diff --git a/domain-server/src/DomainGatekeeper.cpp b/domain-server/src/DomainGatekeeper.cpp
index 90b22ffdd8..d360ab4802 100644
--- a/domain-server/src/DomainGatekeeper.cpp
+++ b/domain-server/src/DomainGatekeeper.cpp
@@ -226,7 +226,7 @@ SharedNodePointer DomainGatekeeper::processAgentConnectRequest(const NodeConnect
     // if the allowed editors list is empty then everyone can adjust locks
     bool canAdjustLocks = allowedEditors.empty();
     
-    if (allowedEditors.contains(username)) {
+    if (allowedEditors.contains(username, Qt::CaseInsensitive)) {
         // we have a non-empty allowed editors list - check if this user is verified to be in it
         if (!verifiedUsername) {
             if (!verifyUserSignature(username, usernameSignature, HifiSockAddr())) {
diff --git a/examples/controllers/handControllerGrab.js b/examples/controllers/handControllerGrab.js
index 29d6595c3a..7809c3d07c 100644
--- a/examples/controllers/handControllerGrab.js
+++ b/examples/controllers/handControllerGrab.js
@@ -74,8 +74,8 @@ var MSEC_PER_SEC = 1000.0;
 
 // these control how long an abandoned pointer line will hang around
 var LIFETIME = 10;
-var ACTION_LIFETIME = 15; // seconds
-var ACTION_LIFETIME_REFRESH = 5;
+var ACTION_TTL = 15; // seconds
+var ACTION_TTL_REFRESH = 5;
 var PICKS_PER_SECOND_PER_HAND = 5;
 var MSECS_PER_SEC = 1000.0;
 
@@ -429,12 +429,12 @@ function MyController(hand, triggerAction) {
             targetRotation: this.currentObjectRotation,
             angularTimeScale: DISTANCE_HOLDING_ACTION_TIMEFRAME,
             tag: getTag(),
-            lifetime: ACTION_LIFETIME
+            ttl: ACTION_TTL
         });
         if (this.actionID === NULL_ACTION_ID) {
             this.actionID = null;
         }
-        this.actionTimeout = now + (ACTION_LIFETIME * MSEC_PER_SEC);
+        this.actionTimeout = now + (ACTION_TTL * MSEC_PER_SEC);
 
         if (this.actionID !== null) {
             this.setState(STATE_CONTINUE_DISTANCE_HOLDING);
@@ -532,9 +532,9 @@ function MyController(hand, triggerAction) {
             linearTimeScale: DISTANCE_HOLDING_ACTION_TIMEFRAME,
             targetRotation: this.currentObjectRotation,
             angularTimeScale: DISTANCE_HOLDING_ACTION_TIMEFRAME,
-            lifetime: ACTION_LIFETIME
+            ttl: ACTION_TTL
         });
-        this.actionTimeout = now + (ACTION_LIFETIME * MSEC_PER_SEC);
+        this.actionTimeout = now + (ACTION_TTL * MSEC_PER_SEC);
     };
 
     this.nearGrabbing = function() {
@@ -587,12 +587,12 @@ function MyController(hand, triggerAction) {
             timeScale: NEAR_GRABBING_ACTION_TIMEFRAME,
             relativePosition: this.offsetPosition,
             relativeRotation: this.offsetRotation,
-            lifetime: ACTION_LIFETIME
+            ttl: ACTION_TTL
         });
         if (this.actionID === NULL_ACTION_ID) {
             this.actionID = null;
         } else {
-            this.actionTimeout = now + (ACTION_LIFETIME * MSEC_PER_SEC);
+            this.actionTimeout = now + (ACTION_TTL * MSEC_PER_SEC);
             this.setState(STATE_CONTINUE_NEAR_GRABBING);
             if (this.hand === RIGHT_HAND) {
                 Entities.callEntityMethod(this.grabbedEntity, "setRightHand");
@@ -632,16 +632,16 @@ function MyController(hand, triggerAction) {
         this.currentObjectTime = now;
         Entities.callEntityMethod(this.grabbedEntity, "continueNearGrab");
 
-        if (this.actionTimeout - now < ACTION_LIFETIME_REFRESH * MSEC_PER_SEC) {
-            // if less than a 5 seconds left, refresh the actions lifetime
+        if (this.actionTimeout - now < ACTION_TTL_REFRESH * MSEC_PER_SEC) {
+            // if less than a 5 seconds left, refresh the actions ttl
             Entities.updateAction(this.grabbedEntity, this.actionID, {
                 hand: this.hand === RIGHT_HAND ? "right" : "left",
                 timeScale: NEAR_GRABBING_ACTION_TIMEFRAME,
                 relativePosition: this.offsetPosition,
                 relativeRotation: this.offsetRotation,
-                lifetime: ACTION_LIFETIME
+                ttl: ACTION_TTL
             });
-            this.actionTimeout = now + (ACTION_LIFETIME * MSEC_PER_SEC);
+            this.actionTimeout = now + (ACTION_TTL * MSEC_PER_SEC);
         }
     };
 
diff --git a/examples/grab.js b/examples/grab.js
index 1a02911db9..ee6c3c4de5 100644
--- a/examples/grab.js
+++ b/examples/grab.js
@@ -47,7 +47,7 @@ var IDENTITY_QUAT = {
     z: 0,
     w: 0
 };
-var ACTION_LIFETIME = 10; // seconds
+var ACTION_TTL = 10; // seconds
 
 function getTag() {
     return "grab-" + MyAvatar.sessionUUID;
@@ -403,7 +403,7 @@ Grabber.prototype.moveEvent = function(event) {
 
     var actionArgs = {
         tag: getTag(),
-        lifetime: ACTION_LIFETIME
+        ttl: ACTION_TTL
     };
 
     if (this.mode === "rotate") {
@@ -424,7 +424,7 @@ Grabber.prototype.moveEvent = function(event) {
             targetRotation: this.lastRotation,
             angularTimeScale: 0.1,
             tag: getTag(),
-            lifetime: ACTION_LIFETIME
+            ttl: ACTION_TTL
         };
 
     } else {
@@ -459,7 +459,7 @@ Grabber.prototype.moveEvent = function(event) {
             targetPosition: this.targetPosition,
             linearTimeScale: 0.1,
             tag: getTag(),
-            lifetime: ACTION_LIFETIME
+            ttl: ACTION_TTL
         };
 
 
diff --git a/interface/src/InterfaceActionFactory.cpp b/interface/src/InterfaceActionFactory.cpp
index f814df9a99..67b3b4a649 100644
--- a/interface/src/InterfaceActionFactory.cpp
+++ b/interface/src/InterfaceActionFactory.cpp
@@ -66,7 +66,8 @@ EntityActionPointer InterfaceActionFactory::factoryBA(EntityItemPointer ownerEnt
     if (action) {
         action->deserialize(data);
         if (action->lifetimeIsOver()) {
-            qDebug() << "InterfaceActionFactory::factoryBA lifetimeIsOver during action creation";
+            qDebug() << "InterfaceActionFactory::factoryBA lifetimeIsOver during action creation --"
+                     << action->getExpires() << "<" << usecTimestampNow();
             return nullptr;
         }
     }
diff --git a/interface/src/avatar/Avatar.cpp b/interface/src/avatar/Avatar.cpp
index 8c29ce1a41..ae3aec3572 100644
--- a/interface/src/avatar/Avatar.cpp
+++ b/interface/src/avatar/Avatar.cpp
@@ -454,7 +454,7 @@ void Avatar::render(RenderArgs* renderArgs, const glm::vec3& cameraPosition) {
         */
 
         bool renderBounding = Menu::getInstance()->isOptionChecked(MenuOption::RenderBoundingCollisionShapes);
-        if (renderBounding && shouldRenderHead(renderArgs)) {
+        if (renderBounding && shouldRenderHead(renderArgs) && _skeletonModel.isRenderable()) {
             _skeletonModel.renderBoundingCollisionShapes(*renderArgs->_batch, 0.7f);
         }
 
diff --git a/interface/src/avatar/AvatarActionHold.cpp b/interface/src/avatar/AvatarActionHold.cpp
index d2f5514e10..238e48d2fd 100644
--- a/interface/src/avatar/AvatarActionHold.cpp
+++ b/interface/src/avatar/AvatarActionHold.cpp
@@ -243,7 +243,7 @@ QByteArray AvatarActionHold::serialize() const {
         dataStream << _linearTimeScale;
         dataStream << _hand;
 
-        dataStream << _expires + getEntityServerClockSkew();
+        dataStream << localTimeToServerTime(_expires);
         dataStream << _tag;
         dataStream << _kinematic;
         dataStream << _kinematicSetVelocity;
@@ -277,8 +277,10 @@ void AvatarActionHold::deserialize(QByteArray serializedArguments) {
         _angularTimeScale = _linearTimeScale;
         dataStream >> _hand;
 
-        dataStream >> _expires;
-        _expires -= getEntityServerClockSkew();
+        quint64 serverExpires;
+        dataStream >> serverExpires;
+        _expires = serverTimeToLocalTime(serverExpires);
+
         dataStream >> _tag;
         dataStream >> _kinematic;
         dataStream >> _kinematicSetVelocity;
diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index 5f0ac435e0..9783590b05 100644
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -77,7 +77,10 @@ AvatarManager::AvatarManager(QObject* parent) :
 
 void AvatarManager::init() {
     _myAvatar->init();
-    _avatarHash.insert(MY_AVATAR_KEY, _myAvatar);
+    {
+        QWriteLocker locker(&_hashLock);
+        _avatarHash.insert(MY_AVATAR_KEY, _myAvatar);
+    }
 
     connect(DependencyManager::get<SceneScriptingInterface>().data(), &SceneScriptingInterface::shouldRenderAvatarsChanged, this, &AvatarManager::updateAvatarRenderStatus, Qt::QueuedConnection);
 
@@ -127,6 +130,7 @@ void AvatarManager::updateOtherAvatars(float deltaTime) {
         } else if (avatar->shouldDie()) {
             removeAvatarMotionState(avatar);
             _avatarFades.push_back(avatarIterator.value());
+            QWriteLocker locker(&_hashLock);
             avatarIterator = _avatarHash.erase(avatarIterator);
         } else {
             avatar->startUpdate();
@@ -202,6 +206,7 @@ void AvatarManager::removeAvatar(const QUuid& sessionUUID) {
         if (avatar != _myAvatar && avatar->isInitialized()) {
             removeAvatarMotionState(avatar);
             _avatarFades.push_back(avatarIterator.value());
+            QWriteLocker locker(&_hashLock);
             _avatarHash.erase(avatarIterator);
         }
     }
@@ -218,6 +223,7 @@ void AvatarManager::clearOtherAvatars() {
         } else {
             removeAvatarMotionState(avatar);
             _avatarFades.push_back(avatarIterator.value());
+            QWriteLocker locker(&_hashLock);
             avatarIterator = _avatarHash.erase(avatarIterator);
         }
     }
@@ -349,5 +355,6 @@ AvatarSharedPointer AvatarManager::getAvatarBySessionID(const QUuid& sessionID)
     if (sessionID == _myAvatar->getSessionUUID()) {
         return std::static_pointer_cast<Avatar>(_myAvatar);
     }
-    return getAvatarHash()[sessionID];
+    QReadLocker locker(&_hashLock);
+    return _avatarHash[sessionID];
 }
diff --git a/interface/src/avatar/MyAvatar.cpp b/interface/src/avatar/MyAvatar.cpp
index e5e45112c1..9dcd77c689 100644
--- a/interface/src/avatar/MyAvatar.cpp
+++ b/interface/src/avatar/MyAvatar.cpp
@@ -209,6 +209,11 @@ void MyAvatar::update(float deltaTime) {
         setPosition(_goToPosition);
         setOrientation(_goToOrientation);
         _goToPending = false;
+        // updateFromHMDSensorMatrix (called from paintGL) expects that the sensorToWorldMatrix is updated for any position changes
+        // that happen between render and Application::update (which calls updateSensorToWorldMatrix to do so).
+        // However, render/MyAvatar::update/Application::update don't always match (e.g., when using the separate avatar update thread),
+        // so we update now. It's ok if it updates again in the normal way.
+        updateSensorToWorldMatrix();
     }
 
     if (_referential) {
@@ -1088,7 +1093,11 @@ void MyAvatar::updateLookAtTargetAvatar() {
     const float KEEP_LOOKING_AT_CURRENT_ANGLE_FACTOR = 1.3f;
     const float GREATEST_LOOKING_AT_DISTANCE = 10.0f;
 
-    foreach (const AvatarSharedPointer& avatarPointer, DependencyManager::get<AvatarManager>()->getAvatarHash()) {
+    AvatarHash hash;
+    DependencyManager::get<AvatarManager>()->withAvatarHash([&] (const AvatarHash& locked) {
+        hash = locked; // make a shallow copy and operate on that, to minimize lock time
+    });
+    foreach (const AvatarSharedPointer& avatarPointer, hash) {
         auto avatar = static_pointer_cast<Avatar>(avatarPointer);
         bool isCurrentTarget = avatar->getIsLookAtTarget();
         float distanceTo = glm::length(avatar->getHead()->getEyePosition() - cameraPosition);
@@ -1120,7 +1129,6 @@ void MyAvatar::updateLookAtTargetAvatar() {
                 glm::vec3 humanLeftEye = humanSystem->getPosition() + (humanSystem->getOrientation() * leftEyeHeadLocal);
                 glm::vec3 humanRightEye = humanSystem->getPosition() + (humanSystem->getOrientation() * rightEyeHeadLocal);
 
-
                 // First find out where (in world space) the person is looking relative to that bridge-of-the-avatar point.
                 // (We will be adding that offset to the camera position, after making some other adjustments.)
                 glm::vec3 gazeOffset = lookAtPosition - getHead()->getEyePosition();
@@ -1132,14 +1140,14 @@ void MyAvatar::updateLookAtTargetAvatar() {
 
                 // If the camera is also not oriented with the head, adjust by getting the offset in head-space...
                 /* Not needed (i.e., code is a no-op), but I'm leaving the example code here in case something like this is needed someday.
-                glm::quat avatarHeadOrientation = getHead()->getOrientation();
-                glm::vec3 gazeOffsetLocalToHead = glm::inverse(avatarHeadOrientation) * gazeOffset;
-                // ... and treat that as though it were in camera space, bringing it back to world space.
-                // But camera is fudged to make the picture feel like the avatar's orientation.
-                glm::quat humanOrientation = humanSystem->getOrientation(); // or just avatar getOrienation() ?
-                gazeOffset = humanOrientation * gazeOffsetLocalToHead;
-                glm::vec3 corrected = humanSystem->getPosition() + gazeOffset;
-               */
+                 glm::quat avatarHeadOrientation = getHead()->getOrientation();
+                 glm::vec3 gazeOffsetLocalToHead = glm::inverse(avatarHeadOrientation) * gazeOffset;
+                 // ... and treat that as though it were in camera space, bringing it back to world space.
+                 // But camera is fudged to make the picture feel like the avatar's orientation.
+                 glm::quat humanOrientation = humanSystem->getOrientation(); // or just avatar getOrienation() ?
+                 gazeOffset = humanOrientation * gazeOffsetLocalToHead;
+                 glm::vec3 corrected = humanSystem->getPosition() + gazeOffset;
+                 */
 
                 // And now we can finally add that offset to the camera.
                 glm::vec3 corrected = qApp->getViewFrustum()->getPosition() + gazeOffset;
diff --git a/interface/src/avatar/SkeletonModel.cpp b/interface/src/avatar/SkeletonModel.cpp
index e39bfe246b..55e1e10a66 100644
--- a/interface/src/avatar/SkeletonModel.cpp
+++ b/interface/src/avatar/SkeletonModel.cpp
@@ -103,15 +103,12 @@ void SkeletonModel::updateRig(float deltaTime, glm::mat4 parentTransform) {
     if (_owningAvatar->isMyAvatar()) {
         _rig->computeMotionAnimationState(deltaTime, _owningAvatar->getPosition(), _owningAvatar->getVelocity(), _owningAvatar->getOrientation());
     }
-    Model::updateRig(deltaTime, parentTransform);
     Head* head = _owningAvatar->getHead();
     if (_owningAvatar->isMyAvatar()) {
         MyAvatar* myAvatar = static_cast<MyAvatar*>(_owningAvatar);
         const FBXGeometry& geometry = _geometry->getFBXGeometry();
 
         Rig::HeadParameters headParams;
-        headParams.modelRotation = getRotation();
-        headParams.modelTranslation = getTranslation();
         headParams.enableLean = qApp->getAvatarUpdater()->isHMDMode();
         headParams.leanSideways = head->getFinalLeanSideways();
         headParams.leanForward = head->getFinalLeanForward();
@@ -145,13 +142,8 @@ void SkeletonModel::updateRig(float deltaTime, glm::mat4 parentTransform) {
             headParams.worldHeadOrientation = head->getFinalOrientationInWorldFrame();
         }
 
-        headParams.eyeLookAt = head->getLookAtPosition();
-        headParams.eyeSaccade = head->getSaccade();
         headParams.leanJointIndex = geometry.leanJointIndex;
         headParams.neckJointIndex = geometry.neckJointIndex;
-        headParams.leftEyeJointIndex = geometry.leftEyeJointIndex;
-        headParams.rightEyeJointIndex = geometry.rightEyeJointIndex;
-
         headParams.isTalking = head->getTimeWithoutTalking() <= 1.5f;
 
         _rig->updateFromHeadParameters(headParams, deltaTime);
@@ -180,7 +172,28 @@ void SkeletonModel::updateRig(float deltaTime, glm::mat4 parentTransform) {
 
         _rig->updateFromHandParameters(handParams, deltaTime);
 
+        // evaluate AnimGraph animation and update jointStates.
+        Model::updateRig(deltaTime, parentTransform);
+
+        Rig::EyeParameters eyeParams;
+        eyeParams.worldHeadOrientation = headParams.worldHeadOrientation;
+        eyeParams.eyeLookAt = head->getLookAtPosition();
+        eyeParams.eyeSaccade = head->getSaccade();
+        eyeParams.modelRotation = getRotation();
+        eyeParams.modelTranslation = getTranslation();
+        eyeParams.leftEyeJointIndex = geometry.leftEyeJointIndex;
+        eyeParams.rightEyeJointIndex = geometry.rightEyeJointIndex;
+
+        _rig->updateFromEyeParameters(eyeParams);
+
+        // rebuild the jointState transform for the eyes only
+        _rig->updateJointState(eyeParams.leftEyeJointIndex, parentTransform);
+        _rig->updateJointState(eyeParams.rightEyeJointIndex, parentTransform);
+
     } else {
+
+        Model::updateRig(deltaTime, parentTransform);
+
         // This is a little more work than we really want.
         //
         // Other avatars joint, including their eyes, should already be set just like any other joints
@@ -197,9 +210,16 @@ void SkeletonModel::updateRig(float deltaTime, glm::mat4 parentTransform) {
         head->setBasePitch(glm::degrees(-eulers.x));
         head->setBaseYaw(glm::degrees(eulers.y));
         head->setBaseRoll(glm::degrees(-eulers.z));
-        _rig->updateEyeJoints(geometry.leftEyeJointIndex, geometry.rightEyeJointIndex,
-                              getTranslation(), getRotation(),
-                              head->getFinalOrientationInWorldFrame(), head->getCorrectedLookAtPosition());
+
+        Rig::EyeParameters eyeParams;
+        eyeParams.worldHeadOrientation = head->getFinalOrientationInWorldFrame();
+        eyeParams.eyeLookAt = head->getCorrectedLookAtPosition();
+        eyeParams.eyeSaccade = glm::vec3();
+        eyeParams.modelRotation = getRotation();
+        eyeParams.modelTranslation = getTranslation();
+        eyeParams.leftEyeJointIndex = geometry.leftEyeJointIndex;
+        eyeParams.rightEyeJointIndex = geometry.rightEyeJointIndex;
+        _rig->updateFromEyeParameters(eyeParams);
      }
 }
 
diff --git a/interface/src/ui/AudioStatsDialog.cpp b/interface/src/ui/AudioStatsDialog.cpp
index e57182e251..a475700e02 100644
--- a/interface/src/ui/AudioStatsDialog.cpp
+++ b/interface/src/ui/AudioStatsDialog.cpp
@@ -65,11 +65,12 @@ AudioStatsDialog::AudioStatsDialog(QWidget* parent) :
     // Get statistics from the Audio Client
     _stats = &DependencyManager::get<AudioClient>()->getStats();
         
-    // Create layouter
+    // Create layout
     _form = new QFormLayout();
+    _form->setSizeConstraint(QLayout::SetFixedSize);
     QDialog::setLayout(_form);
         
-    // Load and initilize all channels
+    // Load and initialize all channels
     renderStats();
 
     _audioDisplayChannels = QVector<QVector<AudioStatsDisplay*>>(1);
@@ -80,10 +81,8 @@ AudioStatsDialog::AudioStatsDialog(QWidget* parent) :
     _downstreamID = addChannel(_form, _downstreamStats, COLOR3);
     _upstreamInjectedID = addChannel(_form, _upstreamInjectedStats, COLOR0);
         
-        
     connect(averageUpdateTimer, SIGNAL(timeout()), this, SLOT(updateTimerTimeout()));
     averageUpdateTimer->start(1000);
-
 }
 
 int AudioStatsDialog::addChannel(QFormLayout* form, QVector<QString>& stats, const unsigned color) {
@@ -243,7 +242,6 @@ void AudioStatsDialog::paintEvent(QPaintEvent* event) {
     }
     
     QDialog::paintEvent(event);
-    setFixedSize(width(), height());
 }
 
 void AudioStatsDialog::reject() {
diff --git a/interface/src/ui/BandwidthDialog.cpp b/interface/src/ui/BandwidthDialog.cpp
index e086005783..f07c844894 100644
--- a/interface/src/ui/BandwidthDialog.cpp
+++ b/interface/src/ui/BandwidthDialog.cpp
@@ -72,8 +72,9 @@ BandwidthDialog::BandwidthDialog(QWidget* parent) :
 
     this->setWindowTitle("Bandwidth Details");
 
-    // Create layouter
+    // Create layout
     QFormLayout* form = new QFormLayout();
+    form->setSizeConstraint(QLayout::SetFixedSize);
     this->QDialog::setLayout(form);
 
     QSharedPointer<BandwidthRecorder> bandwidthRecorder = DependencyManager::get<BandwidthRecorder>();
@@ -118,7 +119,6 @@ void BandwidthDialog::paintEvent(QPaintEvent* event) {
     for (unsigned int i=0; i<_CHANNELCOUNT; i++)
         _allChannelDisplays[i]->paint();
     this->QDialog::paintEvent(event);
-    this->setFixedSize(this->width(), this->height());
 }
 
 void BandwidthDialog::reject() {
diff --git a/libraries/animation/src/Rig.cpp b/libraries/animation/src/Rig.cpp
index 6fd6f5cbf9..3fe4c2e83e 100644
--- a/libraries/animation/src/Rig.cpp
+++ b/libraries/animation/src/Rig.cpp
@@ -22,34 +22,6 @@
 #include "AnimSkeleton.h"
 #include "IKTarget.h"
 
-
-void Rig::HeadParameters::dump() const {
-    qCDebug(animation, "HeadParameters =");
-    qCDebug(animation, "    leanSideways = %0.5f", (double)leanSideways);
-    qCDebug(animation, "    leanForward = %0.5f", (double)leanForward);
-    qCDebug(animation, "    torsoTwist = %0.5f", (double)torsoTwist);
-    glm::vec3 axis = glm::axis(localHeadOrientation);
-    float theta = glm::angle(localHeadOrientation);
-    qCDebug(animation, "    localHeadOrientation axis = (%.5f, %.5f, %.5f), theta = %0.5f", (double)axis.x, (double)axis.y, (double)axis.z, (double)theta);
-    axis = glm::axis(worldHeadOrientation);
-    theta = glm::angle(worldHeadOrientation);
-    qCDebug(animation, "    localHead pitch = %.5f, yaw = %.5f, roll = %.5f", (double)localHeadPitch, (double)localHeadYaw, (double)localHeadRoll);
-    qCDebug(animation, "    localHeadPosition = (%.5f, %.5f, %.5f)", (double)localHeadPosition.x, (double)localHeadPosition.y, (double)localHeadPosition.z);
-    qCDebug(animation, "    isInHMD = %s", isInHMD ? "true" : "false");
-    qCDebug(animation, "    worldHeadOrientation axis = (%.5f, %.5f, %.5f), theta = %0.5f", (double)axis.x, (double)axis.y, (double)axis.z, (double)theta);
-    axis = glm::axis(modelRotation);
-    theta = glm::angle(modelRotation);
-    qCDebug(animation, "    modelRotation axis = (%.5f, %.5f, %.5f), theta = %0.5f", (double)axis.x, (double)axis.y, (double)axis.z, (double)theta);
-    qCDebug(animation, "    modelTranslation = (%.5f, %.5f, %.5f)", (double)modelTranslation.x, (double)modelTranslation.y, (double)modelTranslation.z);
-    qCDebug(animation, "    eyeLookAt = (%.5f, %.5f, %.5f)", (double)eyeLookAt.x, (double)eyeLookAt.y, (double)eyeLookAt.z);
-    qCDebug(animation, "    eyeSaccade = (%.5f, %.5f, %.5f)", (double)eyeSaccade.x, (double)eyeSaccade.y, (double)eyeSaccade.z);
-    qCDebug(animation, "    leanJointIndex = %.d", leanJointIndex);
-    qCDebug(animation, "    neckJointIndex = %.d", neckJointIndex);
-    qCDebug(animation, "    leftEyeJointIndex = %.d", leftEyeJointIndex);
-    qCDebug(animation, "    rightEyeJointIndex = %.d", rightEyeJointIndex);
-    qCDebug(animation, "    isTalking = %s", isTalking ? "true" : "false");
-}
-
 void insertSorted(QList<AnimationHandlePointer>& handles, const AnimationHandlePointer& handle) {
     for (QList<AnimationHandlePointer>::iterator it = handles.begin(); it != handles.end(); it++) {
         if (handle->getPriority() > (*it)->getPriority()) {
@@ -981,8 +953,6 @@ void Rig::updateFromHeadParameters(const HeadParameters& params, float dt) {
         _animVars.unset("lean");
     }
     updateNeckJoint(params.neckJointIndex, params);
-    updateEyeJoints(params.leftEyeJointIndex, params.rightEyeJointIndex, params.modelTranslation, params.modelRotation,
-                    params.worldHeadOrientation, params.eyeLookAt, params.eyeSaccade);
 
     if (_enableAnimGraph) {
         _animVars.set("isTalking", params.isTalking);
@@ -990,6 +960,13 @@ void Rig::updateFromHeadParameters(const HeadParameters& params, float dt) {
     }
 }
 
+void Rig::updateFromEyeParameters(const EyeParameters& params) {
+    updateEyeJoint(params.leftEyeJointIndex, params.modelTranslation, params.modelRotation,
+                   params.worldHeadOrientation, params.eyeLookAt, params.eyeSaccade);
+    updateEyeJoint(params.rightEyeJointIndex, params.modelTranslation, params.modelRotation,
+                   params.worldHeadOrientation, params.eyeLookAt, params.eyeSaccade);
+}
+
 static const glm::vec3 X_AXIS(1.0f, 0.0f, 0.0f);
 static const glm::vec3 Y_AXIS(0.0f, 1.0f, 0.0f);
 static const glm::vec3 Z_AXIS(0.0f, 0.0f, 1.0f);
@@ -1145,12 +1122,6 @@ void Rig::updateNeckJoint(int index, const HeadParameters& params) {
     }
 }
 
-void Rig::updateEyeJoints(int leftEyeIndex, int rightEyeIndex, const glm::vec3& modelTranslation, const glm::quat& modelRotation,
-                          const glm::quat& worldHeadOrientation, const glm::vec3& lookAtSpot, const glm::vec3& saccade) {
-    updateEyeJoint(leftEyeIndex, modelTranslation, modelRotation, worldHeadOrientation, lookAtSpot, saccade);
-    updateEyeJoint(rightEyeIndex, modelTranslation, modelRotation, worldHeadOrientation, lookAtSpot, saccade);
-}
-
 void Rig::updateEyeJoint(int index, const glm::vec3& modelTranslation, const glm::quat& modelRotation, const glm::quat& worldHeadOrientation, const glm::vec3& lookAtSpot, const glm::vec3& saccade) {
     if (index >= 0 && _jointStates[index].getParentIndex() >= 0) {
         auto& state = _jointStates[index];
diff --git a/libraries/animation/src/Rig.h b/libraries/animation/src/Rig.h
index c9c42cbbb6..6e0a88d768 100644
--- a/libraries/animation/src/Rig.h
+++ b/libraries/animation/src/Rig.h
@@ -57,24 +57,26 @@ public:
         float leanForward = 0.0f; // degrees
         float torsoTwist = 0.0f; // degrees
         bool enableLean = false;
-        glm::quat modelRotation = glm::quat();
+        glm::quat worldHeadOrientation = glm::quat();
         glm::quat localHeadOrientation = glm::quat();
         float localHeadPitch = 0.0f; // degrees
         float localHeadYaw = 0.0f; // degrees
         float localHeadRoll = 0.0f; // degrees
         glm::vec3 localHeadPosition = glm::vec3();
         bool isInHMD = false;
+        int leanJointIndex = -1;
+        int neckJointIndex = -1;
+        bool isTalking = false;
+    };
+
+    struct EyeParameters {
         glm::quat worldHeadOrientation = glm::quat();
         glm::vec3 eyeLookAt = glm::vec3();  // world space
         glm::vec3 eyeSaccade = glm::vec3(); // world space
         glm::vec3 modelTranslation = glm::vec3();
-        int leanJointIndex = -1;
-        int neckJointIndex = -1;
+        glm::quat modelRotation = glm::quat();
         int leftEyeJointIndex = -1;
         int rightEyeJointIndex = -1;
-        bool isTalking = false;
-
-        void dump() const;
     };
 
     struct HandParameters {
@@ -185,9 +187,7 @@ public:
     bool getEnableAnimGraph() const { return _enableAnimGraph; }
 
     void updateFromHeadParameters(const HeadParameters& params, float dt);
-    void updateEyeJoints(int leftEyeIndex, int rightEyeIndex, const glm::vec3& modelTranslation, const glm::quat& modelRotation,
-                         const glm::quat& worldHeadOrientation, const glm::vec3& lookAtSpot, const glm::vec3& saccade = glm::vec3(0.0f));
-
+    void updateFromEyeParameters(const EyeParameters& params);
     void updateFromHandParameters(const HandParameters& params, float dt);
 
     virtual void setHandPosition(int jointIndex, const glm::vec3& position, const glm::quat& rotation,
diff --git a/libraries/avatars/src/AvatarHashMap.cpp b/libraries/avatars/src/AvatarHashMap.cpp
index 520bb34887..3f1e668cd0 100644
--- a/libraries/avatars/src/AvatarHashMap.cpp
+++ b/libraries/avatars/src/AvatarHashMap.cpp
@@ -22,7 +22,12 @@ AvatarHashMap::AvatarHashMap() {
     connect(DependencyManager::get<NodeList>().data(), &NodeList::uuidChanged, this, &AvatarHashMap::sessionUUIDChanged);
 }
 
+void AvatarHashMap::withAvatarHash(std::function<void(const AvatarHash& hash)> callback) {
+    QReadLocker locker(&_hashLock);
+    callback(_avatarHash);
+}
 bool AvatarHashMap::isAvatarInRange(const glm::vec3& position, const float range) {
+    QReadLocker locker(&_hashLock);
     foreach(const AvatarSharedPointer& sharedAvatar, _avatarHash) {
         glm::vec3 avatarPosition = sharedAvatar->getPosition();
         float distance = glm::distance(avatarPosition, position);
@@ -43,6 +48,7 @@ AvatarSharedPointer AvatarHashMap::addAvatar(const QUuid& sessionUUID, const QWe
     AvatarSharedPointer avatar = newSharedAvatar();
     avatar->setSessionUUID(sessionUUID);
     avatar->setOwningAvatarMixer(mixerWeakPointer);
+    QWriteLocker locker(&_hashLock);
     _avatarHash.insert(sessionUUID, avatar);
 
     return avatar;
@@ -134,6 +140,7 @@ void AvatarHashMap::processKillAvatar(QSharedPointer<NLPacket> packet, SharedNod
 }
 
 void AvatarHashMap::removeAvatar(const QUuid& sessionUUID) {
+    QWriteLocker locker(&_hashLock);
     _avatarHash.remove(sessionUUID);
 }
 
diff --git a/libraries/avatars/src/AvatarHashMap.h b/libraries/avatars/src/AvatarHashMap.h
index 804233b76a..93364eb1ef 100644
--- a/libraries/avatars/src/AvatarHashMap.h
+++ b/libraries/avatars/src/AvatarHashMap.h
@@ -16,6 +16,7 @@
 #include <QtCore/QSharedPointer>
 #include <QtCore/QUuid>
 
+#include <functional>
 #include <memory>
 
 #include <DependencyManager.h>
@@ -30,7 +31,7 @@ class AvatarHashMap : public QObject, public Dependency {
     SINGLETON_DEPENDENCY
 
 public:
-    const AvatarHash& getAvatarHash() { return _avatarHash; }
+    void withAvatarHash(std::function<void(const AvatarHash& hash)>);
     int size() { return _avatarHash.size(); }
 
 public slots:
@@ -52,6 +53,9 @@ protected:
     virtual void removeAvatar(const QUuid& sessionUUID);
 
     AvatarHash _avatarHash;
+    // "Case-based safety": Most access to the _avatarHash is on the same thread. Write access is protected by a write-lock.
+    // If you read from a different thread, you must read-lock the _hashLock. (Scripted write access is not supported).
+    QReadWriteLock _hashLock;
 
 private:
     QUuid _lastOwnerSessionUUID;
diff --git a/libraries/entities/src/EntityActionInterface.h b/libraries/entities/src/EntityActionInterface.h
index d97b5e8106..b257df3325 100644
--- a/libraries/entities/src/EntityActionInterface.h
+++ b/libraries/entities/src/EntityActionInterface.h
@@ -47,6 +47,7 @@ public:
     static QString actionTypeToString(EntityActionType actionType);
 
     virtual bool lifetimeIsOver() { return false; }
+    virtual quint64 getExpires() { return 0; }
 
     bool locallyAddedButNotYetReceived = false;
 
diff --git a/libraries/entities/src/EntityItem.cpp b/libraries/entities/src/EntityItem.cpp
index 1fd9acc1e2..f012ba6eee 100644
--- a/libraries/entities/src/EntityItem.cpp
+++ b/libraries/entities/src/EntityItem.cpp
@@ -1790,9 +1790,17 @@ const QByteArray EntityItem::getActionDataInternal() const {
 const QByteArray EntityItem::getActionData() const {
     QByteArray result;
     assertUnlocked();
-    withReadLock([&] {
-        result = getActionDataInternal();
-    });
+
+    if (_actionDataDirty) {
+        withWriteLock([&] {
+            getActionDataInternal();
+            result = _allActionsDataCache;
+        });
+    } else {
+        withReadLock([&] {
+            result = _allActionsDataCache;
+        });
+    }
     return result;
 }
 
diff --git a/libraries/fbx/src/FBXReader.cpp b/libraries/fbx/src/FBXReader.cpp
index 1eda5304e4..f9bb089a9c 100644
--- a/libraries/fbx/src/FBXReader.cpp
+++ b/libraries/fbx/src/FBXReader.cpp
@@ -64,7 +64,7 @@ Extents FBXGeometry::getUnscaledMeshExtents() const {
     glm::vec3 minimum = glm::vec3(offset * glm::vec4(extents.minimum, 1.0f));
     glm::vec3 maximum = glm::vec3(offset * glm::vec4(extents.maximum, 1.0f));
     Extents scaledExtents = { minimum, maximum };
-        
+
     return scaledExtents;
 }
 
@@ -73,7 +73,7 @@ bool FBXGeometry::convexHullContains(const glm::vec3& point) const {
     if (!getUnscaledMeshExtents().containsPoint(point)) {
         return false;
     }
-    
+
     auto checkEachPrimitive = [=](FBXMesh& mesh, QVector<int> indices, int primitiveSize) -> bool {
         // Check whether the point is "behind" all the primitives.
         for (int j = 0; j < indices.size(); j += primitiveSize) {
@@ -87,11 +87,11 @@ bool FBXGeometry::convexHullContains(const glm::vec3& point) const {
         }
         return true;
     };
-    
+
     // Check that the point is contained in at least one convex mesh.
     for (auto mesh : meshes) {
         bool insideMesh = true;
-        
+
         // To be considered inside a convex mesh,
         // the point needs to be "behind" all the primitives respective planes.
         for (auto part : mesh.parts) {
@@ -108,7 +108,7 @@ bool FBXGeometry::convexHullContains(const glm::vec3& point) const {
             return true;
         }
     }
-    
+
     // It wasn't in any mesh, return false.
     return false;
 }
@@ -194,7 +194,7 @@ public:
     glm::vec3 rotationMax;  // radians
 };
 
-glm::mat4 getGlobalTransform(const QMultiHash<QString, QString>& _connectionParentMap,
+glm::mat4 getGlobalTransform(const QMultiMap<QString, QString>& _connectionParentMap,
         const QHash<QString, FBXModel>& models, QString nodeID, bool mixamoHack) {
     glm::mat4 globalTransform;
     while (!nodeID.isNull()) {
@@ -228,12 +228,12 @@ void printNode(const FBXNode& node, int indentLevel) {
     int indentLength = 2;
     QByteArray spaces(indentLevel * indentLength, ' ');
     QDebug nodeDebug = qDebug(modelformat);
-    
+
     nodeDebug.nospace() << spaces.data() << node.name.data() << ": ";
     foreach (const QVariant& property, node.properties) {
         nodeDebug << property;
     }
-    
+
     foreach (const FBXNode& child, node.children) {
         printNode(child, indentLevel + 1);
     }
@@ -246,7 +246,7 @@ public:
     glm::mat4 transformLink;
 };
 
-void appendModelIDs(const QString& parentID, const QMultiHash<QString, QString>& connectionChildMap,
+void appendModelIDs(const QString& parentID, const QMultiMap<QString, QString>& connectionChildMap,
         QHash<QString, FBXModel>& models, QSet<QString>& remainingModels, QVector<QString>& modelIDs) {
     if (remainingModels.contains(parentID)) {
         modelIDs.append(parentID);
@@ -331,7 +331,7 @@ void addBlendshapes(const ExtractedBlendshape& extracted, const QList<WeightedIn
     }
 }
 
-QString getTopModelID(const QMultiHash<QString, QString>& connectionParentMap,
+QString getTopModelID(const QMultiMap<QString, QString>& connectionParentMap,
         const QHash<QString, FBXModel>& models, const QString& modelID) {
     QString topID = modelID;
     forever {
@@ -342,7 +342,7 @@ QString getTopModelID(const QMultiHash<QString, QString>& connectionParentMap,
             }
         }
         return topID;
-        
+
         outerContinue: ;
     }
 }
@@ -361,7 +361,7 @@ public:
 };
 
 bool checkMaterialsHaveTextures(const QHash<QString, FBXMaterial>& materials,
-        const QHash<QString, QByteArray>& textureFilenames, const QMultiHash<QString, QString>& _connectionChildMap) {
+        const QHash<QString, QByteArray>& textureFilenames, const QMultiMap<QString, QString>& _connectionChildMap) {
     foreach (const QString& materialID, materials.keys()) {
         foreach (const QString& childID, _connectionChildMap.values(materialID)) {
             if (textureFilenames.contains(childID)) {
@@ -443,8 +443,8 @@ QByteArray fileOnUrl(const QByteArray& filenameString, const QString& url) {
 }
 
 FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QString& url) {
-    const FBXNode& node = _fbxNode; 
-    QHash<QString, ExtractedMesh> meshes;
+    const FBXNode& node = _fbxNode;
+    QMap<QString, ExtractedMesh> meshes;
     QHash<QString, QString> modelIDsToNames;
     QHash<QString, int> meshIDsToMeshIndices;
     QHash<QString, QString> ooChildToParent;
@@ -497,7 +497,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
     QVector<QString> humanIKJointIDs(humanIKJointNames.size());
 
     QVariantHash blendshapeMappings = mapping.value("bs").toHash();
-    
+
     QMultiHash<QByteArray, WeightedIndex> blendshapeIndices;
     for (int i = 0;; i++) {
         QByteArray blendshapeName = FACESHIFT_BLENDSHAPES[i];
@@ -527,7 +527,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
     QString hifiGlobalNodeID;
     unsigned int meshIndex = 0;
     foreach (const FBXNode& child, node.children) {
-    
+
         if (child.name == "FBXHeaderExtension") {
             foreach (const FBXNode& object, child.children) {
                 if (object.name == "SceneInfo") {
@@ -537,7 +537,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
                                 if (subsubobject.name == "Author") {
                                     geometry.author = subsubobject.properties.at(0).toString();
                                 }
-                            } 
+                            }
                         } else if (subobject.name == "Properties70") {
                             foreach (const FBXNode& subsubobject, subobject.children) {
                                 if (subsubobject.name == "P" && subsubobject.properties.size() >= 5 &&
@@ -620,7 +620,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
                     if (humanIKJointIndex != -1) {
                         humanIKJointIDs[humanIKJointIndex] = getID(object.properties);
                     }
-                    
+
                     glm::vec3 translation;
                     // NOTE: the euler angles as supplied by the FBX file are in degrees
                     glm::vec3 rotationOffset;
@@ -709,7 +709,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
                             // it's a mesh as well as a model
                             mesh = &meshes[getID(object.properties)];
                             *mesh = extractMesh(object, meshIndex);
-                             
+
                         } else if (subobject.name == "Shape") {
                             ExtractedBlendshape blendshape =  { subobject.properties.at(0).toString(),
                                 extractBlendshape(subobject) };
@@ -720,7 +720,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
                             QString attributetype = subobject.properties.at(0).toString();
                             if (!attributetype.empty()) {
                                 if (attributetype == "Light") {
-                                    QString lightprop; 
+                                    QString lightprop;
                                     foreach (const QVariant& vprop, subobject.properties) {
                                         lightprop = vprop.toString();
                                     }
@@ -731,23 +731,23 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
                         } else {
                             QString whatisthat = subobject.name;
                             if (whatisthat == "Shape") {
-                            } 
+                            }
                         }
 #endif
                     }
-                    
+
                     // add the blendshapes included in the model, if any
                     if (mesh) {
                         foreach (const ExtractedBlendshape& extracted, blendshapes) {
                             addBlendshapes(extracted, blendshapeIndices.values(extracted.id.toLatin1()), *mesh);
                         }
                     }
-                    
+
                     // see FBX documentation, http://download.autodesk.com/us/fbx/20112/FBX_SDK_HELP/index.html
                     model.translation = translation;
 
-                    model.preTransform = glm::translate(rotationOffset) * glm::translate(rotationPivot);      
-                    model.preRotation = glm::quat(glm::radians(preRotation));            
+                    model.preTransform = glm::translate(rotationOffset) * glm::translate(rotationPivot);
+                    model.preRotation = glm::quat(glm::radians(preRotation));
                     model.rotation = glm::quat(glm::radians(rotation));
                     model.postRotation = glm::quat(glm::radians(postRotation));
 
@@ -862,7 +862,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
                         if (subobject.name == "RelativeFilename") {
                             filename = subobject.properties.at(0).toByteArray();
                             filename = fileOnUrl(filename, url);
-                            
+
                         } else if (subobject.name == "Content" && !subobject.properties.isEmpty()) {
                             content = subobject.properties.at(0).toByteArray();
                         }
@@ -905,10 +905,10 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
 
                                     } else if (property.properties.at(0) == "Emissive") {
                                         material.emissiveColor = getVec3(property.properties, index);
-                                    
+
                                     } else if (property.properties.at(0) == "Shininess") {
                                         material.shininess = property.properties.at(index).value<double>();
-                                    
+
                                     } else if (property.properties.at(0) == "Opacity") {
                                         material.opacity = property.properties.at(index).value<double>();
                                     }
@@ -1001,7 +1001,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
                         }
                     }
                     animationCurves.insert(getID(object.properties), curve);
-                
+
                 }
 #if defined(DEBUG_FBXREADER)
                  else {
@@ -1013,7 +1013,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
                     } else {
                         unknown++;
                     }
-                } 
+                }
 #endif
             }
         } else if (child.name == "Connections") {
@@ -1041,14 +1041,14 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
                             diffuseTextures.insert(getID(connection.properties, 2), getID(connection.properties, 1));
 
                         } else if (type.contains("transparentcolor")) { // it should be TransparentColor...
-                            // THis is how Maya assign a texture that affect diffuse color AND transparency ? 
+                            // THis is how Maya assign a texture that affect diffuse color AND transparency ?
                             diffuseTextures.insert(getID(connection.properties, 2), getID(connection.properties, 1));
                         } else if (type.contains("bump")) {
                             bumpTextures.insert(getID(connection.properties, 2), getID(connection.properties, 1));
                         } else if (type.contains("normal")) {
                             normalTextures.insert(getID(connection.properties, 2), getID(connection.properties, 1));
                         } else if (type.contains("specular") || type.contains("reflection")) {
-                            specularTextures.insert(getID(connection.properties, 2), getID(connection.properties, 1));    
+                            specularTextures.insert(getID(connection.properties, 2), getID(connection.properties, 1));
 
                         } else if (type == "lcl rotation") {
                             localRotations.insert(getID(connection.properties, 2), getID(connection.properties, 1));
@@ -1097,7 +1097,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
             } else {
                 unknown++;
             }
-        } 
+        }
 #endif
     }
 
@@ -1142,7 +1142,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
             }
         }
         outerBreak:
-    
+
         // make sure the parent is in the child map
         QString parent = _connectionParentMap.value(model.key());
         if (!_connectionChildMap.contains(parent, model.key())) {
@@ -1172,7 +1172,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
         frame.translations.resize(modelIDs.size());
         geometry.animationFrames.append(frame);
     }
-    
+
     // convert the models to joints
     QVariantList freeJoints = mapping.values("freeJoint");
     geometry.hasSkeletonJoints = false;
@@ -1181,7 +1181,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
         FBXJoint joint;
         joint.isFree = freeJoints.contains(model.name);
         joint.parentIndex = model.parentIndex;
- 
+
         // get the indices of all ancestors starting with the first free one (if any)
         int jointIndex = geometry.joints.size();
         joint.freeLineage.append(jointIndex);
@@ -1203,7 +1203,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
         joint.rotationMax = model.rotationMax;
         glm::quat combinedRotation = joint.preRotation * joint.rotation * joint.postRotation;
         if (joint.parentIndex == -1) {
-            joint.transform = geometry.offset * glm::translate(joint.translation) * joint.preTransform * 
+            joint.transform = geometry.offset * glm::translate(joint.translation) * joint.preTransform *
                 glm::mat4_cast(combinedRotation) * joint.postTransform;
             joint.inverseDefaultRotation = glm::inverse(combinedRotation);
            joint.distanceToParent = 0.0f;
@@ -1272,11 +1272,11 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
     geometry.rightHandJointIndex = modelIDs.indexOf(jointRightHandID);
     geometry.leftToeJointIndex = modelIDs.indexOf(jointLeftToeID);
     geometry.rightToeJointIndex = modelIDs.indexOf(jointRightToeID);
-    
+
     foreach (const QString& id, humanIKJointIDs) {
         geometry.humanIKJointIndices.append(modelIDs.indexOf(id));
     }
-    
+
     // extract the translation component of the neck transform
     if (geometry.neckJointIndex != -1) {
         const glm::mat4& transform = geometry.joints.at(geometry.neckJointIndex).transform;
@@ -1285,7 +1285,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
 
     geometry.bindExtents.reset();
     geometry.meshExtents.reset();
-    
+
     // Create the Material Library
     consolidateFBXMaterials();
     geometry.materials = _fbxMaterials;
@@ -1293,9 +1293,9 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
     // see if any materials have texture children
     bool materialsHaveTextures = checkMaterialsHaveTextures(_fbxMaterials, _textureFilenames, _connectionChildMap);
 
-    for (QHash<QString, ExtractedMesh>::iterator it = meshes.begin(); it != meshes.end(); it++) {
+    for (QMap<QString, ExtractedMesh>::iterator it = meshes.begin(); it != meshes.end(); it++) {
         ExtractedMesh& extracted = it.value();
-        
+
         extracted.mesh.meshExtents.reset();
 
         // accumulate local transforms
@@ -1335,7 +1335,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
                 }
 
                 materialIndex++;
-                
+
             } else if (_textureFilenames.contains(childID)) {
                 FBXTexture texture = getTexture(childID);
                 for (int j = 0; j < extracted.partMaterialTextures.size(); j++) {
@@ -1360,7 +1360,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
                     setTangents(extracted.mesh, part.quadIndices.at(i + 2), part.quadIndices.at(i + 3));
                     setTangents(extracted.mesh, part.quadIndices.at(i + 3), part.quadIndices.at(i));
                 }
-                // <= size - 3 in order to prevent overflowing triangleIndices when (i % 3) != 0 
+                // <= size - 3 in order to prevent overflowing triangleIndices when (i % 3) != 0
                 // This is most likely evidence of a further problem in extractMesh()
                 for (int i = 0; i <= part.triangleIndices.size() - 3; i += 3) {
                     setTangents(extracted.mesh, part.triangleIndices.at(i), part.triangleIndices.at(i + 1));
@@ -1500,7 +1500,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
                 glm::vec4& weights = extracted.mesh.clusterWeights[i];
                 float total = weights.x + weights.y + weights.z + weights.w;
                 if (total != 1.0f && total != 0.0f) {
-                    weights /= total; 
+                    weights /= total;
                 }
             }
         } else {
@@ -1573,7 +1573,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
                 avgRadius += glm::length(offset - projection * axis);
             }
             avgRadius /= (float)points.size();
-        
+
             // compute endpoints of capsule in joint-frame
             glm::vec3 capsuleBegin = avgPoint;
             glm::vec3 capsuleEnd = avgPoint;
@@ -1594,27 +1594,27 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
         joint.shapeInfo.radius = avgRadius;
     }
     geometry.palmDirection = parseVec3(mapping.value("palmDirection", "0, -1, 0").toString());
-    
+
     // Add sitting points
     QVariantHash sittingPoints = mapping.value("sit").toHash();
     for (QVariantHash::const_iterator it = sittingPoints.constBegin(); it != sittingPoints.constEnd(); it++) {
         SittingPoint sittingPoint;
         sittingPoint.name = it.key();
-        
+
         QVariantList properties = it->toList();
         sittingPoint.position = parseVec3(properties.at(0).toString());
         sittingPoint.rotation = glm::quat(glm::radians(parseVec3(properties.at(1).toString())));
-        
+
         geometry.sittingPoints.append(sittingPoint);
     }
-    
+
     // attempt to map any meshes to a named model
-    for (QHash<QString, int>::const_iterator m = meshIDsToMeshIndices.constBegin(); 
+    for (QHash<QString, int>::const_iterator m = meshIDsToMeshIndices.constBegin();
             m != meshIDsToMeshIndices.constEnd(); m++) {
-            
+
         const QString& meshID = m.key();
         int meshIndex = m.value();
-        
+
         if (ooChildToParent.contains(meshID)) {
             const QString& modelID = ooChildToParent.value(meshID);
             if (modelIDsToNames.contains(modelID)) {
@@ -1623,7 +1623,7 @@ FBXGeometry* FBXReader::extractFBXGeometry(const QVariantHash& mapping, const QS
             }
         }
     }
-    
+
     return geometryPtr;
 }
 
@@ -1641,5 +1641,3 @@ FBXGeometry* readFBX(QIODevice* device, const QVariantHash& mapping, const QStri
 
     return reader.extractFBXGeometry(mapping, url);
 }
-
-
diff --git a/libraries/fbx/src/FBXReader.h b/libraries/fbx/src/FBXReader.h
index 0af7b28136..8014718815 100644
--- a/libraries/fbx/src/FBXReader.h
+++ b/libraries/fbx/src/FBXReader.h
@@ -413,8 +413,8 @@ public:
     float _lightmapOffset = 0.0f;
     float _lightmapLevel;
 
-    QMultiHash<QString, QString> _connectionParentMap;
-    QMultiHash<QString, QString> _connectionChildMap;
+    QMultiMap<QString, QString> _connectionParentMap;
+    QMultiMap<QString, QString> _connectionChildMap;
 
     static glm::vec3 getVec3(const QVariantList& properties, int index);
     static QVector<glm::vec4> createVec4Vector(const QVector<double>& doubleVector);
diff --git a/libraries/physics/src/ObjectAction.cpp b/libraries/physics/src/ObjectAction.cpp
index ce4ebfd22f..ff8382a143 100644
--- a/libraries/physics/src/ObjectAction.cpp
+++ b/libraries/physics/src/ObjectAction.cpp
@@ -85,11 +85,11 @@ bool ObjectAction::updateArguments(QVariantMap arguments) {
         quint64 previousExpires = _expires;
         QString previousTag = _tag;
 
-        bool lifetimeSet = true;
-        float lifetime = EntityActionInterface::extractFloatArgument("action", arguments, "lifetime", lifetimeSet, false);
-        if (lifetimeSet) {
+        bool ttlSet = true;
+        float ttl = EntityActionInterface::extractFloatArgument("action", arguments, "ttl", ttlSet, false);
+        if (ttlSet) {
             quint64 now = usecTimestampNow();
-            _expires = now + (quint64)(lifetime * USECS_PER_SECOND);
+            _expires = now + (quint64)(ttl * USECS_PER_SECOND);
         } else {
             _expires = 0;
         }
@@ -114,10 +114,10 @@ QVariantMap ObjectAction::getArguments() {
     QVariantMap arguments;
     withReadLock([&]{
         if (_expires == 0) {
-            arguments["lifetime"] = 0.0f;
+            arguments["ttl"] = 0.0f;
         } else {
             quint64 now = usecTimestampNow();
-            arguments["lifetime"] = (float)(_expires - now) / (float)USECS_PER_SECOND;
+            arguments["ttl"] = (float)(_expires - now) / (float)USECS_PER_SECOND;
         }
         arguments["tag"] = _tag;
     });
@@ -245,3 +245,31 @@ bool ObjectAction::lifetimeIsOver() {
     }
     return false;
 }
+
+quint64 ObjectAction::localTimeToServerTime(quint64 timeValue) const {
+    // 0 indicates no expiration
+    if (timeValue == 0) {
+        return 0;
+    }
+
+    int serverClockSkew = getEntityServerClockSkew();
+    if (serverClockSkew < 0 && timeValue <= (quint64)(-serverClockSkew)) {
+        return 1; // non-zero but long-expired value to avoid negative roll-over
+    }
+
+    return timeValue + serverClockSkew;
+}
+
+quint64 ObjectAction::serverTimeToLocalTime(quint64 timeValue) const {
+    // 0 indicates no expiration
+    if (timeValue == 0) {
+        return 0;
+    }
+
+    int serverClockSkew = getEntityServerClockSkew();
+    if (serverClockSkew > 0 && timeValue <= (quint64)serverClockSkew) {
+        return 1; // non-zero but long-expired value to avoid negative roll-over
+    }
+
+    return timeValue - serverClockSkew;
+}
diff --git a/libraries/physics/src/ObjectAction.h b/libraries/physics/src/ObjectAction.h
index 98e58475c6..fca446aec4 100644
--- a/libraries/physics/src/ObjectAction.h
+++ b/libraries/physics/src/ObjectAction.h
@@ -47,11 +47,10 @@ public:
     virtual void deserialize(QByteArray serializedArguments) = 0;
 
     virtual bool lifetimeIsOver();
+    virtual quint64 getExpires() { return _expires; }
 
 protected:
 
-    int getEntityServerClockSkew() const;
-
     virtual btRigidBody* getRigidBody();
     virtual glm::vec3 getPosition();
     virtual void setPosition(glm::vec3 position);
@@ -68,6 +67,12 @@ protected:
 
     quint64 _expires; // in seconds since epoch
     QString _tag;
+
+    quint64 localTimeToServerTime(quint64 timeValue) const;
+    quint64 serverTimeToLocalTime(quint64 timeValue) const;
+
+private:
+    int getEntityServerClockSkew() const;
 };
 
 #endif // hifi_ObjectAction_h
diff --git a/libraries/physics/src/ObjectActionOffset.cpp b/libraries/physics/src/ObjectActionOffset.cpp
index b6edf22ffc..2cfd98497b 100644
--- a/libraries/physics/src/ObjectActionOffset.cpp
+++ b/libraries/physics/src/ObjectActionOffset.cpp
@@ -160,7 +160,7 @@ QByteArray ObjectActionOffset::serialize() const {
         dataStream << _linearDistance;
         dataStream << _linearTimeScale;
         dataStream << _positionalTargetSet;
-        dataStream << _expires + getEntityServerClockSkew();
+        dataStream << localTimeToServerTime(_expires);
         dataStream << _tag;
     });
 
@@ -189,8 +189,11 @@ void ObjectActionOffset::deserialize(QByteArray serializedArguments) {
         dataStream >> _linearDistance;
         dataStream >> _linearTimeScale;
         dataStream >> _positionalTargetSet;
-        dataStream >> _expires;
-        _expires -= getEntityServerClockSkew();
+
+        quint64 serverExpires;
+        dataStream >> serverExpires;
+        _expires = serverTimeToLocalTime(serverExpires);
+
         dataStream >> _tag;
         _active = true;
     });
diff --git a/libraries/physics/src/ObjectActionSpring.cpp b/libraries/physics/src/ObjectActionSpring.cpp
index a74756eb53..c1cd2db5ca 100644
--- a/libraries/physics/src/ObjectActionSpring.cpp
+++ b/libraries/physics/src/ObjectActionSpring.cpp
@@ -198,7 +198,7 @@ QByteArray ObjectActionSpring::serialize() const {
         dataStream << _rotationalTarget;
         dataStream << _angularTimeScale;
         dataStream << _rotationalTargetSet;
-        dataStream << _expires + getEntityServerClockSkew();
+        dataStream << localTimeToServerTime(_expires);
         dataStream << _tag;
     });
 
@@ -232,8 +232,10 @@ void ObjectActionSpring::deserialize(QByteArray serializedArguments) {
         dataStream >> _angularTimeScale;
         dataStream >> _rotationalTargetSet;
 
-        dataStream >> _expires;
-        _expires -= getEntityServerClockSkew();
+        quint64 serverExpires;
+        dataStream >> serverExpires;
+        _expires = serverTimeToLocalTime(serverExpires);
+
         dataStream >> _tag;
 
         _active = true;
diff --git a/libraries/render-utils/src/MeshPartPayload.cpp b/libraries/render-utils/src/MeshPartPayload.cpp
index 30b72891dd..44acb61a52 100644
--- a/libraries/render-utils/src/MeshPartPayload.cpp
+++ b/libraries/render-utils/src/MeshPartPayload.cpp
@@ -229,7 +229,7 @@ void MeshPartPayload::bindTransform(gpu::Batch& batch, const ModelRender::Locati
 
 void MeshPartPayload::render(RenderArgs* args) const {
     PerformanceTimer perfTimer("MeshPartPayload::render");
-    if (!model->_readyWhenAdded) {
+    if (!model->_readyWhenAdded || !model->_isVisible) {
         return; // bail asap
     }
 
diff --git a/libraries/script-engine/src/ScriptEngine.cpp b/libraries/script-engine/src/ScriptEngine.cpp
index c6b702f178..ddcdc9ca72 100644
--- a/libraries/script-engine/src/ScriptEngine.cpp
+++ b/libraries/script-engine/src/ScriptEngine.cpp
@@ -101,7 +101,7 @@ static bool hasCorrectSyntax(const QScriptProgram& program) {
     return true;
 }
 
-static bool hadUncauchtExceptions(QScriptEngine& engine, const QString& fileName) {
+static bool hadUncaughtExceptions(QScriptEngine& engine, const QString& fileName) {
     if (engine.hasUncaughtException()) {
         const auto backtrace = engine.uncaughtExceptionBacktrace();
         const auto exception = engine.uncaughtException().toString();
@@ -615,7 +615,7 @@ QScriptValue ScriptEngine::evaluate(const QString& sourceCode, const QString& fi
     const auto result = QScriptEngine::evaluate(program);
     --_evaluatesPending;
     
-    const auto hadUncaughtException = hadUncauchtExceptions(*this, program.fileName());
+    const auto hadUncaughtException = hadUncaughtExceptions(*this, program.fileName());
     if (_wantSignals) {
         emit evaluationFinished(result, hadUncaughtException);
     }
@@ -684,9 +684,8 @@ void ScriptEngine::run() {
         }
         lastUpdate = now;
 
-        if (hadUncauchtExceptions(*this, _fileNameString)) {
-            stop();
-        }
+        // Debug and clear exceptions
+        hadUncaughtExceptions(*this, _fileNameString);
     }
 
     stopAllTimers(); // make sure all our timers are stopped if the script is ending
@@ -1021,7 +1020,7 @@ void ScriptEngine::entityScriptContentAvailable(const EntityItemID& entityID, co
 
     QScriptEngine sandbox;
     QScriptValue testConstructor = sandbox.evaluate(program);
-    if (hadUncauchtExceptions(sandbox, program.fileName())) {
+    if (hadUncaughtExceptions(sandbox, program.fileName())) {
         return;
     }
     
diff --git a/libraries/shared/src/shared/ReadWriteLockable.h b/libraries/shared/src/shared/ReadWriteLockable.h
index a7d30d562b..98dff4a841 100644
--- a/libraries/shared/src/shared/ReadWriteLockable.h
+++ b/libraries/shared/src/shared/ReadWriteLockable.h
@@ -14,7 +14,7 @@
 class ReadWriteLockable {
 public:
     template <typename F>
-    bool withWriteLock(F f, bool require = true) {
+    bool withWriteLock(F f, bool require = true) const {
         if (!require) {
             bool result = _lock.tryLockForWrite();
             if (result) {
@@ -22,7 +22,7 @@ public:
                 _lock.unlock();
             }
             return result;
-        } 
+        }
 
         QWriteLocker locker(&_lock);
         f();
@@ -30,7 +30,7 @@ public:
     }
 
     template <typename F>
-    bool withTryWriteLock(F f) {
+    bool withTryWriteLock(F f) const {
         return withWriteLock(f, false);
     }