diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index 4f1153b4f4..86ea351609 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -16,7 +16,7 @@ Contributing
   git checkout -b new_branch_name 
   ```
 4. Code
-  * Follow the [coding standard](http://docs.highfidelity.io/v1.0/docs/coding-standard)
+  * Follow the [coding standard](https://readme.highfidelity.com/v1.0/docs/coding-standard)
 5. Commit
   * Use [well formed commit messages](http://tbaggery.com/2008/04/19/a-note-about-git-commit-messages.html)
 6. Update your branch
diff --git a/examples/defaultScripts.js b/examples/defaultScripts.js
index 65c4fb315b..2c3ee65c92 100644
--- a/examples/defaultScripts.js
+++ b/examples/defaultScripts.js
@@ -11,7 +11,7 @@
 Script.load("away.js");
 Script.load("progress.js");
 Script.load("edit.js");
-Script.load("marketplace.js");
+Script.load("examples.js");
 Script.load("selectAudioDevice.js");
 Script.load("notifications.js");
 Script.load("users.js");
diff --git a/examples/marketplace.js b/examples/examples.js
similarity index 66%
rename from examples/marketplace.js
rename to examples/examples.js
index 146e55c496..bfa85473de 100644
--- a/examples/marketplace.js
+++ b/examples/examples.js
@@ -1,5 +1,5 @@
 //
-//  marketplace.js
+//  examples.js
 //  examples
 //
 //  Created by Eric Levin on 8 Jan 2016
@@ -16,9 +16,9 @@ Script.include([
 HIFI_PUBLIC_BUCKET = "http://s3.amazonaws.com/hifi-public/";
 var toolIconUrl = HIFI_PUBLIC_BUCKET + "images/tools/";
 
-var MARKETPLACE_URL = "https://metaverse.highfidelity.com/marketplace";
-var marketplaceWindow = new OverlayWebWindow({
-    title: 'Marketplace',
+var EXAMPLES_URL = "https://metaverse.highfidelity.com/examples";
+var examplesWindow = new OverlayWebWindow({
+    title: 'Examples',
     source: "about:blank",
     width: 900,
     height: 700,
@@ -29,43 +29,43 @@ var toolHeight = 50;
 var toolWidth = 50;
 
 
-function showMarketplace(marketplaceID) {
-    var url = MARKETPLACE_URL;
+function showExamples(marketplaceID) {
+    var url = EXAMPLES_URL;
     if (marketplaceID) {
         url = url + "/items/" + marketplaceID;
     }
-    print("setting marketplace URL to " + url);
-    marketplaceWindow.setURL(url);
-    marketplaceWindow.setVisible(true);
+    print("setting examples URL to " + url);
+    examplesWindow.setURL(url);
+    examplesWindow.setVisible(true);
 }
 
-function hideMarketplace() {
-    marketplaceWindow.setVisible(false);
-    marketplaceWindow.setURL("about:blank");
+function hideExamples() {
+    examplesWindow.setVisible(false);
+    examplesWindow.setURL("about:blank");
 }
 
-function toggleMarketplace() {
-    if (marketplaceWindow.visible) {
-        hideMarketplace();
+function toggleExamples() {
+    if (examplesWindow.visible) {
+        hideExamples();
     } else {
-        showMarketplace();
+        showExamples();
     }
 }
 
 var toolBar = (function() {
     var that = {},
         toolBar,
-        browseMarketplaceButton;
+        browseExamplesButton;
 
     function initialize() {
-        toolBar = new ToolBar(0, 0, ToolBar.VERTICAL, "highfidelity.marketplace.toolbar", function(windowDimensions, toolbar) {
+        toolBar = new ToolBar(0, 0, ToolBar.VERTICAL, "highfidelity.examples.toolbar", function(windowDimensions, toolbar) {
             return {
                 x: windowDimensions.x - 8 - toolbar.width,
                 y: 135
             };
         });
-        browseMarketplaceButton = toolBar.addTool({
-            imageURL: toolIconUrl + "market-01.svg",
+        browseExamplesButton = toolBar.addTool({
+            imageURL: toolIconUrl + "examples-01.svg",
             subImage: {
                 x: 0,
                 y: Tool.IMAGE_WIDTH,
@@ -79,10 +79,10 @@ var toolBar = (function() {
             showButtonDown: true
         });
 
-        toolBar.showTool(browseMarketplaceButton, true);
+        toolBar.showTool(browseExamplesButton, true);
     }
 
-    var browseMarketplaceButtonDown = false;
+    var browseExamplesButtonDown = false;
     that.mousePressEvent = function(event) {
         var clickedOverlay,
             url,
@@ -98,10 +98,8 @@ var toolBar = (function() {
             y: event.y
         });
 
-
-
-        if (browseMarketplaceButton === toolBar.clicked(clickedOverlay)) {
-            toggleMarketplace();
+        if (browseExamplesButton === toolBar.clicked(clickedOverlay)) {
+            toggleExamples();
             return true;
         }
 
@@ -112,7 +110,7 @@ var toolBar = (function() {
         var handled = false;
 
 
-        if (browseMarketplaceButtonDown) {
+        if (browseExamplesButtonDown) {
             var clickedOverlay = Overlays.getOverlayAtPoint({
                 x: event.x,
                 y: event.y
@@ -120,7 +118,7 @@ var toolBar = (function() {
         }
 
         newModelButtonDown = false;
-        browseMarketplaceButtonDown = false;
+        browseExamplesButtonDown = false;
 
         return handled;
     }
diff --git a/ice-server/src/IceServer.cpp b/ice-server/src/IceServer.cpp
index a512d5a049..c1e92f276f 100644
--- a/ice-server/src/IceServer.cpp
+++ b/ice-server/src/IceServer.cpp
@@ -62,8 +62,6 @@ bool IceServer::packetVersionMatch(const udt::Packet& packet) {
     if (headerVersion == versionForPacketType(headerType)) {
         return true;
     } else {
-        qDebug() << "Packet version mismatch for packet" << headerType << " from" << packet.getSenderSockAddr();
-        
         return false;
     }
 }
diff --git a/interface/resources/qml/controls/WebView.qml b/interface/resources/qml/controls/WebView.qml
index 1361e6e322..2f94740fe6 100644
--- a/interface/resources/qml/controls/WebView.qml
+++ b/interface/resources/qml/controls/WebView.qml
@@ -5,6 +5,8 @@ WebEngineView {
     id: root
     property var newUrl;
 
+    profile.httpUserAgent: "Mozilla/5.0 Chrome (HighFidelityInterface)"
+
     Component.onCompleted: {
         console.log("Connecting JS messaging to Hifi Logging")
         // Ensure the JS from the web-engine makes it to our logging
diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index 36410c8d09..0172b3ce3a 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -18,23 +18,12 @@
 #include <glm/gtx/vector_angle.hpp>
 #include <glm/gtc/type_ptr.hpp>
 
-#include <Qt>
-#include <QtCore/QDebug>
-#include <QtCore/QJsonDocument>
-#include <QtCore/QJsonObject>
-#include <QtCore/QObject>
-#include <QtCore/QUrl>
-#include <QtCore/QTimer>
 #include <QtCore/QAbstractNativeEventFilter>
 #include <QtCore/QMimeData>
 #include <QtCore/QThreadPool>
 
 #include <QtGui/QScreen>
-#include <QtGui/QImage>
-#include <QtGui/QWheelEvent>
 #include <QtGui/QWindow>
-#include <QtGui/QKeyEvent>
-#include <QtGui/QMouseEvent>
 #include <QtGui/QDesktopServices>
 
 #include <QtNetwork/QLocalSocket>
@@ -44,28 +33,18 @@
 #include <QtQml/QQmlEngine>
 #include <QtQuick/QQuickWindow>
 
-#include <QtWidgets/QActionGroup>
 #include <QtWidgets/QDesktopWidget>
-#include <QtWidgets/QFileDialog>
-#include <QtWidgets/QInputDialog>
-#include <QtWidgets/QMenuBar>
 #include <QtWidgets/QMessageBox>
 
 #include <QtMultimedia/QMediaPlayer>
 
-#include <QtNetwork/QNetworkDiskCache>
-
-#include <gl/Config.h>
 #include <gl/QOpenGLContextWrapper.h>
 
-#include <shared/JSONHelpers.h>
-
 #include <ResourceScriptingInterface.h>
 #include <AccountManager.h>
 #include <AddressManager.h>
 #include <BuildInfo.h>
 #include <AssetClient.h>
-#include <AssetUpload.h>
 #include <AutoUpdater.h>
 #include <AudioInjectorManager.h>
 #include <CursorManager.h>
@@ -110,12 +89,9 @@
 #include <ScriptCache.h>
 #include <SoundCache.h>
 #include <ScriptEngines.h>
-#include <TextureCache.h>
 #include <Tooltip.h>
 #include <udt/PacketHeaders.h>
 #include <UserActivityLogger.h>
-#include <UUID.h>
-#include <VrMenu.h>
 #include <recording/Deck.h>
 #include <recording/Recorder.h>
 #include <QmlWebWindowClass.h>
@@ -137,7 +113,6 @@
 #include "InterfaceActionFactory.h"
 #include "InterfaceLogging.h"
 #include "LODManager.h"
-#include "Menu.h"
 #include "ModelPackager.h"
 #include "PluginContainerProxy.h"
 #include "scripting/AccountScriptingInterface.h"
@@ -171,7 +146,7 @@
 
 
 
-// ON WIndows PC, NVidia Optimus laptop, we want to enable NVIDIA GPU
+// ON Windows PC, Nvidia Optimus laptop, we want to enable NVIDIA GPU
 // FIXME seems to be broken.
 #if defined(Q_OS_WIN)
 extern "C" {
@@ -254,14 +229,14 @@ public:
         });
     }
 
-    void updateHeartbeat() {
+    static void updateHeartbeat() {
         auto now = usecTimestampNow();
         auto elapsed = now - _heartbeat;
         _movingAverage.addSample(elapsed);
         _heartbeat = now;
     }
 
-    void deadlockDetectionCrash() {
+    static void deadlockDetectionCrash() {
         uint32_t* crashTrigger = nullptr;
         *crashTrigger = 0xDEAD10CC;
     }
@@ -390,7 +365,7 @@ public:
     LambdaEvent(std::function<void()> && fun) :
     QEvent(static_cast<QEvent::Type>(Lambda)), _fun(fun) {
     }
-    void call() { _fun(); }
+    void call() const { _fun(); }
 };
 
 void messageHandler(QtMsgType type, const QMessageLogContext& context, const QString& message) {
@@ -528,7 +503,7 @@ Application::Application(int& argc, char** argv, QElapsedTimer& startupTimer) :
     _maxOctreePPS(maxOctreePacketsPerSecond.get()),
     _lastFaceTrackerUpdate(0)
 {
-    // FIXME this may be excessivly conservative.  On the other hand
+    // FIXME this may be excessively conservative.  On the other hand
     // maybe I'm used to having an 8-core machine
     // Perhaps find the ideal thread count  and subtract 2 or 3
     // (main thread, present thread, random OS load)
@@ -1014,12 +989,12 @@ Application::Application(int& argc, char** argv, QElapsedTimer& startupTimer) :
     connect(applicationUpdater.data(), &AutoUpdater::newVersionIsAvailable, dialogsManager.data(), &DialogsManager::showUpdateDialog);
     applicationUpdater->checkForUpdate();
 
-    // Now that menu is initalized we can sync myAvatar with it's state.
+    // Now that menu is initialized we can sync myAvatar with it's state.
     getMyAvatar()->updateMotionBehaviorFromMenu();
 
 // FIXME spacemouse code still needs cleanup
 #if 0
-    // the 3Dconnexion device wants to be initiliazed after a window is displayed.
+    // the 3Dconnexion device wants to be initialized after a window is displayed.
     SpacemouseManager::getInstance().init();
 #endif
 
@@ -1124,7 +1099,7 @@ void Application::showCursor(const QCursor& cursor) {
     _cursorNeedsChanging = true;
 }
 
-void Application::updateHeartbeat() {
+void Application::updateHeartbeat() const {
     static_cast<DeadlockWatchdogThread*>(_deadlockWatchdogThread)->updateHeartbeat();
 }
 
@@ -1218,12 +1193,12 @@ void Application::cleanupBeforeQuit() {
 
 Application::~Application() {
     EntityTreePointer tree = getEntities()->getTree();
-    tree->setSimulation(NULL);
+    tree->setSimulation(nullptr);
 
     _octreeProcessor.terminate();
     _entityEditSender.terminate();
 
-    _physicsEngine->setCharacterController(NULL);
+    _physicsEngine->setCharacterController(nullptr);
 
     ModelEntityItem::cleanupLoadedAnimations();
 
@@ -1264,7 +1239,7 @@ Application::~Application() {
     
     _window->deleteLater();
 
-    qInstallMessageHandler(NULL); // NOTE: Do this as late as possible so we continue to get our log messages
+    qInstallMessageHandler(nullptr); // NOTE: Do this as late as possible so we continue to get our log messages
 }
 
 void Application::initializeGL() {
@@ -1744,7 +1719,7 @@ void Application::runTests() {
     runUnitTests();
 }
 
-void Application::audioMuteToggled() {
+void Application::audioMuteToggled() const {
     QAction* muteAction = Menu::getInstance()->getActionForOption(MenuOption::MuteAudio);
     Q_CHECK_PTR(muteAction);
     muteAction->setChecked(DependencyManager::get<AudioClient>()->isMuted());
@@ -1826,7 +1801,7 @@ bool Application::event(QEvent* event) {
     }
 
     if ((int)event->type() == (int)Lambda) {
-        ((LambdaEvent*)event)->call();
+        static_cast<LambdaEvent*>(event)->call();
         return true;
     }
 
@@ -1860,25 +1835,25 @@ bool Application::event(QEvent* event) {
 
     switch (event->type()) {
         case QEvent::MouseMove:
-            mouseMoveEvent((QMouseEvent*)event);
+            mouseMoveEvent(static_cast<QMouseEvent*>(event));
             return true;
         case QEvent::MouseButtonPress:
-            mousePressEvent((QMouseEvent*)event);
+            mousePressEvent(static_cast<QMouseEvent*>(event));
             return true;
         case QEvent::MouseButtonDblClick:
-            mouseDoublePressEvent((QMouseEvent*)event);
+            mouseDoublePressEvent(static_cast<QMouseEvent*>(event));
             return true;
         case QEvent::MouseButtonRelease:
-            mouseReleaseEvent((QMouseEvent*)event);
+            mouseReleaseEvent(static_cast<QMouseEvent*>(event));
             return true;
         case QEvent::KeyPress:
-            keyPressEvent((QKeyEvent*)event);
+            keyPressEvent(static_cast<QKeyEvent*>(event));
             return true;
         case QEvent::KeyRelease:
-            keyReleaseEvent((QKeyEvent*)event);
+            keyReleaseEvent(static_cast<QKeyEvent*>(event));
             return true;
         case QEvent::FocusOut:
-            focusOutEvent((QFocusEvent*)event);
+            focusOutEvent(static_cast<QFocusEvent*>(event));
             return true;
         case QEvent::TouchBegin:
             touchBeginEvent(static_cast<QTouchEvent*>(event));
@@ -2306,13 +2281,13 @@ void Application::focusOutEvent(QFocusEvent* event) {
 
     // synthesize events for keys currently pressed, since we may not get their release events
     foreach (int key, _keysPressed) {
-        QKeyEvent event(QEvent::KeyRelease, key, Qt::NoModifier);
-        keyReleaseEvent(&event);
+        QKeyEvent keyEvent(QEvent::KeyRelease, key, Qt::NoModifier);
+        keyReleaseEvent(&keyEvent);
     }
     _keysPressed.clear();
 }
 
-void Application::maybeToggleMenuVisible(QMouseEvent* event) {
+void Application::maybeToggleMenuVisible(QMouseEvent* event) const {
 #ifndef Q_OS_MAC
     // If in full screen, and our main windows menu bar is hidden, and we're close to the top of the QMainWindow
     // then show the menubar.
@@ -2428,7 +2403,7 @@ void Application::mousePressEvent(QMouseEvent* event) {
     }
 }
 
-void Application::mouseDoublePressEvent(QMouseEvent* event) {
+void Application::mouseDoublePressEvent(QMouseEvent* event) const {
     // if one of our scripts have asked to capture this event, then stop processing it
     if (_controllerScriptingInterface->isMouseCaptured()) {
         return;
@@ -2528,7 +2503,7 @@ void Application::touchEndEvent(QTouchEvent* event) {
     // put any application specific touch behavior below here..
 }
 
-void Application::wheelEvent(QWheelEvent* event) {
+void Application::wheelEvent(QWheelEvent* event) const {
     _altPressed = false;
     _controllerScriptingInterface->emitWheelEvent(event); // send events to any registered scripts
 
@@ -2707,9 +2682,11 @@ float Application::getAverageSimsPerSecond() {
     }
     return _simsPerSecondReport;
 }
+
 void Application::setAvatarSimrateSample(float sample) {
     _avatarSimsPerSecond.updateAverage(sample);
 }
+
 float Application::getAvatarSimrate() {
     uint64_t now = usecTimestampNow();
 
@@ -2724,7 +2701,7 @@ void Application::setLowVelocityFilter(bool lowVelocityFilter) {
     controller::InputDevice::setLowVelocityFilter(lowVelocityFilter);
 }
 
-ivec2 Application::getMouse() {
+ivec2 Application::getMouse() const {
     auto reticlePosition = getApplicationCompositor().getReticlePosition();
 
     // in the HMD, the reticlePosition is the mouse position
@@ -2741,11 +2718,11 @@ FaceTracker* Application::getActiveFaceTracker() {
     auto dde = DependencyManager::get<DdeFaceTracker>();
 
     return (dde->isActive() ? static_cast<FaceTracker*>(dde.data()) :
-            (faceshift->isActive() ? static_cast<FaceTracker*>(faceshift.data()) : NULL));
+            (faceshift->isActive() ? static_cast<FaceTracker*>(faceshift.data()) : nullptr));
 }
 
 FaceTracker* Application::getSelectedFaceTracker() {
-    FaceTracker* faceTracker = NULL;
+    FaceTracker* faceTracker = nullptr;
 #ifdef HAVE_FACESHIFT
     if (Menu::getInstance()->isOptionChecked(MenuOption::Faceshift)) {
         faceTracker = DependencyManager::get<Faceshift>().data();
@@ -2759,7 +2736,7 @@ FaceTracker* Application::getSelectedFaceTracker() {
     return faceTracker;
 }
 
-void Application::setActiveFaceTracker() {
+void Application::setActiveFaceTracker() const {
 #if defined(HAVE_FACESHIFT) || defined(HAVE_DDE)
     bool isMuted = Menu::getInstance()->isOptionChecked(MenuOption::MuteFaceTracking);
 #endif
@@ -2816,60 +2793,68 @@ bool Application::exportEntities(const QString& filename, const QVector<EntityIt
     auto entityTree = getEntities()->getTree();
     auto exportTree = std::make_shared<EntityTree>();
     exportTree->createRootElement();
-
     glm::vec3 root(TREE_SCALE, TREE_SCALE, TREE_SCALE);
-    for (auto entityID : entityIDs) { // Gather entities and properties.
-        auto entityItem = entityTree->findEntityByEntityItemID(entityID);
-        if (!entityItem) {
-            qCWarning(interfaceapp) << "Skipping export of" << entityID << "that is not in scene.";
-            continue;
-        }
-
-        if (!givenOffset) {
-            EntityItemID parentID = entityItem->getParentID();
-            if (parentID.isInvalidID() || !entityIDs.contains(parentID) || !entityTree->findEntityByEntityItemID(parentID)) {
-                auto position = entityItem->getPosition(); // If parent wasn't selected, we want absolute position, which isn't in properties.
-                root.x = glm::min(root.x, position.x);
-                root.y = glm::min(root.y, position.y);
-                root.z = glm::min(root.z, position.z);
+    bool success = true;
+    entityTree->withReadLock([&] {
+        for (auto entityID : entityIDs) { // Gather entities and properties.
+            auto entityItem = entityTree->findEntityByEntityItemID(entityID);
+            if (!entityItem) {
+                qCWarning(interfaceapp) << "Skipping export of" << entityID << "that is not in scene.";
+                continue;
             }
+
+            if (!givenOffset) {
+                EntityItemID parentID = entityItem->getParentID();
+                if (parentID.isInvalidID() || !entityIDs.contains(parentID) || !entityTree->findEntityByEntityItemID(parentID)) {
+                    auto position = entityItem->getPosition(); // If parent wasn't selected, we want absolute position, which isn't in properties.
+                    root.x = glm::min(root.x, position.x);
+                    root.y = glm::min(root.y, position.y);
+                    root.z = glm::min(root.z, position.z);
+                }
+            }
+            entities[entityID] = entityItem;
         }
-        entities[entityID] = entityItem;
-    }
 
-    if (entities.size() == 0) {
-        return false;
-    }
+        if (entities.size() == 0) {
+            success = false;
+            return;
+        }
 
-    if (givenOffset) {
-        root = *givenOffset;
-    }
-    for (EntityItemPointer& entityDatum : entities) {
-        auto properties = entityDatum->getProperties();
-        EntityItemID parentID = properties.getParentID();
-        if (parentID.isInvalidID()) {
-            properties.setPosition(properties.getPosition() - root);
-        } else if (!entities.contains(parentID)) {
-            entityDatum->globalizeProperties(properties, "Parent %3 of %2 %1 is not selected for export.", -root);
-        } // else valid parent -- don't offset
-        exportTree->addEntity(entityDatum->getEntityItemID(), properties);
-    }
+        if (givenOffset) {
+            root = *givenOffset;
+        }
+        for (EntityItemPointer& entityDatum : entities) {
+            auto properties = entityDatum->getProperties();
+            EntityItemID parentID = properties.getParentID();
+            if (parentID.isInvalidID()) {
+                properties.setPosition(properties.getPosition() - root);
+            }
+            else if (!entities.contains(parentID)) {
+                entityDatum->globalizeProperties(properties, "Parent %3 of %2 %1 is not selected for export.", -root);
+            } // else valid parent -- don't offset
+            exportTree->addEntity(entityDatum->getEntityItemID(), properties);
+        }
+    });
+    if (success) {
+        exportTree->writeToJSONFile(filename.toLocal8Bit().constData());
 
-    exportTree->writeToJSONFile(filename.toLocal8Bit().constData());
-
-    // restore the main window's active state
-    _window->activateWindow();
-    return true;
+        // restore the main window's active state
+        _window->activateWindow();
+    }
+    return success;
 }
 
 bool Application::exportEntities(const QString& filename, float x, float y, float z, float scale) {
     glm::vec3 offset(x, y, z);
     QVector<EntityItemPointer> entities;
     QVector<EntityItemID> ids;
-    getEntities()->getTree()->findEntities(AACube(offset, scale), entities);
-    foreach(EntityItemPointer entity, entities) {
-        ids << entity->getEntityItemID();
-    }
+    auto entityTree = getEntities()->getTree();
+    entityTree->withReadLock([&] {
+        entityTree->findEntities(AACube(offset, scale), entities);
+        foreach(EntityItemPointer entity, entities) {
+            ids << entity->getEntityItemID();
+        }
+    });
     return exportEntities(filename, ids, &offset);
 }
 
@@ -2888,7 +2873,7 @@ void Application::loadSettings() {
     _settingsLoaded = true;
 }
 
-void Application::saveSettings() {
+void Application::saveSettings() const {
     sessionRunTime.set(_sessionRunTimer.elapsed() / MSECS_PER_SEC);
     DependencyManager::get<AudioClient>()->saveSettings();
     DependencyManager::get<LODManager>()->saveSettings();
@@ -2899,12 +2884,15 @@ void Application::saveSettings() {
 }
 
 bool Application::importEntities(const QString& urlOrFilename) {
-    _entityClipboard->eraseAllOctreeElements();
+    bool success = false;
+    _entityClipboard->withWriteLock([&] {
+        _entityClipboard->eraseAllOctreeElements();
 
-    bool success = _entityClipboard->readFromURL(urlOrFilename);
-    if (success) {
-        _entityClipboard->reaverageOctreeElements();
-    }
+        success = _entityClipboard->readFromURL(urlOrFilename);
+        if (success) {
+            _entityClipboard->reaverageOctreeElements();
+        }
+    });
     return success;
 }
 
@@ -2975,7 +2963,7 @@ void Application::init() {
     connect(getMyAvatar(), &MyAvatar::newCollisionSoundURL, DependencyManager::get<SoundCache>().data(), &SoundCache::getSound);
 }
 
-void Application::updateLOD() {
+void Application::updateLOD() const {
     PerformanceTimer perfTimer("LOD");
     // adjust it unless we were asked to disable this feature, or if we're currently in throttleRendering mode
     if (!isThrottleRendering()) {
@@ -3177,13 +3165,13 @@ void Application::reloadResourceCaches() {
     getMyAvatar()->resetFullAvatarURL();
 }
 
-void Application::rotationModeChanged() {
+void Application::rotationModeChanged() const {
     if (!Menu::getInstance()->isOptionChecked(MenuOption::CenterPlayerInView)) {
         getMyAvatar()->setHeadPitch(0);
     }
 }
 
-void Application::updateDialogs(float deltaTime) {
+void Application::updateDialogs(float deltaTime) const {
     PerformanceTimer perfTimer("updateDialogs");
     bool showWarnings = Menu::getInstance()->isOptionChecked(MenuOption::PipelineWarnings);
     PerformanceWarning warn(showWarnings, "Application::updateDialogs()");
@@ -3219,7 +3207,7 @@ void Application::update(float deltaTime) {
     if (!_physicsEnabled && _processOctreeStatsCounter > 0) {
 
         // process octree stats packets are sent in between full sends of a scene.
-        // We keep physics disabled until we've recieved a full scene and everything near the avatar in that
+        // We keep physics disabled until we've received a full scene and everything near the avatar in that
         // scene is ready to compute its collision shape.
 
         if (nearbyEntitiesAreReadyForPhysics()) {
@@ -3524,7 +3512,7 @@ int Application::sendNackPackets() {
 
             QSet<OCTREE_PACKET_SEQUENCE> missingSequenceNumbers;
             _octreeServerSceneStats.withReadLock([&] {
-                // retreive octree scene stats of this node
+                // retrieve octree scene stats of this node
                 if (_octreeServerSceneStats.find(nodeUUID) == _octreeServerSceneStats.end()) {
                     return;
                 }
@@ -3724,7 +3712,7 @@ bool Application::isHMDMode() const {
 }
 float Application::getTargetFrameRate() { return getActiveDisplayPlugin()->getTargetFrameRate(); }
 
-QRect Application::getDesirableApplicationGeometry() {
+QRect Application::getDesirableApplicationGeometry() const {
     QRect applicationGeometry = getWindow()->geometry();
 
     // If our parent window is on the HMD, then don't use its geometry, instead use
@@ -3737,7 +3725,7 @@ QRect Application::getDesirableApplicationGeometry() {
 
         // if our app's screen is the hmd screen, we don't want to place the
         // running scripts widget on it. So we need to pick a better screen.
-        // we will use the screen for the HMDTools since it's a guarenteed
+        // we will use the screen for the HMDTools since it's a guaranteed
         // better screen.
         if (appScreen == hmdScreen) {
             QScreen* betterScreen = hmdTools->windowHandle()->screen();
@@ -3766,7 +3754,7 @@ void Application::loadViewFrustum(Camera& camera, ViewFrustum& viewFrustum) {
     viewFrustum.calculate();
 }
 
-glm::vec3 Application::getSunDirection() {
+glm::vec3 Application::getSunDirection() const {
     // Sun direction is in fact just the location of the sun relative to the origin
     auto skyStage = DependencyManager::get<SceneScriptingInterface>()->getSkyStage();
     return skyStage->getSunLight()->getDirection();
@@ -3968,7 +3956,8 @@ void Application::displaySide(RenderArgs* renderArgs, Camera& theCamera, bool se
             RenderArgs::DebugFlags renderDebugFlags = RenderArgs::RENDER_DEBUG_NONE;
 
             if (Menu::getInstance()->isOptionChecked(MenuOption::PhysicsShowHulls)) {
-                renderDebugFlags = (RenderArgs::DebugFlags) (renderDebugFlags | (int)RenderArgs::RENDER_DEBUG_HULLS);
+                renderDebugFlags = static_cast<RenderArgs::DebugFlags>(renderDebugFlags |
+                    static_cast<int>(RenderArgs::RENDER_DEBUG_HULLS));
             }
             renderArgs->_debugFlags = renderDebugFlags;
             //ViveControllerManager::getInstance().updateRendering(renderArgs, _main3DScene, pendingChanges);
@@ -4033,7 +4022,7 @@ void Application::renderRearViewMirror(RenderArgs* renderArgs, const QRect& regi
                                   myAvatar->getOrientation() * glm::vec3(0.0f, 0.0f, -1.0f) * MIRROR_REARVIEW_BODY_DISTANCE * myAvatar->getScale());
 
     } else { // HEAD zoom level
-        // FIXME note that the positioing of the camera relative to the avatar can suffer limited
+        // FIXME note that the positioning of the camera relative to the avatar can suffer limited
         // precision as the user's position moves further away from the origin.  Thus at
         // /1e7,1e7,1e7 (well outside the buildable volume) the mirror camera veers and sways
         // wildly as you rotate your avatar because the floating point values are becoming
@@ -4079,7 +4068,7 @@ void Application::resetSensors(bool andReload) {
     QMetaObject::invokeMethod(DependencyManager::get<AudioClient>().data(), "reset", Qt::QueuedConnection);
 }
 
-void Application::updateWindowTitle(){
+void Application::updateWindowTitle() const {
 
     QString buildVersion = " (build " + applicationVersion() + ")";
     auto nodeList = DependencyManager::get<NodeList>();
@@ -4137,14 +4126,14 @@ void Application::resettingDomain() {
     _notifiedPacketVersionMismatchThisDomain = false;
 }
 
-void Application::nodeAdded(SharedNodePointer node) {
+void Application::nodeAdded(SharedNodePointer node) const {
     if (node->getType() == NodeType::AvatarMixer) {
         // new avatar mixer, send off our identity packet right away
         getMyAvatar()->sendIdentityPacket();
     }
 }
 
-void Application::nodeActivated(SharedNodePointer node) {
+void Application::nodeActivated(SharedNodePointer node) const {
     if (node->getType() == NodeType::AssetServer) {
         // asset server just connected - check if we have the asset browser showing
 
@@ -4278,7 +4267,7 @@ int Application::processOctreeStats(ReceivedMessage& message, SharedNodePointer
         statsMessageLength = octreeStats.unpackFromPacket(message);
 
         // see if this is the first we've heard of this node...
-        NodeToJurisdictionMap* jurisdiction = NULL;
+        NodeToJurisdictionMap* jurisdiction = nullptr;
         QString serverType;
         if (sendingNode->getType() == NodeType::EntityServer) {
             jurisdiction = &_entityServerJurisdictions;
@@ -4434,7 +4423,7 @@ bool Application::acceptURL(const QString& urlString, bool defaultUpload) {
     return defaultUpload;
 }
 
-void Application::setSessionUUID(const QUuid& sessionUUID) {
+void Application::setSessionUUID(const QUuid& sessionUUID) const {
     // HACK: until we swap the library dependency order between physics and entities
     // we cache the sessionID in two distinct places for physics.
     Physics::setSessionUUID(sessionUUID); // TODO: remove this one
@@ -4575,7 +4564,7 @@ bool Application::displayAvatarAttachmentConfirmationDialog(const QString& name)
     }
 }
 
-void Application::toggleRunningScriptsWidget() {
+void Application::toggleRunningScriptsWidget() const {
     static const QUrl url("hifi/dialogs/RunningScripts.qml");
     DependencyManager::get<OffscreenUi>()->show(url, "RunningScripts");
     //if (_runningScriptsWidget->isVisible()) {
@@ -4612,7 +4601,7 @@ void Application::packageModel() {
     ModelPackager::package();
 }
 
-void Application::openUrl(const QUrl& url) {
+void Application::openUrl(const QUrl& url) const {
     if (!url.isEmpty()) {
         if (url.scheme() == HIFI_URL_SCHEME) {
             DependencyManager::get<AddressManager>()->handleLookupString(url.toString());
@@ -4642,7 +4631,7 @@ void Application::setPreviousScriptLocation(const QString& location) {
     _previousScriptLocation.set(location);
 }
 
-void Application::loadScriptURLDialog() {
+void Application::loadScriptURLDialog() const {
     auto newScript = OffscreenUi::getText(nullptr, "Open and Run Script", "Script URL");
     if (!newScript.isEmpty()) {
         DependencyManager::get<ScriptEngines>()->loadScript(newScript);
@@ -4707,7 +4696,7 @@ void Application::notifyPacketVersionMismatch() {
     }
 }
 
-void Application::checkSkeleton() {
+void Application::checkSkeleton() const {
     if (getMyAvatar()->getSkeletonModel()->isActive() && !getMyAvatar()->getSkeletonModel()->hasSkeleton()) {
         qCDebug(interfaceapp) << "MyAvatar model has no skeleton";
 
@@ -4788,7 +4777,7 @@ void Application::setMaxOctreePacketsPerSecond(int maxOctreePPS) {
     }
 }
 
-int Application::getMaxOctreePacketsPerSecond() {
+int Application::getMaxOctreePacketsPerSecond() const {
     return _maxOctreePPS;
 }
 
@@ -4812,7 +4801,7 @@ DisplayPlugin* Application::getActiveDisplayPlugin() {
 }
 
 const DisplayPlugin* Application::getActiveDisplayPlugin() const {
-    return ((Application*)this)->getActiveDisplayPlugin();
+    return const_cast<Application*>(this)->getActiveDisplayPlugin();
 }
 
 static void addDisplayPluginToMenu(DisplayPluginPointer displayPlugin, bool active = false) {
@@ -4892,7 +4881,7 @@ void Application::updateDisplayMode() {
             }
         }
 
-        // concactonate the groupings into a single list in the order: standard, advanced, developer
+        // concatenate the groupings into a single list in the order: standard, advanced, developer
         standard.insert(std::end(standard), std::begin(advanced), std::end(advanced));
         standard.insert(std::end(standard), std::begin(developer), std::end(developer));
 
@@ -4904,7 +4893,7 @@ void Application::updateDisplayMode() {
             first = false;
         }
 
-        // after all plugins have been added to the menu, add a seperator to the menu
+        // after all plugins have been added to the menu, add a separator to the menu
         auto menu = Menu::getInstance();
         auto parent = menu->getMenu(MenuOption::OutputMenu);
         parent->addSeparator();
@@ -4975,7 +4964,7 @@ void Application::updateDisplayMode() {
 
     emit activeDisplayPluginChanged();
 
-    // reset the avatar, to set head and hand palms back to a resonable default pose.
+    // reset the avatar, to set head and hand palms back to a reasonable default pose.
     getMyAvatar()->reset(false);
 
     Q_ASSERT_X(_displayPlugin, "Application::updateDisplayMode", "could not find an activated display plugin");
@@ -5104,7 +5093,7 @@ void Application::setActiveDisplayPlugin(const QString& pluginName) {
     updateDisplayMode();
 }
 
-void Application::handleLocalServerConnection() {
+void Application::handleLocalServerConnection() const {
     auto server = qobject_cast<QLocalServer*>(sender());
 
     qDebug() << "Got connection on local server from additional instance - waiting for parameters";
@@ -5117,7 +5106,7 @@ void Application::handleLocalServerConnection() {
     qApp->getWindow()->activateWindow();
 }
 
-void Application::readArgumentsFromLocalSocket() {
+void Application::readArgumentsFromLocalSocket() const {
     auto socket = qobject_cast<QLocalSocket*>(sender());
 
     auto message = socket->readAll();
diff --git a/interface/src/Application.h b/interface/src/Application.h
index 4f67fbb545..e3196febd5 100644
--- a/interface/src/Application.h
+++ b/interface/src/Application.h
@@ -135,14 +135,14 @@ public:
     const ViewFrustum* getDisplayViewFrustum() const;
     ViewFrustum* getShadowViewFrustum() override { return &_shadowViewFrustum; }
     const OctreePacketProcessor& getOctreePacketProcessor() const { return _octreeProcessor; }
-    EntityTreeRenderer* getEntities() { return DependencyManager::get<EntityTreeRenderer>().data(); }
+    EntityTreeRenderer* getEntities() const { return DependencyManager::get<EntityTreeRenderer>().data(); }
     QUndoStack* getUndoStack() { return &_undoStack; }
-    MainWindow* getWindow() { return _window; }
-    EntityTreePointer getEntityClipboard() { return _entityClipboard; }
+    MainWindow* getWindow() const { return _window; }
+    EntityTreePointer getEntityClipboard() const { return _entityClipboard; }
     EntityTreeRenderer* getEntityClipboardRenderer() { return &_entityClipboardRenderer; }
     EntityEditPacketSender* getEntityEditPacketSender() { return &_entityEditSender; }
 
-    ivec2 getMouse();
+    ivec2 getMouse() const;
 
     FaceTracker* getActiveFaceTracker();
     FaceTracker* getSelectedFaceTracker();
@@ -155,7 +155,7 @@ public:
 
     bool isForeground() const { return _isForeground; }
 
-    uint32_t getFrameCount() { return _frameCount; }
+    uint32_t getFrameCount() const { return _frameCount; }
     float getFps() const { return _fps; }
     float getTargetFrameRate(); // frames/second
     float getLastInstanteousFps() const { return _lastInstantaneousFps; }
@@ -179,7 +179,7 @@ public:
     DisplayPlugin* getActiveDisplayPlugin();
     const DisplayPlugin* getActiveDisplayPlugin() const;
 
-    FileLogger* getLogger() { return _logger; }
+    FileLogger* getLogger() const { return _logger; }
 
     glm::vec2 getViewportDimensions() const;
 
@@ -189,7 +189,7 @@ public:
 
     bool isAboutToQuit() const { return _aboutToQuit; }
 
-    // the isHMDmode is true whenever we use the interface from an HMD and not a standard flat display
+    // the isHMDMode is true whenever we use the interface from an HMD and not a standard flat display
     // rendering of several elements depend on that
     // TODO: carry that information on the Camera as a setting
     bool isHMDMode() const;
@@ -197,14 +197,14 @@ public:
     glm::mat4 getEyeOffset(int eye) const;
     glm::mat4 getEyeProjection(int eye) const;
 
-    QRect getDesirableApplicationGeometry();
+    QRect getDesirableApplicationGeometry() const;
     Bookmarks* getBookmarks() const { return _bookmarks; }
 
     virtual bool canAcceptURL(const QString& url) const override;
     virtual bool acceptURL(const QString& url, bool defaultUpload = false) override;
 
     void setMaxOctreePacketsPerSecond(int maxOctreePPS);
-    int getMaxOctreePacketsPerSecond();
+    int getMaxOctreePacketsPerSecond() const;
 
     render::ScenePointer getMain3DScene() override { return _main3DScene; }
     render::ScenePointer getMain3DScene() const { return _main3DScene; }
@@ -239,22 +239,22 @@ public slots:
     bool exportEntities(const QString& filename, float x, float y, float z, float scale);
     bool importEntities(const QString& url);
 
-    void setLowVelocityFilter(bool lowVelocityFilter);
+    static void setLowVelocityFilter(bool lowVelocityFilter);
     Q_INVOKABLE void loadDialog();
-    Q_INVOKABLE void loadScriptURLDialog();
+    Q_INVOKABLE void loadScriptURLDialog() const;
     void toggleLogDialog();
-    void toggleRunningScriptsWidget();
+    void toggleRunningScriptsWidget() const;
     void toggleAssetServerWidget(QString filePath = "");
 
-    void handleLocalServerConnection();
-    void readArgumentsFromLocalSocket();
+    void handleLocalServerConnection() const;
+    void readArgumentsFromLocalSocket() const;
 
-    void packageModel();
+    static void packageModel();
 
-    void openUrl(const QUrl& url);
+    void openUrl(const QUrl& url) const;
 
     void resetSensors(bool andReload = false);
-    void setActiveFaceTracker();
+    void setActiveFaceTracker() const;
 
 #ifdef HAVE_IVIEWHMD
     void setActiveEyeTracker();
@@ -264,7 +264,7 @@ public slots:
 #endif
 
     void aboutApp();
-    void showHelp();
+    static void showHelp();
 
     void cycleCamera();
     void cameraMenuChanged();
@@ -273,14 +273,14 @@ public slots:
 
     void reloadResourceCaches();
 
-    void updateHeartbeat();
+    void updateHeartbeat() const;
 
-    void crashApplication();
-    void deadlockApplication();
+    static void crashApplication();
+    static void deadlockApplication();
 
-    void rotationModeChanged();
+    void rotationModeChanged() const;
 
-    void runTests();
+    static void runTests();
 
 private slots:
     void showDesktop();
@@ -290,7 +290,7 @@ private slots:
 
     void resettingDomain();
 
-    void audioMuteToggled();
+    void audioMuteToggled() const;
     void faceTrackerMuteToggled();
 
     void activeChanged(Qt::ApplicationState state);
@@ -298,7 +298,7 @@ private slots:
     void notifyPacketVersionMismatch();
 
     void loadSettings();
-    void saveSettings();
+    void saveSettings() const;
 
     bool acceptSnapshot(const QString& urlString);
     bool askToSetAvatarUrl(const QString& url);
@@ -308,18 +308,18 @@ private slots:
     void displayAvatarAttachmentWarning(const QString& message) const;
     bool displayAvatarAttachmentConfirmationDialog(const QString& name) const;
 
-    void setSessionUUID(const QUuid& sessionUUID);
+    void setSessionUUID(const QUuid& sessionUUID) const;
     void domainChanged(const QString& domainHostname);
-    void updateWindowTitle();
-    void nodeAdded(SharedNodePointer node);
-    void nodeActivated(SharedNodePointer node);
+    void updateWindowTitle() const;
+    void nodeAdded(SharedNodePointer node) const;
+    void nodeActivated(SharedNodePointer node) const;
     void nodeKilled(SharedNodePointer node);
-    void packetSent(quint64 length);
+    static void packetSent(quint64 length);
     void updateDisplayMode();
     void updateInputModes();
 
 private:
-    void initDisplay();
+    static void initDisplay();
     void init();
 
     void cleanupBeforeQuit();
@@ -327,14 +327,14 @@ private:
     void update(float deltaTime);
 
     // Various helper functions called during update()
-    void updateLOD();
+    void updateLOD() const;
     void updateThreads(float deltaTime);
-    void updateDialogs(float deltaTime);
+    void updateDialogs(float deltaTime) const;
 
     void queryOctree(NodeType_t serverType, PacketType packetType, NodeToJurisdictionMap& jurisdictions);
-    void loadViewFrustum(Camera& camera, ViewFrustum& viewFrustum);
+    static void loadViewFrustum(Camera& camera, ViewFrustum& viewFrustum);
 
-    glm::vec3 getSunDirection();
+    glm::vec3 getSunDirection() const;
 
     void renderRearViewMirror(RenderArgs* renderArgs, const QRect& region);
 
@@ -344,7 +344,7 @@ private:
 
     MyAvatar* getMyAvatar() const;
 
-    void checkSkeleton();
+    void checkSkeleton() const;
 
     void initializeAcceptedFiles();
 
@@ -366,18 +366,18 @@ private:
 
     void mouseMoveEvent(QMouseEvent* event);
     void mousePressEvent(QMouseEvent* event);
-    void mouseDoublePressEvent(QMouseEvent* event);
+    void mouseDoublePressEvent(QMouseEvent* event) const;
     void mouseReleaseEvent(QMouseEvent* event);
 
     void touchBeginEvent(QTouchEvent* event);
     void touchEndEvent(QTouchEvent* event);
     void touchUpdateEvent(QTouchEvent* event);
 
-    void wheelEvent(QWheelEvent* event);
+    void wheelEvent(QWheelEvent* event) const;
     void dropEvent(QDropEvent* event);
-    void dragEnterEvent(QDragEnterEvent* event);
+    static void dragEnterEvent(QDragEnterEvent* event);
 
-    void maybeToggleMenuVisible(QMouseEvent* event);
+    void maybeToggleMenuVisible(QMouseEvent* event) const;
 
     MainWindow* _window;
     QElapsedTimer& _sessionRunTimer;
@@ -423,7 +423,7 @@ private:
     int _avatarSimsPerSecondReport {0};
     quint64 _lastAvatarSimsPerSecondUpdate {0};
     Camera _myCamera;                            // My view onto the world
-    Camera _mirrorCamera;                        // Cammera for mirror view
+    Camera _mirrorCamera;                        // Camera for mirror view
     QRect _mirrorViewRect;
 
     Setting::Handle<QString> _previousScriptLocation;
diff --git a/libraries/entities-renderer/src/EntityTreeRenderer.cpp b/libraries/entities-renderer/src/EntityTreeRenderer.cpp
index edc7f7d754..b87329d5b6 100644
--- a/libraries/entities-renderer/src/EntityTreeRenderer.cpp
+++ b/libraries/entities-renderer/src/EntityTreeRenderer.cpp
@@ -297,7 +297,14 @@ void EntityTreeRenderer::applyZonePropertiesToScene(std::shared_ptr<ZoneEntityIt
     auto sceneLocation = sceneStage->getLocation();
     auto sceneTime = sceneStage->getTime();
     
+    // Skybox and procedural skybox data
+    auto skybox = std::dynamic_pointer_cast<ProceduralSkybox>(skyStage->getSkybox());
+    static QString userData;
+
     if (!zone) {
+        userData = QString();
+        skybox->clear();
+
         _pendingSkyboxTexture = false;
         _skyboxTexture.clear();
 
@@ -373,9 +380,7 @@ void EntityTreeRenderer::applyZonePropertiesToScene(std::shared_ptr<ZoneEntityIt
 
     switch (zone->getBackgroundMode()) {
         case BACKGROUND_MODE_SKYBOX: {
-            auto skybox = std::dynamic_pointer_cast<ProceduralSkybox>(skyStage->getSkybox());
             skybox->setColor(zone->getSkyboxProperties().getColorVec3());
-            static QString userData;
             if (userData != zone->getUserData()) {
                 userData = zone->getUserData();
                 skybox->parse(userData);
@@ -414,9 +419,15 @@ void EntityTreeRenderer::applyZonePropertiesToScene(std::shared_ptr<ZoneEntityIt
 
         case BACKGROUND_MODE_INHERIT:
         default:
-            skyStage->setBackgroundMode(model::SunSkyStage::SKY_DOME); // let the application background through
-            _pendingSkyboxTexture = false;
+            // Clear the skybox to release its textures
+            userData = QString();
+            skybox->clear();
+
             _skyboxTexture.clear();
+            _pendingSkyboxTexture = false;
+
+            // Let the application background through
+            skyStage->setBackgroundMode(model::SunSkyStage::SKY_DOME);
             break;
     }
 
diff --git a/libraries/entities/src/EntityTree.cpp b/libraries/entities/src/EntityTree.cpp
index 5292e12ae8..92c3ce216f 100644
--- a/libraries/entities/src/EntityTree.cpp
+++ b/libraries/entities/src/EntityTree.cpp
@@ -1323,7 +1323,9 @@ QVector<EntityItemID> EntityTree::sendEntities(EntityEditPacketSender* packetSen
     // We need to keep a map so that we can map parent identifiers correctly.
     QHash<EntityItemID, EntityItemID> map;
     args.map = &map;
-    recurseTreeWithOperation(sendEntitiesOperation, &args);
+    withReadLock([&] {
+        recurseTreeWithOperation(sendEntitiesOperation, &args);
+    });
     packetSender->releaseQueuedMessages();
 
     return map.values().toVector();
diff --git a/libraries/fbx/src/FBXReader_Node.cpp b/libraries/fbx/src/FBXReader_Node.cpp
index a6fba5a4d5..68e9d6abac 100644
--- a/libraries/fbx/src/FBXReader_Node.cpp
+++ b/libraries/fbx/src/FBXReader_Node.cpp
@@ -9,17 +9,20 @@
 //  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
 //
 
-#include <iostream>
-#include <QBuffer>
-#include <QDataStream>
-#include <QIODevice>
-#include <QStringList>
-#include <QTextStream>
-#include <QtDebug>
-#include <QtEndian>
-#include <QFileInfo>
 #include "FBXReader.h"
 
+#include <iostream>
+#include <QtCore/QBuffer>
+#include <QtCore/QDataStream>
+#include <QtCore/QIODevice>
+#include <QtCore/QStringList>
+#include <QtCore/QTextStream>
+#include <QtCore/QDebug>
+#include <QtCore/QtEndian>
+#include <QtCore/QFileInfo>
+
+#include <shared/NsightHelpers.h>
+
 template<class T> int streamSize() {
     return sizeof(T);
 }
@@ -299,6 +302,7 @@ FBXNode parseTextFBXNode(Tokenizer& tokenizer) {
 }
 
 FBXNode FBXReader::parseFBX(QIODevice* device) {
+    PROFILE_RANGE_EX(__FUNCTION__, 0xff0000ff, device);
     // verify the prolog
     const QByteArray BINARY_PROLOG = "Kaydara FBX Binary  ";
     if (device->peek(BINARY_PROLOG.size()) != BINARY_PROLOG) {
diff --git a/libraries/fbx/src/OBJReader.cpp b/libraries/fbx/src/OBJReader.cpp
index c28d680fb0..84c6c7aaa4 100644
--- a/libraries/fbx/src/OBJReader.cpp
+++ b/libraries/fbx/src/OBJReader.cpp
@@ -12,17 +12,20 @@
 // http://www.scratchapixel.com/old/lessons/3d-advanced-lessons/obj-file-format/obj-file-format/
 // http://paulbourke.net/dataformats/obj/
 
+#include "OBJReader.h"
 
-#include <QBuffer>
-#include <QIODevice>
-#include <QtNetwork/QNetworkAccessManager>
-#include <QtNetwork/QNetworkRequest>
-#include <QEventLoop>
 #include <ctype.h>  // .obj files are not locale-specific. The C/ASCII charset applies.
 
+#include <QtCore/QBuffer>
+#include <QtCore/QIODevice>
+#include <QtCore/QEventLoop>
+#include <QtNetwork/QNetworkAccessManager>
+#include <QtNetwork/QNetworkRequest>
+
+#include <shared/NsightHelpers.h>
 #include <NetworkAccessManager.h>
+
 #include "FBXReader.h"
-#include "OBJReader.h"
 #include "ModelFormatLogging.h"
 
 QHash<QString, float> COMMENT_SCALE_HINTS = {{"This file uses centimeters as units", 1.0f / 100.0f},
@@ -404,7 +407,7 @@ done:
 
 
 FBXGeometry* OBJReader::readOBJ(QByteArray& model, const QVariantHash& mapping, const QUrl& url) {
-
+    PROFILE_RANGE_EX(__FUNCTION__, 0xffff0000, nullptr);
     QBuffer buffer { &model };
     buffer.open(QIODevice::ReadOnly);
 
diff --git a/libraries/gpu/src/gpu/GLBackendTexture.cpp b/libraries/gpu/src/gpu/GLBackendTexture.cpp
index 3fc7906285..242b9100e1 100755
--- a/libraries/gpu/src/gpu/GLBackendTexture.cpp
+++ b/libraries/gpu/src/gpu/GLBackendTexture.cpp
@@ -10,6 +10,7 @@
 //
 #include "GPULogging.h"
 #include "GLBackendShared.h"
+#include "GLTexelFormat.h"
 
 using namespace gpu;
 
@@ -36,369 +37,6 @@ void GLBackend::GLTexture::setSize(GLuint size) {
     _size = size;
 }
 
-class GLTexelFormat {
-public:
-    GLenum internalFormat;
-    GLenum format;
-    GLenum type;
-
-    static GLTexelFormat evalGLTexelFormat(const Element& dstFormat, const Element& srcFormat) {
-        if (dstFormat != srcFormat) {
-            GLTexelFormat texel = {GL_RGBA, GL_RGBA, GL_UNSIGNED_BYTE};
-
-            switch(dstFormat.getDimension()) {
-            case gpu::SCALAR: {
-                texel.format = GL_RED;
-                texel.type = _elementTypeToGLType[dstFormat.getType()];
-
-                switch(dstFormat.getSemantic()) {
-                case gpu::RGB:
-                case gpu::RGBA:
-                    texel.internalFormat = GL_RED;
-                    break;
-                case gpu::DEPTH:
-                    texel.internalFormat = GL_DEPTH_COMPONENT;
-                    break;
-                case gpu::DEPTH_STENCIL:
-                    texel.type = GL_UNSIGNED_INT_24_8;
-                    texel.format = GL_DEPTH_STENCIL;
-                    texel.internalFormat = GL_DEPTH24_STENCIL8;
-                    break;
-                default:
-                    qCDebug(gpulogging) << "Unknown combination of texel format";
-                }
-                break;
-            }
-
-            case gpu::VEC2: {
-                texel.format = GL_RG;
-                texel.type = _elementTypeToGLType[dstFormat.getType()];
-
-                switch(dstFormat.getSemantic()) {
-                case gpu::RGB:
-                case gpu::RGBA:
-                    texel.internalFormat = GL_RG;
-                    break;
-                default:
-                    qCDebug(gpulogging) << "Unknown combination of texel format";
-                }
-
-                break;
-            }
-
-            case gpu::VEC3: {
-                texel.format = GL_RGB;
-
-                texel.type = _elementTypeToGLType[dstFormat.getType()];
-
-                switch(dstFormat.getSemantic()) {
-                case gpu::RGB:
-                case gpu::RGBA:
-                    texel.internalFormat = GL_RGB;
-                    break;
-                default:
-                    qCDebug(gpulogging) << "Unknown combination of texel format";
-                }
-
-                break;
-            }
-
-            case gpu::VEC4: {
-                texel.format = GL_RGBA;
-                texel.type = _elementTypeToGLType[dstFormat.getType()];
-
-                switch(srcFormat.getSemantic()) {
-                case gpu::BGRA:
-                case gpu::SBGRA:
-                    texel.format = GL_BGRA;
-                    break; 
-                case gpu::RGB:
-                case gpu::RGBA:
-                case gpu::SRGB:
-                case gpu::SRGBA:
-                default:
-                    break;
-                };
-
-                switch(dstFormat.getSemantic()) {
-                case gpu::RGB:
-                    texel.internalFormat = GL_RGB;
-                    break;
-                case gpu::RGBA:
-                    texel.internalFormat = GL_RGBA;
-                    break;
-                case gpu::SRGB:
-                    texel.internalFormat = GL_SRGB;
-                    break;
-                case gpu::SRGBA:
-                    texel.internalFormat = GL_SRGB_ALPHA;
-                    break;
-                default:
-                    qCDebug(gpulogging) << "Unknown combination of texel format";
-                }
-                break;
-            }
-
-            default:
-                qCDebug(gpulogging) << "Unknown combination of texel format";
-            }
-            return texel;
-        } else {
-            GLTexelFormat texel = {GL_RGBA, GL_RGBA, GL_UNSIGNED_BYTE};
-
-            switch(dstFormat.getDimension()) {
-            case gpu::SCALAR: {
-                texel.format = GL_RED;
-                texel.type = _elementTypeToGLType[dstFormat.getType()];
-
-                switch(dstFormat.getSemantic()) {
-                case gpu::RGB:
-                case gpu::RGBA:
-                case gpu::SRGB:
-                case gpu::SRGBA:
-                    texel.internalFormat = GL_RED;
-                    switch (dstFormat.getType()) {
-                        case gpu::UINT32: {
-                            texel.internalFormat = GL_R32UI;
-                            break;
-                            }
-                        case gpu::INT32: {
-                            texel.internalFormat = GL_R32I;
-                            break;
-                            }
-                        case gpu::NUINT32: {
-                            texel.internalFormat = GL_RED;
-                            break;
-                            }
-                        case gpu::NINT32: {
-                            texel.internalFormat = GL_RED_SNORM;
-                            break;
-                            }
-                        case gpu::FLOAT: {
-                            texel.internalFormat = GL_R32F;
-                            break;
-                            }
-                        case gpu::UINT16: {
-                            texel.internalFormat = GL_R16UI;
-                            break;
-                            }
-                        case gpu::INT16: {
-                            texel.internalFormat = GL_R16I;
-                            break;
-                            }
-                        case gpu::NUINT16: {
-                            texel.internalFormat = GL_R16;
-                            break;
-                            }
-                        case gpu::NINT16: {
-                            texel.internalFormat = GL_R16_SNORM;
-                            break;
-                            }
-                        case gpu::HALF: {
-                            texel.internalFormat = GL_R16F;
-                            break;
-                            }
-                        case gpu::UINT8: {
-                            texel.internalFormat = GL_R8UI;
-                            break;
-                            }
-                        case gpu::INT8: {
-                            texel.internalFormat = GL_R8I;
-                            break;
-                            }
-                        case gpu::NUINT8: {
-                            if ((dstFormat.getSemantic() == gpu::SRGB || dstFormat.getSemantic() == gpu::SRGBA)) {
-                                texel.internalFormat = GL_SLUMINANCE;
-                            } else {
-                                texel.internalFormat = GL_R8;
-                            }
-                            break;
-                            }
-                        case gpu::NINT8: {
-                            texel.internalFormat = GL_R8_SNORM;
-                            break;
-                            }
-                        case gpu::NUM_TYPES: { // quiet compiler
-                            Q_UNREACHABLE();
-                            }
-                        
-                    }
-                    break;
-
-                case gpu::R11G11B10:
-                    texel.format = GL_RGB;
-                    // the type should be float
-                    texel.internalFormat = GL_R11F_G11F_B10F;
-                    break;
-
-                case gpu::DEPTH:
-                    texel.format = GL_DEPTH_COMPONENT; // It's depth component to load it
-                    texel.internalFormat = GL_DEPTH_COMPONENT;
-                    switch (dstFormat.getType()) {
-                    case gpu::UINT32:
-                    case gpu::INT32:
-                    case gpu::NUINT32:
-                    case gpu::NINT32: {
-                        texel.internalFormat = GL_DEPTH_COMPONENT32;
-                        break;
-                        }
-                    case gpu::FLOAT: {
-                        texel.internalFormat = GL_DEPTH_COMPONENT32F;
-                       break;
-                    }
-                    case gpu::UINT16:
-                    case gpu::INT16:
-                    case gpu::NUINT16:
-                    case gpu::NINT16:
-                    case gpu::HALF: {
-                        texel.internalFormat = GL_DEPTH_COMPONENT16;
-                        break;
-                        }
-                    case gpu::UINT8:
-                    case gpu::INT8:
-                    case gpu::NUINT8:
-                    case gpu::NINT8: {
-                        texel.internalFormat = GL_DEPTH_COMPONENT24;
-                        break;
-                        }
-                    case gpu::NUM_TYPES: { // quiet compiler
-                        Q_UNREACHABLE();
-                    }
-                    }
-                    break;
-                case gpu::DEPTH_STENCIL:
-                    texel.type = GL_UNSIGNED_INT_24_8;
-                    texel.format = GL_DEPTH_STENCIL;
-                    texel.internalFormat = GL_DEPTH24_STENCIL8;
-                    break;
-                default:
-                    qCDebug(gpulogging) << "Unknown combination of texel format";
-                }
-
-                break;
-            }
-
-            case gpu::VEC2: {
-                texel.format = GL_RG;
-                texel.type = _elementTypeToGLType[dstFormat.getType()];
-
-                switch(dstFormat.getSemantic()) {
-                case gpu::RGB:
-                case gpu::RGBA:
-                    texel.internalFormat = GL_RG;
-                    break;
-                default:
-                    qCDebug(gpulogging) << "Unknown combination of texel format";
-                }
-
-                break;
-            }
-
-            case gpu::VEC3: {
-                texel.format = GL_RGB;
-
-                texel.type = _elementTypeToGLType[dstFormat.getType()];
-
-                switch(dstFormat.getSemantic()) {
-                case gpu::RGB:
-                case gpu::RGBA:
-                    texel.internalFormat = GL_RGB;
-                    break;
-                case gpu::SRGB:
-                case gpu::SRGBA:
-                    texel.internalFormat = GL_SRGB; // standard 2.2 gamma correction color
-                    break;
-                default:
-                    qCDebug(gpulogging) << "Unknown combination of texel format";
-                }
-                break;
-            }
-
-            case gpu::VEC4: {
-                texel.format = GL_RGBA;
-                texel.type = _elementTypeToGLType[dstFormat.getType()];
-
-                switch(dstFormat.getSemantic()) {
-                case gpu::RGB:
-                    texel.internalFormat = GL_RGB;
-                    break;
-                case gpu::RGBA:
-                    texel.internalFormat = GL_RGBA;
-                    switch (dstFormat.getType()) {
-                    case gpu::UINT32:
-                        texel.format = GL_RGBA_INTEGER;
-                        texel.internalFormat = GL_RGBA32UI;
-                        break;
-                    case gpu::INT32:
-                        texel.format = GL_RGBA_INTEGER;
-                        texel.internalFormat = GL_RGBA32I;
-                        break;
-                    case gpu::FLOAT:
-                        texel.internalFormat = GL_RGBA32F;
-                        break;
-                    case gpu::UINT16:
-                        texel.format = GL_RGBA_INTEGER;
-                        texel.internalFormat = GL_RGBA16UI;
-                        break;
-                    case gpu::INT16:
-                        texel.format = GL_RGBA_INTEGER;
-                        texel.internalFormat = GL_RGBA16I;
-                        break;
-                    case gpu::NUINT16:
-                        texel.format = GL_RGBA;
-                        texel.internalFormat = GL_RGBA16;
-                        break;
-                    case gpu::NINT16:
-                        texel.format = GL_RGBA;
-                        texel.internalFormat = GL_RGBA16_SNORM;
-                        break;
-                    case gpu::HALF:
-                        texel.format = GL_RGBA;
-                        texel.internalFormat = GL_RGBA16F;
-                        break;
-                    case gpu::UINT8:
-                        texel.format = GL_RGBA_INTEGER;
-                        texel.internalFormat = GL_RGBA8UI;
-                        break;
-                    case gpu::INT8:
-                        texel.format = GL_RGBA_INTEGER;
-                        texel.internalFormat = GL_RGBA8I;
-                        break;
-                    case gpu::NUINT8:
-                        texel.format = GL_RGBA;
-                        texel.internalFormat = GL_RGBA8;
-                        break;
-                    case gpu::NINT8:
-                        texel.format = GL_RGBA;
-                        texel.internalFormat = GL_RGBA8_SNORM;
-                        break;
-                    case gpu::NUINT32:
-                    case gpu::NINT32:
-                    case gpu::NUM_TYPES: // quiet compiler
-                        Q_UNREACHABLE();
-                    }
-                    break;
-                case gpu::SRGB:
-                    texel.internalFormat = GL_SRGB;
-                    break;
-                case gpu::SRGBA:
-                    texel.internalFormat = GL_SRGB_ALPHA; // standard 2.2 gamma correction color
-                    break;
-                default:
-                    qCDebug(gpulogging) << "Unknown combination of texel format";
-                }
-                break;
-            }
-
-            default:
-                qCDebug(gpulogging) << "Unknown combination of texel format";
-            }
-            return texel;
-        }
-    }
-};
-
-
 GLBackend::GLTexture* GLBackend::syncGPUObject(const Texture& texture) {
     GLTexture* object = Backend::getGPUObject<GLBackend::GLTexture>(texture);
 
diff --git a/libraries/gpu/src/gpu/GLTexelFormat.h b/libraries/gpu/src/gpu/GLTexelFormat.h
new file mode 100644
index 0000000000..274b5eeba3
--- /dev/null
+++ b/libraries/gpu/src/gpu/GLTexelFormat.h
@@ -0,0 +1,372 @@
+//
+//  Created by Bradley Austin Davis on 2016/04/03
+//  Copyright 2013-2016 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 "GLBackendShared.h"
+
+class GLTexelFormat {
+public:
+    GLenum internalFormat;
+    GLenum format;
+    GLenum type;
+
+    static GLTexelFormat evalGLTexelFormat(const gpu::Element& dstFormat, const gpu::Element& srcFormat) {
+        using namespace gpu;
+        if (dstFormat != srcFormat) {
+            GLTexelFormat texel = { GL_RGBA8, GL_RGBA, GL_UNSIGNED_BYTE };
+
+            switch (dstFormat.getDimension()) {
+            case gpu::SCALAR: {
+                texel.format = GL_RED;
+                texel.type = _elementTypeToGLType[dstFormat.getType()];
+
+                switch (dstFormat.getSemantic()) {
+                case gpu::RGB:
+                case gpu::RGBA:
+                    texel.internalFormat = GL_R8;
+                    break;
+                case gpu::DEPTH:
+                    texel.internalFormat = GL_DEPTH_COMPONENT32;
+                    break;
+                case gpu::DEPTH_STENCIL:
+                    texel.type = GL_UNSIGNED_INT_24_8;
+                    texel.format = GL_DEPTH_STENCIL;
+                    texel.internalFormat = GL_DEPTH24_STENCIL8;
+                    break;
+                default:
+                    qCDebug(gpulogging) << "Unknown combination of texel format";
+                }
+                break;
+            }
+
+            case gpu::VEC2: {
+                texel.format = GL_RG;
+                texel.type = _elementTypeToGLType[dstFormat.getType()];
+
+                switch (dstFormat.getSemantic()) {
+                case gpu::RGB:
+                case gpu::RGBA:
+                    texel.internalFormat = GL_RG8;
+                    break;
+                default:
+                    qCDebug(gpulogging) << "Unknown combination of texel format";
+                }
+
+                break;
+            }
+
+            case gpu::VEC3: {
+                texel.format = GL_RGB;
+
+                texel.type = _elementTypeToGLType[dstFormat.getType()];
+
+                switch (dstFormat.getSemantic()) {
+                case gpu::RGB:
+                case gpu::RGBA:
+                    texel.internalFormat = GL_RGB8;
+                    break;
+                default:
+                    qCDebug(gpulogging) << "Unknown combination of texel format";
+                }
+
+                break;
+            }
+
+            case gpu::VEC4: {
+                texel.format = GL_RGBA;
+                texel.type = _elementTypeToGLType[dstFormat.getType()];
+
+                switch (srcFormat.getSemantic()) {
+                case gpu::BGRA:
+                case gpu::SBGRA:
+                    texel.format = GL_BGRA;
+                    break;
+                case gpu::RGB:
+                case gpu::RGBA:
+                case gpu::SRGB:
+                case gpu::SRGBA:
+                default:
+                    break;
+                };
+
+                switch (dstFormat.getSemantic()) {
+                case gpu::RGB:
+                    texel.internalFormat = GL_RGB8;
+                    break;
+                case gpu::RGBA:
+                    texel.internalFormat = GL_RGBA8;
+                    break;
+                case gpu::SRGB:
+                    texel.internalFormat = GL_SRGB8;
+                    break;
+                case gpu::SRGBA:
+                    texel.internalFormat = GL_SRGB8_ALPHA8;
+                    break;
+                default:
+                    qCDebug(gpulogging) << "Unknown combination of texel format";
+                }
+                break;
+            }
+
+            default:
+                qCDebug(gpulogging) << "Unknown combination of texel format";
+            }
+            return texel;
+        } else {
+            GLTexelFormat texel = { GL_RGBA8, GL_RGBA, GL_UNSIGNED_BYTE };
+
+            switch (dstFormat.getDimension()) {
+            case gpu::SCALAR: {
+                texel.format = GL_RED;
+                texel.type = _elementTypeToGLType[dstFormat.getType()];
+
+                switch (dstFormat.getSemantic()) {
+                case gpu::RGB:
+                case gpu::RGBA:
+                case gpu::SRGB:
+                case gpu::SRGBA:
+                    texel.internalFormat = GL_R8;
+                    switch (dstFormat.getType()) {
+                    case gpu::UINT32: {
+                        texel.internalFormat = GL_R32UI;
+                        break;
+                    }
+                    case gpu::INT32: {
+                        texel.internalFormat = GL_R32I;
+                        break;
+                    }
+                    case gpu::NUINT32: {
+                        texel.internalFormat = GL_R8;
+                        break;
+                    }
+                    case gpu::NINT32: {
+                        texel.internalFormat = GL_R8_SNORM;
+                        break;
+                    }
+                    case gpu::FLOAT: {
+                        texel.internalFormat = GL_R32F;
+                        break;
+                    }
+                    case gpu::UINT16: {
+                        texel.internalFormat = GL_R16UI;
+                        break;
+                    }
+                    case gpu::INT16: {
+                        texel.internalFormat = GL_R16I;
+                        break;
+                    }
+                    case gpu::NUINT16: {
+                        texel.internalFormat = GL_R16;
+                        break;
+                    }
+                    case gpu::NINT16: {
+                        texel.internalFormat = GL_R16_SNORM;
+                        break;
+                    }
+                    case gpu::HALF: {
+                        texel.internalFormat = GL_R16F;
+                        break;
+                    }
+                    case gpu::UINT8: {
+                        texel.internalFormat = GL_R8UI;
+                        break;
+                    }
+                    case gpu::INT8: {
+                        texel.internalFormat = GL_R8I;
+                        break;
+                    }
+                    case gpu::NUINT8: {
+                        if ((dstFormat.getSemantic() == gpu::SRGB || dstFormat.getSemantic() == gpu::SRGBA)) {
+                            texel.internalFormat = GL_SLUMINANCE8;
+                        } else {
+                            texel.internalFormat = GL_R8;
+                        }
+                        break;
+                    }
+                    case gpu::NINT8: {
+                        texel.internalFormat = GL_R8_SNORM;
+                        break;
+                    }
+                    case gpu::NUM_TYPES: { // quiet compiler
+                        Q_UNREACHABLE();
+                    }
+
+                    }
+                    break;
+
+                case gpu::R11G11B10:
+                    texel.format = GL_RGB;
+                    // the type should be float
+                    texel.internalFormat = GL_R11F_G11F_B10F;
+                    break;
+
+                case gpu::DEPTH:
+                    texel.format = GL_DEPTH_COMPONENT; // It's depth component to load it
+                    texel.internalFormat = GL_DEPTH_COMPONENT32;
+                    switch (dstFormat.getType()) {
+                    case gpu::UINT32:
+                    case gpu::INT32:
+                    case gpu::NUINT32:
+                    case gpu::NINT32: {
+                        texel.internalFormat = GL_DEPTH_COMPONENT32;
+                        break;
+                    }
+                    case gpu::FLOAT: {
+                        texel.internalFormat = GL_DEPTH_COMPONENT32F;
+                        break;
+                    }
+                    case gpu::UINT16:
+                    case gpu::INT16:
+                    case gpu::NUINT16:
+                    case gpu::NINT16:
+                    case gpu::HALF: {
+                        texel.internalFormat = GL_DEPTH_COMPONENT16;
+                        break;
+                    }
+                    case gpu::UINT8:
+                    case gpu::INT8:
+                    case gpu::NUINT8:
+                    case gpu::NINT8: {
+                        texel.internalFormat = GL_DEPTH_COMPONENT24;
+                        break;
+                    }
+                    case gpu::NUM_TYPES: { // quiet compiler
+                        Q_UNREACHABLE();
+                    }
+                    }
+                    break;
+                case gpu::DEPTH_STENCIL:
+                    texel.type = GL_UNSIGNED_INT_24_8;
+                    texel.format = GL_DEPTH_STENCIL;
+                    texel.internalFormat = GL_DEPTH24_STENCIL8;
+                    break;
+                default:
+                    qCDebug(gpulogging) << "Unknown combination of texel format";
+                }
+
+                break;
+            }
+
+            case gpu::VEC2: {
+                texel.format = GL_RG;
+                texel.type = _elementTypeToGLType[dstFormat.getType()];
+
+                switch (dstFormat.getSemantic()) {
+                case gpu::RGB:
+                case gpu::RGBA:
+                    texel.internalFormat = GL_RG8;
+                    break;
+                default:
+                    qCDebug(gpulogging) << "Unknown combination of texel format";
+                }
+
+                break;
+            }
+
+            case gpu::VEC3: {
+                texel.format = GL_RGB;
+
+                texel.type = _elementTypeToGLType[dstFormat.getType()];
+
+                switch (dstFormat.getSemantic()) {
+                case gpu::RGB:
+                case gpu::RGBA:
+                    texel.internalFormat = GL_RGB8;
+                    break;
+                case gpu::SRGB:
+                case gpu::SRGBA:
+                    texel.internalFormat = GL_SRGB8; // standard 2.2 gamma correction color
+                    break;
+                default:
+                    qCDebug(gpulogging) << "Unknown combination of texel format";
+                }
+                break;
+            }
+
+            case gpu::VEC4: {
+                texel.format = GL_RGBA;
+                texel.type = _elementTypeToGLType[dstFormat.getType()];
+
+                switch (dstFormat.getSemantic()) {
+                case gpu::RGB:
+                    texel.internalFormat = GL_RGB8;
+                    break;
+                case gpu::RGBA:
+                    texel.internalFormat = GL_RGBA8;
+                    switch (dstFormat.getType()) {
+                    case gpu::UINT32:
+                        texel.format = GL_RGBA_INTEGER;
+                        texel.internalFormat = GL_RGBA32UI;
+                        break;
+                    case gpu::INT32:
+                        texel.format = GL_RGBA_INTEGER;
+                        texel.internalFormat = GL_RGBA32I;
+                        break;
+                    case gpu::FLOAT:
+                        texel.internalFormat = GL_RGBA32F;
+                        break;
+                    case gpu::UINT16:
+                        texel.format = GL_RGBA_INTEGER;
+                        texel.internalFormat = GL_RGBA16UI;
+                        break;
+                    case gpu::INT16:
+                        texel.format = GL_RGBA_INTEGER;
+                        texel.internalFormat = GL_RGBA16I;
+                        break;
+                    case gpu::NUINT16:
+                        texel.format = GL_RGBA;
+                        texel.internalFormat = GL_RGBA16;
+                        break;
+                    case gpu::NINT16:
+                        texel.format = GL_RGBA;
+                        texel.internalFormat = GL_RGBA16_SNORM;
+                        break;
+                    case gpu::HALF:
+                        texel.format = GL_RGBA;
+                        texel.internalFormat = GL_RGBA16F;
+                        break;
+                    case gpu::UINT8:
+                        texel.format = GL_RGBA_INTEGER;
+                        texel.internalFormat = GL_RGBA8UI;
+                        break;
+                    case gpu::INT8:
+                        texel.format = GL_RGBA_INTEGER;
+                        texel.internalFormat = GL_RGBA8I;
+                        break;
+                    case gpu::NUINT8:
+                        texel.format = GL_RGBA;
+                        texel.internalFormat = GL_RGBA8;
+                        break;
+                    case gpu::NINT8:
+                        texel.format = GL_RGBA;
+                        texel.internalFormat = GL_RGBA8_SNORM;
+                        break;
+                    case gpu::NUINT32:
+                    case gpu::NINT32:
+                    case gpu::NUM_TYPES: // quiet compiler
+                        Q_UNREACHABLE();
+                    }
+                    break;
+                case gpu::SRGB:
+                    texel.internalFormat = GL_SRGB8;
+                    break;
+                case gpu::SRGBA:
+                    texel.internalFormat = GL_SRGB8_ALPHA8; // standard 2.2 gamma correction color
+                    break;
+                default:
+                    qCDebug(gpulogging) << "Unknown combination of texel format";
+                }
+                break;
+            }
+
+            default:
+                qCDebug(gpulogging) << "Unknown combination of texel format";
+            }
+            return texel;
+        }
+    }
+};
diff --git a/libraries/model-networking/src/model-networking/ModelCache.cpp b/libraries/model-networking/src/model-networking/ModelCache.cpp
index 41c2a2e194..4985859c40 100644
--- a/libraries/model-networking/src/model-networking/ModelCache.cpp
+++ b/libraries/model-networking/src/model-networking/ModelCache.cpp
@@ -118,10 +118,8 @@ void GeometryReader::run() {
     }
     QThread::currentThread()->setPriority(QThread::LowPriority);
 
-    // Ensure the resource is still being requested
-    auto resource = _resource.toStrongRef();
-    if (!resource) {
-        qCWarning(modelnetworking) << "Abandoning load of" << _url << "; could not get strong ref";
+    if (!_resource.data()) {
+        qCWarning(modelnetworking) << "Abandoning load of" << _url << "; resource was deleted";
         return;
     }
 
@@ -146,14 +144,28 @@ void GeometryReader::run() {
                 throw QString("unsupported format");
             }
 
-            QMetaObject::invokeMethod(resource.data(), "setGeometryDefinition",
-                Q_ARG(void*, fbxGeometry));
+            // Ensure the resource has not been deleted, and won't be while invokeMethod is in flight.
+            auto resource = _resource.toStrongRef();
+            if (!resource) {
+                qCWarning(modelnetworking) << "Abandoning load of" << _url << "; could not get strong ref";
+                delete fbxGeometry;
+            } else {
+                QMetaObject::invokeMethod(resource.data(), "setGeometryDefinition", Qt::BlockingQueuedConnection, Q_ARG(void*, fbxGeometry));
+            }
         } else {
             throw QString("url is invalid");
         }
     } catch (const QString& error) {
+
         qCDebug(modelnetworking) << "Error reading " << _url << ": " << error;
-        QMetaObject::invokeMethod(resource.data(), "finishedLoading", Q_ARG(bool, false));
+
+        auto resource = _resource.toStrongRef();
+        // Ensure the resoruce has not been deleted, and won't be while invokeMethod is in flight.
+        if (!resource) {
+            qCWarning(modelnetworking) << "Abandoning load of" << _url << "; could not get strong ref";
+        } else {
+            QMetaObject::invokeMethod(resource.data(), "finishedLoading", Qt::BlockingQueuedConnection, Q_ARG(bool, false));
+        }
     }
 
     QThread::currentThread()->setPriority(originalPriority);
@@ -232,7 +244,7 @@ std::shared_ptr<NetworkGeometry> ModelCache::getGeometry(const QUrl& url, const
     GeometryExtra geometryExtra = { mapping, textureBaseUrl };
     GeometryResource::Pointer resource = getResource(url, QUrl(), true, &geometryExtra).staticCast<GeometryResource>();
     if (resource) {
-        if (resource->isLoaded() && !resource->hasTextures()) {
+        if (resource->isLoaded() && resource->shouldSetTextures()) {
             resource->setTextures();
         }
         return std::make_shared<NetworkGeometry>(resource);
diff --git a/libraries/model-networking/src/model-networking/ModelCache.h b/libraries/model-networking/src/model-networking/ModelCache.h
index 81883d972d..f479dc9ce2 100644
--- a/libraries/model-networking/src/model-networking/ModelCache.h
+++ b/libraries/model-networking/src/model-networking/ModelCache.h
@@ -107,7 +107,8 @@ protected:
     friend class GeometryMappingResource;
 
     // Geometries may not hold onto textures while cached - that is for the texture cache
-    bool hasTextures() const { return !_materials.empty(); }
+    // Instead, these methods clear and reset textures from the geometry when caching/loading
+    bool shouldSetTextures() const { return _geometry && _materials.empty(); }
     void setTextures();
     void resetTextures();
 
diff --git a/libraries/model-networking/src/model-networking/TextureCache.cpp b/libraries/model-networking/src/model-networking/TextureCache.cpp
index bbe907694a..91e5fda06b 100644
--- a/libraries/model-networking/src/model-networking/TextureCache.cpp
+++ b/libraries/model-networking/src/model-networking/TextureCache.cpp
@@ -11,19 +11,21 @@
 
 #include "TextureCache.h"
 
+#include <mutex>
+
 #include <QNetworkReply>
 #include <QPainter>
 #include <QRunnable>
 #include <QThreadPool>
 #include <QImageReader>
 
-#include <mutex>
-
 #include <glm/glm.hpp>
 #include <glm/gtc/random.hpp>
 
 #include <gpu/Batch.h>
 
+#include <shared/NsightHelpers.h>
+
 #include <Finally.h>
 #include <PathUtils.h>
 
@@ -280,6 +282,7 @@ void ImageReader::listSupportedImageFormats() {
 }
 
 void ImageReader::run() {
+    PROFILE_RANGE_EX(__FUNCTION__, 0xffff0000, nullptr);
     auto originalPriority = QThread::currentThread()->priority();
     if (originalPriority == QThread::InheritPriority) {
         originalPriority = QThread::NormalPriority;
@@ -326,6 +329,8 @@ void ImageReader::run() {
         }
 
         auto url = _url.toString().toStdString();
+
+        PROFILE_RANGE_EX(__FUNCTION__"::textureLoader", 0xffffff00, nullptr);
         texture = resource.dynamicCast<NetworkTexture>()->getTextureLoader()(image, url);
     }
 
diff --git a/libraries/model/src/model/Skybox.h b/libraries/model/src/model/Skybox.h
index e9e7ee8b26..8c9e7bb1d6 100755
--- a/libraries/model/src/model/Skybox.h
+++ b/libraries/model/src/model/Skybox.h
@@ -35,6 +35,8 @@ public:
     void setCubemap(const gpu::TexturePointer& cubemap);
     const gpu::TexturePointer& getCubemap() const { return _cubemap; }
 
+    virtual void clear() { setCubemap(nullptr); }
+
     void prepare(gpu::Batch& batch, int textureSlot = SKYBOX_SKYMAP_SLOT, int bufferSlot = SKYBOX_CONSTANTS_SLOT) const;
     virtual void render(gpu::Batch& batch, const ViewFrustum& frustum) const;
 
diff --git a/libraries/procedural/src/procedural/Procedural.cpp b/libraries/procedural/src/procedural/Procedural.cpp
index d3aed38198..cedf76b37a 100644
--- a/libraries/procedural/src/procedural/Procedural.cpp
+++ b/libraries/procedural/src/procedural/Procedural.cpp
@@ -96,6 +96,7 @@ bool Procedural::parseVersion(const QJsonValue& version) {
 bool Procedural::parseUrl(const QUrl& shaderUrl) {
     if (!shaderUrl.isValid()) {
         qWarning() << "Invalid shader URL: " << shaderUrl;
+        _networkShader.reset();
         return false;
     }
 
@@ -110,6 +111,7 @@ bool Procedural::parseUrl(const QUrl& shaderUrl) {
         _shaderPath = _shaderUrl.toLocalFile();
         qDebug() << "Shader path: " << _shaderPath;
         if (!QFile(_shaderPath).exists()) {
+            _networkShader.reset();
             return false;;
         }
     } else {
@@ -135,9 +137,14 @@ bool Procedural::parseTextures(const QJsonArray& channels) {
 
         auto textureCache = DependencyManager::get<TextureCache>();
         size_t channelCount = std::min(MAX_PROCEDURAL_TEXTURE_CHANNELS, (size_t)_parsedChannels.size());
-        for (size_t i = 0; i < channelCount; ++i) {
-            QString url = _parsedChannels.at((int)i).toString();
-            _channels[i] = textureCache->getTexture(QUrl(url));
+        size_t channel = 0;
+        for (; channel < channelCount; ++channel) {
+            QString url = _parsedChannels.at((int)channel).toString();
+            _channels[channel] = textureCache->getTexture(QUrl(url));
+        }
+        for (; channel < MAX_PROCEDURAL_TEXTURE_CHANNELS; ++channel) {
+            // Release those textures no longer in use
+            _channels[channel] = textureCache->getTexture(QUrl());
         }
 
         _channelsDirty = true;
@@ -149,20 +156,21 @@ bool Procedural::parseTextures(const QJsonArray& channels) {
 void Procedural::parse(const QJsonObject& proceduralData) {
     _enabled = false;
 
-    if (proceduralData.isEmpty()) {
-        return;
-    }
-
     auto version = proceduralData[VERSION_KEY];
     auto shaderUrl = proceduralData[URL_KEY].toString();
     shaderUrl = ResourceManager::normalizeURL(shaderUrl);
     auto uniforms = proceduralData[UNIFORMS_KEY].toObject();
     auto channels = proceduralData[CHANNELS_KEY].toArray();
 
-    if (parseVersion(version) &&
-        parseUrl(shaderUrl) &&
-        parseUniforms(uniforms) &&
-        parseTextures(channels)) {
+    bool isValid = true;
+
+    // Run through parsing regardless of validity to clear old cached resources
+    isValid = parseVersion(version) && isValid;
+    isValid = parseUrl(shaderUrl) && isValid;
+    isValid = parseUniforms(uniforms) && isValid;
+    isValid = parseTextures(channels) && isValid;
+
+    if (!proceduralData.isEmpty() && isValid) {
         _enabled = true;
     }
 }
diff --git a/libraries/procedural/src/procedural/ProceduralSkybox.cpp b/libraries/procedural/src/procedural/ProceduralSkybox.cpp
index 4ff38eac74..1aa59c90d7 100644
--- a/libraries/procedural/src/procedural/ProceduralSkybox.cpp
+++ b/libraries/procedural/src/procedural/ProceduralSkybox.cpp
@@ -25,6 +25,14 @@ ProceduralSkybox::ProceduralSkybox() : model::Skybox() {
     _procedural._state->setStencilTest(true, 0xFF, gpu::State::StencilTest(0, 0xFF, gpu::EQUAL, gpu::State::STENCIL_OP_KEEP, gpu::State::STENCIL_OP_KEEP, gpu::State::STENCIL_OP_KEEP));
 }
 
+void ProceduralSkybox::clear() {
+    // Parse and prepare a procedural with no shaders to release textures
+    parse(QString());
+    _procedural.ready();
+
+    Skybox::clear();
+}
+
 void ProceduralSkybox::render(gpu::Batch& batch, const ViewFrustum& frustum) const {
     if (_procedural.ready()) {
         ProceduralSkybox::render(batch, frustum, (*this));
diff --git a/libraries/procedural/src/procedural/ProceduralSkybox.h b/libraries/procedural/src/procedural/ProceduralSkybox.h
index e817ce271d..2b8f2327a0 100644
--- a/libraries/procedural/src/procedural/ProceduralSkybox.h
+++ b/libraries/procedural/src/procedural/ProceduralSkybox.h
@@ -24,6 +24,8 @@ public:
 
     void parse(const QString& userData) { _procedural.parse(userData); }
 
+    virtual void clear() override;
+
     virtual void render(gpu::Batch& batch, const ViewFrustum& frustum) const;
     static void render(gpu::Batch& batch, const ViewFrustum& frustum, const ProceduralSkybox& skybox);
 
diff --git a/libraries/render-utils/src/Model.cpp b/libraries/render-utils/src/Model.cpp
index 858f7d3ee7..eda856342c 100644
--- a/libraries/render-utils/src/Model.cpp
+++ b/libraries/render-utils/src/Model.cpp
@@ -159,11 +159,13 @@ void Model::updateRenderItems() {
         Transform collisionMeshOffset;
         collisionMeshOffset.postTranslate(self->_offset);
 
+        uint32_t deleteGeometryCounter = self->_deleteGeometryCounter;
+
         render::PendingChanges pendingChanges;
         foreach (auto itemID, self->_modelMeshRenderItems.keys()) {
-            pendingChanges.updateItem<ModelMeshPartPayload>(itemID, [modelTransform, modelMeshOffset](ModelMeshPartPayload& data) {
+            pendingChanges.updateItem<ModelMeshPartPayload>(itemID, [modelTransform, modelMeshOffset, deleteGeometryCounter](ModelMeshPartPayload& data) {
                 // Ensure the model geometry was not reset between frames
-                if (data._model->isLoaded()) {
+                if (data._model && data._model->isLoaded() && deleteGeometryCounter == data._model->_deleteGeometryCounter) {
                     // lazy update of cluster matrices used for rendering.  We need to update them here, so we can correctly update the bounding box.
                     data._model->updateClusterMatrices(modelTransform.getTranslation(), modelTransform.getRotation());
 
@@ -1146,6 +1148,7 @@ void Model::setBlendedVertices(int blendNumber, const std::weak_ptr<NetworkGeome
 }
 
 void Model::deleteGeometry() {
+    _deleteGeometryCounter++;
     _blendedVertexBuffers.clear();
     _meshStates.clear();
     _rig->destroyAnimGraph();
diff --git a/libraries/render-utils/src/Model.h b/libraries/render-utils/src/Model.h
index 4e6e727b44..581184918d 100644
--- a/libraries/render-utils/src/Model.h
+++ b/libraries/render-utils/src/Model.h
@@ -394,6 +394,8 @@ protected:
 
     friend class ModelMeshPartPayload;
     RigPointer _rig;
+
+    uint32_t _deleteGeometryCounter { 0 };
 };
 
 Q_DECLARE_METATYPE(ModelPointer)
diff --git a/libraries/shared/src/shared/NsightHelpers.h b/libraries/shared/src/shared/NsightHelpers.h
index 9853171b34..c637c78162 100644
--- a/libraries/shared/src/shared/NsightHelpers.h
+++ b/libraries/shared/src/shared/NsightHelpers.h
@@ -20,7 +20,7 @@ public:
 };
 
 #define PROFILE_RANGE(name) ProfileRange profileRangeThis(name);
-#define PROFILE_RANGE_EX(name, argbColor, payload) ProfileRange profileRangeThis(name, argbColor, payload);
+#define PROFILE_RANGE_EX(name, argbColor, payload) ProfileRange profileRangeThis(name, argbColor, (uint64_t)payload);
 #else
 #define PROFILE_RANGE(name)
 #define PROFILE_RANGE_EX(name, argbColor, payload)