diff --git a/assignment-client/src/Agent.cpp b/assignment-client/src/Agent.cpp
index 73444d1198..d61a1a49b7 100644
--- a/assignment-client/src/Agent.cpp
+++ b/assignment-client/src/Agent.cpp
@@ -344,8 +344,6 @@ void Agent::scriptRequestFinished() {
 void Agent::executeScript() {
     _scriptEngine = scriptEngineFactory(ScriptEngine::AGENT_SCRIPT, _scriptContents, _payload);
 
-    DependencyManager::get<RecordingScriptingInterface>()->setScriptEngine(_scriptEngine);
-
     // setup an Avatar for the script to use
     auto scriptedAvatar = DependencyManager::get<ScriptableAvatar>();
 
diff --git a/assignment-client/src/entities/EntityServer.cpp b/assignment-client/src/entities/EntityServer.cpp
index 8b86ba5eb2..868e570e0c 100644
--- a/assignment-client/src/entities/EntityServer.cpp
+++ b/assignment-client/src/entities/EntityServer.cpp
@@ -522,11 +522,8 @@ void EntityServer::startDynamicDomainVerification() {
                             qCDebug(entities) << "Entity passed dynamic domain verification:" << entityID;
                         }
                     } else {
-                        qCDebug(entities) << "Call to" << networkReply->url() << "failed with error" << networkReply->error() << "; deleting entity" << entityID
+                        qCDebug(entities) << "Call to" << networkReply->url() << "failed with error" << networkReply->error() << "; NOT deleting entity" << entityID
                             << "More info:" << jsonObject;
-                        tree->withWriteLock([&] {
-                            tree->deleteEntity(entityID, true);
-                        });
                     }
 
                     networkReply->deleteLater();
diff --git a/interface/resources/qml/hifi/AvatarApp.qml b/interface/resources/qml/hifi/AvatarApp.qml
index 0a2dcb951b..a88a584c63 100644
--- a/interface/resources/qml/hifi/AvatarApp.qml
+++ b/interface/resources/qml/hifi/AvatarApp.qml
@@ -480,7 +480,7 @@ Rectangle {
             MouseArea {
                 anchors.fill: parent
                 onClicked: {
-                    popup.showSpecifyAvatarUrl(function() {
+                    popup.showSpecifyAvatarUrl(currentAvatar.avatarUrl, function() {
                         var url = popup.inputText.text;
                         emitSendToScript({'method' : 'applyExternalAvatar', 'avatarURL' : url})
                     }, function(link) {
diff --git a/interface/resources/qml/hifi/avatarapp/MessageBoxes.qml b/interface/resources/qml/hifi/avatarapp/MessageBoxes.qml
index 125b30fa95..fd65d014a0 100644
--- a/interface/resources/qml/hifi/avatarapp/MessageBoxes.qml
+++ b/interface/resources/qml/hifi/avatarapp/MessageBoxes.qml
@@ -3,7 +3,7 @@ import QtQuick 2.5
 MessageBox {
     id: popup
 
-    function showSpecifyAvatarUrl(callback, linkCallback) {
+    function showSpecifyAvatarUrl(url, callback, linkCallback) {
         popup.onButton2Clicked = callback;
         popup.titleText = 'Specify Avatar URL'
         popup.bodyText = 'This will not overwrite your existing favorite if you are wearing one.<br>' +
@@ -12,6 +12,8 @@ MessageBox {
                 '</a>'
         popup.inputText.visible = true;
         popup.inputText.placeholderText = 'Enter Avatar Url';
+        popup.inputText.text = url;
+        popup.inputText.selectAll();
         popup.button1text = 'CANCEL';
         popup.button2text = 'CONFIRM';
 
diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index b30b7c8d9d..f1c3b72991 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -4844,12 +4844,6 @@ void Application::loadSettings() {
 
         isFirstPerson = (qApp->isHMDMode());
 
-        // Flying should be disabled by default in HMD mode on first run, and it
-        // should be enabled by default in desktop mode.
-
-        auto myAvatar = getMyAvatar();
-        myAvatar->setFlyingEnabled(!isFirstPerson);
-
     } else {
         // if this is not the first run, the camera will be initialized differently depending on user settings
 
@@ -6539,9 +6533,6 @@ void Application::registerScriptEngineWithApplicationServices(ScriptEnginePointe
     entityScriptingInterface->setPacketSender(&_entityEditSender);
     entityScriptingInterface->setEntityTree(getEntities()->getTree());
 
-    // give the script engine to the RecordingScriptingInterface for its callbacks
-    DependencyManager::get<RecordingScriptingInterface>()->setScriptEngine(scriptEngine);
-
     if (property(hifi::properties::TEST).isValid()) {
         scriptEngine->registerGlobalObject("Test", TestScriptingInterface::getInstance());
     }
diff --git a/interface/src/avatar/MyAvatar.cpp b/interface/src/avatar/MyAvatar.cpp
index bf7276d5d5..e87dcc85cd 100755
--- a/interface/src/avatar/MyAvatar.cpp
+++ b/interface/src/avatar/MyAvatar.cpp
@@ -577,9 +577,11 @@ void MyAvatar::updateChildCauterization(SpatiallyNestablePointer object, bool ca
 
 void MyAvatar::simulate(float deltaTime) {
     PerformanceTimer perfTimer("simulate");
-
+    
     animateScaleChanges(deltaTime);
 
+    setFlyingEnabled(getFlyingEnabled());
+
     if (_cauterizationNeedsUpdate) {
         _cauterizationNeedsUpdate = false;
 
@@ -724,16 +726,18 @@ void MyAvatar::simulate(float deltaTime) {
                         properties.setQueryAACubeDirty();
                         properties.setLastEdited(now);
 
-                        packetSender->queueEditEntityMessage(PacketType::EntityEdit, entityTree, entity->getID(), properties);
+                        packetSender->queueEditEntityMessage(PacketType::EntityEdit, entityTree,
+                                                             entity->getID(), properties);
                         entity->setLastBroadcast(usecTimestampNow());
 
                         entity->forEachDescendant([&](SpatiallyNestablePointer descendant) {
-                            EntityItemPointer entityDescendant = std::static_pointer_cast<EntityItem>(descendant);
-                            if (!entityDescendant->getClientOnly() && descendant->updateQueryAACube()) {
+                            EntityItemPointer entityDescendant = std::dynamic_pointer_cast<EntityItem>(descendant);
+                            if (entityDescendant && !entityDescendant->getClientOnly() && descendant->updateQueryAACube()) {
                                 EntityItemProperties descendantProperties;
                                 descendantProperties.setQueryAACube(descendant->getQueryAACube());
                                 descendantProperties.setLastEdited(now);
-                                packetSender->queueEditEntityMessage(PacketType::EntityEdit, entityTree, entityDescendant->getID(), descendantProperties);
+                                packetSender->queueEditEntityMessage(PacketType::EntityEdit, entityTree,
+                                                                     entityDescendant->getID(), descendantProperties);
                                 entityDescendant->setLastBroadcast(now); // for debug/physics status icons
                             }
                         });
@@ -1131,6 +1135,8 @@ void MyAvatar::saveData() {
     settings.setValue("collisionSoundURL", _collisionSoundURL);
     settings.setValue("useSnapTurn", _useSnapTurn);
     settings.setValue("userHeight", getUserHeight());
+    settings.setValue("flyingDesktop", getFlyingDesktopPref());
+    settings.setValue("flyingHMD", getFlyingHMDPref());
     settings.setValue("enabledFlying", getFlyingEnabled());
 
     settings.endGroup();
@@ -1281,8 +1287,13 @@ void MyAvatar::loadData() {
         settings.remove("avatarEntityData");
     }
     setAvatarEntityDataChanged(true);
+
+    // Flying preferences must be loaded before calling setFlyingEnabled()
     Setting::Handle<bool> firstRunVal { Settings::firstRun, true };
-    setFlyingEnabled(firstRunVal.get() ? getFlyingEnabled() : settings.value("enabledFlying").toBool());
+    setFlyingDesktopPref(firstRunVal.get() ? true : settings.value("flyingDesktop").toBool());
+    setFlyingHMDPref(firstRunVal.get() ? false : settings.value("flyingHMD").toBool());
+    setFlyingEnabled(getFlyingEnabled());
+
     setDisplayName(settings.value("displayName").toString());
     setCollisionSoundURL(settings.value("collisionSoundURL", DEFAULT_AVATAR_COLLISION_SOUND_URL).toString());
     setSnapTurn(settings.value("useSnapTurn", _useSnapTurn).toBool());
@@ -2825,6 +2836,12 @@ void MyAvatar::setFlyingEnabled(bool enabled) {
         return;
     }
 
+    if (qApp->isHMDMode()) {
+        setFlyingHMDPref(enabled);
+    } else {
+        setFlyingDesktopPref(enabled);
+    }
+
     _enableFlying = enabled;
 }
 
@@ -2840,7 +2857,33 @@ bool MyAvatar::isInAir() {
 
 bool MyAvatar::getFlyingEnabled() {
     // May return true even if client is not allowed to fly in the zone.
-    return _enableFlying;
+    return (qApp->isHMDMode() ? getFlyingHMDPref() : getFlyingDesktopPref());
+}
+
+void MyAvatar::setFlyingDesktopPref(bool enabled) {
+    if (QThread::currentThread() != thread()) {
+        QMetaObject::invokeMethod(this, "setFlyingDesktopPref", Q_ARG(bool, enabled));
+        return;
+    }
+
+    _flyingPrefDesktop = enabled;
+}
+
+bool MyAvatar::getFlyingDesktopPref() {
+    return _flyingPrefDesktop;
+}
+
+void MyAvatar::setFlyingHMDPref(bool enabled) {
+    if (QThread::currentThread() != thread()) {
+        QMetaObject::invokeMethod(this, "setFlyingHMDPref", Q_ARG(bool, enabled));
+        return;
+    }
+
+    _flyingPrefHMD = enabled;
+}
+
+bool MyAvatar::getFlyingHMDPref() {
+    return _flyingPrefHMD;
 }
 
 // Public interface for targetscale
@@ -3042,7 +3085,7 @@ static glm::vec3 dampenCgMovement(glm::vec3 cgUnderHeadHandsAvatarSpace, float b
 }
 
 // computeCounterBalance returns the center of gravity in Avatar space
-glm::vec3 MyAvatar::computeCounterBalance() const {
+glm::vec3 MyAvatar::computeCounterBalance() {
     struct JointMass {
         QString name;
         float weight;
@@ -3060,7 +3103,8 @@ glm::vec3 MyAvatar::computeCounterBalance() const {
     JointMass cgLeftHandMass(QString("LeftHand"), DEFAULT_AVATAR_LEFTHAND_MASS, glm::vec3(0.0f, 0.0f, 0.0f));
     JointMass cgRightHandMass(QString("RightHand"), DEFAULT_AVATAR_RIGHTHAND_MASS, glm::vec3(0.0f, 0.0f, 0.0f));
     glm::vec3 tposeHead = DEFAULT_AVATAR_HEAD_POS;
-    glm::vec3 tposeHips = glm::vec3(0.0f, 0.0f, 0.0f);
+    glm::vec3 tposeHips = DEFAULT_AVATAR_HIPS_POS;
+    glm::vec3 tposeRightFoot = DEFAULT_AVATAR_RIGHTFOOT_POS;
 
     if (_skeletonModel->getRig().indexOfJoint(cgHeadMass.name) != -1) {
         cgHeadMass.position = getAbsoluteJointTranslationInObjectFrame(_skeletonModel->getRig().indexOfJoint(cgHeadMass.name));
@@ -3079,6 +3123,9 @@ glm::vec3 MyAvatar::computeCounterBalance() const {
     if (_skeletonModel->getRig().indexOfJoint("Hips") != -1) {
         tposeHips = getAbsoluteDefaultJointTranslationInObjectFrame(_skeletonModel->getRig().indexOfJoint("Hips"));
     }
+    if (_skeletonModel->getRig().indexOfJoint("RightFoot") != -1) {
+        tposeRightFoot = getAbsoluteDefaultJointTranslationInObjectFrame(_skeletonModel->getRig().indexOfJoint("RightFoot"));
+    }
 
     // find the current center of gravity position based on head and hand moments
     glm::vec3 sumOfMoments = (cgHeadMass.weight * cgHeadMass.position) + (cgLeftHandMass.weight * cgLeftHandMass.position) + (cgRightHandMass.weight * cgRightHandMass.position);
@@ -3099,9 +3146,12 @@ glm::vec3 MyAvatar::computeCounterBalance() const {
     glm::vec3 counterBalancedCg = (1.0f / DEFAULT_AVATAR_HIPS_MASS) * counterBalancedForHead;
 
     // find the height of the hips
+    const float UPPER_LEG_FRACTION = 0.3333f;
     glm::vec3 xzDiff((cgHeadMass.position.x - counterBalancedCg.x), 0.0f, (cgHeadMass.position.z - counterBalancedCg.z));
     float headMinusHipXz = glm::length(xzDiff);
     float headHipDefault = glm::length(tposeHead - tposeHips);
+    float hipFootDefault = tposeHips.y - tposeRightFoot.y;
+    float sitSquatThreshold = tposeHips.y - (UPPER_LEG_FRACTION * hipFootDefault);
     float hipHeight = 0.0f;
     if (headHipDefault > headMinusHipXz) {
         hipHeight = sqrtf((headHipDefault * headHipDefault) - (headMinusHipXz * headMinusHipXz));
@@ -3113,6 +3163,10 @@ glm::vec3 MyAvatar::computeCounterBalance() const {
     if (counterBalancedCg.y > (tposeHips.y + 0.05f)) {
         // if the height is higher than default hips, clamp to default hips
         counterBalancedCg.y = tposeHips.y + 0.05f;
+    } else if (counterBalancedCg.y < sitSquatThreshold) {
+        //do a height reset
+        setResetMode(true);
+        _follow.activate(FollowHelper::Vertical);
     }
     return counterBalancedCg;
 }
@@ -3162,7 +3216,7 @@ static void drawBaseOfSupport(float baseOfSupportScale, float footLocal, glm::ma
 // this function finds the hips position using a center of gravity model that
 // balances the head and hands with the hips over the base of support
 // returns the rotation (-z forward) and position of the Avatar in Sensor space
-glm::mat4 MyAvatar::deriveBodyUsingCgModel() const {
+glm::mat4 MyAvatar::deriveBodyUsingCgModel() {
     glm::mat4 sensorToWorldMat = getSensorToWorldMatrix();
     glm::mat4 worldToSensorMat = glm::inverse(sensorToWorldMat);
     auto headPose = getControllerPoseInSensorFrame(controller::Action::HEAD);
@@ -3180,7 +3234,7 @@ glm::mat4 MyAvatar::deriveBodyUsingCgModel() const {
     }
 
     // get the new center of gravity
-    const glm::vec3 cgHipsPosition = computeCounterBalance();
+    glm::vec3 cgHipsPosition = computeCounterBalance();
 
     // find the new hips rotation using the new head-hips axis as the up axis
     glm::mat4 avatarHipsMat = computeNewHipsMatrix(glmExtractRotation(avatarHeadMat), extractTranslation(avatarHeadMat), cgHipsPosition);
diff --git a/interface/src/avatar/MyAvatar.h b/interface/src/avatar/MyAvatar.h
index 2ef6c2041b..d36e43ca25 100644
--- a/interface/src/avatar/MyAvatar.h
+++ b/interface/src/avatar/MyAvatar.h
@@ -955,6 +955,30 @@ public:
      */
     Q_INVOKABLE bool getFlyingEnabled();
 
+    /**jsdoc
+     * @function MyAvatar.setFlyingDesktopPref
+     * @param {boolean} enabled
+     */
+    Q_INVOKABLE void setFlyingDesktopPref(bool enabled);
+
+    /**jsdoc
+     * @function MyAvatar.getFlyingDesktopPref
+     * @returns {boolean}
+     */
+    Q_INVOKABLE bool getFlyingDesktopPref();
+
+    /**jsdoc
+     * @function MyAvatar.setFlyingDesktopPref
+     * @param {boolean} enabled
+     */
+    Q_INVOKABLE void setFlyingHMDPref(bool enabled);
+
+    /**jsdoc
+     * @function MyAvatar.getFlyingDesktopPref
+     * @returns {boolean}
+     */
+    Q_INVOKABLE bool getFlyingHMDPref();
+
 
     /**jsdoc
      * @function MyAvatar.getAvatarScale
@@ -1019,12 +1043,12 @@ public:
     // results are in sensor frame (-z forward)
     glm::mat4 deriveBodyFromHMDSensor() const;
 
-    glm::vec3 computeCounterBalance() const;
+    glm::vec3 computeCounterBalance();
 
     // derive avatar body position and orientation from using the current HMD Sensor location in relation to the previous
     // location of the base of support of the avatar.
     // results are in sensor frame (-z foward)
-    glm::mat4 deriveBodyUsingCgModel() const;
+    glm::mat4 deriveBodyUsingCgModel();
 
     /**jsdoc
      * @function MyAvatar.isUp
@@ -1505,6 +1529,8 @@ private:
     std::bitset<MAX_DRIVE_KEYS> _disabledDriveKeys;
 
     bool _enableFlying { false };
+    bool _flyingPrefDesktop { true };
+    bool _flyingPrefHMD { false };
     bool _wasPushing { false };
     bool _isPushing { false };
     bool _isBeingPushed { false };
diff --git a/interface/src/ui/PreferencesDialog.cpp b/interface/src/ui/PreferencesDialog.cpp
index 135b59a152..50a4d17cae 100644
--- a/interface/src/ui/PreferencesDialog.cpp
+++ b/interface/src/ui/PreferencesDialog.cpp
@@ -313,8 +313,8 @@ void setupPreferences() {
                                                        getter, setter));
     }
     {
-        auto getter = [=]()->bool { return myAvatar->getFlyingEnabled(); };
-        auto setter = [=](bool value) { myAvatar->setFlyingEnabled(value); };
+        auto getter = [=]()->bool { return myAvatar->getFlyingHMDPref(); };
+        auto setter = [=](bool value) { myAvatar->setFlyingHMDPref(value); };
         preferences->addPreference(new CheckPreference(VR_MOVEMENT, "Flying & jumping", getter, setter));
     }
     {
diff --git a/libraries/entities-renderer/src/RenderableModelEntityItem.cpp b/libraries/entities-renderer/src/RenderableModelEntityItem.cpp
index d8ac3dc63e..3f3c751943 100644
--- a/libraries/entities-renderer/src/RenderableModelEntityItem.cpp
+++ b/libraries/entities-renderer/src/RenderableModelEntityItem.cpp
@@ -699,14 +699,6 @@ void RenderableModelEntityItem::computeShapeInfo(ShapeInfo& shapeInfo) {
     adjustShapeInfoByRegistration(shapeInfo);
 }
 
-void RenderableModelEntityItem::setCollisionShape(const btCollisionShape* shape) {
-    const void* key = static_cast<const void*>(shape);
-    if (_collisionMeshKey != key) {
-        _collisionMeshKey = key;
-        emit requestCollisionGeometryUpdate();
-    }
-}
-
 void RenderableModelEntityItem::setJointMap(std::vector<int> jointMap) {
     if (jointMap.size() > 0) {
         _jointMap = jointMap;
@@ -1278,10 +1270,6 @@ bool ModelEntityRenderer::needsRenderUpdateFromTypedEntity(const TypedEntityPoin
     return false;
 }
 
-void ModelEntityRenderer::setCollisionMeshKey(const void*key) {
-    _collisionMeshKey = key;
-}
-
 void ModelEntityRenderer::doRenderUpdateSynchronousTyped(const ScenePointer& scene, Transaction& transaction, const TypedEntityPointer& entity) {
     DETAILED_PROFILE_RANGE(simulation_physics, __FUNCTION__);
     if (_hasModel != entity->hasModel()) {
diff --git a/libraries/entities-renderer/src/RenderableModelEntityItem.h b/libraries/entities-renderer/src/RenderableModelEntityItem.h
index 91e5496b97..7a6c882c5a 100644
--- a/libraries/entities-renderer/src/RenderableModelEntityItem.h
+++ b/libraries/entities-renderer/src/RenderableModelEntityItem.h
@@ -78,8 +78,6 @@ public:
     virtual bool isReadyToComputeShape() const override;
     virtual void computeShapeInfo(ShapeInfo& shapeInfo) override;
 
-    void setCollisionShape(const btCollisionShape* shape) override;
-
     virtual bool contains(const glm::vec3& point) const override;
     void stopModelOverrideIfNoParent();
 
@@ -112,10 +110,6 @@ public:
     virtual QStringList getJointNames() const override;
 
     bool getMeshes(MeshProxyList& result) override; // deprecated
-    const void* getCollisionMeshKey() const { return _collisionMeshKey; }
-
-signals:
-    void requestCollisionGeometryUpdate();
 
 private:
     bool needsUpdateModelBounds() const;
@@ -130,7 +124,6 @@ private:
     QVariantMap _originalTextures;
     bool _dimensionsInitialized { true };
     bool _needsJointSimulation { false };
-    const void* _collisionMeshKey { nullptr };
 };
 
 namespace render { namespace entities { 
@@ -161,7 +154,6 @@ protected:
     virtual bool needsRenderUpdate() const override;
     virtual void doRender(RenderArgs* args) override;
     virtual void doRenderUpdateSynchronousTyped(const ScenePointer& scene, Transaction& transaction, const TypedEntityPointer& entity) override;
-    void setCollisionMeshKey(const void* key);
 
     render::hifi::Tag getTagMask() const override;
 
diff --git a/libraries/entities-renderer/src/RenderableParticleEffectEntityItem.cpp b/libraries/entities-renderer/src/RenderableParticleEffectEntityItem.cpp
index 309671f49e..73f46245c4 100644
--- a/libraries/entities-renderer/src/RenderableParticleEffectEntityItem.cpp
+++ b/libraries/entities-renderer/src/RenderableParticleEffectEntityItem.cpp
@@ -101,6 +101,10 @@ void ParticleEffectEntityRenderer::doRenderUpdateSynchronousTyped(const ScenePoi
         _timeUntilNextEmit = 0;
         withWriteLock([&]{
             _particleProperties = newParticleProperties;
+            if (!_prevEmitterShouldTrailInitialized) {
+                _prevEmitterShouldTrailInitialized = true;
+                _prevEmitterShouldTrail = _particleProperties.emission.shouldTrail;
+            }
         });
     }
     _emitting = entity->getIsEmitting();
@@ -144,7 +148,12 @@ void ParticleEffectEntityRenderer::doRenderUpdateAsynchronousTyped(const TypedEn
         particleUniforms.color.middle = _particleProperties.getColorMiddle();
         particleUniforms.color.finish = _particleProperties.getColorFinish();
         particleUniforms.color.spread = _particleProperties.getColorSpread();
+        particleUniforms.spin.start = _particleProperties.spin.range.start;
+        particleUniforms.spin.middle = _particleProperties.spin.gradient.target;
+        particleUniforms.spin.finish = _particleProperties.spin.range.finish;
+        particleUniforms.spin.spread = _particleProperties.spin.gradient.spread;
         particleUniforms.lifespan = _particleProperties.lifespan;
+        particleUniforms.rotateWithEntity = _particleProperties.rotateWithEntity ? 1 : 0;
     });
     // Update particle uniforms
     memcpy(&_uniformBuffer.edit<ParticleUniforms>(), &particleUniforms, sizeof(ParticleUniforms));
@@ -176,7 +185,7 @@ ParticleEffectEntityRenderer::CpuParticle ParticleEffectEntityRenderer::createPa
     const auto& azimuthFinish = particleProperties.azimuth.finish;
     const auto& emitDimensions = particleProperties.emission.dimensions;
     const auto& emitAcceleration = particleProperties.emission.acceleration.target;
-    auto emitOrientation = particleProperties.emission.orientation;
+    auto emitOrientation = baseTransform.getRotation() * particleProperties.emission.orientation;
     const auto& emitRadiusStart = glm::max(particleProperties.radiusStart, EPSILON); // Avoid math complications at center
     const auto& emitSpeed = particleProperties.emission.speed.target;
     const auto& speedSpread = particleProperties.emission.speed.spread;
@@ -185,10 +194,9 @@ ParticleEffectEntityRenderer::CpuParticle ParticleEffectEntityRenderer::createPa
 
     particle.seed = randFloatInRange(-1.0f, 1.0f);
     particle.expiration = now + (uint64_t)(particleProperties.lifespan * USECS_PER_SECOND);
-    if (particleProperties.emission.shouldTrail) {
-        particle.position = baseTransform.getTranslation();
-        emitOrientation = baseTransform.getRotation() * emitOrientation;
-    }
+
+    particle.relativePosition = glm::vec3(0.0f);
+    particle.basePosition = baseTransform.getTranslation();
 
     // Position, velocity, and acceleration
     if (polarStart == 0.0f && polarFinish == 0.0f && emitDimensions.z == 0.0f) {
@@ -237,7 +245,7 @@ ParticleEffectEntityRenderer::CpuParticle ParticleEffectEntityRenderer::createPa
                 radii.y > 0.0f ? y / (radii.y * radii.y) : 0.0f,
                 radii.z > 0.0f ? z / (radii.z * radii.z) : 0.0f
             ));
-            particle.position += emitOrientation * emitPosition;
+            particle.relativePosition += emitOrientation * emitPosition;
         }
 
         particle.velocity = (emitSpeed + randFloatInRange(-1.0f, 1.0f) * speedSpread) * (emitOrientation * emitDirection);
@@ -262,8 +270,8 @@ void ParticleEffectEntityRenderer::stepSimulation() {
         particleProperties = _particleProperties;
     });
 
+    const auto& modelTransform = getModelTransform();
     if (_emitting && particleProperties.emitting()) {
-        const auto& modelTransform = getModelTransform();
         uint64_t emitInterval = particleProperties.emitIntervalUsecs();
         if (emitInterval > 0 && interval >= _timeUntilNextEmit) {
             auto timeRemaining = interval;
@@ -288,15 +296,23 @@ void ParticleEffectEntityRenderer::stepSimulation() {
     const float deltaTime = (float)interval / (float)USECS_PER_SECOND;
     // update the particles 
     for (auto& particle : _cpuParticles) {
+        if (_prevEmitterShouldTrail != particleProperties.emission.shouldTrail) {
+            if (_prevEmitterShouldTrail) {
+                particle.relativePosition = particle.relativePosition + particle.basePosition - modelTransform.getTranslation();
+            }
+            particle.basePosition = modelTransform.getTranslation();
+        }
         particle.integrate(deltaTime);
     }
+    _prevEmitterShouldTrail = particleProperties.emission.shouldTrail;
 
     // Build particle primitives
     static GpuParticles gpuParticles;
     gpuParticles.clear();
     gpuParticles.reserve(_cpuParticles.size()); // Reserve space
-    std::transform(_cpuParticles.begin(), _cpuParticles.end(), std::back_inserter(gpuParticles), [](const CpuParticle& particle) {
-        return GpuParticle(particle.position, glm::vec2(particle.lifetime, particle.seed));
+    std::transform(_cpuParticles.begin(), _cpuParticles.end(), std::back_inserter(gpuParticles), [&particleProperties, &modelTransform](const CpuParticle& particle) {
+        glm::vec3 position = particle.relativePosition + (particleProperties.emission.shouldTrail ? particle.basePosition : modelTransform.getTranslation());
+        return GpuParticle(position, glm::vec2(particle.lifetime, particle.seed));
     });
 
     // Update particle buffer
@@ -324,15 +340,11 @@ void ParticleEffectEntityRenderer::doRender(RenderArgs* args) {
     }
 
     Transform transform; 
-    // In trail mode, the particles are created in world space.
-    // so we only set a transform if they're not in trail mode
-    if (!_particleProperties.emission.shouldTrail) {
-
-        withReadLock([&] {
-            transform = _renderTransform;
-        });
-        transform.setScale(vec3(1));
-    }
+    // The particles are in world space, so the transform is unused, except for the rotation, which we use
+    // if the particles are marked rotateWithEntity
+    withReadLock([&] {
+        transform.setRotation(_renderTransform.getRotation());
+    });
     batch.setModelTransform(transform);
     batch.setUniformBuffer(PARTICLE_UNIFORM_SLOT, _uniformBuffer);
     batch.setInputFormat(_vertexFormat);
@@ -341,5 +353,3 @@ void ParticleEffectEntityRenderer::doRender(RenderArgs* args) {
     auto numParticles = _particleBuffer->getSize() / sizeof(GpuParticle);
     batch.drawInstanced((gpu::uint32)numParticles, gpu::TRIANGLE_STRIP, (gpu::uint32)VERTEX_PER_PARTICLE);
 }
-
-
diff --git a/libraries/entities-renderer/src/RenderableParticleEffectEntityItem.h b/libraries/entities-renderer/src/RenderableParticleEffectEntityItem.h
index 8e9353894a..7655918c58 100644
--- a/libraries/entities-renderer/src/RenderableParticleEffectEntityItem.h
+++ b/libraries/entities-renderer/src/RenderableParticleEffectEntityItem.h
@@ -49,13 +49,14 @@ private:
         float seed { 0.0f };
         uint64_t expiration { 0 };
         float lifetime { 0.0f };
-        glm::vec3 position;
+        glm::vec3 basePosition;
+        glm::vec3 relativePosition;
         glm::vec3 velocity;
         glm::vec3 acceleration;
 
         void integrate(float deltaTime) {
             glm::vec3 atSquared = (0.5f * deltaTime * deltaTime) * acceleration;
-            position += velocity * deltaTime + atSquared;
+            relativePosition += velocity * deltaTime + atSquared;
             velocity += acceleration * deltaTime;
             lifetime += deltaTime;
         }
@@ -74,15 +75,18 @@ private:
     struct ParticleUniforms {
         InterpolationData<float> radius;
         InterpolationData<glm::vec4> color; // rgba
+        InterpolationData<float> spin;
         float lifespan;
-        glm::vec3 spare;
+        int rotateWithEntity;
+        glm::vec2 spare;
     };
 
-
     static CpuParticle createParticle(uint64_t now, const Transform& baseTransform, const particle::Properties& particleProperties);
     void stepSimulation();
 
     particle::Properties _particleProperties;
+    bool _prevEmitterShouldTrail;
+    bool _prevEmitterShouldTrailInitialized { false };
     CpuParticles _cpuParticles;
     bool _emitting { false };
     uint64_t _timeUntilNextEmit { 0 };
diff --git a/libraries/entities-renderer/src/RenderableWebEntityItem.cpp b/libraries/entities-renderer/src/RenderableWebEntityItem.cpp
index 793b4aa158..004a965c28 100644
--- a/libraries/entities-renderer/src/RenderableWebEntityItem.cpp
+++ b/libraries/entities-renderer/src/RenderableWebEntityItem.cpp
@@ -178,10 +178,6 @@ void WebEntityRenderer::doRenderUpdateSynchronousTyped(const ScenePointer& scene
 
 
     withWriteLock([&] {
-        if (_contentType == ContentType::NoContent) {
-            return;
-        }
-
         // This work must be done on the main thread
         // If we couldn't create a new web surface, exit
         if (!hasWebSurface() && !buildWebSurface(entity)) {
@@ -315,7 +311,13 @@ bool WebEntityRenderer::buildWebSurface(const TypedEntityPointer& entity) {
         });
     } else if (_contentType == ContentType::QmlContent) {
         _webSurface->load(_lastSourceUrl);
+    } else if (_contentType == ContentType::NoContent) {
+        // Show empty white panel
+        _webSurface->load("controls/WebEntityView.qml", [this](QQmlContext* context, QObject* item) {
+            item->setProperty(URL_PROPERTY, "");
+        });
     }
+
     _fadeStartTime = usecTimestampNow();
     _webSurface->resume();
 
diff --git a/libraries/entities-renderer/src/textured_particle.slv b/libraries/entities-renderer/src/textured_particle.slv
index 7653bc0a42..22254c0ab0 100644
--- a/libraries/entities-renderer/src/textured_particle.slv
+++ b/libraries/entities-renderer/src/textured_particle.slv
@@ -27,11 +27,20 @@ struct Colors {
     vec4 finish;
     vec4 spread;
 };
+struct Spin {
+    float start;
+    float middle;
+    float finish;
+    float spread;
+};
 
 struct ParticleUniforms {
     Radii radius;
     Colors color;
-    vec4 lifespan; // x is lifespan, 3 spare floats
+    Spin spin;
+    float lifespan;
+    int rotateWithEntity;
+    vec2 spare;
 };
 
 layout(std140) uniform particleBuffer {
@@ -44,15 +53,6 @@ layout(location=2) in vec2 inColor; // This is actual Lifetime + Seed
 out vec4 varColor;
 out vec2 varTexcoord;
 
-const int NUM_VERTICES_PER_PARTICLE = 4;
-// This ordering ensures that un-rotated particles render upright in the viewer.
-const vec4 UNIT_QUAD[NUM_VERTICES_PER_PARTICLE] = vec4[NUM_VERTICES_PER_PARTICLE](
-    vec4(-1.0, 1.0, 0.0, 0.0),
-    vec4(-1.0, -1.0, 0.0, 0.0),
-    vec4(1.0, 1.0, 0.0, 0.0),
-    vec4(1.0, -1.0, 0.0, 0.0)
-);
-
 float bezierInterpolate(float y1, float y2, float y3, float u) {
     // https://en.wikipedia.org/wiki/Bezier_curve
     return (1.0 - u) * (1.0 - u) * y1 + 2.0 * (1.0 - u) * u * y2 + u * u * y3;
@@ -103,6 +103,15 @@ vec4 interpolate3Vec4(vec4 y1, vec4 y2, vec4 y3, float u) {
                 interpolate3Points(y1.w, y2.w, y3.w, u));
 }
 
+const int NUM_VERTICES_PER_PARTICLE = 4;
+const vec2 TEX_COORDS[NUM_VERTICES_PER_PARTICLE] = vec2[NUM_VERTICES_PER_PARTICLE](
+    vec2(-1.0, 0.0),
+    vec2(-1.0, 1.0),
+    vec2(0.0, 0.0),
+    vec2(0.0, 1.0)
+);
+
+
 void main(void) {
     TransformCamera cam = getTransformCamera();
     TransformObject obj = getTransformObject();
@@ -113,28 +122,54 @@ void main(void) {
     int twoTriID = gl_VertexID - particleID * NUM_VERTICES_PER_PARTICLE;
 
     // Particle properties
-    float age = inColor.x / particle.lifespan.x;
+    float age = inColor.x / particle.lifespan;
     float seed = inColor.y;
 
-    // Pass the texcoord and the z texcoord is representing the texture icon
-    // Offset for corrected vertex ordering.
-    varTexcoord = vec2((UNIT_QUAD[twoTriID].xy -1.0) * vec2(0.5, -0.5)); 
+    // Pass the texcoord
+    varTexcoord = TEX_COORDS[twoTriID].xy;
     varColor = interpolate3Vec4(particle.color.start, particle.color.middle, particle.color.finish, age);
     vec3 colorSpread = 2.0 * vec3(hifi_hash(seed), hifi_hash(seed * 2.0), hifi_hash(seed * 3.0)) - 1.0;
     varColor.rgb = clamp(varColor.rgb + colorSpread * particle.color.spread.rgb, vec3(0), vec3(1));
     float alphaSpread = 2.0 * hifi_hash(seed * 4.0) - 1.0;
     varColor.a = clamp(varColor.a + alphaSpread * particle.color.spread.a, 0.0, 1.0);
 
+    float spin = interpolate3Points(particle.spin.start, particle.spin.middle, particle.spin.finish, age);
+    float spinSpread = 2.0 * hifi_hash(seed * 5.0) - 1.0;
+    spin = spin + spinSpread * particle.spin.spread;
+
     // anchor point in eye space
     float radius = interpolate3Points(particle.radius.start, particle.radius.middle, particle.radius.finish, age);
-    float radiusSpread = 2.0 * hifi_hash(seed * 5.0) - 1.0;
+    float radiusSpread = 2.0 * hifi_hash(seed * 6.0) - 1.0;
     radius = max(radius + radiusSpread * particle.radius.spread, 0.0);
-    vec4 quadPos = radius * UNIT_QUAD[twoTriID];
 
-    vec4 anchorPoint;
-    vec4 _inPosition = vec4(inPosition, 1.0);
-    <$transformModelToEyePos(cam, obj, _inPosition, anchorPoint)$>
+    // inPosition is in world space
+    vec4 anchorPoint = cam._view * vec4(inPosition, 1.0);
 
-    vec4 eyePos = anchorPoint + quadPos;
+    mat3 view3 = mat3(cam._view);
+    vec3 UP = vec3(0, 1, 0);
+    vec3 modelUpWorld;
+    <$transformModelToWorldDir(cam, obj, UP, modelUpWorld)$>
+    vec3 upWorld = mix(UP, normalize(modelUpWorld), particle.rotateWithEntity);
+    vec3 upEye = normalize(view3 * upWorld);
+    vec3 FORWARD = vec3(0, 0, -1);
+    vec3 particleRight = normalize(cross(FORWARD, upEye));
+    vec3 particleUp = cross(particleRight, FORWARD);     // don't need to normalize
+    // This ordering ensures that un-rotated particles render upright in the viewer.
+    vec3 UNIT_QUAD[NUM_VERTICES_PER_PARTICLE] = vec3[NUM_VERTICES_PER_PARTICLE](
+        normalize(-particleRight + particleUp),
+        normalize(-particleRight - particleUp),
+        normalize(particleRight + particleUp),
+        normalize(particleRight - particleUp)
+    );
+    float c = cos(spin);
+    float s = sin(spin);
+    mat4 rotation = mat4(
+        c, -s, 0, 0,
+        s, c, 0, 0,
+        0, 0, 1, 0,
+        0, 0, 0, 1
+    );
+    vec4 quadPos = radius * vec4(UNIT_QUAD[twoTriID], 0.0);
+    vec4 eyePos = anchorPoint + rotation * quadPos;
     <$transformEyeToClipPos(cam, eyePos, gl_Position)$>
 }
diff --git a/libraries/entities/src/EntityItem.h b/libraries/entities/src/EntityItem.h
index 3a11fd821a..81cb18dee4 100644
--- a/libraries/entities/src/EntityItem.h
+++ b/libraries/entities/src/EntityItem.h
@@ -378,8 +378,6 @@ public:
     /// return preferred shape type (actual physical shape may differ)
     virtual ShapeType getShapeType() const { return SHAPE_TYPE_NONE; }
 
-    virtual void setCollisionShape(const btCollisionShape* shape) {}
-
     void setPosition(const glm::vec3& value);
     virtual void setParentID(const QUuid& parentID) override;
     virtual void setShapeType(ShapeType type) { /* do nothing */ }
diff --git a/libraries/entities/src/EntityItemProperties.cpp b/libraries/entities/src/EntityItemProperties.cpp
index efd2376677..2d0fcd0496 100644
--- a/libraries/entities/src/EntityItemProperties.cpp
+++ b/libraries/entities/src/EntityItemProperties.cpp
@@ -369,6 +369,11 @@ EntityPropertyFlags EntityItemProperties::getChangedProperties() const {
     CHECK_PROPERTY_CHANGE(PROP_MATERIAL_MAPPING_ROT, materialMappingRot);
     CHECK_PROPERTY_CHANGE(PROP_MATERIAL_DATA, materialData);
     CHECK_PROPERTY_CHANGE(PROP_VISIBLE_IN_SECONDARY_CAMERA, isVisibleInSecondaryCamera);
+    CHECK_PROPERTY_CHANGE(PROP_PARTICLE_SPIN, particleSpin);
+    CHECK_PROPERTY_CHANGE(PROP_SPIN_SPREAD, spinSpread);
+    CHECK_PROPERTY_CHANGE(PROP_SPIN_START, spinStart);
+    CHECK_PROPERTY_CHANGE(PROP_SPIN_FINISH, spinFinish);
+    CHECK_PROPERTY_CHANGE(PROP_PARTICLE_ROTATE_WITH_ENTITY, rotateWithEntity);
 
     // Certifiable Properties
     CHECK_PROPERTY_CHANGE(PROP_ITEM_NAME, itemName);
@@ -908,6 +913,15 @@ EntityPropertyFlags EntityItemProperties::getChangedProperties() const {
  *     <code>alpha</code> value is used.
  * @property {number} alphaSpread=0 - The spread in alpha that each particle is given. If <code>alpha == 0.5</code>
  *     and <code>alphaSpread == 0.25</code>, each particle will have an alpha in the range <code>0.25</code> &ndash; <code>0.75</code>.
+ * @property {number} particleSpin=0 - The spin of each particle at the middle of its life. In the range <code>-2*PI</code> &ndash; <code>2*PI</code>.
+ * @property {number} spinStart=NaN - The spin of each particle at the start of its life. In the range <code>-2*PI</code> &ndash; <code>2*PI</code>.
+ *     If <code>NaN</code>, the <code>particleSpin</code> value is used.
+ * @property {number} spinFinish=NaN - The spin of each particle at the end of its life. In the range <code>-2*PI</code> &ndash; <code>2*PI</code>.
+ *     If <code>NaN</code>, the <code>particleSpin</code> value is used.
+ * @property {number} spinSpread=0 - The spread in spin that each particle is given. In the range <code>0</code> &ndash; <code>2*PI</code>.  If <code>particleSpin == PI</code>
+ *     and <code>spinSpread == PI/2</code>, each particle will have a spin in the range <code>PI/2</code> &ndash; <code>3*PI/2</code>.
+ * @property {boolean} rotateWithEntity=false - Whether or not the particles' spin will rotate with the entity.  If false, when <code>particleSpin == 0</code>, the particles will point
+ * up in the world.  If true, they will point towards the entity's up vector, based on its orientation.
  *
  * @property {ShapeType} shapeType="none" - <em>Currently not used.</em> <em>Read-only.</em>
  *
@@ -1291,6 +1305,11 @@ QScriptValue EntityItemProperties::copyToScriptValue(QScriptEngine* engine, bool
         COPY_PROPERTY_TO_QSCRIPTVALUE(PROP_ALPHA_START, alphaStart);
         COPY_PROPERTY_TO_QSCRIPTVALUE(PROP_ALPHA_FINISH, alphaFinish);
         COPY_PROPERTY_TO_QSCRIPTVALUE(PROP_EMITTER_SHOULD_TRAIL, emitterShouldTrail);
+        COPY_PROPERTY_TO_QSCRIPTVALUE(PROP_PARTICLE_SPIN, particleSpin);
+        COPY_PROPERTY_TO_QSCRIPTVALUE(PROP_SPIN_SPREAD, spinSpread);
+        COPY_PROPERTY_TO_QSCRIPTVALUE(PROP_SPIN_START, spinStart);
+        COPY_PROPERTY_TO_QSCRIPTVALUE(PROP_SPIN_FINISH, spinFinish);
+        COPY_PROPERTY_TO_QSCRIPTVALUE(PROP_PARTICLE_ROTATE_WITH_ENTITY, rotateWithEntity);
     }
 
     // Models only
@@ -1583,6 +1602,11 @@ void EntityItemProperties::copyFromScriptValue(const QScriptValue& object, bool
     COPY_PROPERTY_FROM_QSCRIPTVALUE(materialMappingRot, float, setMaterialMappingRot);
     COPY_PROPERTY_FROM_QSCRIPTVALUE(materialData, QString, setMaterialData);
     COPY_PROPERTY_FROM_QSCRIPTVALUE(isVisibleInSecondaryCamera, bool, setIsVisibleInSecondaryCamera);
+    COPY_PROPERTY_FROM_QSCRIPTVALUE(particleSpin, float, setParticleSpin);
+    COPY_PROPERTY_FROM_QSCRIPTVALUE(spinSpread, float, setSpinSpread);
+    COPY_PROPERTY_FROM_QSCRIPTVALUE(spinStart, float, setSpinStart);
+    COPY_PROPERTY_FROM_QSCRIPTVALUE(spinFinish, float, setSpinFinish);
+    COPY_PROPERTY_FROM_QSCRIPTVALUE(rotateWithEntity, bool, setRotateWithEntity);
 
     // Certifiable Properties
     COPY_PROPERTY_FROM_QSCRIPTVALUE(itemName, QString, setItemName);
@@ -1751,6 +1775,11 @@ void EntityItemProperties::merge(const EntityItemProperties& other) {
     COPY_PROPERTY_IF_CHANGED(radiusSpread);
     COPY_PROPERTY_IF_CHANGED(radiusStart);
     COPY_PROPERTY_IF_CHANGED(radiusFinish);
+    COPY_PROPERTY_IF_CHANGED(particleSpin);
+    COPY_PROPERTY_IF_CHANGED(spinSpread);
+    COPY_PROPERTY_IF_CHANGED(spinStart);
+    COPY_PROPERTY_IF_CHANGED(spinFinish);
+    COPY_PROPERTY_IF_CHANGED(rotateWithEntity);
 
     // Certifiable Properties
     COPY_PROPERTY_IF_CHANGED(itemName);
@@ -1964,6 +1993,12 @@ void EntityItemProperties::entityPropertyFlagsFromScriptValue(const QScriptValue
 
         ADD_PROPERTY_TO_MAP(PROP_VISIBLE_IN_SECONDARY_CAMERA, IsVisibleInSecondaryCamera, isVisibleInSecondaryCamera, bool);
 
+        ADD_PROPERTY_TO_MAP(PROP_PARTICLE_SPIN, ParticleSpin, particleSpin, float);
+        ADD_PROPERTY_TO_MAP(PROP_SPIN_SPREAD, SpinSpread, spinSpread, float);
+        ADD_PROPERTY_TO_MAP(PROP_SPIN_START, SpinStart, spinStart, float);
+        ADD_PROPERTY_TO_MAP(PROP_SPIN_FINISH, SpinFinish, spinFinish, float);
+        ADD_PROPERTY_TO_MAP(PROP_PARTICLE_ROTATE_WITH_ENTITY, RotateWithEntity, rotateWithEntity, float);
+
         // Certifiable Properties
         ADD_PROPERTY_TO_MAP(PROP_ITEM_NAME, ItemName, itemName, QString);
         ADD_PROPERTY_TO_MAP(PROP_ITEM_DESCRIPTION, ItemDescription, itemDescription, QString);
@@ -2292,6 +2327,11 @@ OctreeElement::AppendState EntityItemProperties::encodeEntityEditPacket(PacketTy
                 APPEND_ENTITY_PROPERTY(PROP_ALPHA_START, properties.getAlphaStart());
                 APPEND_ENTITY_PROPERTY(PROP_ALPHA_FINISH, properties.getAlphaFinish());
                 APPEND_ENTITY_PROPERTY(PROP_EMITTER_SHOULD_TRAIL, properties.getEmitterShouldTrail());
+                APPEND_ENTITY_PROPERTY(PROP_PARTICLE_SPIN, properties.getParticleSpin());
+                APPEND_ENTITY_PROPERTY(PROP_SPIN_SPREAD, properties.getSpinSpread());
+                APPEND_ENTITY_PROPERTY(PROP_SPIN_START, properties.getSpinStart());
+                APPEND_ENTITY_PROPERTY(PROP_SPIN_FINISH, properties.getSpinFinish());
+                APPEND_ENTITY_PROPERTY(PROP_PARTICLE_ROTATE_WITH_ENTITY, properties.getRotateWithEntity())
             }
 
             if (properties.getType() == EntityTypes::Zone) {
@@ -2667,6 +2707,11 @@ bool EntityItemProperties::decodeEntityEditPacket(const unsigned char* data, int
         READ_ENTITY_PROPERTY_TO_PROPERTIES(PROP_ALPHA_START, float, setAlphaStart);
         READ_ENTITY_PROPERTY_TO_PROPERTIES(PROP_ALPHA_FINISH, float, setAlphaFinish);
         READ_ENTITY_PROPERTY_TO_PROPERTIES(PROP_EMITTER_SHOULD_TRAIL, bool, setEmitterShouldTrail);
+        READ_ENTITY_PROPERTY_TO_PROPERTIES(PROP_PARTICLE_SPIN, float, setParticleSpin);
+        READ_ENTITY_PROPERTY_TO_PROPERTIES(PROP_SPIN_SPREAD, float, setSpinSpread);
+        READ_ENTITY_PROPERTY_TO_PROPERTIES(PROP_SPIN_START, float, setSpinStart);
+        READ_ENTITY_PROPERTY_TO_PROPERTIES(PROP_SPIN_FINISH, float, setSpinFinish);
+        READ_ENTITY_PROPERTY_TO_PROPERTIES(PROP_PARTICLE_ROTATE_WITH_ENTITY, bool, setRotateWithEntity);
     }
 
     if (properties.getType() == EntityTypes::Zone) {
@@ -2936,7 +2981,7 @@ void EntityItemProperties::markAllChanged() {
     _shapeTypeChanged = true;
 
     _isEmittingChanged = true;
-    _emitterShouldTrail = true;
+    _emitterShouldTrailChanged = true;
     _maxParticlesChanged = true;
     _lifespanChanged = true;
     _emitRateChanged = true;
@@ -2961,6 +3006,11 @@ void EntityItemProperties::markAllChanged() {
     _colorFinishChanged = true;
     _alphaStartChanged = true;
     _alphaFinishChanged = true;
+    _particleSpinChanged = true;
+    _spinStartChanged = true;
+    _spinFinishChanged = true;
+    _spinSpreadChanged = true;
+    _rotateWithEntityChanged = true;
 
     _materialURLChanged = true;
     _materialMappingModeChanged = true;
@@ -3309,6 +3359,21 @@ QList<QString> EntityItemProperties::listChangedProperties() {
     if (radiusFinishChanged()) {
         out += "radiusFinish";
     }
+    if (particleSpinChanged()) {
+        out += "particleSpin";
+    }
+    if (spinSpreadChanged()) {
+        out += "spinSpread";
+    }
+    if (spinStartChanged()) {
+        out += "spinStart";
+    }
+    if (spinFinishChanged()) {
+        out += "spinFinish";
+    }
+    if (rotateWithEntityChanged()) {
+        out += "rotateWithEntity";
+    }
     if (materialURLChanged()) {
         out += "materialURL";
     }
diff --git a/libraries/entities/src/EntityItemProperties.h b/libraries/entities/src/EntityItemProperties.h
index 93b8c991d5..04e54c54a5 100644
--- a/libraries/entities/src/EntityItemProperties.h
+++ b/libraries/entities/src/EntityItemProperties.h
@@ -235,6 +235,12 @@ public:
 
     DEFINE_PROPERTY(PROP_VISIBLE_IN_SECONDARY_CAMERA, IsVisibleInSecondaryCamera, isVisibleInSecondaryCamera, bool, ENTITY_ITEM_DEFAULT_VISIBLE_IN_SECONDARY_CAMERA);
 
+    DEFINE_PROPERTY(PROP_PARTICLE_SPIN, ParticleSpin, particleSpin, float, particle::DEFAULT_PARTICLE_SPIN);
+    DEFINE_PROPERTY(PROP_SPIN_SPREAD, SpinSpread, spinSpread, float, particle::DEFAULT_SPIN_SPREAD);
+    DEFINE_PROPERTY(PROP_SPIN_START, SpinStart, spinStart, float, particle::DEFAULT_SPIN_START);
+    DEFINE_PROPERTY(PROP_SPIN_FINISH, SpinFinish, spinFinish, float, particle::DEFAULT_SPIN_FINISH);
+    DEFINE_PROPERTY(PROP_PARTICLE_ROTATE_WITH_ENTITY, RotateWithEntity, rotateWithEntity, bool, particle::DEFAULT_ROTATE_WITH_ENTITY);
+
     // Certifiable Properties - related to Proof of Purchase certificates
     DEFINE_PROPERTY_REF(PROP_ITEM_NAME, ItemName, itemName, QString, ENTITY_ITEM_DEFAULT_ITEM_NAME);
     DEFINE_PROPERTY_REF(PROP_ITEM_DESCRIPTION, ItemDescription, itemDescription, QString, ENTITY_ITEM_DEFAULT_ITEM_DESCRIPTION);
diff --git a/libraries/entities/src/EntityPropertyFlags.h b/libraries/entities/src/EntityPropertyFlags.h
index d43a991f22..156c5d9dd4 100644
--- a/libraries/entities/src/EntityPropertyFlags.h
+++ b/libraries/entities/src/EntityPropertyFlags.h
@@ -251,6 +251,12 @@ enum EntityPropertyList {
 
     PROP_VISIBLE_IN_SECONDARY_CAMERA, // not sent over the wire, only used locally
 
+    PROP_PARTICLE_SPIN,
+    PROP_SPIN_START,
+    PROP_SPIN_FINISH,
+    PROP_SPIN_SPREAD,
+    PROP_PARTICLE_ROTATE_WITH_ENTITY,
+
     ////////////////////////////////////////////////////////////////////////////////////////////////////
     // ATTENTION: add new properties to end of list just ABOVE this line
     PROP_AFTER_LAST_ITEM,
diff --git a/libraries/entities/src/ParticleEffectEntityItem.cpp b/libraries/entities/src/ParticleEffectEntityItem.cpp
index 18cf7c9252..238f41b05f 100644
--- a/libraries/entities/src/ParticleEffectEntityItem.cpp
+++ b/libraries/entities/src/ParticleEffectEntityItem.cpp
@@ -91,6 +91,8 @@ bool operator==(const Properties& a, const Properties& b) {
         (a.color == b.color) &&
         (a.alpha == b.alpha) &&
         (a.radius == b.radius) &&
+        (a.spin == b.spin) &&
+        (a.rotateWithEntity == b.rotateWithEntity) &&
         (a.radiusStart == b.radiusStart) &&
         (a.lifespan == b.lifespan) &&
         (a.maxParticles == b.maxParticles) &&
@@ -130,7 +132,11 @@ bool Properties::valid() const {
         (radius.gradient.target == glm::clamp(radius.gradient.target, MINIMUM_PARTICLE_RADIUS, MAXIMUM_PARTICLE_RADIUS)) &&
         (radius.range.start == glm::clamp(radius.range.start, MINIMUM_PARTICLE_RADIUS, MAXIMUM_PARTICLE_RADIUS)) &&
         (radius.range.finish == glm::clamp(radius.range.finish, MINIMUM_PARTICLE_RADIUS, MAXIMUM_PARTICLE_RADIUS)) &&
-        (radius.gradient.spread == glm::clamp(radius.gradient.spread, MINIMUM_PARTICLE_RADIUS, MAXIMUM_PARTICLE_RADIUS));
+        (radius.gradient.spread == glm::clamp(radius.gradient.spread, MINIMUM_PARTICLE_RADIUS, MAXIMUM_PARTICLE_RADIUS)) &&
+        (spin.gradient.target == glm::clamp(spin.gradient.target, MINIMUM_PARTICLE_SPIN, MAXIMUM_PARTICLE_SPIN)) &&
+        (spin.range.start == glm::clamp(spin.range.start, MINIMUM_PARTICLE_SPIN, MAXIMUM_PARTICLE_SPIN)) &&
+        (spin.range.finish == glm::clamp(spin.range.finish, MINIMUM_PARTICLE_SPIN, MAXIMUM_PARTICLE_SPIN)) &&
+        (spin.gradient.spread == glm::clamp(spin.gradient.spread, MINIMUM_PARTICLE_SPIN, MAXIMUM_PARTICLE_SPIN));
 }
 
 bool Properties::emitting() const {
@@ -332,6 +338,43 @@ void ParticleEffectEntityItem::setRadiusSpread(float radiusSpread) {
     }
 }
 
+void ParticleEffectEntityItem::setParticleSpin(float particleSpin) {
+    particleSpin = glm::clamp(particleSpin, MINIMUM_PARTICLE_SPIN, MAXIMUM_PARTICLE_SPIN);
+    if (particleSpin != _particleProperties.spin.gradient.target) {
+        withWriteLock([&] {
+            _particleProperties.spin.gradient.target = particleSpin;
+        });
+    }
+}
+
+void ParticleEffectEntityItem::setSpinStart(float spinStart) {
+    spinStart =
+        glm::isnan(spinStart) ? spinStart : glm::clamp(spinStart, MINIMUM_PARTICLE_SPIN, MAXIMUM_PARTICLE_SPIN);
+    if (spinStart != _particleProperties.spin.range.start) {
+        withWriteLock([&] {
+            _particleProperties.spin.range.start = spinStart;
+        });
+    }
+}
+
+void ParticleEffectEntityItem::setSpinFinish(float spinFinish) {
+    spinFinish =
+        glm::isnan(spinFinish) ? spinFinish : glm::clamp(spinFinish, MINIMUM_PARTICLE_SPIN, MAXIMUM_PARTICLE_SPIN);
+    if (spinFinish != _particleProperties.spin.range.finish) {
+        withWriteLock([&] {
+            _particleProperties.spin.range.finish = spinFinish;
+        });
+    }
+}
+
+void ParticleEffectEntityItem::setSpinSpread(float spinSpread) {
+    spinSpread = glm::clamp(spinSpread, MINIMUM_PARTICLE_SPIN, MAXIMUM_PARTICLE_SPIN);
+    if (spinSpread != _particleProperties.spin.gradient.spread) {
+        withWriteLock([&] {
+            _particleProperties.spin.gradient.spread = spinSpread;
+        });
+    }
+}
 
 void ParticleEffectEntityItem::computeAndUpdateDimensions() {
     particle::Properties particleProperties;
@@ -398,6 +441,11 @@ EntityItemProperties ParticleEffectEntityItem::getProperties(EntityPropertyFlags
     COPY_ENTITY_PROPERTY_TO_PROPERTIES(alphaFinish, getAlphaFinish);
     COPY_ENTITY_PROPERTY_TO_PROPERTIES(textures, getTextures);
     COPY_ENTITY_PROPERTY_TO_PROPERTIES(emitterShouldTrail, getEmitterShouldTrail);
+    COPY_ENTITY_PROPERTY_TO_PROPERTIES(particleSpin, getParticleSpin);
+    COPY_ENTITY_PROPERTY_TO_PROPERTIES(spinSpread, getSpinSpread);
+    COPY_ENTITY_PROPERTY_TO_PROPERTIES(spinStart, getSpinStart);
+    COPY_ENTITY_PROPERTY_TO_PROPERTIES(spinFinish, getSpinFinish);
+    COPY_ENTITY_PROPERTY_TO_PROPERTIES(rotateWithEntity, getRotateWithEntity);
 
     return properties;
 }
@@ -435,6 +483,11 @@ bool ParticleEffectEntityItem::setProperties(const EntityItemProperties& propert
     SET_ENTITY_PROPERTY_FROM_PROPERTIES(alphaFinish, setAlphaFinish);
     SET_ENTITY_PROPERTY_FROM_PROPERTIES(textures, setTextures);
     SET_ENTITY_PROPERTY_FROM_PROPERTIES(emitterShouldTrail, setEmitterShouldTrail);
+    SET_ENTITY_PROPERTY_FROM_PROPERTIES(particleSpin, setParticleSpin);
+    SET_ENTITY_PROPERTY_FROM_PROPERTIES(spinSpread, setSpinSpread);
+    SET_ENTITY_PROPERTY_FROM_PROPERTIES(spinStart, setSpinStart);
+    SET_ENTITY_PROPERTY_FROM_PROPERTIES(spinFinish, setSpinFinish);
+    SET_ENTITY_PROPERTY_FROM_PROPERTIES(rotateWithEntity, setRotateWithEntity);
 
     if (somethingChanged) {
         bool wantDebug = false;
@@ -515,6 +568,12 @@ int ParticleEffectEntityItem::readEntitySubclassDataFromBuffer(const unsigned ch
 
     READ_ENTITY_PROPERTY(PROP_EMITTER_SHOULD_TRAIL, bool, setEmitterShouldTrail);
 
+    READ_ENTITY_PROPERTY(PROP_PARTICLE_SPIN, float, setParticleSpin);
+    READ_ENTITY_PROPERTY(PROP_SPIN_SPREAD, float, setSpinSpread);
+    READ_ENTITY_PROPERTY(PROP_SPIN_START, float, setSpinStart);
+    READ_ENTITY_PROPERTY(PROP_SPIN_FINISH, float, setSpinFinish);
+    READ_ENTITY_PROPERTY(PROP_PARTICLE_ROTATE_WITH_ENTITY, bool, setRotateWithEntity);
+
     return bytesRead;
 }
 
@@ -551,6 +610,11 @@ EntityPropertyFlags ParticleEffectEntityItem::getEntityProperties(EncodeBitstrea
     requestedProperties += PROP_AZIMUTH_START;
     requestedProperties += PROP_AZIMUTH_FINISH;
     requestedProperties += PROP_EMITTER_SHOULD_TRAIL;
+    requestedProperties += PROP_PARTICLE_SPIN;
+    requestedProperties += PROP_SPIN_SPREAD;
+    requestedProperties += PROP_SPIN_START;
+    requestedProperties += PROP_SPIN_FINISH;
+    requestedProperties += PROP_PARTICLE_ROTATE_WITH_ENTITY;
 
     return requestedProperties;
 }
@@ -594,6 +658,11 @@ void ParticleEffectEntityItem::appendSubclassData(OctreePacketData* packetData,
     APPEND_ENTITY_PROPERTY(PROP_AZIMUTH_START, getAzimuthStart());
     APPEND_ENTITY_PROPERTY(PROP_AZIMUTH_FINISH, getAzimuthFinish());
     APPEND_ENTITY_PROPERTY(PROP_EMITTER_SHOULD_TRAIL, getEmitterShouldTrail());
+    APPEND_ENTITY_PROPERTY(PROP_PARTICLE_SPIN, getParticleSpin());
+    APPEND_ENTITY_PROPERTY(PROP_SPIN_SPREAD, getSpinSpread());
+    APPEND_ENTITY_PROPERTY(PROP_SPIN_START, getSpinStart());
+    APPEND_ENTITY_PROPERTY(PROP_SPIN_FINISH, getSpinFinish());
+    APPEND_ENTITY_PROPERTY(PROP_PARTICLE_ROTATE_WITH_ENTITY, getRotateWithEntity());
 }
 
 
@@ -665,6 +734,12 @@ void ParticleEffectEntityItem::setEmitterShouldTrail(bool emitterShouldTrail) {
     });
 }
 
+void ParticleEffectEntityItem::setRotateWithEntity(bool rotateWithEntity) {
+    withWriteLock([&] {
+        _particleProperties.rotateWithEntity = rotateWithEntity;
+    });
+}
+
 particle::Properties ParticleEffectEntityItem::getParticleProperties() const {
     particle::Properties result;  
     withReadLock([&] {
@@ -689,6 +764,12 @@ particle::Properties ParticleEffectEntityItem::getParticleProperties() const {
         if (glm::isnan(result.radius.range.finish)) {
             result.radius.range.finish = getParticleRadius();
         }
+        if (glm::isnan(result.spin.range.start)) {
+            result.spin.range.start = getParticleSpin();
+        }
+        if (glm::isnan(result.spin.range.finish)) {
+            result.spin.range.finish = getParticleSpin();
+        }
     });
 
     if (!result.valid()) {
diff --git a/libraries/entities/src/ParticleEffectEntityItem.h b/libraries/entities/src/ParticleEffectEntityItem.h
index 7e507ab46a..480b78ffcc 100644
--- a/libraries/entities/src/ParticleEffectEntityItem.h
+++ b/libraries/entities/src/ParticleEffectEntityItem.h
@@ -39,7 +39,7 @@ namespace particle {
     static const float MINIMUM_EMIT_RATE = 0.0f;
     static const float MAXIMUM_EMIT_RATE = 100000.0f;
     static const float DEFAULT_EMIT_SPEED = 5.0f;
-    static const float MINIMUM_EMIT_SPEED = 0.0f;
+    static const float MINIMUM_EMIT_SPEED = -1000.0f;
     static const float MAXIMUM_EMIT_SPEED = 1000.0f;  // Approx mach 3
     static const float DEFAULT_SPEED_SPREAD = 1.0f;
     static const glm::quat DEFAULT_EMIT_ORIENTATION = glm::angleAxis(-PI_OVER_TWO, Vectors::UNIT_X);  // Vertical
@@ -69,8 +69,15 @@ namespace particle {
     static const float DEFAULT_RADIUS_SPREAD = 0.0f;
     static const float DEFAULT_RADIUS_START = UNINITIALIZED;
     static const float DEFAULT_RADIUS_FINISH = UNINITIALIZED;
+    static const float DEFAULT_PARTICLE_SPIN = 0.0f;
+    static const float DEFAULT_SPIN_START = UNINITIALIZED;
+    static const float DEFAULT_SPIN_FINISH = UNINITIALIZED;
+    static const float DEFAULT_SPIN_SPREAD = 0.0f;
+    static const float MINIMUM_PARTICLE_SPIN = -2.0f * SCRIPT_MAXIMUM_PI;
+    static const float MAXIMUM_PARTICLE_SPIN = 2.0f * SCRIPT_MAXIMUM_PI;
     static const QString DEFAULT_TEXTURES = "";
     static const bool DEFAULT_EMITTER_SHOULD_TRAIL = false;
+    static const bool DEFAULT_ROTATE_WITH_ENTITY = false;
 
     template <typename T>
     struct Range {
@@ -151,6 +158,8 @@ namespace particle {
         RangeGradient<float> alpha { DEFAULT_ALPHA, DEFAULT_ALPHA_START, DEFAULT_ALPHA_FINISH, DEFAULT_ALPHA_SPREAD };
         float radiusStart { DEFAULT_EMIT_RADIUS_START };
         RangeGradient<float> radius { DEFAULT_PARTICLE_RADIUS, DEFAULT_RADIUS_START, DEFAULT_RADIUS_FINISH, DEFAULT_RADIUS_SPREAD };
+        RangeGradient<float> spin { DEFAULT_PARTICLE_SPIN, DEFAULT_SPIN_START, DEFAULT_SPIN_FINISH, DEFAULT_SPIN_SPREAD };
+        bool rotateWithEntity { DEFAULT_ROTATE_WITH_ENTITY };
         float lifespan { DEFAULT_LIFESPAN };
         uint32_t maxParticles { DEFAULT_MAX_PARTICLES };
         EmitProperties emission;
@@ -168,6 +177,8 @@ namespace particle {
         Properties& operator =(const Properties& other) {
             color = other.color;
             alpha = other.alpha;
+            spin = other.spin;
+            rotateWithEntity = other.rotateWithEntity;
             radius = other.radius;
             lifespan = other.lifespan;
             maxParticles = other.maxParticles;
@@ -306,6 +317,21 @@ public:
     void setRadiusSpread(float radiusSpread);
     float getRadiusSpread() const { return _particleProperties.radius.gradient.spread; }
 
+    void setParticleSpin(float particleSpin);
+    float getParticleSpin() const { return _particleProperties.spin.gradient.target; }
+
+    void setSpinStart(float spinStart);
+    float getSpinStart() const { return _particleProperties.spin.range.start; }
+
+    void setSpinFinish(float spinFinish);
+    float getSpinFinish() const { return _particleProperties.spin.range.finish; }
+
+    void setSpinSpread(float spinSpread);
+    float getSpinSpread() const { return _particleProperties.spin.gradient.spread; }
+
+    void setRotateWithEntity(bool rotateWithEntity);
+    bool getRotateWithEntity() const { return _particleProperties.rotateWithEntity; }
+
     void computeAndUpdateDimensions();
 
     void setTextures(const QString& textures);
diff --git a/libraries/gpu/src/gpu/Transform.slh b/libraries/gpu/src/gpu/Transform.slh
index 50c0bc13ed..864a106350 100644
--- a/libraries/gpu/src/gpu/Transform.slh
+++ b/libraries/gpu/src/gpu/Transform.slh
@@ -238,7 +238,7 @@ TransformObject getTransformObject() {
 <@endfunc@>
 
 <@func transformModelToWorldDir(cameraTransform, objectTransform, modelDir, worldDir)@>
-    { // transformModelToEyeDir		
+    { // transformModelToWorldDir
         vec3 mr0 = <$objectTransform$>._modelInverse[0].xyz;
         vec3 mr1 = <$objectTransform$>._modelInverse[1].xyz;
         vec3 mr2 = <$objectTransform$>._modelInverse[2].xyz;
diff --git a/libraries/networking/src/udt/PacketHeaders.cpp b/libraries/networking/src/udt/PacketHeaders.cpp
index 13ffcb5120..d0bd7fc872 100644
--- a/libraries/networking/src/udt/PacketHeaders.cpp
+++ b/libraries/networking/src/udt/PacketHeaders.cpp
@@ -33,7 +33,7 @@ PacketVersion versionForPacketType(PacketType packetType) {
         case PacketType::EntityEdit:
         case PacketType::EntityData:
         case PacketType::EntityPhysics:
-            return static_cast<PacketVersion>(EntityVersion::ParticleEntityFix);
+            return static_cast<PacketVersion>(EntityVersion::ParticleSpin);
         case PacketType::EntityQuery:
             return static_cast<PacketVersion>(EntityQueryPacketVersion::ConicalFrustums);
         case PacketType::AvatarIdentity:
diff --git a/libraries/networking/src/udt/PacketHeaders.h b/libraries/networking/src/udt/PacketHeaders.h
index 6e1aca83e5..2ffadfef4b 100644
--- a/libraries/networking/src/udt/PacketHeaders.h
+++ b/libraries/networking/src/udt/PacketHeaders.h
@@ -238,7 +238,8 @@ enum class EntityVersion : PacketVersion {
     CloneableData,
     CollisionMask16Bytes,
     YieldSimulationOwnership,
-    ParticleEntityFix
+    ParticleEntityFix,
+    ParticleSpin
 };
 
 enum class EntityScriptCallMethodVersion : PacketVersion {
diff --git a/libraries/physics/src/CollisionRenderMeshCache.cpp b/libraries/physics/src/CollisionRenderMeshCache.cpp
deleted file mode 100644
index 6f66b9af10..0000000000
--- a/libraries/physics/src/CollisionRenderMeshCache.cpp
+++ /dev/null
@@ -1,217 +0,0 @@
-//
-//  CollisionRenderMeshCache.cpp
-//  libraries/physics/src
-//
-//  Created by Andrew Meadows 2016.07.13
-//  Copyright 2016 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
-//
-
-#include "CollisionRenderMeshCache.h"
-
-#include <cassert>
-
-#include <btBulletDynamicsCommon.h>
-#include <BulletCollision/CollisionShapes/btShapeHull.h>
-
-#include <ShapeInfo.h> // for MAX_HULL_POINTS
-
-const int32_t MAX_HULL_INDICES = 6 * MAX_HULL_POINTS;
-const int32_t MAX_HULL_NORMALS = MAX_HULL_INDICES;
-float tempVertices[MAX_HULL_NORMALS];
-graphics::Index tempIndexBuffer[MAX_HULL_INDICES];
-
-bool copyShapeToMesh(const btTransform& transform, const btConvexShape* shape,
-        gpu::BufferView& vertices, gpu::BufferView& indices, gpu::BufferView& parts,
-        gpu::BufferView& normals) {
-    assert(shape);
-
-    btShapeHull hull(shape);
-    if (!hull.buildHull(shape->getMargin())) {
-        return false;
-    }
-
-    int32_t numHullIndices = hull.numIndices();
-    assert(numHullIndices <= MAX_HULL_INDICES);
-
-    int32_t numHullVertices = hull.numVertices();
-    assert(numHullVertices <= MAX_HULL_POINTS);
-
-    { // new part
-        graphics::Mesh::Part part;
-        part._startIndex = (graphics::Index)indices.getNumElements();
-        part._numIndices = (graphics::Index)numHullIndices;
-        // FIXME: the render code cannot handle the case where part._baseVertex != 0
-        //part._baseVertex = vertices.getNumElements(); // DOES NOT WORK
-        part._baseVertex = 0;
-
-        gpu::BufferView::Size numBytes = sizeof(graphics::Mesh::Part);
-        const gpu::Byte* data = reinterpret_cast<const gpu::Byte*>(&part);
-        parts._buffer->append(numBytes, data);
-        parts._size = parts._buffer->getSize();
-    }
-
-    const int32_t SIZE_OF_VEC3 = 3 * sizeof(float);
-    graphics::Index indexOffset = (graphics::Index)vertices.getNumElements();
-
-    { // new indices
-        const uint32_t* hullIndices = hull.getIndexPointer();
-        // FIXME: the render code cannot handle the case where part._baseVertex != 0
-        // so we must add an offset to each index
-        for (int32_t i = 0; i < numHullIndices; ++i) {
-            tempIndexBuffer[i] = hullIndices[i] + indexOffset;
-        }
-        const gpu::Byte* data = reinterpret_cast<const gpu::Byte*>(tempIndexBuffer);
-        gpu::BufferView::Size numBytes = (gpu::BufferView::Size)(sizeof(graphics::Index) * numHullIndices);
-        indices._buffer->append(numBytes, data);
-        indices._size = indices._buffer->getSize();
-    }
-    { // new vertices
-        const btVector3* hullVertices = hull.getVertexPointer();
-        assert(numHullVertices <= MAX_HULL_POINTS);
-        for (int32_t i = 0; i < numHullVertices; ++i) {
-            btVector3 transformedPoint = transform * hullVertices[i];
-            memcpy(tempVertices + 3 * i, transformedPoint.m_floats, SIZE_OF_VEC3);
-        }
-        gpu::BufferView::Size numBytes = sizeof(float) * (3 * numHullVertices);
-        const gpu::Byte* data = reinterpret_cast<const gpu::Byte*>(tempVertices);
-        vertices._buffer->append(numBytes, data);
-        vertices._size = vertices._buffer->getSize();
-    }
-    { // new normals
-        // compute average point
-        btVector3 avgVertex(0.0f, 0.0f, 0.0f);
-        const btVector3* hullVertices = hull.getVertexPointer();
-        for (int i = 0; i < numHullVertices; ++i) {
-            avgVertex += hullVertices[i];
-        }
-        avgVertex = transform * (avgVertex * (1.0f / (float)numHullVertices));
-
-        for (int i = 0; i < numHullVertices; ++i) {
-            btVector3 norm = transform * hullVertices[i] - avgVertex;
-            btScalar normLength = norm.length();
-            if (normLength > FLT_EPSILON) {
-                norm /= normLength;
-            }
-            memcpy(tempVertices + 3 * i, norm.m_floats, SIZE_OF_VEC3);
-        }
-        gpu::BufferView::Size numBytes = sizeof(float) * (3 * numHullVertices);
-        const gpu::Byte* data = reinterpret_cast<const gpu::Byte*>(tempVertices);
-        normals._buffer->append(numBytes, data);
-        normals._size = vertices._buffer->getSize();
-    }
-    return true;
-}
-
-graphics::MeshPointer createMeshFromShape(const void* pointer) {
-    graphics::MeshPointer mesh;
-    if (!pointer) {
-        return mesh;
-    }
-
-    // pointer must be a const btCollisionShape* (cast to void*), but it only
-    // needs to be valid here when its render mesh is created, after this call
-    // the cache doesn't care what happens to the shape behind the pointer
-    const btCollisionShape* shape = static_cast<const btCollisionShape*>(pointer);
-
-    int32_t shapeType = shape->getShapeType();
-    if (shapeType == (int32_t)COMPOUND_SHAPE_PROXYTYPE || shape->isConvex()) {
-        // allocate buffers for it
-        gpu::BufferView vertices(new gpu::Buffer(), gpu::Element(gpu::VEC3, gpu::FLOAT, gpu::XYZ));
-        gpu::BufferView indices(new gpu::Buffer(), gpu::Element(gpu::SCALAR, gpu::UINT32, gpu::INDEX));
-        gpu::BufferView parts(new gpu::Buffer(), gpu::Element(gpu::VEC4, gpu::UINT32, gpu::PART));
-        gpu::BufferView normals(new gpu::Buffer(), gpu::Element(gpu::VEC3, gpu::FLOAT, gpu::XYZ));
-
-        int32_t numSuccesses = 0;
-        if (shapeType == (int32_t)COMPOUND_SHAPE_PROXYTYPE) {
-            const btCompoundShape* compoundShape = static_cast<const btCompoundShape*>(shape);
-            int32_t numSubShapes = compoundShape->getNumChildShapes();
-            for (int32_t i = 0; i < numSubShapes; ++i) {
-                const btCollisionShape* childShape = compoundShape->getChildShape(i);
-                if (childShape->isConvex()) {
-                    const btConvexShape* convexShape = static_cast<const btConvexShape*>(childShape);
-                    if (copyShapeToMesh(compoundShape->getChildTransform(i), convexShape, vertices, indices, parts, normals)) {
-                        numSuccesses++;
-                    }
-                }
-            }
-        } else {
-            // shape is convex
-            const btConvexShape* convexShape = static_cast<const btConvexShape*>(shape);
-            btTransform transform;
-            transform.setIdentity();
-            if (copyShapeToMesh(transform, convexShape, vertices, indices, parts, normals)) {
-                numSuccesses++;
-            }
-        }
-        if (numSuccesses > 0) {
-            mesh = std::make_shared<graphics::Mesh>();
-            mesh->setVertexBuffer(vertices);
-            mesh->setIndexBuffer(indices);
-            mesh->setPartBuffer(parts);
-            mesh->addAttribute(gpu::Stream::NORMAL, normals);
-        } else {
-            // TODO: log failure message here
-        }
-    }
-    return mesh;
-}
-
-CollisionRenderMeshCache::CollisionRenderMeshCache() {
-}
-
-CollisionRenderMeshCache::~CollisionRenderMeshCache() {
-    _meshMap.clear();
-    _pendingGarbage.clear();
-}
-
-graphics::MeshPointer CollisionRenderMeshCache::getMesh(CollisionRenderMeshCache::Key key) {
-    graphics::MeshPointer mesh;
-    if (key) {
-        CollisionMeshMap::const_iterator itr = _meshMap.find(key);
-        if (itr == _meshMap.end()) {
-            // make mesh and add it to map
-            mesh = createMeshFromShape(key);
-            if (mesh) {
-                _meshMap.insert(std::make_pair(key, mesh));
-            }
-        } else {
-            mesh = itr->second;
-        }
-    }
-    const uint32_t MAX_NUM_PENDING_GARBAGE = 20;
-    if (_pendingGarbage.size() > MAX_NUM_PENDING_GARBAGE) {
-        collectGarbage();
-    }
-    return mesh;
-}
-
-bool CollisionRenderMeshCache::releaseMesh(CollisionRenderMeshCache::Key key) {
-    if (!key) {
-        return false;
-    }
-    CollisionMeshMap::const_iterator itr = _meshMap.find(key);
-    if (itr != _meshMap.end()) {
-        _pendingGarbage.push_back(key);
-        return true;
-    }
-    return false;
-}
-
-void CollisionRenderMeshCache::collectGarbage() {
-    uint32_t numShapes = (uint32_t)_pendingGarbage.size();
-    for (uint32_t i = 0; i < numShapes; ++i) {
-        CollisionRenderMeshCache::Key key = _pendingGarbage[i];
-        CollisionMeshMap::const_iterator itr = _meshMap.find(key);
-        if (itr != _meshMap.end()) {
-            if ((*itr).second.use_count() == 1) {
-                // we hold the only reference
-                _meshMap.erase(itr);
-            }
-        }
-    }
-    _pendingGarbage.clear();
-}
-
diff --git a/libraries/physics/src/CollisionRenderMeshCache.h b/libraries/physics/src/CollisionRenderMeshCache.h
deleted file mode 100644
index c5b643c0cc..0000000000
--- a/libraries/physics/src/CollisionRenderMeshCache.h
+++ /dev/null
@@ -1,48 +0,0 @@
-//
-//  CollisionRenderMeshCache.h
-//  libraries/physics/src
-//
-//  Created by Andrew Meadows 2016.07.13
-//  Copyright 2016 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
-//
-
-#ifndef hifi_CollisionRenderMeshCache_h
-#define hifi_CollisionRenderMeshCache_h
-
-#include <memory>
-#include <vector>
-#include <unordered_map>
-
-#include <graphics/Geometry.h>
-
-
-class CollisionRenderMeshCache {
-public:
-    using Key = const void*; // must actually be a const btCollisionShape*
-
-    CollisionRenderMeshCache();
-    ~CollisionRenderMeshCache();
-
-    /// \return pointer to geometry
-    graphics::MeshPointer getMesh(Key key);
-
-    /// \return true if geometry was found and released
-    bool releaseMesh(Key key);
-
-    /// delete geometries that have zero references
-    void collectGarbage();
-
-    // validation methods
-    uint32_t getNumMeshes() const { return (uint32_t)_meshMap.size(); }
-    bool hasMesh(Key key) const { return _meshMap.find(key) == _meshMap.end(); }
-
-private:
-    using CollisionMeshMap = std::unordered_map<Key, graphics::MeshPointer>;
-    CollisionMeshMap _meshMap;
-    std::vector<Key> _pendingGarbage;
-};
-
-#endif // hifi_CollisionRenderMeshCache_h
diff --git a/libraries/physics/src/EntityMotionState.cpp b/libraries/physics/src/EntityMotionState.cpp
index a610a6f2a6..925cfee740 100644
--- a/libraries/physics/src/EntityMotionState.cpp
+++ b/libraries/physics/src/EntityMotionState.cpp
@@ -307,13 +307,6 @@ const btCollisionShape* EntityMotionState::computeNewShape() {
     return getShapeManager()->getShape(shapeInfo);
 }
 
-void EntityMotionState::setShape(const btCollisionShape* shape) {
-    if (_shape != shape) {
-        ObjectMotionState::setShape(shape);
-        _entity->setCollisionShape(_shape);
-    }
-}
-
 bool EntityMotionState::remoteSimulationOutOfSync(uint32_t simulationStep) {
     // NOTE: this method is only ever called when the entity simulation is locally owned
     DETAILED_PROFILE_RANGE(simulation_physics, "CheckOutOfSync");
diff --git a/libraries/physics/src/EntityMotionState.h b/libraries/physics/src/EntityMotionState.h
index b215537d55..653e3f4252 100644
--- a/libraries/physics/src/EntityMotionState.h
+++ b/libraries/physics/src/EntityMotionState.h
@@ -118,7 +118,6 @@ protected:
 
     bool isReadyToComputeShape() const override;
     const btCollisionShape* computeNewShape() override;
-    void setShape(const btCollisionShape* shape) override;
     void setMotionType(PhysicsMotionType motionType) override;
 
     // EntityMotionState keeps a SharedPointer to its EntityItem which is only set in the CTOR
diff --git a/libraries/physics/src/ObjectMotionState.cpp b/libraries/physics/src/ObjectMotionState.cpp
index 0e6eb2511d..310cf7cec1 100644
--- a/libraries/physics/src/ObjectMotionState.cpp
+++ b/libraries/physics/src/ObjectMotionState.cpp
@@ -155,26 +155,25 @@ void ObjectMotionState::setMotionType(PhysicsMotionType motionType) {
 // Update the Continuous Collision Detection (CCD) configuration settings of our RigidBody so that
 // CCD will be enabled automatically when its speed surpasses a certain threshold.
 void ObjectMotionState::updateCCDConfiguration() {
-    if (_body) {
-        if (_shape) {
-            // If this object moves faster than its bounding radius * RADIUS_MOTION_THRESHOLD_MULTIPLIER,
-            // CCD will be enabled for this object.
-            const auto RADIUS_MOTION_THRESHOLD_MULTIPLIER = 0.5f;
+    assert(_body);
+    if (_shape && _shape->getShapeType() != TRIANGLE_MESH_SHAPE_PROXYTYPE) {
+        // find minumum dimension of shape
+        btVector3 aabbMin, aabbMax;
+        btTransform transform;
+        transform.setIdentity();
+        _shape->getAabb(transform, aabbMin, aabbMax);
+        aabbMin = aabbMax - aabbMin;
+        btScalar radius = *((btScalar*)(aabbMin) + aabbMin.minAxis());
 
-            btVector3 center;
-            btScalar radius;
-            _shape->getBoundingSphere(center, radius);
-            _body->setCcdMotionThreshold(radius * RADIUS_MOTION_THRESHOLD_MULTIPLIER);
+        // use the minimum dimension as the radius of the CCD proxy sphere
+        _body->setCcdSweptSphereRadius(radius);
 
-            // TODO: Ideally the swept sphere radius would be contained by the object. Using the bounding sphere
-            // radius works well for spherical objects, but may cause issues with other shapes. For arbitrary
-            // objects we may want to consider a different approach, such as grouping rigid bodies together.
-
-            _body->setCcdSweptSphereRadius(radius);
-        } else {
-            // Disable CCD
-            _body->setCcdMotionThreshold(0);
-        }
+        // also use the radius as the motion threshold for enabling CCD
+        _body->setCcdMotionThreshold(radius);
+    } else {
+        // disable CCD
+        _body->setCcdSweptSphereRadius(0.0f);
+        _body->setCcdMotionThreshold(0.0f);
     }
 }
 
@@ -188,8 +187,8 @@ void ObjectMotionState::setRigidBody(btRigidBody* body) {
         if (_body) {
             _body->setUserPointer(this);
             assert(_body->getCollisionShape() == _shape);
+            updateCCDConfiguration();
         }
-        updateCCDConfiguration();
     }
 }
 
@@ -199,6 +198,9 @@ void ObjectMotionState::setShape(const btCollisionShape* shape) {
             getShapeManager()->releaseShape(_shape);
         }
         _shape = shape;
+        if (_body) {
+            updateCCDConfiguration();
+        }
     }
 }
 
@@ -312,7 +314,6 @@ bool ObjectMotionState::handleHardAndEasyChanges(uint32_t& flags, PhysicsEngine*
         } else {
             _body->setCollisionShape(const_cast<btCollisionShape*>(newShape));
             setShape(newShape);
-            updateCCDConfiguration();
         }
     }
     if (flags & EASY_DIRTY_PHYSICS_FLAGS) {
diff --git a/libraries/script-engine/src/RecordingScriptingInterface.cpp b/libraries/script-engine/src/RecordingScriptingInterface.cpp
index 55895e31a4..cc2edfcca7 100644
--- a/libraries/script-engine/src/RecordingScriptingInterface.cpp
+++ b/libraries/script-engine/src/RecordingScriptingInterface.cpp
@@ -59,7 +59,7 @@ void RecordingScriptingInterface::playClip(NetworkClipLoaderPointer clipLoader,
 
     if (callback.isFunction()) {
         QScriptValueList args { true, url };
-        callback.call(_scriptEngine->globalObject(), args);
+        callback.call(QScriptValue(), args);
     }
 }
 
@@ -78,7 +78,7 @@ void RecordingScriptingInterface::loadRecording(const QString& url, QScriptValue
     auto weakClipLoader = clipLoader.toWeakRef();
 
     // when clip loaded, call the callback with the URL and success boolean
-    connect(clipLoader.data(), &recording::NetworkClipLoader::clipLoaded, this,
+    connect(clipLoader.data(), &recording::NetworkClipLoader::clipLoaded, callback.engine(),
             [this, weakClipLoader, url, callback]() mutable {
 
         if (auto clipLoader = weakClipLoader.toStrongRef()) {
@@ -92,12 +92,12 @@ void RecordingScriptingInterface::loadRecording(const QString& url, QScriptValue
     });
 
     // when clip load fails, call the callback with the URL and failure boolean
-    connect(clipLoader.data(), &recording::NetworkClipLoader::failed, this, [this, weakClipLoader, url, callback](QNetworkReply::NetworkError error) mutable {
+    connect(clipLoader.data(), &recording::NetworkClipLoader::failed, callback.engine(), [this, weakClipLoader, url, callback](QNetworkReply::NetworkError error) mutable {
         qCDebug(scriptengine) << "Failed to load recording from" << url;
 
         if (callback.isFunction()) {
             QScriptValueList args { false, url };
-            callback.call(_scriptEngine->currentContext()->thisObject(), args);
+            callback.call(QScriptValue(), args);
         }
 
         if (auto clipLoader = weakClipLoader.toStrongRef()) {
diff --git a/libraries/script-engine/src/RecordingScriptingInterface.h b/libraries/script-engine/src/RecordingScriptingInterface.h
index 29d9b31049..c4d576351f 100644
--- a/libraries/script-engine/src/RecordingScriptingInterface.h
+++ b/libraries/script-engine/src/RecordingScriptingInterface.h
@@ -36,8 +36,6 @@ class RecordingScriptingInterface : public QObject, public Dependency {
 public:
     RecordingScriptingInterface();
 
-    void setScriptEngine(QSharedPointer<BaseScriptEngine> scriptEngine) { _scriptEngine = scriptEngine; }
-
 public slots:
 
     /**jsdoc
@@ -246,7 +244,6 @@ protected:
     Flag _useSkeletonModel { false };
     recording::ClipPointer _lastClip;
 
-    QSharedPointer<BaseScriptEngine> _scriptEngine;
     QSet<recording::NetworkClipLoaderPointer> _clipLoaders;
 
 private:
diff --git a/libraries/shared/src/AvatarConstants.h b/libraries/shared/src/AvatarConstants.h
index 3dc344dc6f..d9b26927e2 100644
--- a/libraries/shared/src/AvatarConstants.h
+++ b/libraries/shared/src/AvatarConstants.h
@@ -23,10 +23,10 @@ const float DEFAULT_AVATAR_EYE_HEIGHT = DEFAULT_AVATAR_HEIGHT - DEFAULT_AVATAR_E
 const float DEFAULT_AVATAR_SUPPORT_BASE_LEFT  = -0.25f;
 const float DEFAULT_AVATAR_SUPPORT_BASE_RIGHT =  0.25f;
 const float DEFAULT_AVATAR_SUPPORT_BASE_FRONT = -0.20f;
-const float DEFAULT_AVATAR_SUPPORT_BASE_BACK  =  0.10f;
+const float DEFAULT_AVATAR_SUPPORT_BASE_BACK  =  0.12f;
 const float DEFAULT_AVATAR_LATERAL_STEPPING_THRESHOLD = 0.10f;
 const float DEFAULT_AVATAR_ANTERIOR_STEPPING_THRESHOLD = 0.04f;
-const float DEFAULT_AVATAR_POSTERIOR_STEPPING_THRESHOLD = 0.07f;
+const float DEFAULT_AVATAR_POSTERIOR_STEPPING_THRESHOLD = 0.05f;
 const float DEFAULT_AVATAR_HEAD_ANGULAR_VELOCITY_STEPPING_THRESHOLD = 0.3f;
 const float DEFAULT_AVATAR_MODE_HEIGHT_STEPPING_THRESHOLD = -0.02f;
 const float DEFAULT_HANDS_VELOCITY_DIRECTION_STEPPING_THRESHOLD = 0.4f;
diff --git a/scripts/system/controllers/controllerModules/teleport.js b/scripts/system/controllers/controllerModules/teleport.js
index 3bf99ca26a..6564c91d8a 100644
--- a/scripts/system/controllers/controllerModules/teleport.js
+++ b/scripts/system/controllers/controllerModules/teleport.js
@@ -325,7 +325,7 @@ Script.include("/~/system/libraries/controllers.js");
             } else if (target === TARGET.SURFACE) {
                 var offset = getAvatarFootOffset();
                 result.intersection.y += offset;
-                MyAvatar.goToLocation(result.intersection, false, {x: 0, y: 0, z: 0, w: 1}, false);
+                MyAvatar.goToLocation(result.intersection, true, HMD.orientation, false);
                 HMD.centerUI();
                 MyAvatar.centerBody();
             }
diff --git a/scripts/system/edit.js b/scripts/system/edit.js
index 1c0b7c2dcb..4b8abff84b 100644
--- a/scripts/system/edit.js
+++ b/scripts/system/edit.js
@@ -392,6 +392,8 @@ var toolBar = (function () {
         entityListTool.sendUpdate();
         selectionManager.setSelections([entityID]);
 
+        Window.setFocus();
+
         return entityID;
     }
 
diff --git a/scripts/system/particle_explorer/particleExplorer.js b/scripts/system/particle_explorer/particleExplorer.js
index cb2c2f3374..f1b7c8600f 100644
--- a/scripts/system/particle_explorer/particleExplorer.js
+++ b/scripts/system/particle_explorer/particleExplorer.js
@@ -361,6 +361,55 @@
                     type: "Row"
                 }
             ],
+            Spin: [
+                {
+                    id: "particleSpin",
+                    name: "Particle Spin",
+                    type: "SliderRadian",
+                    min: -360.0,
+                    max: 360.0
+                },
+                {
+                    type: "Row"
+                },
+                {
+                    id: "spinSpread",
+                    name: "Spin Spread",
+                    type: "SliderRadian",
+                    max: 360.0
+                },
+                {
+                    type: "Row"
+                },
+                {
+                    id: "spinStart",
+                    name: "Spin Start",
+                    type: "SliderRadian",
+                    min: -360.0,
+                    max: 360.0
+                },
+                {
+                    type: "Row"
+                },
+                {
+                    id: "spinFinish",
+                    name: "Spin Finish",
+                    type: "SliderRadian",
+                    min: -360.0,
+                    max: 360.0
+                },
+                {
+                    type: "Row"
+                },
+                {
+                    id: "rotateWithEntity",
+                    name: "Rotate with Entity",
+                    type: "Boolean"
+                },
+                {
+                    type: "Row"
+                }
+            ],
             Polar: [
                 {
                     id: "polarStart",
diff --git a/scripts/system/particle_explorer/particleExplorerTool.js b/scripts/system/particle_explorer/particleExplorerTool.js
index 1914180ff9..a3be004329 100644
--- a/scripts/system/particle_explorer/particleExplorerTool.js
+++ b/scripts/system/particle_explorer/particleExplorerTool.js
@@ -75,6 +75,12 @@ ParticleExplorerTool = function(createToolsWindow) {
         if (isNaN(properties.colorFinish.red)) {
             properties.colorFinish = properties.color;
         }
+        if (isNaN(properties.spinStart)) {
+            properties.spinStart = properties.particleSpin;
+        }
+        if (isNaN(properties.spinFinish)) {
+            properties.spinFinish = properties.particleSpin;
+        }
         sendParticleProperties(properties);
     }
     
@@ -88,8 +94,8 @@ ParticleExplorerTool = function(createToolsWindow) {
         if (data.messageType === "settings_update") {
             var updatedSettings = data.updatedSettings;
 
-            var optionalProps = ["alphaStart", "alphaFinish", "radiusStart", "radiusFinish", "colorStart", "colorFinish"];
-            var fallbackProps = ["alpha", "particleRadius", "color"];
+            var optionalProps = ["alphaStart", "alphaFinish", "radiusStart", "radiusFinish", "colorStart", "colorFinish", "spinStart", "spinFinish"];
+            var fallbackProps = ["alpha", "particleRadius", "color", "particleSpin"];
             for (var i = 0; i < optionalProps.length; i++) {
                 var fallbackProp = fallbackProps[Math.floor(i / 2)];
                 var optionalValue = updatedSettings[optionalProps[i]];
diff --git a/tests/physics/src/CollisionRenderMeshCacheTests.cpp b/tests/physics/src/CollisionRenderMeshCacheTests.cpp
deleted file mode 100644
index da28598dda..0000000000
--- a/tests/physics/src/CollisionRenderMeshCacheTests.cpp
+++ /dev/null
@@ -1,277 +0,0 @@
-//
-//  CollisionRenderMeshCacheTests.cpp
-//  tests/physics/src
-//
-//  Created by Andrew Meadows on 2014.10.30
-//  Copyright 2014 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
-//
-
-#include "CollisionRenderMeshCacheTests.h"
-
-#include <iostream>
-#include <cstdlib>
-
-#include <btBulletDynamicsCommon.h>
-#include <BulletCollision/CollisionShapes/btShapeHull.h>
-
-#include <CollisionRenderMeshCache.h>
-#include <ShapeInfo.h> // for MAX_HULL_POINTS
-
-#include "MeshUtil.h"
-
-
-QTEST_MAIN(CollisionRenderMeshCacheTests)
-
-const float INV_SQRT_THREE = 0.577350269f;
-
-const uint32_t numSphereDirections = 6 + 8;
-btVector3 sphereDirections[] = {
-    btVector3(1.0f, 0.0f, 0.0f),
-    btVector3(-1.0f, 0.0f, 0.0f),
-    btVector3(0.0f, 1.0f, 0.0f),
-    btVector3(0.0f, -1.0f, 0.0f),
-    btVector3(0.0f, 0.0f, 1.0f),
-    btVector3(0.0f, 0.0f, -1.0f),
-    btVector3(INV_SQRT_THREE, INV_SQRT_THREE, INV_SQRT_THREE),
-    btVector3(INV_SQRT_THREE, INV_SQRT_THREE, -INV_SQRT_THREE),
-    btVector3(INV_SQRT_THREE, -INV_SQRT_THREE, INV_SQRT_THREE),
-    btVector3(INV_SQRT_THREE, -INV_SQRT_THREE, -INV_SQRT_THREE),
-    btVector3(-INV_SQRT_THREE, INV_SQRT_THREE, INV_SQRT_THREE),
-    btVector3(-INV_SQRT_THREE, INV_SQRT_THREE, -INV_SQRT_THREE),
-    btVector3(-INV_SQRT_THREE, -INV_SQRT_THREE, INV_SQRT_THREE),
-    btVector3(-INV_SQRT_THREE, -INV_SQRT_THREE, -INV_SQRT_THREE)
-};
-
-float randomFloat() {
-    return 2.0f * ((float)rand() / (float)RAND_MAX) - 1.0f;
-}
-
-btBoxShape* createBoxShape(const btVector3& extent) {
-    btBoxShape* shape = new btBoxShape(0.5f * extent);
-    return shape;
-}
-
-btConvexHullShape* createConvexHull(float radius) {
-    btConvexHullShape* hull = new btConvexHullShape();
-    for (uint32_t i = 0; i < numSphereDirections; ++i) {
-        btVector3 point = radius * sphereDirections[i];
-        hull->addPoint(point, false);
-    }
-    hull->recalcLocalAabb();
-    return hull;
-}
-
-void CollisionRenderMeshCacheTests::testShapeHullManifold() {
-    // make a box shape
-    btVector3 extent(1.0f, 2.0f, 3.0f);
-    btBoxShape* box = createBoxShape(extent);
-
-    // wrap it with a ShapeHull
-    btShapeHull hull(box);
-    const float MARGIN = 0.0f;
-    hull.buildHull(MARGIN);
-
-    // verify the vertex count is capped
-    uint32_t numVertices = (uint32_t)hull.numVertices();
-    QVERIFY(numVertices <= MAX_HULL_POINTS);
-
-    // verify the mesh is inside the radius
-    btVector3 halfExtents = box->getHalfExtentsWithMargin();
-    float ACCEPTABLE_EXTENTS_ERROR = 0.01f;
-    float maxRadius = halfExtents.length() + ACCEPTABLE_EXTENTS_ERROR;
-    const btVector3* meshVertices = hull.getVertexPointer();
-    for (uint32_t i = 0; i < numVertices; ++i) {
-        btVector3 vertex = meshVertices[i];
-        QVERIFY(vertex.length() <= maxRadius);
-    }
-
-    // verify the index count is capped
-    uint32_t numIndices = (uint32_t)hull.numIndices();
-    QVERIFY(numIndices < 6 * MAX_HULL_POINTS);
-
-    // verify the index count is a multiple of 3
-    QVERIFY(numIndices % 3 == 0);
-
-    // verify the mesh is closed
-    const uint32_t* meshIndices = hull.getIndexPointer();
-    bool isClosed = MeshUtil::isClosedManifold(meshIndices, numIndices);
-    QVERIFY(isClosed);
-
-    // verify the triangle normals are outward using right-hand-rule
-    const uint32_t INDICES_PER_TRIANGLE = 3;
-    for (uint32_t i = 0; i < numIndices; i += INDICES_PER_TRIANGLE) {
-        btVector3 A = meshVertices[meshIndices[i]];
-        btVector3 B = meshVertices[meshIndices[i+1]];
-        btVector3 C = meshVertices[meshIndices[i+2]];
-
-        btVector3 face = (B - A).cross(C - B);
-        btVector3 center = (A + B + C) / 3.0f;
-        QVERIFY(face.dot(center) > 0.0f);
-    }
-
-    // delete unmanaged memory
-    delete box;
-}
-
-void CollisionRenderMeshCacheTests::testCompoundShape() {
-    uint32_t numSubShapes = 3;
-
-    btVector3 centers[] = {
-        btVector3(1.0f, 0.0f, 0.0f),
-        btVector3(0.0f, -2.0f, 0.0f),
-        btVector3(0.0f, 0.0f, 3.0f),
-    };
-
-    float radii[] = { 3.0f, 2.0f, 1.0f };
-
-    btCompoundShape* compoundShape = new btCompoundShape();
-    for (uint32_t i = 0; i < numSubShapes; ++i) {
-        btTransform transform;
-        transform.setOrigin(centers[i]);
-        btConvexHullShape* hull = createConvexHull(radii[i]);
-        compoundShape->addChildShape(transform, hull);
-    }
-
-    // create the cache
-    CollisionRenderMeshCache cache;
-    QVERIFY(cache.getNumMeshes() == 0);
-
-    // get the mesh once
-    graphics::MeshPointer mesh = cache.getMesh(compoundShape);
-    QVERIFY((bool)mesh);
-    QVERIFY(cache.getNumMeshes() == 1);
-
-    // get the mesh again
-    graphics::MeshPointer mesh2 = cache.getMesh(compoundShape);
-    QVERIFY(mesh2 == mesh);
-    QVERIFY(cache.getNumMeshes() == 1);
-
-    // forget the mesh once
-    cache.releaseMesh(compoundShape);
-    mesh.reset();
-    QVERIFY(cache.getNumMeshes() == 1);
-
-    // collect garbage (should still cache mesh)
-    cache.collectGarbage();
-    QVERIFY(cache.getNumMeshes() == 1);
-
-    // forget the mesh a second time (should still cache mesh)
-    cache.releaseMesh(compoundShape);
-    mesh2.reset();
-    QVERIFY(cache.getNumMeshes() == 1);
-
-    // collect garbage (should no longer cache mesh)
-    cache.collectGarbage();
-    QVERIFY(cache.getNumMeshes() == 0);
-
-    // delete unmanaged memory
-    for (int i = 0; i < compoundShape->getNumChildShapes(); ++i) {
-        delete compoundShape->getChildShape(i);
-    }
-    delete compoundShape;
-}
-
-void CollisionRenderMeshCacheTests::testMultipleShapes() {
-    // shapeA is compound of hulls
-    uint32_t numSubShapes = 3;
-    btVector3 centers[] = {
-        btVector3(1.0f, 0.0f, 0.0f),
-        btVector3(0.0f, -2.0f, 0.0f),
-        btVector3(0.0f, 0.0f, 3.0f),
-    };
-    float radii[] = { 3.0f, 2.0f, 1.0f };
-    btCompoundShape* shapeA = new btCompoundShape();
-    for (uint32_t i = 0; i < numSubShapes; ++i) {
-        btTransform transform;
-        transform.setOrigin(centers[i]);
-        btConvexHullShape* hull = createConvexHull(radii[i]);
-        shapeA->addChildShape(transform, hull);
-    }
-
-    // shapeB is compound of boxes
-    btVector3 extents[] = {
-        btVector3(1.0f, 2.0f, 3.0f),
-        btVector3(2.0f, 3.0f, 1.0f),
-        btVector3(3.0f, 1.0f, 2.0f),
-    };
-    btCompoundShape* shapeB = new btCompoundShape();
-    for (uint32_t i = 0; i < numSubShapes; ++i) {
-        btTransform transform;
-        transform.setOrigin(centers[i]);
-        btBoxShape* box = createBoxShape(extents[i]);
-        shapeB->addChildShape(transform, box);
-    }
-
-    // shapeC is just a box
-    btVector3 extentC(7.0f, 3.0f, 5.0f);
-    btBoxShape* shapeC = createBoxShape(extentC);
-
-    // create the cache
-    CollisionRenderMeshCache cache;
-    QVERIFY(cache.getNumMeshes() == 0);
-
-    // get the meshes
-    graphics::MeshPointer meshA = cache.getMesh(shapeA);
-    graphics::MeshPointer meshB = cache.getMesh(shapeB);
-    graphics::MeshPointer meshC = cache.getMesh(shapeC);
-    QVERIFY((bool)meshA);
-    QVERIFY((bool)meshB);
-    QVERIFY((bool)meshC);
-    QVERIFY(cache.getNumMeshes() == 3);
-
-    // get the meshes again
-    graphics::MeshPointer meshA2 = cache.getMesh(shapeA);
-    graphics::MeshPointer meshB2 = cache.getMesh(shapeB);
-    graphics::MeshPointer meshC2 = cache.getMesh(shapeC);
-    QVERIFY(meshA == meshA2);
-    QVERIFY(meshB == meshB2);
-    QVERIFY(meshC == meshC2);
-    QVERIFY(cache.getNumMeshes() == 3);
-
-    // forget the meshes once
-    cache.releaseMesh(shapeA);
-    cache.releaseMesh(shapeB);
-    cache.releaseMesh(shapeC);
-    meshA2.reset();
-    meshB2.reset();
-    meshC2.reset();
-    QVERIFY(cache.getNumMeshes() == 3);
-
-    // collect garbage (should still cache mesh)
-    cache.collectGarbage();
-    QVERIFY(cache.getNumMeshes() == 3);
-
-    // forget again, one mesh at a time...
-    // shapeA...
-    cache.releaseMesh(shapeA);
-    meshA.reset();
-    QVERIFY(cache.getNumMeshes() == 3);
-    cache.collectGarbage();
-    QVERIFY(cache.getNumMeshes() == 2);
-    // shapeB...
-    cache.releaseMesh(shapeB);
-    meshB.reset();
-    QVERIFY(cache.getNumMeshes() == 2);
-    cache.collectGarbage();
-    QVERIFY(cache.getNumMeshes() == 1);
-    // shapeC...
-    cache.releaseMesh(shapeC);
-    meshC.reset();
-    QVERIFY(cache.getNumMeshes() == 1);
-    cache.collectGarbage();
-    QVERIFY(cache.getNumMeshes() == 0);
-
-    // delete unmanaged memory
-    for (int i = 0; i < shapeA->getNumChildShapes(); ++i) {
-        delete shapeA->getChildShape(i);
-    }
-    delete shapeA;
-    for (int i = 0; i < shapeB->getNumChildShapes(); ++i) {
-        delete shapeB->getChildShape(i);
-    }
-    delete shapeB;
-    delete shapeC;
-}
diff --git a/tests/physics/src/CollisionRenderMeshCacheTests.h b/tests/physics/src/CollisionRenderMeshCacheTests.h
deleted file mode 100644
index 640314a2a0..0000000000
--- a/tests/physics/src/CollisionRenderMeshCacheTests.h
+++ /dev/null
@@ -1,26 +0,0 @@
-//
-//  CollisionRenderMeshCacheTests.h
-//  tests/physics/src
-//
-//  Created by Andrew Meadows on 2014.10.30
-//  Copyright 2014 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
-//
-
-#ifndef hifi_CollisionRenderMeshCacheTests_h
-#define hifi_CollisionRenderMeshCacheTests_h
-
-#include <QtTest/QtTest>
-
-class CollisionRenderMeshCacheTests : public QObject {
-    Q_OBJECT
-
-private slots:
-    void testShapeHullManifold();
-    void testCompoundShape();
-    void testMultipleShapes();
-};
-
-#endif // hifi_CollisionRenderMeshCacheTests_h