAway) { return; }
+    var energy = computeEnergy(collision, idA);
+    health += energy;
+    flash({red: 0, green: 255, blue: 0});
+    updateDisplay();
+}
+
+function positionStick(stickOrientation) {
+    var baseOffset = Vec3.sum(attachmentOffset, {x: 0.0, y: 0.0, z: -dimensions.z / 2});
+    var offset = Vec3.multiplyQbyV(stickOrientation, baseOffset);
+    Entities.updateAction(stickID, actionID, {relativePosition: offset,
+                                              relativeRotation: stickOrientation});
+}
+
+
+function mouseMoveEvent(event) {
+    attachmentOffset = MOUSE_CONTROLLER_OFFSET;
+    if (!stickID || actionID === nullActionID || isAway) {
+        return;
+    }
+    var windowCenterX = Window.innerWidth / 2;
+    var windowCenterY = Window.innerHeight / 2;
+    var mouseXCenterOffset = event.x - windowCenterX;
+    var mouseYCenterOffset = event.y - windowCenterY;
+    var mouseXRatio = mouseXCenterOffset / windowCenterX;
+    var mouseYRatio = mouseYCenterOffset / windowCenterY;
+
+    var stickOrientation = Quat.fromPitchYawRollDegrees(mouseYRatio * -90, mouseXRatio * -90, 0);
+    positionStick(stickOrientation);
+}
+
+
+function initControls() {
+    if (hand === "right") {
+        controllerID = 3; // right handed
+    } else {
+        controllerID = 4; // left handed
+    }
+}
+
+
+function update() {
+    var palmPosition = Controller.getSpatialControlPosition(controllerID);
+    controllerActive = (Vec3.length(palmPosition) > 0);
+    if (!controllerActive) {
+        return;
+    }
+
+    var stickOrientation = Controller.getSpatialControlRawRotation(controllerID);
+    var adjustment = Quat.fromPitchYawRollDegrees(180, 0, 0);
+    stickOrientation = Quat.multiply(stickOrientation, adjustment);
+
+    positionStick(stickOrientation);
+}
+
+function toggleAway() {
+    isAway = !isAway;
+    if (isAway) {
+        positionStick(AWAY_ORIENTATION);
+        removeDisplay();
+    } else {
+        updateDisplay();
+    }
+}
+
+function onClick(event) {
+    switch (Overlays.getOverlayAtPoint(event)) {
+    case swordButton:
+        if (!stickID) {
+            initControls();
+            stickID = Entities.addEntity({
+                type: "Model",
+                modelURL: (whichModel === "sword") ? swordModel : stickModel,
+                //compoundShapeURL: "https://hifi-public.s3.amazonaws.com/eric/models/stick.obj",
+                shapeType: "box",
+                dimensions: dimensions,
+                position: MyAvatar.getRightPalmPosition(), // initial position doesn't matter, as long as it's close
+                rotation: MyAvatar.orientation,
+                damping: 0.1,
+                collisionSoundURL: "http://public.highfidelity.io/sounds/Collisions-hitsandslaps/swordStrike1.wav",
+                restitution: 0.01,
+                collisionsWillMove: true
+            });
+            actionID = Entities.addAction("hold", stickID, {relativePosition: {x: 0.0, y: 0.0, z: -dimensions.z / 2},
+                                                            hand: hand,
+                                                            timeScale: 0.15});
+            if (actionID === nullActionID) {
+                print('*** FAILED TO MAKE SWORD ACTION ***');
+                cleanUp();
+            }
+            Script.addEventHandler(stickID, 'collisionWithEntity', scoreHit);
+            updateDisplay();
+        } else {
+            toggleAway();
+        }
+        break;
+    case targetButton:
+        var position = Vec3.sum(MyAvatar.position, {x: 1.0, y: 0.4, z: 0.0});
+        var boxId = Entities.addEntity({
+            type: "Box",
+            name: "dummy",
+            position: position,
+            dimensions: {x: 0.3, y: 0.7, z: 0.3},
+            gravity: {x: 0.0, y: -3.0, z: 0.0},
+            damping: 0.2,
+            collisionsWillMove: true
+        });
+
+        var pointToOffsetFrom = Vec3.sum(position, {x: 0.0, y: 2.0, z: 0.0});
+        var action = Entities.addAction("offset", boxId, {pointToOffsetFrom: pointToOffsetFrom,
+                                             linearDistance: 2.0,
+                                             // linearTimeScale: 0.005
+                                             linearTimeScale: 0.1
+                                            });
+        targetIDs.push({entity: boxId, action: action});
+        break;
+    case cleanupButton:
+        cleanUp('leaveButtons');
+        break;
+    }
+}
+
+Script.scriptEnding.connect(cleanUp);
+Controller.mouseMoveEvent.connect(mouseMoveEvent);
+Controller.mousePressEvent.connect(onClick);
+Script.update.connect(update);
+MyAvatar.collisionWithEntity.connect(gotHit);
diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index c1397beb28..0926d9eb07 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -1014,6 +1014,7 @@ void Application::paintGL() {
 
 void Application::runTests() {
     runTimingTests();
+    runUnitTests();
 }
 
 void Application::audioMuteToggled() {
@@ -1182,7 +1183,6 @@ bool Application::event(QEvent* event) {
 }
 
 bool Application::eventFilter(QObject* object, QEvent* event) {
-
     if (event->type() == QEvent::ShortcutOverride) {
         if (DependencyManager::get<OffscreenUi>()->shouldSwallowShortcut(event)) {
             event->accept();
@@ -1787,6 +1787,7 @@ void Application::checkFPS() {
 }
 
 void Application::idle() {
+    PROFILE_RANGE(__FUNCTION__);
     static SimpleAverage<float> interIdleDurations;
     static uint64_t lastIdleEnd{ 0 };
 
@@ -2304,38 +2305,42 @@ void Application::updateMyAvatarLookAtPosition() {
     bool isLookingAtSomeone = false;
     glm::vec3 lookAtSpot;
     if (_myCamera.getMode() == CAMERA_MODE_MIRROR) {
-        //  When I am in mirror mode, just look right at the camera (myself)
+        //  When I am in mirror mode, just look right at the camera (myself); don't switch gaze points because when physically
+        //  looking in a mirror one's eyes appear steady.
         if (!OculusManager::isConnected()) {
             lookAtSpot = _myCamera.getPosition();
         } else {
-            if (_myAvatar->isLookingAtLeftEye()) {
-                lookAtSpot = OculusManager::getLeftEyePosition();
-            } else {
-                lookAtSpot = OculusManager::getRightEyePosition();
-            }
+            lookAtSpot = _myCamera.getPosition() + OculusManager::getMidEyePosition();
         }
-
     } else {
         AvatarSharedPointer lookingAt = _myAvatar->getLookAtTargetAvatar().lock();
         if (lookingAt && _myAvatar != lookingAt.get()) {
-            isLookingAtSomeone = true;
             //  If I am looking at someone else, look directly at one of their eyes
-            if (tracker && !tracker->isMuted()) {
-                //  If a face tracker is active, look at the eye for the side my gaze is biased toward
-                if (tracker->getEstimatedEyeYaw() > _myAvatar->getHead()->getFinalYaw()) {
-                    // Look at their right eye
-                    lookAtSpot = static_cast<Avatar*>(lookingAt.get())->getHead()->getRightEyePosition();
-                } else {
-                    // Look at their left eye
-                    lookAtSpot = static_cast<Avatar*>(lookingAt.get())->getHead()->getLeftEyePosition();
+            isLookingAtSomeone = true;
+            Head* lookingAtHead = static_cast<Avatar*>(lookingAt.get())->getHead();
+
+            const float MAXIMUM_FACE_ANGLE = 65.0f * RADIANS_PER_DEGREE;
+            glm::vec3 lookingAtFaceOrientation = lookingAtHead->getFinalOrientationInWorldFrame() * IDENTITY_FRONT;
+            glm::vec3 fromLookingAtToMe = glm::normalize(_myAvatar->getHead()->getEyePosition()
+                - lookingAtHead->getEyePosition());
+            float faceAngle = glm::angle(lookingAtFaceOrientation, fromLookingAtToMe);
+
+            if (faceAngle < MAXIMUM_FACE_ANGLE) {
+                // Randomly look back and forth between look targets
+                switch (_myAvatar->getEyeContactTarget()) {
+                    case LEFT_EYE:
+                        lookAtSpot = lookingAtHead->getLeftEyePosition();
+                        break;
+                    case RIGHT_EYE:
+                        lookAtSpot = lookingAtHead->getRightEyePosition();
+                        break;
+                    case MOUTH:
+                        lookAtSpot = lookingAtHead->getMouthPosition();
+                        break;
                 }
             } else {
-                //  Need to add randomly looking back and forth between left and right eye for case with no tracker
-                if (_myAvatar->isLookingAtLeftEye()) {
-                    lookAtSpot = static_cast<Avatar*>(lookingAt.get())->getHead()->getLeftEyePosition();
-                } else {
-                    lookAtSpot = static_cast<Avatar*>(lookingAt.get())->getHead()->getRightEyePosition();
-                }
+                // Just look at their head (mid point between eyes)
+                lookAtSpot = lookingAtHead->getEyePosition();
             }
         } else {
             //  I am not looking at anyone else, so just look forward
@@ -2343,14 +2348,13 @@ void Application::updateMyAvatarLookAtPosition() {
                 (_myAvatar->getHead()->getFinalOrientationInWorldFrame() * glm::vec3(0.0f, 0.0f, -TREE_SCALE));
         }
     }
-    //
-    //  Deflect the eyes a bit to match the detected Gaze from 3D camera if active
-    //
-    if (tracker && !tracker->isMuted()) {
+
+    // Deflect the eyes a bit to match the detected gaze from Faceshift if active.
+    // DDE doesn't track eyes.
+    if (tracker && typeid(*tracker) == typeid(Faceshift) && !tracker->isMuted()) {
         float eyePitch = tracker->getEstimatedEyePitch();
         float eyeYaw = tracker->getEstimatedEyeYaw();
         const float GAZE_DEFLECTION_REDUCTION_DURING_EYE_CONTACT = 0.1f;
-        // deflect using Faceshift gaze data
         glm::vec3 origin = _myAvatar->getHead()->getEyePosition();
         float pitchSign = (_myCamera.getMode() == CAMERA_MODE_MIRROR) ? -1.0f : 1.0f;
         float deflection = DependencyManager::get<Faceshift>()->getEyeDeflection();
diff --git a/interface/src/GLCanvas.cpp b/interface/src/GLCanvas.cpp
index 0eda678fa9..aff7c75cc9 100644
--- a/interface/src/GLCanvas.cpp
+++ b/interface/src/GLCanvas.cpp
@@ -58,6 +58,7 @@ void GLCanvas::initializeGL() {
 }
 
 void GLCanvas::paintGL() {
+    PROFILE_RANGE(__FUNCTION__);
     if (!_throttleRendering && !Application::getInstance()->getWindow()->isMinimized()) {
         Application::getInstance()->paintGL();
     }
diff --git a/interface/src/InterfaceActionFactory.cpp b/interface/src/InterfaceActionFactory.cpp
index ccff5b4dc6..363fb66e76 100644
--- a/interface/src/InterfaceActionFactory.cpp
+++ b/interface/src/InterfaceActionFactory.cpp
@@ -18,16 +18,16 @@
 #include "InterfaceActionFactory.h"
 
 
-EntityActionPointer interfaceActionFactory(EntityActionType type, QUuid id, EntityItemPointer ownerEntity) {
+EntityActionPointer interfaceActionFactory(EntityActionType type, const QUuid& id, EntityItemPointer ownerEntity) {
     switch (type) {
         case ACTION_TYPE_NONE:
             return nullptr;
         case ACTION_TYPE_OFFSET:
-            return (EntityActionPointer) new ObjectActionOffset(type, id, ownerEntity);
+            return (EntityActionPointer) new ObjectActionOffset(id, ownerEntity);
         case ACTION_TYPE_SPRING:
-            return (EntityActionPointer) new ObjectActionSpring(type, id, ownerEntity);
+            return (EntityActionPointer) new ObjectActionSpring(id, ownerEntity);
         case ACTION_TYPE_HOLD:
-            return (EntityActionPointer) new AvatarActionHold(type, id, ownerEntity);
+            return (EntityActionPointer) new AvatarActionHold(id, ownerEntity);
     }
 
     assert(false);
@@ -37,7 +37,7 @@ EntityActionPointer interfaceActionFactory(EntityActionType type, QUuid id, Enti
 
 EntityActionPointer InterfaceActionFactory::factory(EntitySimulation* simulation,
                                                     EntityActionType type,
-                                                    QUuid id,
+                                                    const QUuid& id,
                                                     EntityItemPointer ownerEntity,
                                                     QVariantMap arguments) {
     EntityActionPointer action = interfaceActionFactory(type, id, ownerEntity);
diff --git a/interface/src/InterfaceActionFactory.h b/interface/src/InterfaceActionFactory.h
index 944e2fb753..004c24163f 100644
--- a/interface/src/InterfaceActionFactory.h
+++ b/interface/src/InterfaceActionFactory.h
@@ -20,7 +20,7 @@ public:
     virtual ~InterfaceActionFactory() { }
     virtual EntityActionPointer factory(EntitySimulation* simulation,
                                         EntityActionType type,
-                                        QUuid id,
+                                        const QUuid& id,
                                         EntityItemPointer ownerEntity,
                                         QVariantMap arguments);
     virtual EntityActionPointer factoryBA(EntitySimulation* simulation,
diff --git a/interface/src/Util.cpp b/interface/src/Util.cpp
index bf4df3f3d2..82f7d55b5d 100644
--- a/interface/src/Util.cpp
+++ b/interface/src/Util.cpp
@@ -21,6 +21,7 @@
 
 #include <QThread>
 
+#include <ByteCountCoding.h>
 #include <SharedUtil.h>
 #include <TextRenderer.h>
 
@@ -229,6 +230,43 @@ void runTimingTests() {
     elapsedUsecs = (float)startTime.nsecsElapsed() * NSEC_TO_USEC;
     qCDebug(interfaceapp, "vec3 assign and dot() usecs: %f, last result:%f",
             (double)(elapsedUsecs / numTests), (double)result);
+
+
+    quint64 BYTE_CODE_MAX_TEST_VALUE = 99999999;
+    quint64 BYTE_CODE_TESTS_SKIP = 999;
+
+    QByteArray extraJunk;
+    const int EXTRA_JUNK_SIZE = 200;
+    extraJunk.append((unsigned char)255);
+    for (int i = 0; i < EXTRA_JUNK_SIZE; i++) {
+        extraJunk.append(QString("junk"));
+    }
+
+    {
+        startTime.start();
+        quint64 tests = 0;
+        quint64 failed = 0;
+        for (quint64 value = 0; value < BYTE_CODE_MAX_TEST_VALUE; value += BYTE_CODE_TESTS_SKIP) {
+            quint64 valueA = value; // usecTimestampNow();
+            ByteCountCoded<quint64> codedValueA = valueA;
+            QByteArray codedValueABuffer = codedValueA;
+            codedValueABuffer.append(extraJunk);
+            ByteCountCoded<quint64> decodedValueA;
+            decodedValueA.decode(codedValueABuffer);
+            quint64 valueADecoded = decodedValueA;
+            tests++;
+            if (valueA != valueADecoded) {
+                qDebug() << "FAILED! value:" << valueA << "decoded:" << valueADecoded;
+                failed++;
+            }
+
+        }
+        elapsedUsecs = (float)startTime.nsecsElapsed() * NSEC_TO_USEC;
+        qCDebug(interfaceapp) << "ByteCountCoded<quint64> usecs: " << elapsedUsecs
+                                << "per test:" << (double) (elapsedUsecs / tests)
+                                << "tests:" << tests
+                                << "failed:" << failed;
+    }
 }
 
 bool rayIntersectsSphere(const glm::vec3& rayStarting, const glm::vec3& rayNormalizedDirection,
@@ -271,3 +309,39 @@ bool pointInSphere(glm::vec3& point, glm::vec3& sphereCenter, double sphereRadiu
     }
     return false;
 }
+
+void runUnitTests() {
+
+    quint64 LAST_TEST = 10;
+    quint64 SKIP_BY = 1;
+    
+    for (quint64 value = 0; value <= LAST_TEST; value += SKIP_BY) {
+        qDebug() << "value:" << value;
+
+        ByteCountCoded<quint64> codedValue = value;
+    
+        QByteArray codedValueBuffer = codedValue;
+        
+        codedValueBuffer.append((unsigned char)255);
+        codedValueBuffer.append(QString("junk"));
+        
+        qDebug() << "codedValueBuffer:";
+        outputBufferBits((const unsigned char*)codedValueBuffer.constData(), codedValueBuffer.size());
+
+        ByteCountCoded<quint64> valueDecoder;
+        size_t bytesConsumed =  valueDecoder.decode(codedValueBuffer);
+        quint64 valueDecoded = valueDecoder;
+        qDebug() << "valueDecoded:" << valueDecoded;
+        qDebug() << "bytesConsumed:" << bytesConsumed;
+        
+
+        if (value == valueDecoded) {
+            qDebug() << "SUCCESS!";
+        } else {
+            qDebug() << "FAILED!";
+        }
+
+    }
+}
+
+
diff --git a/interface/src/Util.h b/interface/src/Util.h
index ed05209747..d252c26bef 100644
--- a/interface/src/Util.h
+++ b/interface/src/Util.h
@@ -30,6 +30,7 @@ void drawText(int x, int y, float scale, float radians, int mono,
 void renderCollisionOverlay(int width, int height, float magnitude, float red = 0, float blue = 0, float green = 0);
 
 void runTimingTests();
+void runUnitTests();
 
 bool rayIntersectsSphere(const glm::vec3& rayStarting, const glm::vec3& rayNormalizedDirection,
     const glm::vec3& sphereCenter, float sphereRadius, float& distance);
diff --git a/interface/src/avatar/AvatarActionHold.cpp b/interface/src/avatar/AvatarActionHold.cpp
index 918521c0da..ca903a9771 100644
--- a/interface/src/avatar/AvatarActionHold.cpp
+++ b/interface/src/avatar/AvatarActionHold.cpp
@@ -17,13 +17,14 @@
 
 const uint16_t AvatarActionHold::holdVersion = 1;
 
-AvatarActionHold::AvatarActionHold(EntityActionType type, QUuid id, EntityItemPointer ownerEntity) :
-    ObjectActionSpring(type, id, ownerEntity),
+AvatarActionHold::AvatarActionHold(const QUuid& id, EntityItemPointer ownerEntity) :
+    ObjectActionSpring(id, ownerEntity),
     _relativePosition(glm::vec3(0.0f)),
     _relativeRotation(glm::quat()),
     _hand("right"),
     _mine(false)
 {
+    _type = ACTION_TYPE_HOLD;
     #if WANT_DEBUG
     qDebug() << "AvatarActionHold::AvatarActionHold";
     #endif
@@ -166,8 +167,7 @@ QVariantMap AvatarActionHold::getArguments() {
 
 
 void AvatarActionHold::deserialize(QByteArray serializedArguments) {
-    if (_mine) {
-        return;
+    if (!_mine) {
+        ObjectActionSpring::deserialize(serializedArguments);
     }
-    ObjectActionSpring::deserialize(serializedArguments);
 }
diff --git a/interface/src/avatar/AvatarActionHold.h b/interface/src/avatar/AvatarActionHold.h
index a47f1ce05d..3500b5dfa1 100644
--- a/interface/src/avatar/AvatarActionHold.h
+++ b/interface/src/avatar/AvatarActionHold.h
@@ -19,11 +19,9 @@
 
 class AvatarActionHold : public ObjectActionSpring {
 public:
-    AvatarActionHold(EntityActionType type, QUuid id, EntityItemPointer ownerEntity);
+    AvatarActionHold(const QUuid& id, EntityItemPointer ownerEntity);
     virtual ~AvatarActionHold();
 
-    virtual EntityActionType getType() { return ACTION_TYPE_HOLD; }
-
     virtual bool updateArguments(QVariantMap arguments);
     virtual QVariantMap getArguments();
 
diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index dbd46cbfbd..944f16fd34 100644
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -256,7 +256,6 @@ void AvatarManager::handleOutgoingChanges(VectorOfMotionStates& motionStates) {
 }
 
 void AvatarManager::handleCollisionEvents(CollisionEvents& collisionEvents) {
-    // TODO: expose avatar collision events to JS
     for (Collision collision : collisionEvents) {
         // TODO: Current physics uses null idA or idB for non-entities. The plan is to handle MOTIONSTATE_TYPE_AVATAR,
         // and then MOTIONSTATE_TYPE_MYAVATAR. As it is, this code only covers the case of my avatar (in which case one
@@ -285,6 +284,7 @@ void AvatarManager::handleCollisionEvents(CollisionEvents& collisionEvents) {
                 const float AVATAR_STRETCH_FACTOR = 1.0f;
 
                 AudioInjector::playSound(collisionSoundURL, energyFactorOfFull, AVATAR_STRETCH_FACTOR, myAvatar->getPosition());
+                myAvatar->collisionWithEntity(collision);
             }
         }
     }
diff --git a/interface/src/avatar/Head.cpp b/interface/src/avatar/Head.cpp
index ed7d84dd24..98126c3a22 100644
--- a/interface/src/avatar/Head.cpp
+++ b/interface/src/avatar/Head.cpp
@@ -296,7 +296,7 @@ void Head::relaxLean(float deltaTime) {
 
 void Head::render(RenderArgs* renderArgs, float alpha, ViewFrustum* renderFrustum, bool postLighting) {
     if (_renderLookatVectors) {
-            renderLookatVectors(renderArgs, _leftEyePosition, _rightEyePosition, getCorrectedLookAtPosition());    
+        renderLookatVectors(renderArgs, _leftEyePosition, _rightEyePosition, getCorrectedLookAtPosition());
     }
 }
 
@@ -324,7 +324,7 @@ glm::vec3 Head::getCorrectedLookAtPosition() {
 }
 
 void Head::setCorrectedLookAtPosition(glm::vec3 correctedLookAtPosition) {
-    _isLookingAtMe = true; 
+    _isLookingAtMe = true;
     _correctedLookAtPosition = correctedLookAtPosition;
 }
 
diff --git a/interface/src/avatar/Head.h b/interface/src/avatar/Head.h
index a208574c26..3f839d53bc 100644
--- a/interface/src/avatar/Head.h
+++ b/interface/src/avatar/Head.h
@@ -22,11 +22,6 @@
 #include "InterfaceConfig.h"
 #include "world.h"
 
-enum eyeContactTargets {
-    LEFT_EYE, 
-    RIGHT_EYE, 
-    MOUTH
-};
 
 const float EYE_EAR_GAP = 0.08f;
 
@@ -77,6 +72,7 @@ public:
     const glm::vec3& getLeftEyePosition() const { return _leftEyePosition; }
     glm::vec3 getRightEarPosition() const { return _rightEyePosition + (getRightDirection() * EYE_EAR_GAP) + (getFrontDirection() * -EYE_EAR_GAP); }
     glm::vec3 getLeftEarPosition() const { return _leftEyePosition + (getRightDirection() * -EYE_EAR_GAP) + (getFrontDirection() * -EYE_EAR_GAP); }
+    glm::vec3 getMouthPosition() const { return _eyePosition - getUpDirection() * glm::length(_rightEyePosition - _leftEyePosition); }
 
     FaceModel& getFaceModel() { return _faceModel; }
     const FaceModel& getFaceModel() const { return _faceModel; }
@@ -148,7 +144,7 @@ private:
     FaceModel _faceModel;
     
     glm::vec3 _correctedLookAtPosition;
-    
+
     int _leftEyeLookAtID;
     int _rightEyeLookAtID;
     
diff --git a/interface/src/avatar/MyAvatar.cpp b/interface/src/avatar/MyAvatar.cpp
index 594a8c198e..aa6b6afc66 100644
--- a/interface/src/avatar/MyAvatar.cpp
+++ b/interface/src/avatar/MyAvatar.cpp
@@ -34,6 +34,9 @@
 #include <TextRenderer.h>
 #include <UserActivityLogger.h>
 
+#include "devices/Faceshift.h"
+#include "devices/OculusManager.h"
+
 #include "Application.h"
 #include "AvatarManager.h"
 #include "Environment.h"
@@ -42,7 +45,6 @@
 #include "MyAvatar.h"
 #include "Physics.h"
 #include "Recorder.h"
-#include "devices/Faceshift.h"
 #include "Util.h"
 #include "InterfaceLogging.h"
 
@@ -97,7 +99,7 @@ MyAvatar::MyAvatar() :
     _shouldRender(true),
     _billboardValid(false),
     _feetTouchFloor(true),
-    _isLookingAtLeftEye(true),
+    _eyeContactTarget(LEFT_EYE),
     _realWorldFieldOfView("realWorldFieldOfView",
                           DEFAULT_REAL_WORLD_FIELD_OF_VIEW_DEGREES),
     _firstPersonSkeletonModel(this),
@@ -884,7 +886,6 @@ void MyAvatar::updateLookAtTargetAvatar() {
     const float KEEP_LOOKING_AT_CURRENT_ANGLE_FACTOR = 1.3f;
     const float GREATEST_LOOKING_AT_DISTANCE = 10.0f;
 
-    int howManyLookingAtMe = 0;
     foreach (const AvatarSharedPointer& avatarPointer, DependencyManager::get<AvatarManager>()->getAvatarHash()) {
         Avatar* avatar = static_cast<Avatar*>(avatarPointer.get());
         bool isCurrentTarget = avatar->getIsLookAtTarget();
@@ -897,17 +898,22 @@ void MyAvatar::updateLookAtTargetAvatar() {
                 _targetAvatarPosition = avatarPointer->getPosition();
                 smallestAngleTo = angleTo;
             }
-            //  Check if this avatar is looking at me, and fix their gaze on my camera if so
             if (Application::getInstance()->isLookingAtMyAvatar(avatar)) {
-                howManyLookingAtMe++;
-                //  Have that avatar look directly at my camera
-                //  Philip TODO: correct to look at left/right eye
-                if (qApp->isHMDMode()) {
-                    avatar->getHead()->setCorrectedLookAtPosition(Application::getInstance()->getViewFrustum()->getPosition());
-                    // FIXME what is the point of this?
-                    // avatar->getHead()->setCorrectedLookAtPosition(OculusManager::getLeftEyePosition());
+                // Alter their gaze to look directly at my camera; this looks more natural than looking at my avatar's face.
+                // Offset their gaze according to whether they're looking at one of my eyes or my mouth.
+                glm::vec3 gazeOffset = avatar->getHead()->getLookAtPosition() - getHead()->getEyePosition();
+                const float HUMAN_EYE_SEPARATION = 0.065f;
+                float myEyeSeparation = glm::length(getHead()->getLeftEyePosition() - getHead()->getRightEyePosition());
+                gazeOffset = gazeOffset * HUMAN_EYE_SEPARATION / myEyeSeparation;
+
+                if (Application::getInstance()->isHMDMode()) {
+                    //avatar->getHead()->setCorrectedLookAtPosition(Application::getInstance()->getCamera()->getPosition()
+                    //    + OculusManager::getMidEyePosition() + gazeOffset);
+                    avatar->getHead()->setCorrectedLookAtPosition(Application::getInstance()->getViewFrustum()->getPosition()
+                        + OculusManager::getMidEyePosition() + gazeOffset);
                 } else {
-                    avatar->getHead()->setCorrectedLookAtPosition(Application::getInstance()->getViewFrustum()->getPosition());
+                    avatar->getHead()->setCorrectedLookAtPosition(Application::getInstance()->getViewFrustum()->getPosition()
+                        + gazeOffset);
                 }
             } else {
                 avatar->getHead()->clearCorrectedLookAtPosition();
@@ -924,12 +930,24 @@ void MyAvatar::clearLookAtTargetAvatar() {
     _lookAtTargetAvatar.reset();
 }
 
-bool MyAvatar::isLookingAtLeftEye() {
-    float const CHANCE_OF_CHANGING_EYE = 0.01f;
-    if (randFloat() < CHANCE_OF_CHANGING_EYE) {
-        _isLookingAtLeftEye = !_isLookingAtLeftEye;
+eyeContactTarget MyAvatar::getEyeContactTarget() {
+    float const CHANCE_OF_CHANGING_TARGET = 0.01f;
+    if (randFloat() < CHANCE_OF_CHANGING_TARGET) {
+        float const FIFTY_FIFTY_CHANCE = 0.5f;
+        switch (_eyeContactTarget) {
+            case LEFT_EYE:
+                _eyeContactTarget = (randFloat() < FIFTY_FIFTY_CHANCE) ? MOUTH : RIGHT_EYE;
+                break;
+            case RIGHT_EYE:
+                _eyeContactTarget = (randFloat() < FIFTY_FIFTY_CHANCE) ? LEFT_EYE : MOUTH;
+                break;
+            case MOUTH:
+                _eyeContactTarget = (randFloat() < FIFTY_FIFTY_CHANCE) ? RIGHT_EYE : LEFT_EYE;
+                break;
+        }
     }
-    return _isLookingAtLeftEye;
+
+    return _eyeContactTarget;
 }
 
 glm::vec3 MyAvatar::getDefaultEyePosition() const {
diff --git a/interface/src/avatar/MyAvatar.h b/interface/src/avatar/MyAvatar.h
index 8410665ed5..4e76143774 100644
--- a/interface/src/avatar/MyAvatar.h
+++ b/interface/src/avatar/MyAvatar.h
@@ -19,6 +19,12 @@
 
 class ModelItemID;
 
+enum eyeContactTarget {
+    LEFT_EYE,
+    RIGHT_EYE,
+    MOUTH
+};
+
 class MyAvatar : public Avatar {
     Q_OBJECT
     Q_PROPERTY(bool shouldRenderLocally READ getShouldRenderLocally WRITE setShouldRenderLocally)
@@ -94,7 +100,7 @@ public:
 
     bool isMyAvatar() const { return true; }
     
-    bool isLookingAtLeftEye();
+    eyeContactTarget getEyeContactTarget();
 
     virtual int parseDataAtOffset(const QByteArray& packet, int offset);
     
@@ -209,6 +215,7 @@ public slots:
 signals:
     void transformChanged();
     void newCollisionSoundURL(const QUrl& url);
+    void collisionWithEntity(const Collision& collision);
 
 private:
 
@@ -251,7 +258,7 @@ private:
     QList<AnimationHandlePointer> _animationHandles;
     
     bool _feetTouchFloor;
-    bool _isLookingAtLeftEye;
+    eyeContactTarget _eyeContactTarget;
 
     RecorderPointer _recorder;
     
diff --git a/interface/src/devices/OculusManager.cpp b/interface/src/devices/OculusManager.cpp
index d88e9e8011..7bab6f58b9 100644
--- a/interface/src/devices/OculusManager.cpp
+++ b/interface/src/devices/OculusManager.cpp
@@ -283,6 +283,7 @@ static ovrVector3f _eyeOffsets[ovrEye_Count];
 
 glm::vec3 OculusManager::getLeftEyePosition() { return _eyePositions[ovrEye_Left]; }
 glm::vec3 OculusManager::getRightEyePosition() { return _eyePositions[ovrEye_Right]; }
+glm::vec3 OculusManager::getMidEyePosition() { return (_eyePositions[ovrEye_Left] + _eyePositions[ovrEye_Right]) / 2.0f; }
 
 void OculusManager::connect(QOpenGLContext* shareContext) {
     qCDebug(interfaceapp) << "Oculus SDK" << OVR_VERSION_STRING;
@@ -692,13 +693,13 @@ void OculusManager::display(QGLWidget * glCanvas, RenderArgs* renderArgs, const
         _eyeRenderPoses[eye] = eyePoses[eye];
         // Set the camera rotation for this eye
 
-        vec3 eyePosition = toGlm(_eyeRenderPoses[eye].Position);
-        eyePosition = whichCamera.getRotation() * eyePosition;
+        _eyePositions[eye] = toGlm(_eyeRenderPoses[eye].Position);
+        _eyePositions[eye] = whichCamera.getRotation() * _eyePositions[eye];
         quat eyeRotation = toGlm(_eyeRenderPoses[eye].Orientation);
         
         // Update our camera to what the application camera is doing
         _camera->setRotation(whichCamera.getRotation() * eyeRotation);
-        _camera->setPosition(whichCamera.getPosition() + eyePosition);
+        _camera->setPosition(whichCamera.getPosition() + _eyePositions[eye]);
         configureCamera(*_camera);
         _camera->update(1.0f / Application::getInstance()->getFps());
 
diff --git a/interface/src/devices/OculusManager.h b/interface/src/devices/OculusManager.h
index 9d9f091296..83ecbf0fb7 100644
--- a/interface/src/devices/OculusManager.h
+++ b/interface/src/devices/OculusManager.h
@@ -47,6 +47,7 @@ public:
     
     static glm::vec3 getLeftEyePosition();
     static glm::vec3 getRightEyePosition();
+    static glm::vec3 getMidEyePosition();
     
     static int getHMDScreen();
 
diff --git a/libraries/entities-renderer/src/RenderableModelEntityItem.cpp b/libraries/entities-renderer/src/RenderableModelEntityItem.cpp
index ae1c97f07f..85b7bafc78 100644
--- a/libraries/entities-renderer/src/RenderableModelEntityItem.cpp
+++ b/libraries/entities-renderer/src/RenderableModelEntityItem.cpp
@@ -161,6 +161,7 @@ namespace render {
     template <> void payloadRender(const RenderableModelEntityItemMeta::Pointer& payload, RenderArgs* args) {
         if (args) {
             if (payload && payload->entity) {
+                PROFILE_RANGE("MetaModelRender");
                 payload->entity->render(args);
             }
         }
diff --git a/libraries/entities/src/EntityActionFactoryInterface.h b/libraries/entities/src/EntityActionFactoryInterface.h
index 5269405d55..9f4056cdff 100644
--- a/libraries/entities/src/EntityActionFactoryInterface.h
+++ b/libraries/entities/src/EntityActionFactoryInterface.h
@@ -25,7 +25,7 @@ class EntityActionFactoryInterface : public QObject, public Dependency {
     virtual ~EntityActionFactoryInterface() { }
     virtual EntityActionPointer factory(EntitySimulation* simulation,
                                         EntityActionType type,
-                                        QUuid id,
+                                        const QUuid& id,
                                         EntityItemPointer ownerEntity,
                                         QVariantMap arguments) { assert(false); return nullptr; }
     virtual EntityActionPointer factoryBA(EntitySimulation* simulation,
diff --git a/libraries/entities/src/EntityActionInterface.h b/libraries/entities/src/EntityActionInterface.h
index 5693e1fb6f..a4f1c8ea15 100644
--- a/libraries/entities/src/EntityActionInterface.h
+++ b/libraries/entities/src/EntityActionInterface.h
@@ -29,10 +29,10 @@ enum EntityActionType {
 
 class EntityActionInterface {
 public:
-    EntityActionInterface() { }
+    EntityActionInterface(EntityActionType type, const QUuid& id) : _id(id), _type(type) { }
     virtual ~EntityActionInterface() { }
-    virtual const QUuid& getID() const = 0;
-    virtual EntityActionType getType() { assert(false); return ACTION_TYPE_NONE; }
+    const QUuid& getID() const { return _id; }
+    EntityActionType getType() const { return _type; }
 
     virtual void removeFromSimulation(EntitySimulation* simulation) const = 0;
     virtual EntityItemWeakPointer getOwnerEntity() const = 0;
@@ -40,7 +40,7 @@ public:
     virtual bool updateArguments(QVariantMap arguments) = 0;
     virtual QVariantMap getArguments() = 0;
 
-    virtual QByteArray serialize() = 0;
+    virtual QByteArray serialize() const = 0;
     virtual void deserialize(QByteArray serializedArguments) = 0;
 
     static EntityActionType actionTypeFromString(QString actionTypeString);
@@ -68,6 +68,8 @@ protected:
     static QString extractStringArgument(QString objectName, QVariantMap arguments,
                                          QString argumentName, bool& ok, bool required = true);
 
+    QUuid _id;
+    EntityActionType _type;
 };
 
 
diff --git a/libraries/entities/src/EntityItem.cpp b/libraries/entities/src/EntityItem.cpp
index 6c27152a97..1165518097 100644
--- a/libraries/entities/src/EntityItem.cpp
+++ b/libraries/entities/src/EntityItem.cpp
@@ -12,9 +12,11 @@
 #include "EntityItem.h"
 
 #include <QtCore/QObject>
+#include <QtEndian>
 
 #include <glm/gtx/transform.hpp>
 
+#include <BufferParser.h>
 #include <ByteCountCoding.h>
 #include <GLMHelpers.h>
 #include <Octree.h>
@@ -354,50 +356,78 @@ int EntityItem::readEntityDataFromBuffer(const unsigned char* data, int bytesLef
     // ~27-35 bytes...
     const int MINIMUM_HEADER_BYTES = 27;
 
-    int bytesRead = 0;
     if (bytesLeftToRead < MINIMUM_HEADER_BYTES) {
         return 0;
     }
 
+    int clockSkew = args.sourceNode ? args.sourceNode->getClockSkewUsec() : 0;
+
+    BufferParser parser(data, bytesLeftToRead);
+
+#ifdef DEBUG
+#define VALIDATE_ENTITY_ITEM_PARSER 1
+#endif
+
+#ifdef VALIDATE_ENTITY_ITEM_PARSER
+    int bytesRead = 0;
     int originalLength = bytesLeftToRead;
     // TODO: figure out a way to avoid the big deep copy below.
     QByteArray originalDataBuffer((const char*)data, originalLength); // big deep copy!
-
-    int clockSkew = args.sourceNode ? args.sourceNode->getClockSkewUsec() : 0;
-
     const unsigned char* dataAt = data;
+#endif
 
     // id
-    QByteArray encodedID = originalDataBuffer.mid(bytesRead, NUM_BYTES_RFC4122_UUID); // maximum possible size
-    _id = QUuid::fromRfc4122(encodedID);
-    dataAt += encodedID.size();
-    bytesRead += encodedID.size();
-    
+    parser.readUuid(_id);
+#ifdef VALIDATE_ENTITY_ITEM_PARSER
+    {
+        QByteArray encodedID = originalDataBuffer.mid(bytesRead, NUM_BYTES_RFC4122_UUID); // maximum possible size
+        QUuid id = QUuid::fromRfc4122(encodedID);
+        dataAt += encodedID.size();
+        bytesRead += encodedID.size();
+        Q_ASSERT(id == _id);
+        Q_ASSERT(parser.offset() == bytesRead);
+    }
+#endif
+
     // type
+    parser.readCompressedCount<quint32>((quint32&)_type);
+#ifdef VALIDATE_ENTITY_ITEM_PARSER
     QByteArray encodedType = originalDataBuffer.mid(bytesRead); // maximum possible size
     ByteCountCoded<quint32> typeCoder = encodedType;
     encodedType = typeCoder; // determine true length
     dataAt += encodedType.size();
     bytesRead += encodedType.size();
     quint32 type = typeCoder;
-    _type = (EntityTypes::EntityType)type;
+    EntityTypes::EntityType oldType = (EntityTypes::EntityType)type;
+    Q_ASSERT(oldType == _type);
+    Q_ASSERT(parser.offset() == bytesRead);
+#endif    
 
     bool overwriteLocalData = true; // assume the new content overwrites our local data
+    quint64 now = usecTimestampNow();
 
     // _created
-    quint64 createdFromBuffer = 0;
-    memcpy(&createdFromBuffer, dataAt, sizeof(createdFromBuffer));
-    dataAt += sizeof(createdFromBuffer);
-    bytesRead += sizeof(createdFromBuffer);
-
-    quint64 now = usecTimestampNow();
-    if (_created == UNKNOWN_CREATED_TIME) {
-        // we don't yet have a _created timestamp, so we accept this one
-        createdFromBuffer -= clockSkew;
-        if (createdFromBuffer > now || createdFromBuffer == UNKNOWN_CREATED_TIME) {
-            createdFromBuffer = now;
+    {
+        quint64 createdFromBuffer = 0;
+        parser.readValue(createdFromBuffer);
+#ifdef VALIDATE_ENTITY_ITEM_PARSER
+        {
+            quint64 createdFromBuffer2 = 0;
+            memcpy(&createdFromBuffer2, dataAt, sizeof(createdFromBuffer2));
+            dataAt += sizeof(createdFromBuffer2);
+            bytesRead += sizeof(createdFromBuffer2);
+            Q_ASSERT(createdFromBuffer2 == createdFromBuffer);
+            Q_ASSERT(parser.offset() == bytesRead);
+        }
+#endif        
+        if (_created == UNKNOWN_CREATED_TIME) {
+            // we don't yet have a _created timestamp, so we accept this one
+            createdFromBuffer -= clockSkew;
+            if (createdFromBuffer > now || createdFromBuffer == UNKNOWN_CREATED_TIME) {
+                createdFromBuffer = now;
+            }
+            _created = createdFromBuffer;
         }
-        _created = createdFromBuffer;
     }
 
     #ifdef WANT_DEBUG
@@ -417,15 +447,21 @@ int EntityItem::readEntityDataFromBuffer(const unsigned char* data, int bytesLef
     #endif
 
     quint64 lastEditedFromBuffer = 0;
-    quint64 lastEditedFromBufferAdjusted = 0;
 
     // TODO: we could make this encoded as a delta from _created
     // _lastEdited
-    memcpy(&lastEditedFromBuffer, dataAt, sizeof(lastEditedFromBuffer));
-    dataAt += sizeof(lastEditedFromBuffer);
-    bytesRead += sizeof(lastEditedFromBuffer);
-    lastEditedFromBufferAdjusted = lastEditedFromBuffer - clockSkew;
-
+    parser.readValue(lastEditedFromBuffer);
+#ifdef VALIDATE_ENTITY_ITEM_PARSER
+    {
+        quint64 lastEditedFromBuffer2 = 0;
+        memcpy(&lastEditedFromBuffer2, dataAt, sizeof(lastEditedFromBuffer2));
+        dataAt += sizeof(lastEditedFromBuffer2);
+        bytesRead += sizeof(lastEditedFromBuffer2);
+        Q_ASSERT(lastEditedFromBuffer2 == lastEditedFromBuffer);
+        Q_ASSERT(parser.offset() == bytesRead);
+    }
+#endif        
+    quint64 lastEditedFromBufferAdjusted = lastEditedFromBuffer - clockSkew;
     if (lastEditedFromBufferAdjusted > now) {
         lastEditedFromBufferAdjusted = now;
     }
@@ -487,9 +523,21 @@ int EntityItem::readEntityDataFromBuffer(const unsigned char* data, int bytesLef
     }
 
     // last updated is stored as ByteCountCoded delta from lastEdited
-    QByteArray encodedUpdateDelta = originalDataBuffer.mid(bytesRead); // maximum possible size
-    ByteCountCoded<quint64> updateDeltaCoder = encodedUpdateDelta;
-    quint64 updateDelta = updateDeltaCoder;
+    quint64 updateDelta;
+    parser.readCompressedCount(updateDelta);
+#ifdef VALIDATE_ENTITY_ITEM_PARSER
+    {
+        QByteArray encodedUpdateDelta = originalDataBuffer.mid(bytesRead); // maximum possible size
+        ByteCountCoded<quint64> updateDeltaCoder = encodedUpdateDelta;
+        quint64 updateDelta2 = updateDeltaCoder;
+        Q_ASSERT(updateDelta == updateDelta2);
+        encodedUpdateDelta = updateDeltaCoder; // determine true length
+        dataAt += encodedUpdateDelta.size();
+        bytesRead += encodedUpdateDelta.size();
+        Q_ASSERT(parser.offset() == bytesRead);
+    }
+#endif        
+    
     if (overwriteLocalData) {
         _lastUpdated = lastEditedFromBufferAdjusted + updateDelta; // don't adjust for clock skew since we already did that
         #ifdef WANT_DEBUG
@@ -499,17 +547,25 @@ int EntityItem::readEntityDataFromBuffer(const unsigned char* data, int bytesLef
         #endif
     }
 
-    encodedUpdateDelta = updateDeltaCoder; // determine true length
-    dataAt += encodedUpdateDelta.size();
-    bytesRead += encodedUpdateDelta.size();
-
     // Newer bitstreams will have a last simulated and a last updated value
     quint64 lastSimulatedFromBufferAdjusted = now;
     if (args.bitstreamVersion >= VERSION_ENTITIES_HAS_LAST_SIMULATED_TIME) {
         // last simulated is stored as ByteCountCoded delta from lastEdited
-        QByteArray encodedSimulatedDelta = originalDataBuffer.mid(bytesRead); // maximum possible size
-        ByteCountCoded<quint64> simulatedDeltaCoder = encodedSimulatedDelta;
-        quint64 simulatedDelta = simulatedDeltaCoder;
+        quint64 simulatedDelta;
+        parser.readCompressedCount(simulatedDelta);
+#ifdef VALIDATE_ENTITY_ITEM_PARSER
+        {
+            QByteArray encodedSimulatedDelta = originalDataBuffer.mid(bytesRead); // maximum possible size
+            ByteCountCoded<quint64> simulatedDeltaCoder = encodedSimulatedDelta;
+            quint64 simulatedDelta2 = simulatedDeltaCoder;
+            Q_ASSERT(simulatedDelta2 == simulatedDelta);
+            encodedSimulatedDelta = simulatedDeltaCoder; // determine true length
+            dataAt += encodedSimulatedDelta.size();
+            bytesRead += encodedSimulatedDelta.size();
+            Q_ASSERT(parser.offset() == bytesRead);
+        }
+#endif
+
         if (overwriteLocalData) {
             lastSimulatedFromBufferAdjusted = lastEditedFromBufferAdjusted + simulatedDelta; // don't adjust for clock skew since we already did that
             if (lastSimulatedFromBufferAdjusted > now) {
@@ -521,9 +577,6 @@ int EntityItem::readEntityDataFromBuffer(const unsigned char* data, int bytesLef
                 qCDebug(entities) << "        lastSimulatedFromBufferAdjusted:" << debugTime(lastSimulatedFromBufferAdjusted, now);
             #endif
         }
-        encodedSimulatedDelta = simulatedDeltaCoder; // determine true length
-        dataAt += encodedSimulatedDelta.size();
-        bytesRead += encodedSimulatedDelta.size();
     }
 
     #ifdef WANT_DEBUG
@@ -537,10 +590,26 @@ int EntityItem::readEntityDataFromBuffer(const unsigned char* data, int bytesLef
 
 
     // Property Flags
-    QByteArray encodedPropertyFlags = originalDataBuffer.mid(bytesRead); // maximum possible size
-    EntityPropertyFlags propertyFlags = encodedPropertyFlags;
-    dataAt += propertyFlags.getEncodedLength();
-    bytesRead += propertyFlags.getEncodedLength();
+    EntityPropertyFlags propertyFlags;
+    parser.readFlags(propertyFlags);
+#ifdef VALIDATE_ENTITY_ITEM_PARSER
+    {
+        QByteArray encodedPropertyFlags = originalDataBuffer.mid(bytesRead); // maximum possible size
+        EntityPropertyFlags propertyFlags2 = encodedPropertyFlags;
+        dataAt += propertyFlags.getEncodedLength();
+        bytesRead += propertyFlags.getEncodedLength();
+        Q_ASSERT(propertyFlags2 == propertyFlags);
+        Q_ASSERT(parser.offset() == bytesRead);
+    }
+#endif
+
+#ifdef VALIDATE_ENTITY_ITEM_PARSER
+    Q_ASSERT(parser.data() + parser.offset() == dataAt);
+#else
+    const unsigned char* dataAt = parser.data() + parser.offset();
+    int bytesRead = parser.offset();
+#endif
+
 
     if (args.bitstreamVersion >= VERSION_ENTITIES_HAVE_SIMULATION_OWNER_AND_ACTIONS_OVER_WIRE) {
         // pack SimulationOwner and terse update properties near each other
@@ -549,6 +618,7 @@ int EntityItem::readEntityDataFromBuffer(const unsigned char* data, int bytesLef
         // even when we would otherwise ignore the rest of the packet.
 
         if (propertyFlags.getHasProperty(PROP_SIMULATION_OWNER)) {
+
             QByteArray simOwnerData;
             int bytes = OctreePacketData::unpackDataFromBytes(dataAt, simOwnerData);
             SimulationOwner newSimOwner;
diff --git a/libraries/entities/src/EntityItemID.cpp b/libraries/entities/src/EntityItemID.cpp
index 4e66f5d156..d882559ee3 100644
--- a/libraries/entities/src/EntityItemID.cpp
+++ b/libraries/entities/src/EntityItemID.cpp
@@ -11,7 +11,7 @@
 
 #include <QtCore/QObject>
 #include <QDebug>
-
+#include <BufferParser.h>
 #include <PacketHeaders.h>
 
 #include "RegisteredMetaTypes.h"
@@ -33,11 +33,8 @@ EntityItemID::EntityItemID(const QUuid& id) : QUuid(id)
 
 EntityItemID EntityItemID::readEntityItemIDFromBuffer(const unsigned char* data, int bytesLeftToRead) {
     EntityItemID result;
-
     if (bytesLeftToRead >= NUM_BYTES_RFC4122_UUID) {
-        // id
-        QByteArray encodedID((const char*)data, NUM_BYTES_RFC4122_UUID);
-        result = QUuid::fromRfc4122(encodedID);
+        BufferParser(data, bytesLeftToRead).readUuid(result);
     }
     return result;
 }
diff --git a/libraries/entities/src/EntityTree.cpp b/libraries/entities/src/EntityTree.cpp
index 3d7fcd8ce5..a951b2bf4f 100644
--- a/libraries/entities/src/EntityTree.cpp
+++ b/libraries/entities/src/EntityTree.cpp
@@ -92,13 +92,11 @@ void EntityTree::postAddEntity(EntityItemPointer entity) {
 bool EntityTree::updateEntity(const EntityItemID& entityID, const EntityItemProperties& properties, const SharedNodePointer& senderNode) {
     EntityTreeElement* containingElement = getContainingElement(entityID);
     if (!containingElement) {
-        qCDebug(entities) << "UNEXPECTED!!!!  EntityTree::updateEntity() entityID doesn't exist!!! entityID=" << entityID;
         return false;
     }
 
     EntityItemPointer existingEntity = containingElement->getEntityWithEntityItemID(entityID);
     if (!existingEntity) {
-        qCDebug(entities) << "UNEXPECTED!!!! don't call updateEntity() on entity items that don't exist. entityID=" << entityID;
         return false;
     }
 
@@ -108,8 +106,6 @@ bool EntityTree::updateEntity(const EntityItemID& entityID, const EntityItemProp
 bool EntityTree::updateEntity(EntityItemPointer entity, const EntityItemProperties& properties, const SharedNodePointer& senderNode) {
     EntityTreeElement* containingElement = getContainingElement(entity->getEntityItemID());
     if (!containingElement) {
-        qCDebug(entities) << "UNEXPECTED!!!!  EntityTree::updateEntity() entity-->element lookup failed!!! entityID=" 
-            << entity->getEntityItemID();
         return false;
     }
     return updateEntityWithElement(entity, properties, containingElement, senderNode);
diff --git a/libraries/gpu/src/gpu/Batch.cpp b/libraries/gpu/src/gpu/Batch.cpp
index e79a7ecdd9..b3e6b6117d 100644
--- a/libraries/gpu/src/gpu/Batch.cpp
+++ b/libraries/gpu/src/gpu/Batch.cpp
@@ -12,6 +12,17 @@
 
 #include <QDebug>
 
+#if defined(NSIGHT_FOUND)
+#include "nvToolsExt.h"
+
+ProfileRange::ProfileRange(const char *name) {
+    nvtxRangePush(name);
+}
+ProfileRange::~ProfileRange() {
+    nvtxRangePop();
+}
+#endif
+
 #define ADD_COMMAND(call) _commands.push_back(COMMAND_##call); _commandOffsets.push_back(_params.size());
 
 using namespace gpu;
diff --git a/libraries/gpu/src/gpu/Batch.h b/libraries/gpu/src/gpu/Batch.h
index 3765077ee2..0cc1a6bee3 100644
--- a/libraries/gpu/src/gpu/Batch.h
+++ b/libraries/gpu/src/gpu/Batch.h
@@ -26,17 +26,11 @@
 #include "Framebuffer.h"
 
 #if defined(NSIGHT_FOUND)
-    #include "nvToolsExt.h"
     class ProfileRange {
     public:
-        ProfileRange(const char *name) {
-            nvtxRangePush(name);
-        }
-        ~ProfileRange() {
-            nvtxRangePop();
-        }
+        ProfileRange(const char *name);
+        ~ProfileRange();
     };
-
     #define PROFILE_RANGE(name) ProfileRange profileRangeThis(name);
 #else
 #define PROFILE_RANGE(name)
diff --git a/libraries/gpu/src/gpu/Context.cpp b/libraries/gpu/src/gpu/Context.cpp
index 9cc6bb3cd7..51335f78df 100644
--- a/libraries/gpu/src/gpu/Context.cpp
+++ b/libraries/gpu/src/gpu/Context.cpp
@@ -33,9 +33,11 @@ bool Context::makeProgram(Shader& shader, const Shader::BindingSet& bindings) {
 }
 
 void Context::render(Batch& batch) {
+    PROFILE_RANGE(__FUNCTION__);
     _backend->render(batch);
 }
 
 void Context::syncCache() {
+    PROFILE_RANGE(__FUNCTION__);
     _backend->syncCache();
 }
\ No newline at end of file
diff --git a/libraries/physics/src/ObjectAction.cpp b/libraries/physics/src/ObjectAction.cpp
index ae29fe79d3..101b69f03a 100644
--- a/libraries/physics/src/ObjectAction.cpp
+++ b/libraries/physics/src/ObjectAction.cpp
@@ -13,9 +13,9 @@
 
 #include "ObjectAction.h"
 
-ObjectAction::ObjectAction(EntityActionType type, QUuid id, EntityItemPointer ownerEntity) :
+ObjectAction::ObjectAction(EntityActionType type, const QUuid& id, EntityItemPointer ownerEntity) :
     btActionInterface(),
-    _id(id),
+    EntityActionInterface(type, id),
     _active(false),
     _ownerEntity(ownerEntity) {
 }
@@ -24,15 +24,15 @@ ObjectAction::~ObjectAction() {
 }
 
 void ObjectAction::updateAction(btCollisionWorld* collisionWorld, btScalar deltaTimeStep) {
-    if (!_active) {
-        return;
-    }
     if (_ownerEntity.expired()) {
         qDebug() << "warning -- action with no entity removing self from btCollisionWorld.";
         btDynamicsWorld* dynamicsWorld = static_cast<btDynamicsWorld*>(collisionWorld);
         dynamicsWorld->removeAction(this);
         return;
     }
+    if (!_active) {
+        return;
+    }
 
     updateActionWorker(deltaTimeStep);
 }
@@ -129,11 +129,3 @@ void ObjectAction::setAngularVelocity(glm::vec3 angularVelocity) {
     rigidBody->activate();
 }
 
-QByteArray ObjectAction::serialize() {
-    assert(false);
-    return QByteArray();
-}
-
-void ObjectAction::deserialize(QByteArray serializedArguments) {
-    assert(false);
-}
diff --git a/libraries/physics/src/ObjectAction.h b/libraries/physics/src/ObjectAction.h
index 0e982aaacf..f619657e92 100644
--- a/libraries/physics/src/ObjectAction.h
+++ b/libraries/physics/src/ObjectAction.h
@@ -17,8 +17,6 @@
 
 #include <btBulletDynamicsCommon.h>
 
-#include <EntityItem.h>
-
 #include "ObjectMotionState.h"
 #include "BulletUtil.h"
 #include "EntityActionInterface.h"
@@ -26,31 +24,25 @@
 
 class ObjectAction : public btActionInterface, public EntityActionInterface {
 public:
-    ObjectAction(EntityActionType type, QUuid id, EntityItemPointer ownerEntity);
+    ObjectAction(EntityActionType type, const QUuid& id, EntityItemPointer ownerEntity);
     virtual ~ObjectAction();
 
-    const QUuid& getID() const { return _id; }
-    virtual EntityActionType getType() { assert(false); return ACTION_TYPE_NONE; }
     virtual void removeFromSimulation(EntitySimulation* simulation) const;
     virtual EntityItemWeakPointer getOwnerEntity() const { return _ownerEntity; }
     virtual void setOwnerEntity(const EntityItemPointer ownerEntity) { _ownerEntity = ownerEntity; }
 
-    virtual bool updateArguments(QVariantMap arguments) { return false; }
-    virtual QVariantMap getArguments() { return QVariantMap(); }
+    virtual bool updateArguments(QVariantMap arguments) = 0;
+    virtual QVariantMap getArguments() = 0;
 
     // this is called from updateAction and should be overridden by subclasses
-    virtual void updateActionWorker(float deltaTimeStep) {}
+    virtual void updateActionWorker(float deltaTimeStep) = 0;
 
     // these are from btActionInterface
     virtual void updateAction(btCollisionWorld* collisionWorld, btScalar deltaTimeStep);
     virtual void debugDraw(btIDebugDraw* debugDrawer);
 
-    virtual QByteArray serialize();
-    virtual void deserialize(QByteArray serializedArguments);
-
-private:
-    QUuid _id;
-    QReadWriteLock _lock;
+    virtual QByteArray serialize() const = 0;
+    virtual void deserialize(QByteArray serializedArguments) = 0;
 
 protected:
 
@@ -70,6 +62,10 @@ protected:
     bool tryLockForWrite() { return _lock.tryLockForWrite(); }
     void unlock() { _lock.unlock(); }
 
+private:
+    QReadWriteLock _lock;
+
+protected:
     bool _active;
     EntityItemWeakPointer _ownerEntity;
 };
diff --git a/libraries/physics/src/ObjectActionOffset.cpp b/libraries/physics/src/ObjectActionOffset.cpp
index 22c6b7e0d3..7cf35b27d7 100644
--- a/libraries/physics/src/ObjectActionOffset.cpp
+++ b/libraries/physics/src/ObjectActionOffset.cpp
@@ -15,8 +15,8 @@
 
 const uint16_t ObjectActionOffset::offsetVersion = 1;
 
-ObjectActionOffset::ObjectActionOffset(EntityActionType type, QUuid id, EntityItemPointer ownerEntity) :
-    ObjectAction(type, id, ownerEntity) {
+ObjectActionOffset::ObjectActionOffset(const QUuid& id, EntityItemPointer ownerEntity) :
+    ObjectAction(ACTION_TYPE_OFFSET, id, ownerEntity) {
     #if WANT_DEBUG
     qDebug() << "ObjectActionOffset::ObjectActionOffset";
     #endif
@@ -127,7 +127,7 @@ QVariantMap ObjectActionOffset::getArguments() {
     return arguments;
 }
 
-QByteArray ObjectActionOffset::serialize() {
+QByteArray ObjectActionOffset::serialize() const {
     QByteArray ba;
     QDataStream dataStream(&ba, QIODevice::WriteOnly);
     dataStream << getType();
@@ -146,13 +146,14 @@ void ObjectActionOffset::deserialize(QByteArray serializedArguments) {
     QDataStream dataStream(serializedArguments);
 
     EntityActionType type;
-    QUuid id;
-    uint16_t serializationVersion;
-
     dataStream >> type;
     assert(type == getType());
+
+    QUuid id;
     dataStream >> id;
     assert(id == getID());
+
+    uint16_t serializationVersion;
     dataStream >> serializationVersion;
     if (serializationVersion != ObjectActionOffset::offsetVersion) {
         return;
diff --git a/libraries/physics/src/ObjectActionOffset.h b/libraries/physics/src/ObjectActionOffset.h
index 28a08c2efe..1918da6996 100644
--- a/libraries/physics/src/ObjectActionOffset.h
+++ b/libraries/physics/src/ObjectActionOffset.h
@@ -19,17 +19,15 @@
 
 class ObjectActionOffset : public ObjectAction {
 public:
-    ObjectActionOffset(EntityActionType type, QUuid id, EntityItemPointer ownerEntity);
+    ObjectActionOffset(const QUuid& id, EntityItemPointer ownerEntity);
     virtual ~ObjectActionOffset();
 
-    virtual EntityActionType getType() { return ACTION_TYPE_OFFSET; }
-
     virtual bool updateArguments(QVariantMap arguments);
     virtual QVariantMap getArguments();
 
     virtual void updateActionWorker(float deltaTimeStep);
 
-    virtual QByteArray serialize();
+    virtual QByteArray serialize() const;
     virtual void deserialize(QByteArray serializedArguments);
 
  private:
diff --git a/libraries/physics/src/ObjectActionSpring.cpp b/libraries/physics/src/ObjectActionSpring.cpp
index fae593f3eb..cb1dd20472 100644
--- a/libraries/physics/src/ObjectActionSpring.cpp
+++ b/libraries/physics/src/ObjectActionSpring.cpp
@@ -17,8 +17,8 @@ const float SPRING_MAX_SPEED = 10.0f;
 
 const uint16_t ObjectActionSpring::springVersion = 1;
 
-ObjectActionSpring::ObjectActionSpring(EntityActionType type, QUuid id, EntityItemPointer ownerEntity) :
-    ObjectAction(type, id, ownerEntity),
+ObjectActionSpring::ObjectActionSpring(const QUuid& id, EntityItemPointer ownerEntity) :
+    ObjectAction(ACTION_TYPE_SPRING, id, ownerEntity),
     _positionalTarget(glm::vec3(0.0f)),
     _linearTimeScale(0.2f),
     _positionalTargetSet(false),
@@ -206,7 +206,7 @@ QVariantMap ObjectActionSpring::getArguments() {
     return arguments;
 }
 
-QByteArray ObjectActionSpring::serialize() {
+QByteArray ObjectActionSpring::serialize() const {
     QByteArray serializedActionArguments;
     QDataStream dataStream(&serializedActionArguments, QIODevice::WriteOnly);
 
@@ -229,13 +229,14 @@ void ObjectActionSpring::deserialize(QByteArray serializedArguments) {
     QDataStream dataStream(serializedArguments);
 
     EntityActionType type;
-    QUuid id;
-    uint16_t serializationVersion;
-
     dataStream >> type;
     assert(type == getType());
+
+    QUuid id;
     dataStream >> id;
     assert(id == getID());
+
+    uint16_t serializationVersion;
     dataStream >> serializationVersion;
     if (serializationVersion != ObjectActionSpring::springVersion) {
         return;
diff --git a/libraries/physics/src/ObjectActionSpring.h b/libraries/physics/src/ObjectActionSpring.h
index c887a046bb..caa64c3d3a 100644
--- a/libraries/physics/src/ObjectActionSpring.h
+++ b/libraries/physics/src/ObjectActionSpring.h
@@ -12,24 +12,19 @@
 #ifndef hifi_ObjectActionSpring_h
 #define hifi_ObjectActionSpring_h
 
-#include <QUuid>
-
-#include <EntityItem.h>
 #include "ObjectAction.h"
 
 class ObjectActionSpring : public ObjectAction {
 public:
-    ObjectActionSpring(EntityActionType type, QUuid id, EntityItemPointer ownerEntity);
+    ObjectActionSpring(const QUuid& id, EntityItemPointer ownerEntity);
     virtual ~ObjectActionSpring();
 
-    virtual EntityActionType getType() { return ACTION_TYPE_SPRING; }
-
     virtual bool updateArguments(QVariantMap arguments);
     virtual QVariantMap getArguments();
 
     virtual void updateActionWorker(float deltaTimeStep);
 
-    virtual QByteArray serialize();
+    virtual QByteArray serialize() const;
     virtual void deserialize(QByteArray serializedArguments);
 
 protected:
diff --git a/libraries/render-utils/src/Model.cpp b/libraries/render-utils/src/Model.cpp
index 1b94c70e57..03140c4dfb 100644
--- a/libraries/render-utils/src/Model.cpp
+++ b/libraries/render-utils/src/Model.cpp
@@ -417,6 +417,7 @@ void Model::reset() {
 }
 
 bool Model::updateGeometry() {
+    PROFILE_RANGE(__FUNCTION__);
     bool needFullUpdate = false;
 
     bool needToRebuild = false;
@@ -690,6 +691,7 @@ void Model::recalculateMeshPartOffsets() {
 // entity-scripts to call.  I think it would be best to do the picking once-per-frame (in cpu, or gpu if possible)
 // and then the calls use the most recent such result. 
 void Model::recalculateMeshBoxes(bool pickAgainstTriangles) {
+    PROFILE_RANGE(__FUNCTION__);
     bool calculatedMeshTrianglesNeeded = pickAgainstTriangles && !_calculatedMeshTrianglesValid;
 
     if (!_calculatedMeshBoxesValid || calculatedMeshTrianglesNeeded || (!_calculatedMeshPartBoxesValid && pickAgainstTriangles) ) {
@@ -1281,6 +1283,7 @@ Blender::Blender(Model* model, int blendNumber, const QWeakPointer<NetworkGeomet
 }
 
 void Blender::run() {
+    PROFILE_RANGE(__FUNCTION__);
     QVector<glm::vec3> vertices, normals;
     if (!_model.isNull()) {
         int offset = 0;
@@ -1392,6 +1395,7 @@ void Model::snapToRegistrationPoint() {
 }
 
 void Model::simulate(float deltaTime, bool fullUpdate) {
+    PROFILE_RANGE(__FUNCTION__);
     fullUpdate = updateGeometry() || fullUpdate || (_scaleToFit && !_scaledToFit)
                     || (_snapModelToRegistrationPoint && !_snappedToRegistrationPoint);
                     
@@ -1829,6 +1833,7 @@ void Model::setupBatchTransform(gpu::Batch& batch, RenderArgs* args) {
 }
 
 AABox Model::getPartBounds(int meshIndex, int partIndex) {
+
     if (meshIndex < _meshStates.size()) {
         const MeshState& state = _meshStates.at(meshIndex);
         bool isSkinned = state.clusterMatrices.size() > 1;
@@ -1859,6 +1864,7 @@ AABox Model::getPartBounds(int meshIndex, int partIndex) {
 }
 
 void Model::renderPart(RenderArgs* args, int meshIndex, int partIndex, bool translucent) {
+ //   PROFILE_RANGE(__FUNCTION__);
     PerformanceTimer perfTimer("Model::renderPart");
     if (!_readyWhenAdded) {
         return; // bail asap
@@ -1933,7 +1939,9 @@ void Model::renderPart(RenderArgs* args, int meshIndex, int partIndex, bool tran
     pickPrograms(batch, mode, translucentMesh, alphaThreshold, hasLightmap, hasTangents, hasSpecular, isSkinned, wireframe,
                  args, locations);
 
-    updateVisibleJointStates();
+    {
+        updateVisibleJointStates();
+    }
 
     // if our index is ever out of range for either meshes or networkMeshes, then skip it, and set our _meshGroupsKnown
     // to false to rebuild out mesh groups.
@@ -2076,9 +2084,13 @@ void Model::renderPart(RenderArgs* args, int meshIndex, int partIndex, bool tran
         }
     }
     
-    _mutex.lock();
-    qint64 offset = _calculatedMeshPartOffset[QPair<int,int>(meshIndex, partIndex)];
-    _mutex.unlock();
+    qint64 offset;
+    {
+        // FIXME_STUTTER: We should n't have any lock here
+        _mutex.lock();
+        offset = _calculatedMeshPartOffset[QPair<int,int>(meshIndex, partIndex)];
+        _mutex.unlock();
+    }
 
     if (part.quadIndices.size() > 0) {
         batch.drawIndexed(gpu::QUADS, part.quadIndices.size(), offset);
diff --git a/libraries/render/CMakeLists.txt b/libraries/render/CMakeLists.txt
index ee99eb00b9..4d2be949e6 100644
--- a/libraries/render/CMakeLists.txt
+++ b/libraries/render/CMakeLists.txt
@@ -9,4 +9,16 @@ add_dependency_external_projects(glm)
 find_package(GLM REQUIRED)
 target_include_directories(${TARGET_NAME} PUBLIC ${GLM_INCLUDE_DIRS})
 
-link_hifi_libraries(shared gpu model)
\ No newline at end of file
+link_hifi_libraries(shared gpu model)
+
+if (WIN32)
+  if (USE_NSIGHT)
+    # try to find the Nsight package and add it to the build if we find it
+    find_package(NSIGHT)
+    if (NSIGHT_FOUND)
+      include_directories(${NSIGHT_INCLUDE_DIRS})
+      add_definitions(-DNSIGHT_FOUND)
+      target_link_libraries(${TARGET_NAME} "${NSIGHT_LIBRARIES}")
+    endif ()
+  endif()
+endif (WIN32)
\ No newline at end of file
diff --git a/libraries/render/src/render/Scene.cpp b/libraries/render/src/render/Scene.cpp
index a7145af4b5..268f2b6841 100644
--- a/libraries/render/src/render/Scene.cpp
+++ b/libraries/render/src/render/Scene.cpp
@@ -11,6 +11,7 @@
 #include "Scene.h"
 
 #include <numeric>
+#include "gpu/Batch.h"
 
 using namespace render;
 
@@ -167,6 +168,7 @@ void consolidateChangeQueue(PendingChangesQueue& queue, PendingChanges& singleBa
 }
  
 void Scene::processPendingChangesQueue() {
+    PROFILE_RANGE(__FUNCTION__);
     _changeQueueMutex.lock();
     PendingChanges consolidatedPendingChanges;
     consolidateChangeQueue(_changeQueue, consolidatedPendingChanges);
diff --git a/libraries/shared/src/BufferParser.h b/libraries/shared/src/BufferParser.h
new file mode 100644
index 0000000000..84bde2be31
--- /dev/null
+++ b/libraries/shared/src/BufferParser.h
@@ -0,0 +1,122 @@
+//
+//  Created by Bradley Austin Davis on 2015/07/08
+//  Copyright 2013-2015 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
+//
+
+#pragma once
+#ifndef hifi_BufferParser_h
+#define hifi_BufferParser_h
+
+#include <cstdint>
+
+#include <QUuid>
+#include <QtEndian>
+
+#include "GLMHelpers.h"
+#include "ByteCountCoding.h"
+#include "PropertyFlags.h"
+
+class BufferParser {
+public:
+    BufferParser(const uint8_t* data, size_t size, size_t offset = 0) :
+        _offset(offset), _data(data), _size(size) {
+    }
+
+    template<typename T>
+    inline void readValue(T& result) {
+        Q_ASSERT(remaining() >= sizeof(T));
+        memcpy(&result, _data + _offset, sizeof(T));
+        _offset += sizeof(T);
+    }
+
+    inline void readUuid(QUuid& result) {
+        readValue(result.data1);
+        readValue(result.data2);
+        readValue(result.data3);
+        readValue(result.data4);
+        result.data1 = qFromBigEndian<quint32>(result.data1);
+        result.data2 = qFromBigEndian<quint16>(result.data2);
+        result.data3 = qFromBigEndian<quint16>(result.data3);
+    }
+
+    template <typename T>
+    inline void readFlags(PropertyFlags<T>& result) {
+        // FIXME doing heap allocation
+        QByteArray encoded((const char*)(_data + _offset), remaining());
+        result.decode(encoded);
+        _offset += result.getEncodedLength();
+    }
+
+    template<typename T>
+    inline void readCompressedCount(T& result) {
+        // FIXME switch to a heapless implementation as soon as Brad provides it.
+        ByteCountCoded<T> codec;
+        _offset += codec.decode(reinterpret_cast<const char*>(_data + _offset), remaining());
+        result = codec.data;
+    }
+
+    inline size_t remaining() const {
+        return _size - _offset;
+    }
+
+    inline size_t offset() const {
+    	return _offset;
+    }
+
+    inline const uint8_t* data() const {
+        return _data;
+    }
+
+private:
+
+    size_t _offset{ 0 };
+    const uint8_t* const _data;
+    const size_t _size;
+};
+
+
+template<>
+inline void BufferParser::readValue<quat>(quat& result) {
+    size_t advance = unpackOrientationQuatFromBytes(_data + _offset, result);
+    _offset += advance;
+}
+
+template<>
+inline void BufferParser::readValue(QString& result) {
+    uint16_t length; readValue(length);
+    result = QString((const char*)_data + _offset);
+}
+
+template<>
+inline void BufferParser::readValue(QUuid& result) {
+    uint16_t length; readValue(length);
+    Q_ASSERT(16 == length);
+    readUuid(result);
+}
+
+template<>
+inline void BufferParser::readValue(xColor& result) {
+    readValue(result.red);
+    readValue(result.blue);
+    readValue(result.green);
+}
+
+template<>
+inline void BufferParser::readValue(QVector<glm::vec3>& result) {
+    uint16_t length; readValue(length);
+    result.resize(length);
+    memcpy(result.data(), _data + _offset, sizeof(glm::vec3) * length);
+    _offset += sizeof(glm::vec3) * length;
+}
+
+template<>
+inline void BufferParser::readValue(QByteArray& result) {
+    uint16_t length; readValue(length);
+    result = QByteArray((char*)_data + _offset, (int)length);
+    _offset += length;
+}
+
+#endif
diff --git a/libraries/shared/src/ByteCountCoding.h b/libraries/shared/src/ByteCountCoding.h
index 2a39ee7a8c..ce6f121ddb 100644
--- a/libraries/shared/src/ByteCountCoding.h
+++ b/libraries/shared/src/ByteCountCoding.h
@@ -21,9 +21,13 @@
 #include <climits>
 #include <limits>
 
+#include <QDebug>
+
 #include <QBitArray>
 #include <QByteArray>
 
+#include "SharedUtil.h"
+
 #include "NumericalConstants.h"
 
 template<typename T> class ByteCountCoded {
@@ -37,7 +41,8 @@ public:
     ByteCountCoded(const QByteArray& fromEncoded) : data(0) { decode(fromEncoded); }
 
     QByteArray encode() const;
-    void decode(const QByteArray& fromEncoded);
+    size_t decode(const QByteArray& fromEncoded);
+    size_t decode(const char* encodedBuffer, int encodedSize);
 
     bool operator==(const ByteCountCoded& other) const { return data == other.data; }
     bool operator!=(const ByteCountCoded& other) const { return data != other.data; }
@@ -110,52 +115,63 @@ template<typename T> inline QByteArray ByteCountCoded<T>::encode() const {
     return output;
 }
 
-template<typename T> inline void ByteCountCoded<T>::decode(const QByteArray& fromEncodedBytes) {
+template<typename T> inline size_t ByteCountCoded<T>::decode(const QByteArray& fromEncodedBytes) {
+    return decode(fromEncodedBytes.constData(), fromEncodedBytes.size());
+}
 
-    // first convert the ByteArray into a BitArray...
-    QBitArray encodedBits;
-    int bitCount = BITS_IN_BYTE * fromEncodedBytes.count();
-    encodedBits.resize(bitCount);
+template<typename T> inline size_t ByteCountCoded<T>::decode(const char* encodedBuffer, int encodedSize) {
+    data = 0; // reset data
+    size_t bytesConsumed = 0;
+    int bitCount = BITS_IN_BYTE * encodedSize;
+
+    int encodedByteCount = 1; // there is at least 1 byte (after the leadBits)
+    int leadBits = 1; // there is always at least 1 lead bit
+    bool inLeadBits = true;
+    int bitAt = 0;
+    int expectedBitCount; // unknown at this point
+    int lastValueBit;
+    T bitValue = 1;
     
-    for(int byte = 0; byte < fromEncodedBytes.count(); byte++) {
-        char originalByte = fromEncodedBytes.at(byte);
+    for(int byte = 0; byte < encodedSize; byte++) {
+        char originalByte = encodedBuffer[byte];
+        bytesConsumed++;
+        unsigned char maskBit = 128; // LEFT MOST BIT set
         for(int bit = 0; bit < BITS_IN_BYTE; bit++) {
-            int shiftBy = BITS_IN_BYTE - (bit + 1);
-            char maskBit = ( 1 << shiftBy);
-            bool bitValue = originalByte & maskBit;
-            encodedBits.setBit(byte * BITS_IN_BYTE + bit, bitValue);
+            bool bitIsSet = originalByte & maskBit;
+            
+            // Processing of the lead bits
+            if (inLeadBits) {
+                if (bitIsSet) {
+                    encodedByteCount++;
+                    leadBits++;
+                } else {
+                    inLeadBits = false; // once we hit our first 0, we know we're out of the lead bits
+                    expectedBitCount = (encodedByteCount * BITS_IN_BYTE) - leadBits;
+                    lastValueBit = expectedBitCount + bitAt;
+
+                    // check to see if the remainder of our buffer is sufficient
+                    if (expectedBitCount > (bitCount - leadBits)) {
+                        break;
+                    }
+                }
+            } else {
+                if (bitAt > lastValueBit) {
+                    break;
+                }
+                
+                if(bitIsSet) {
+                    data += bitValue;
+                }
+                bitValue *= 2;
+            }
+            bitAt++;
+            maskBit = maskBit >> 1;
         }
-    }
-    
-    // next, read the leading bits to determine the correct number of bytes to decode (may not match the QByteArray)
-    int encodedByteCount = 0;
-    int leadBits = 1;
-    int bitAt;
-    for (bitAt = 0; bitAt < bitCount; bitAt++) {
-        if (encodedBits.at(bitAt)) {
-            encodedByteCount++;
-            leadBits++;
-        } else {
+        if (!inLeadBits && bitAt > lastValueBit) {
             break;
         }
     }
-    encodedByteCount++; // always at least one byte
-    int expectedBitCount = encodedByteCount * BITS_IN_BYTE;
-
-    T value = 0;
-    
-    if (expectedBitCount <= (encodedBits.size() - leadBits)) {
-        // Now, keep reading...
-        int valueStartsAt = bitAt + 1; 
-        T bitValue = 1;
-        for (bitAt = valueStartsAt; bitAt < expectedBitCount; bitAt++) {
-            if(encodedBits.at(bitAt)) {
-                value += bitValue;
-            }
-            bitValue *= 2;
-        }
-    }
-    data = value;
+    return bytesConsumed;
 }
 #endif // hifi_ByteCountCoding_h
 
diff --git a/libraries/shared/src/QVariantGLM.cpp b/libraries/shared/src/QVariantGLM.cpp
index 7cebacee8e..7a3ab92cca 100644
--- a/libraries/shared/src/QVariantGLM.cpp
+++ b/libraries/shared/src/QVariantGLM.cpp
@@ -20,7 +20,7 @@ QVariantList glmToQList(const glm::quat& g) {
     return QVariantList() << g.x << g.y << g.z << g.w;
 }
 
-QVariantList rgbColorToQList(rgbColor& v) {
+QVariantList rgbColorToQList(const rgbColor& v) {
     return QVariantList() << (int)(v[0]) << (int)(v[1]) << (int)(v[2]);
 }
 
@@ -42,12 +42,12 @@ QVariantMap glmToQMap(const glm::quat& glmQuat) {
 }
 
 
-glm::vec3 qListToGlmVec3(const QVariant q) {
+glm::vec3 qListToGlmVec3(const QVariant& q) {
     QVariantList qList = q.toList();
     return glm::vec3(qList[RED_INDEX].toFloat(), qList[GREEN_INDEX].toFloat(), qList[BLUE_INDEX].toFloat());
 }
 
-glm::quat qListToGlmQuat(const QVariant q) {
+glm::quat qListToGlmQuat(const QVariant& q) {
     QVariantList qList = q.toList();
     float x = qList[0].toFloat();
     float y = qList[1].toFloat();
@@ -56,7 +56,7 @@ glm::quat qListToGlmQuat(const QVariant q) {
     return glm::quat(w, x, y, z);
 }
 
-void qListtoRgbColor(const QVariant q, rgbColor returnValue) {
+void qListtoRgbColor(const QVariant& q, rgbColor& returnValue) {
     QVariantList qList = q.toList();
     returnValue[RED_INDEX] = qList[RED_INDEX].toInt();
     returnValue[GREEN_INDEX] = qList[GREEN_INDEX].toInt();
diff --git a/libraries/shared/src/QVariantGLM.h b/libraries/shared/src/QVariantGLM.h
index 922aa7c4aa..3a91110250 100644
--- a/libraries/shared/src/QVariantGLM.h
+++ b/libraries/shared/src/QVariantGLM.h
@@ -19,11 +19,11 @@
 
 QVariantList glmToQList(const glm::vec3& g);
 QVariantList glmToQList(const glm::quat& g);
-QVariantList rgbColorToQList(rgbColor& v);
+QVariantList rgbColorToQList(const rgbColor& v);
 
 QVariantMap glmToQMap(const glm::vec3& glmVector);
 QVariantMap glmToQMap(const glm::quat& glmQuat);
 
-glm::vec3 qListToGlmVec3(const QVariant q);
-glm::quat qListToGlmQuat(const QVariant q);
-void qListtoRgbColor(const QVariant q, rgbColor returnValue);
+glm::vec3 qListToGlmVec3(const QVariant& q);
+glm::quat qListToGlmQuat(const QVariant& q);
+void qListtoRgbColor(const QVariant& q, rgbColor& returnValue);
diff --git a/libraries/shared/src/RegisteredMetaTypes.cpp b/libraries/shared/src/RegisteredMetaTypes.cpp
index 62f2be0512..dce31b2971 100644
--- a/libraries/shared/src/RegisteredMetaTypes.cpp
+++ b/libraries/shared/src/RegisteredMetaTypes.cpp
@@ -229,6 +229,7 @@ QScriptValue collisionToScriptValue(QScriptEngine* engine, const Collision& coll
     obj.setProperty("idB", quuidToScriptValue(engine, collision.idB));
     obj.setProperty("penetration", vec3toScriptValue(engine, collision.penetration));
     obj.setProperty("contactPoint", vec3toScriptValue(engine, collision.contactPoint));
+    obj.setProperty("velocityChange", vec3toScriptValue(engine, collision.velocityChange));
     return obj;
 }