diff --git a/interface/resources/qml/LoginDialog/LinkAccountBody.qml b/interface/resources/qml/LoginDialog/LinkAccountBody.qml
index 4196b7f168..57293cb5e3 100644
--- a/interface/resources/qml/LoginDialog/LinkAccountBody.qml
+++ b/interface/resources/qml/LoginDialog/LinkAccountBody.qml
@@ -346,7 +346,15 @@ Item {
         target: loginDialog
         onHandleLoginCompleted: {
             console.log("Login Succeeded, linking steam account")
-
+            var poppedUp = Settings.getValue("loginDialogPoppedUp", false);
+            if (poppedUp) {
+                console.log("[ENCOURAGELOGINDIALOG]: logging in")
+                var data = {
+                    "action": "user logged in"
+                };
+                UserActivityLogger.logAction("encourageLoginDialog", data);
+                Settings.setValue("loginDialogPoppedUp", false);
+            }
             if (loginDialog.isSteamRunning()) {
                 loginDialog.linkSteam()
             } else {
@@ -354,23 +362,20 @@ Item {
                 bodyLoader.item.width = root.pane.width
                 bodyLoader.item.height = root.pane.height
             }
-            if (Settings.getValue("loginDialogPoppedUp", false)) {
-                var data = {
-                    "action": "user logged in"
-                };
-                UserActivityLogger.logAction("encourageLoginDialog", data);
-            }
         }
         onHandleLoginFailed: {
             console.log("Login Failed")
-            mainTextContainer.visible = true
-            toggleLoading(false)
-            if (Settings.getValue("loginDialogPoppedUp", false)) {
+            var poppedUp = Settings.getValue("loginDialogPoppedUp", false);
+            if (poppedUp) {
+                console.log("[ENCOURAGELOGINDIALOG]: failed logging in")
                 var data = {
                     "action": "user failed logging in"
                 };
                 UserActivityLogger.logAction("encourageLoginDialog", data);
+                Settings.setValue("loginDialogPoppedUp", false);
             }
+            mainTextContainer.visible = true
+            toggleLoading(false)
         }
         onHandleLinkCompleted: {
             console.log("Link Succeeded")
diff --git a/libraries/fbx/src/FBX.h b/libraries/fbx/src/FBX.h
index 7bd87a4554..fdebb16bc8 100644
--- a/libraries/fbx/src/FBX.h
+++ b/libraries/fbx/src/FBX.h
@@ -240,7 +240,6 @@ public:
     QVector<glm::vec3> vertices;
     QVector<glm::vec3> normals;
     QVector<glm::vec3> tangents;
-    mutable QVector<NormalType> normalsAndTangents; // Populated later if needed for blendshapes
     QVector<glm::vec3> colors;
     QVector<glm::vec2> texCoords;
     QVector<glm::vec2> texCoords1;
diff --git a/libraries/gpu-gl-common/src/gpu/gl/GLBackend.cpp b/libraries/gpu-gl-common/src/gpu/gl/GLBackend.cpp
index c1848d99b1..4fea4f2dc5 100644
--- a/libraries/gpu-gl-common/src/gpu/gl/GLBackend.cpp
+++ b/libraries/gpu-gl-common/src/gpu/gl/GLBackend.cpp
@@ -201,9 +201,10 @@ void GLBackend::renderPassTransfer(const Batch& batch) {
                 {
                     Vec2u outputSize{ 1,1 };
 
-                    if (_output._framebuffer) {
-                        outputSize.x = _output._framebuffer->getWidth();
-                        outputSize.y = _output._framebuffer->getHeight();
+                    auto framebuffer = acquire(_output._framebuffer);
+                    if (framebuffer) {
+                        outputSize.x = framebuffer->getWidth();
+                        outputSize.y = framebuffer->getHeight();
                     } else if (glm::dot(_transform._projectionJitter, _transform._projectionJitter)>0.0f) {
                         qCWarning(gpugllogging) << "Jittering needs to have a frame buffer to be set";
                     }
@@ -220,6 +221,7 @@ void GLBackend::renderPassTransfer(const Batch& batch) {
                     _stereo._contextDisable = false;
                     break;
 
+                case Batch::COMMAND_setFramebuffer:
                 case Batch::COMMAND_setViewportTransform:
                 case Batch::COMMAND_setViewTransform:
                 case Batch::COMMAND_setProjectionTransform:
diff --git a/libraries/gpu-gl-common/src/gpu/gl/GLBackend.h b/libraries/gpu-gl-common/src/gpu/gl/GLBackend.h
index 9b3a28e6fd..0b76ef17de 100644
--- a/libraries/gpu-gl-common/src/gpu/gl/GLBackend.h
+++ b/libraries/gpu-gl-common/src/gpu/gl/GLBackend.h
@@ -30,7 +30,6 @@
 
 #include "GLShared.h"
 
-
 // Different versions for the stereo drawcall
 // Current preferred is  "instanced" which draw the shape twice but instanced and rely on clipping plane to draw left/right side only
 #if defined(USE_GLES)
@@ -40,7 +39,6 @@
 #define GPU_STEREO_TECHNIQUE_INSTANCED
 #endif
 
-
 // Let these be configured by the one define picked above
 #ifdef GPU_STEREO_TECHNIQUE_DOUBLED_SIMPLE
 #define GPU_STEREO_DRAWCALL_DOUBLED
@@ -56,8 +54,153 @@
 #define GPU_STEREO_CAMERA_BUFFER
 #endif
 
+//
+// GL Backend pointer storage mechanism
+// One of the following three defines must be defined.
+// GPU_POINTER_STORAGE_SHARED
+
+// The platonic ideal, use references to smart pointers.
+// However, this produces artifacts because there are too many places in the code right now that
+// create temporary values (undesirable smart pointer duplications) and then those temp variables
+// get passed on and have their reference taken, and then invalidated
+// GPU_POINTER_STORAGE_REF
+
+// Raw pointer manipulation.  Seems more dangerous than the reference wrappers,
+// but in practice, the danger of grabbing a reference to a temporary variable
+// is causing issues
+// GPU_POINTER_STORAGE_RAW
+
+#if defined(USE_GLES)
+#define GPU_POINTER_STORAGE_SHARED
+#else
+#define GPU_POINTER_STORAGE_RAW
+#endif
+
 namespace gpu { namespace gl {
 
+#if defined(GPU_POINTER_STORAGE_SHARED)
+template <typename T>
+static inline bool compare(const std::shared_ptr<T>& a, const std::shared_ptr<T>& b) {
+    return a == b;
+}
+
+template <typename T>
+static inline T* acquire(const std::shared_ptr<T>& pointer) {
+    return pointer.get();
+}
+
+template <typename T>
+static inline void reset(std::shared_ptr<T>& pointer) {
+    return pointer.reset();
+}
+
+template <typename T>
+static inline bool valid(const std::shared_ptr<T>& pointer) {
+    return pointer.operator bool();
+}
+
+template <typename T>
+static inline void assign(std::shared_ptr<T>& pointer, const std::shared_ptr<T>& source) {
+    pointer = source;
+}
+
+using BufferReference = BufferPointer;
+using TextureReference = TexturePointer;
+using FramebufferReference = FramebufferPointer;
+using FormatReference = Stream::FormatPointer;
+using PipelineReference = PipelinePointer;
+
+#define GPU_REFERENCE_INIT_VALUE nullptr
+
+#elif defined(GPU_POINTER_STORAGE_REF)
+
+template <typename T>
+class PointerReferenceWrapper : public std::reference_wrapper<const std::shared_ptr<T>> {
+    using Parent = std::reference_wrapper<const std::shared_ptr<T>>;
+
+public:
+    using Pointer = std::shared_ptr<T>;
+    PointerReferenceWrapper() : Parent(EMPTY()) {}
+    PointerReferenceWrapper(const Pointer& pointer) : Parent(pointer) {}
+    void clear() { *this = EMPTY(); }
+
+private:
+    static const Pointer& EMPTY() {
+        static const Pointer EMPTY_VALUE;
+        return EMPTY_VALUE;
+    };
+};
+
+template <typename T>
+static bool compare(const PointerReferenceWrapper<T>& reference, const std::shared_ptr<T>& pointer) {
+    return reference.get() == pointer;
+}
+
+template <typename T>
+static inline T* acquire(const PointerReferenceWrapper<T>& reference) {
+    return reference.get().get();
+}
+
+template <typename T>
+static void assign(PointerReferenceWrapper<T>& reference, const std::shared_ptr<T>& pointer) {
+    reference = pointer;
+}
+
+template <typename T>
+static bool valid(const PointerReferenceWrapper<T>& reference) {
+    return reference.get().operator bool();
+}
+
+template <typename T>
+static inline void reset(PointerReferenceWrapper<T>& reference) {
+    return reference.clear();
+}
+
+using BufferReference = PointerReferenceWrapper<Buffer>;
+using TextureReference = PointerReferenceWrapper<Texture>;
+using FramebufferReference = PointerReferenceWrapper<Framebuffer>;
+using FormatReference = PointerReferenceWrapper<Stream::Format>;
+using PipelineReference = PointerReferenceWrapper<Pipeline>;
+
+#define GPU_REFERENCE_INIT_VALUE
+
+#elif defined(GPU_POINTER_STORAGE_RAW)
+
+template <typename T>
+static bool compare(const T* const& rawPointer, const std::shared_ptr<T>& pointer) {
+    return rawPointer == pointer.get();
+}
+
+template <typename T>
+static inline T* acquire(T*& rawPointer) {
+    return rawPointer;
+}
+
+template <typename T>
+static inline bool valid(const T* const& rawPointer) {
+    return rawPointer;
+}
+
+template <typename T>
+static inline void reset(T*& rawPointer) {
+    rawPointer = nullptr;
+}
+
+template <typename T>
+static inline void assign(T*& rawPointer, const std::shared_ptr<T>& pointer) {
+    rawPointer = pointer.get();
+}
+
+using BufferReference = Buffer*;
+using TextureReference = Texture*;
+using FramebufferReference = Framebuffer*;
+using FormatReference = Stream::Format*;
+using PipelineReference = Pipeline*;
+
+#define GPU_REFERENCE_INIT_VALUE nullptr
+
+#endif
+
 class GLBackend : public Backend, public std::enable_shared_from_this<GLBackend> {
     // Context Backend static interface required
     friend class gpu::Context;
@@ -67,8 +210,8 @@ class GLBackend : public Backend, public std::enable_shared_from_this<GLBackend>
 protected:
     explicit GLBackend(bool syncCache);
     GLBackend();
-public:
 
+public:
 #if defined(USE_GLES)
     // https://www.khronos.org/registry/OpenGL-Refpages/es3/html/glGet.xhtml
     static const GLint MIN_REQUIRED_TEXTURE_IMAGE_UNITS = 16;
@@ -109,8 +252,8 @@ public:
     // This is the ugly "download the pixels to sysmem for taking a snapshot"
     // Just avoid using it, it's ugly and will break performances
     virtual void downloadFramebuffer(const FramebufferPointer& srcFramebuffer,
-                                     const Vec4i& region, QImage& destImage) final override;
-
+                                     const Vec4i& region,
+                                     QImage& destImage) final override;
 
     // this is the maximum numeber of available input buffers
     size_t getNumInputBuffers() const { return _input._invalidBuffers.size(); }
@@ -131,7 +274,6 @@ public:
     static const int MAX_NUM_RESOURCE_TABLE_TEXTURES = 2;
     size_t getMaxNumResourceTextureTables() const { return MAX_NUM_RESOURCE_TABLE_TEXTURES; }
 
-
     // Draw Stage
     virtual void do_draw(const Batch& batch, size_t paramOffset) = 0;
     virtual void do_drawIndexed(const Batch& batch, size_t paramOffset) = 0;
@@ -183,7 +325,6 @@ public:
     // Reset stages
     virtual void do_resetStages(const Batch& batch, size_t paramOffset) final;
 
-    
     virtual void do_disableContextViewCorrection(const Batch& batch, size_t paramOffset) final;
     virtual void do_restoreContextViewCorrection(const Batch& batch, size_t paramOffset) final;
 
@@ -203,7 +344,7 @@ public:
     virtual void do_popProfileRange(const Batch& batch, size_t paramOffset) final;
 
     // TODO: As long as we have gl calls explicitely issued from interface
-    // code, we need to be able to record and batch these calls. THe long 
+    // code, we need to be able to record and batch these calls. THe long
     // term strategy is to get rid of any GL calls in favor of the HIFI GPU API
     virtual void do_glUniform1i(const Batch& batch, size_t paramOffset) final;
     virtual void do_glUniform1f(const Batch& batch, size_t paramOffset) final;
@@ -228,7 +369,9 @@ public:
     virtual void do_setStateAntialiasedLineEnable(bool enable) final;
     virtual void do_setStateDepthBias(Vec2 bias) final;
     virtual void do_setStateDepthTest(State::DepthTest test) final;
-    virtual void do_setStateStencil(State::StencilActivation activation, State::StencilTest frontTest, State::StencilTest backTest) final;
+    virtual void do_setStateStencil(State::StencilActivation activation,
+                                    State::StencilTest frontTest,
+                                    State::StencilTest backTest) final;
     virtual void do_setStateAlphaToCoverageEnable(bool enable) final;
     virtual void do_setStateSampleMask(uint32 mask) final;
     virtual void do_setStateBlend(State::BlendFunction blendFunction) final;
@@ -257,7 +400,9 @@ public:
     virtual void releaseQuery(GLuint id) const;
     virtual void queueLambda(const std::function<void()> lambda) const;
 
-    bool isTextureManagementSparseEnabled() const override { return (_textureManagement._sparseCapable && Texture::getEnableSparseTextures()); }
+    bool isTextureManagementSparseEnabled() const override {
+        return (_textureManagement._sparseCapable && Texture::getEnableSparseTextures());
+    }
 
 protected:
     virtual GLint getRealUniformLocation(GLint location) const;
@@ -266,11 +411,11 @@ protected:
 
     // FIXME instead of a single flag, create a features struct similar to
     // https://www.khronos.org/registry/vulkan/specs/1.0/man/html/VkPhysicalDeviceFeatures.html
-    virtual bool supportsBindless() const { return false;  }
+    virtual bool supportsBindless() const { return false; }
 
     static const size_t INVALID_OFFSET = (size_t)-1;
-    bool _inRenderTransferPass { false };
-    int _currentDraw { -1 };
+    bool _inRenderTransferPass{ false };
+    int _currentDraw{ -1 };
 
     std::list<std::string> profileRanges;
     mutable Mutex _trashMutex;
@@ -299,46 +444,36 @@ protected:
     virtual void updateInput() = 0;
 
     struct InputStageState {
-        bool _invalidFormat { true };
-        bool _lastUpdateStereoState{ false }; 
+        bool _invalidFormat{ true };
+        bool _lastUpdateStereoState{ false };
         bool _hadColorAttribute{ true };
-        Stream::FormatPointer _format;
+        FormatReference _format{ GPU_REFERENCE_INIT_VALUE };
         std::string _formatKey;
 
         typedef std::bitset<MAX_NUM_ATTRIBUTES> ActivationCache;
-        ActivationCache _attributeActivation { 0 };
+        ActivationCache _attributeActivation{ 0 };
 
         typedef std::bitset<MAX_NUM_INPUT_BUFFERS> BuffersState;
 
         BuffersState _invalidBuffers{ 0 };
         BuffersState _attribBindingBuffers{ 0 };
 
-        Buffers _buffers;
-        Offsets _bufferOffsets;
-        Offsets _bufferStrides;
-        std::vector<GLuint> _bufferVBOs;
+        std::array<BufferReference, MAX_NUM_INPUT_BUFFERS> _buffers{};
+        std::array<Offset, MAX_NUM_INPUT_BUFFERS> _bufferOffsets{};
+        std::array<Offset, MAX_NUM_INPUT_BUFFERS> _bufferStrides{};
+        std::array<GLuint, MAX_NUM_INPUT_BUFFERS> _bufferVBOs{};
 
         glm::vec4 _colorAttribute{ 0.0f };
 
-        BufferPointer _indexBuffer;
-        Offset _indexBufferOffset { 0 };
-        Type _indexBufferType { UINT32 };
-        
-        BufferPointer _indirectBuffer;
+        BufferReference _indexBuffer{};
+        Offset _indexBufferOffset{ 0 };
+        Type _indexBufferType{ UINT32 };
+
+        BufferReference _indirectBuffer{};
         Offset _indirectBufferOffset{ 0 };
         Offset _indirectBufferStride{ 0 };
 
-        GLuint _defaultVAO { 0 };
-
-        InputStageState() :
-            _invalidFormat(true),
-            _format(0),
-            _formatKey(),
-            _attributeActivation(0),
-            _buffers(_invalidBuffers.size(), BufferPointer(0)),
-            _bufferOffsets(_invalidBuffers.size(), 0),
-            _bufferStrides(_invalidBuffers.size(), 0),
-            _bufferVBOs(_invalidBuffers.size(), 0) {}
+        GLuint _defaultVAO{ 0 };
     } _input;
 
     virtual void initTransform() = 0;
@@ -349,7 +484,7 @@ protected:
     virtual void resetTransformStage();
 
     // Allows for correction of the camera pose to account for changes
-    // between the time when a was recorded and the time(s) when it is 
+    // between the time when a was recorded and the time(s) when it is
     // executed
     // Prev is the previous correction used at previous frame
     struct CameraCorrection {
@@ -364,9 +499,12 @@ protected:
         struct Cameras {
             TransformCamera _cams[2];
 
-            Cameras() {};
+            Cameras(){};
             Cameras(const TransformCamera& cam) { memcpy(_cams, &cam, sizeof(TransformCamera)); };
-            Cameras(const TransformCamera& camL, const TransformCamera& camR) { memcpy(_cams, &camL, sizeof(TransformCamera)); memcpy(_cams + 1, &camR, sizeof(TransformCamera)); };
+            Cameras(const TransformCamera& camL, const TransformCamera& camR) {
+                memcpy(_cams, &camL, sizeof(TransformCamera));
+                memcpy(_cams + 1, &camR, sizeof(TransformCamera));
+            };
         };
 
         using CameraBufferElement = Cameras;
@@ -380,25 +518,24 @@ protected:
 
         mutable std::map<std::string, GLvoid*> _drawCallInfoOffsets;
 
-        GLuint _objectBuffer { 0 };
-        GLuint _cameraBuffer { 0 };
-        GLuint _drawCallInfoBuffer { 0 };
-        GLuint _objectBufferTexture { 0 };
-        size_t _cameraUboSize { 0 };
+        GLuint _objectBuffer{ 0 };
+        GLuint _cameraBuffer{ 0 };
+        GLuint _drawCallInfoBuffer{ 0 };
+        GLuint _objectBufferTexture{ 0 };
+        size_t _cameraUboSize{ 0 };
         bool _viewIsCamera{ false };
-        bool _skybox { false };
+        bool _skybox{ false };
         Transform _view;
         CameraCorrection _correction;
         bool _viewCorrectionEnabled{ true };
 
-
         Mat4 _projection;
-        Vec4i _viewport { 0, 0, 1, 1 };
-        Vec2 _depthRange { 0.0f, 1.0f };
+        Vec4i _viewport{ 0, 0, 1, 1 };
+        Vec2 _depthRange{ 0.0f, 1.0f };
         Vec2 _projectionJitter{ 0.0f, 0.0f };
-        bool _invalidView { false };
-        bool _invalidProj { false };
-        bool _invalidViewport { false };
+        bool _invalidView{ false };
+        bool _invalidProj{ false };
+        bool _invalidViewport{ false };
 
         bool _enabledDrawcallInfoBuffer{ false };
 
@@ -417,45 +554,54 @@ protected:
 
     struct UniformStageState {
         struct BufferState {
-            BufferPointer buffer;
+            BufferReference buffer{};
             GLintptr offset{ 0 };
             GLsizeiptr size{ 0 };
-            BufferState(const BufferPointer& buffer = nullptr, GLintptr offset = 0, GLsizeiptr size = 0);
-            bool operator ==(BufferState& other) const {
-                return offset == other.offset && size == other.size && buffer == other.buffer;
+
+            BufferState& operator=(const BufferState& other) = delete;
+            void reset() {
+                gpu::gl::reset(buffer);
+                offset = 0;
+                size = 0;
+            }
+            bool compare(const BufferPointer& buffer, GLintptr offset, GLsizeiptr size) {
+                const auto& self = *this;
+                return (self.offset == offset && self.size == size && gpu::gl::compare(self.buffer, buffer));
             }
         };
 
         // MAX_NUM_UNIFORM_BUFFERS-1 is the max uniform index BATCHES are allowed to set, but
-        // MIN_REQUIRED_UNIFORM_BUFFER_BINDINGS is used here because the backend sets some 
-        // internal UBOs for things like camera correction 
+        // MIN_REQUIRED_UNIFORM_BUFFER_BINDINGS is used here because the backend sets some
+        // internal UBOs for things like camera correction
         std::array<BufferState, MIN_REQUIRED_UNIFORM_BUFFER_BINDINGS> _buffers;
     } _uniform;
 
-    // Helper function that provides common code 
+    // Helper function that provides common code
     void bindUniformBuffer(uint32_t slot, const BufferPointer& buffer, GLintptr offset = 0, GLsizeiptr size = 0);
     void releaseUniformBuffer(uint32_t slot);
     void resetUniformStage();
 
     // update resource cache and do the gl bind/unbind call with the current gpu::Buffer cached at slot s
     // This is using different gl object  depending on the gl version
-    virtual bool bindResourceBuffer(uint32_t slot, BufferPointer& buffer) = 0;
+    virtual bool bindResourceBuffer(uint32_t slot, const BufferPointer& buffer) = 0;
     virtual void releaseResourceBuffer(uint32_t slot) = 0;
 
-    // Helper function that provides common code used by do_setResourceTexture and 
+    // Helper function that provides common code used by do_setResourceTexture and
     // do_setResourceTextureTable (in non-bindless mode)
     void bindResourceTexture(uint32_t slot, const TexturePointer& texture);
 
-
     // update resource cache and do the gl unbind call with the current gpu::Texture cached at slot s
     void releaseResourceTexture(uint32_t slot);
 
     void resetResourceStage();
 
     struct ResourceStageState {
-        std::array<BufferPointer, MAX_NUM_RESOURCE_BUFFERS> _buffers;
-        std::array<TexturePointer, MAX_NUM_RESOURCE_TEXTURES> _textures;
-        //Textures _textures { { MAX_NUM_RESOURCE_TEXTURES } };
+        struct TextureState {
+            TextureReference _texture{};
+            GLenum _target;
+        };
+        std::array<BufferReference, MAX_NUM_RESOURCE_BUFFERS> _buffers{};
+        std::array<TextureState, MAX_NUM_RESOURCE_TEXTURES> _textures{};
         int findEmptyTextureSlot() const;
     } _resource;
 
@@ -470,21 +616,22 @@ protected:
     void resetPipelineStage();
 
     struct PipelineStageState {
-        PipelinePointer _pipeline;
+        PipelineReference _pipeline{};
 
-        GLuint _program { 0 };
-        bool _cameraCorrection { false };
-        GLShader* _programShader { nullptr };
-        bool _invalidProgram { false };
+        GLuint _program{ 0 };
+        bool _cameraCorrection{ false };
+        GLShader* _programShader{ nullptr };
+        bool _invalidProgram{ false };
 
-        BufferView _cameraCorrectionBuffer { gpu::BufferView(std::make_shared<gpu::Buffer>(sizeof(CameraCorrection), nullptr )) };
-        BufferView _cameraCorrectionBufferIdentity { gpu::BufferView(std::make_shared<gpu::Buffer>(sizeof(CameraCorrection), nullptr )) };
+        BufferView _cameraCorrectionBuffer{ gpu::BufferView(std::make_shared<gpu::Buffer>(sizeof(CameraCorrection), nullptr)) };
+        BufferView _cameraCorrectionBufferIdentity{ gpu::BufferView(
+            std::make_shared<gpu::Buffer>(sizeof(CameraCorrection), nullptr)) };
 
         State::Data _stateCache{ State::DEFAULT };
-        State::Signature _stateSignatureCache { 0 };
+        State::Signature _stateSignatureCache{ 0 };
 
-        GLState* _state { nullptr };
-        bool _invalidState { false };
+        GLState* _state{ nullptr };
+        bool _invalidState{ false };
 
         PipelineStageState() {
             _cameraCorrectionBuffer.edit<CameraCorrection>() = CameraCorrection();
@@ -498,9 +645,9 @@ protected:
     virtual GLShader* compileBackendProgram(const Shader& program, const Shader::CompilationHandler& handler);
     virtual GLShader* compileBackendShader(const Shader& shader, const Shader::CompilationHandler& handler);
     virtual std::string getBackendShaderHeader() const = 0;
-    // For a program, this will return a string containing all the source files (without any 
-    // backend headers or defines).  For a vertex, fragment or geometry shader, this will 
-    // return the fully customized shader with all the version and backend specific 
+    // For a program, this will return a string containing all the source files (without any
+    // backend headers or defines).  For a vertex, fragment or geometry shader, this will
+    // return the fully customized shader with all the version and backend specific
     // preprocessor directives
     // The program string returned can be used as a key for a cache of shader binaries
     // The shader strings can be reliably sent to the low level `compileShader` functions
@@ -516,22 +663,22 @@ protected:
     // Synchronize the state cache of this Backend with the actual real state of the GL Context
     void syncOutputStateCache();
     void resetOutputStage();
-    
+
     struct OutputStageState {
-        FramebufferPointer _framebuffer { nullptr };
-        GLuint _drawFBO { 0 };
+        FramebufferReference _framebuffer{};
+        GLuint _drawFBO{ 0 };
     } _output;
 
     void resetQueryStage();
     struct QueryStageState {
-        uint32_t _rangeQueryDepth { 0 };
+        uint32_t _rangeQueryDepth{ 0 };
     } _queryStage;
 
     void resetStages();
 
     // Stores cached binary versions of the shaders for quicker startup on subsequent runs
-    // Note that shaders in the cache can still fail to load due to hardware or driver 
-    // changes that invalidate the cached binary, in which case we fall back on compiling 
+    // Note that shaders in the cache can still fail to load due to hardware or driver
+    // changes that invalidate the cached binary, in which case we fall back on compiling
     // the source again
     struct ShaderBinaryCache {
         std::mutex _mutex;
@@ -543,7 +690,7 @@ protected:
     virtual void killShaderBinaryCache();
 
     struct TextureManagementStageState {
-        bool _sparseCapable { false };
+        bool _sparseCapable{ false };
         GLTextureTransferEnginePointer _transferEngine;
     } _textureManagement;
     virtual void initTextureManagementStage();
@@ -556,6 +703,6 @@ protected:
     friend class GLShader;
 };
 
-} }
+}}  // namespace gpu::gl
 
 #endif
diff --git a/libraries/gpu-gl-common/src/gpu/gl/GLBackendInput.cpp b/libraries/gpu-gl-common/src/gpu/gl/GLBackendInput.cpp
index 8d46b4c6e3..85e6ba5382 100644
--- a/libraries/gpu-gl-common/src/gpu/gl/GLBackendInput.cpp
+++ b/libraries/gpu-gl-common/src/gpu/gl/GLBackendInput.cpp
@@ -17,10 +17,10 @@ using namespace gpu;
 using namespace gpu::gl;
 
 void GLBackend::do_setInputFormat(const Batch& batch, size_t paramOffset) {
-    Stream::FormatPointer format = batch._streamFormats.get(batch._params[paramOffset]._uint);
-    if (format != _input._format) {
-        _input._format = format;
+    const auto& format = batch._streamFormats.get(batch._params[paramOffset]._uint);
+    if (!compare(_input._format, format)) {
         if (format) {
+            assign(_input._format, format);
             auto inputFormat = GLInputFormat::sync((*format));
             assert(inputFormat);
             if (_input._formatKey != inputFormat->key) {
@@ -28,6 +28,7 @@ void GLBackend::do_setInputFormat(const Batch& batch, size_t paramOffset) {
                 _input._invalidFormat = true;
             }
         } else {
+            reset(_input._format);
             _input._formatKey.clear();
             _input._invalidFormat = true;
         }
@@ -37,13 +38,13 @@ void GLBackend::do_setInputFormat(const Batch& batch, size_t paramOffset) {
 void GLBackend::do_setInputBuffer(const Batch& batch, size_t paramOffset) {
     Offset stride = batch._params[paramOffset + 0]._uint;
     Offset offset = batch._params[paramOffset + 1]._uint;
-    BufferPointer buffer = batch._buffers.get(batch._params[paramOffset + 2]._uint);
+    const auto& buffer = batch._buffers.get(batch._params[paramOffset + 2]._uint);
     uint32 channel = batch._params[paramOffset + 3]._uint;
 
     if (channel < getNumInputBuffers()) {
         bool isModified = false;
-        if (_input._buffers[channel] != buffer) {
-            _input._buffers[channel] = buffer;
+        if (!compare(_input._buffers[channel], buffer)) {
+            assign(_input._buffers[channel], buffer);
             _input._bufferVBOs[channel] = getBufferIDUnsynced((*buffer));
             isModified = true;
         }
@@ -94,18 +95,18 @@ void GLBackend::resetInputStage() {
     // Reset index buffer
     _input._indexBufferType = UINT32;
     _input._indexBufferOffset = 0;
-    _input._indexBuffer.reset();
+    reset(_input._indexBuffer);
     glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, 0);
     (void) CHECK_GL_ERROR();
 
     // Reset vertex buffer and format
-    _input._format.reset();
+    reset(_input._format);
     _input._formatKey.clear();
     _input._invalidFormat = false;
     _input._attributeActivation.reset();
 
     for (uint32_t i = 0; i < _input._buffers.size(); i++) {
-        _input._buffers[i].reset();
+        reset(_input._buffers[i]);
         _input._bufferOffsets[i] = 0;
         _input._bufferStrides[i] = 0;
         _input._bufferVBOs[i] = 0;
@@ -119,9 +120,9 @@ void GLBackend::do_setIndexBuffer(const Batch& batch, size_t paramOffset) {
     _input._indexBufferType = (Type)batch._params[paramOffset + 2]._uint;
     _input._indexBufferOffset = batch._params[paramOffset + 0]._uint;
 
-    BufferPointer indexBuffer = batch._buffers.get(batch._params[paramOffset + 1]._uint);
-    if (indexBuffer != _input._indexBuffer) {
-        _input._indexBuffer = indexBuffer;
+    const auto& indexBuffer = batch._buffers.get(batch._params[paramOffset + 1]._uint);
+    if (!compare(_input._indexBuffer, indexBuffer)) {
+        assign(_input._indexBuffer, indexBuffer);
         if (indexBuffer) {
             glBindBuffer(GL_ELEMENT_ARRAY_BUFFER, getBufferIDUnsynced(*indexBuffer));
         } else {
@@ -136,9 +137,9 @@ void GLBackend::do_setIndirectBuffer(const Batch& batch, size_t paramOffset) {
     _input._indirectBufferOffset = batch._params[paramOffset + 1]._uint;
     _input._indirectBufferStride = batch._params[paramOffset + 2]._uint;
 
-    BufferPointer buffer = batch._buffers.get(batch._params[paramOffset]._uint);
-    if (buffer != _input._indirectBuffer) {
-        _input._indirectBuffer = buffer;
+    const auto& buffer = batch._buffers.get(batch._params[paramOffset]._uint);
+    if (!compare(_input._indirectBuffer, buffer)) {
+        assign(_input._indirectBuffer, buffer);
         if (buffer) {
             glBindBuffer(GL_DRAW_INDIRECT_BUFFER, getBufferIDUnsynced(*buffer));
         } else {
@@ -152,7 +153,7 @@ void GLBackend::do_setIndirectBuffer(const Batch& batch, size_t paramOffset) {
 
 void GLBackend::updateInput() {
     bool isStereoNow = isStereo();
-    // track stereo state change potentially happening wihtout changing the input format
+    // track stereo state change potentially happening without changing the input format
     // this is a rare case requesting to invalid the format
 #ifdef GPU_STEREO_DRAWCALL_INSTANCED
     _input._invalidFormat |= (isStereoNow != _input._lastUpdateStereoState);
@@ -163,13 +164,14 @@ void GLBackend::updateInput() {
         InputStageState::ActivationCache newActivation;
 
         // Assign the vertex format required
-        if (_input._format) {
+        auto format = acquire(_input._format);
+        if (format) {
             bool hasColorAttribute{ false };
 
             _input._attribBindingBuffers.reset();
 
-            const Stream::Format::AttributeMap& attributes = _input._format->getAttributes();
-            auto& inputChannels = _input._format->getChannels();
+            const auto& attributes = format->getAttributes();
+            const auto& inputChannels = format->getChannels();
             for (auto& channelIt : inputChannels) {
                 auto bufferChannelNum = (channelIt).first;
                 const Stream::Format::ChannelMap::value_type::second_type& channel = (channelIt).second;
diff --git a/libraries/gpu-gl-common/src/gpu/gl/GLBackendOutput.cpp b/libraries/gpu-gl-common/src/gpu/gl/GLBackendOutput.cpp
index d1ab34da90..411e16b18e 100644
--- a/libraries/gpu-gl-common/src/gpu/gl/GLBackendOutput.cpp
+++ b/libraries/gpu-gl-common/src/gpu/gl/GLBackendOutput.cpp
@@ -27,12 +27,12 @@ void GLBackend::syncOutputStateCache() {
     glGetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, &currentFBO);
 
     _output._drawFBO = currentFBO;
-    _output._framebuffer.reset();
+    reset(_output._framebuffer);
 }
 
 void GLBackend::resetOutputStage() {
-    if (_output._framebuffer) {
-        _output._framebuffer.reset();
+    if (valid(_output._framebuffer)) {
+        reset(_output._framebuffer);
         _output._drawFBO = 0;
         glBindFramebuffer(GL_DRAW_FRAMEBUFFER, 0);
     }
@@ -41,7 +41,7 @@ void GLBackend::resetOutputStage() {
 }
 
 void GLBackend::do_setFramebuffer(const Batch& batch, size_t paramOffset) {
-    auto framebuffer = batch._framebuffers.get(batch._params[paramOffset]._uint);
+    const auto& framebuffer = batch._framebuffers.get(batch._params[paramOffset]._uint);
     setFramebuffer(framebuffer);
 }
 
@@ -55,13 +55,13 @@ void GLBackend::do_setFramebufferSwapChain(const Batch& batch, size_t paramOffse
 }
 
 void GLBackend::setFramebuffer(const FramebufferPointer& framebuffer) {
-    if (_output._framebuffer != framebuffer) {
+    if (!compare(_output._framebuffer, framebuffer)) {
         auto newFBO = getFramebufferID(framebuffer);
         if (_output._drawFBO != newFBO) {
             _output._drawFBO = newFBO;
             glBindFramebuffer(GL_DRAW_FRAMEBUFFER, newFBO);
         }
-        _output._framebuffer = framebuffer;
+        assign(_output._framebuffer, framebuffer);
     }
 }
 
@@ -114,8 +114,9 @@ void GLBackend::do_clearFramebuffer(const Batch& batch, size_t paramOffset) {
     }
 
     std::vector<GLenum> drawBuffers;
+    auto framebuffer = acquire(_output._framebuffer);
     if (masks & Framebuffer::BUFFER_COLORS) {
-        if (_output._framebuffer) {
+        if (framebuffer) {
             for (unsigned int i = 0; i < Framebuffer::MAX_NUM_RENDER_BUFFERS; i++) {
                 if (masks & (1 << i)) {
                     drawBuffers.push_back(GL_COLOR_ATTACHMENT0 + i);
@@ -163,8 +164,8 @@ void GLBackend::do_clearFramebuffer(const Batch& batch, size_t paramOffset) {
     }
     
     // Restore the color draw buffers only if a frmaebuffer is bound
-    if (_output._framebuffer && !drawBuffers.empty()) {
-        auto glFramebuffer = syncGPUObject(*_output._framebuffer);
+    if (framebuffer && !drawBuffers.empty()) {
+        auto glFramebuffer = syncGPUObject(*framebuffer);
         if (glFramebuffer) {
             glDrawBuffers((GLsizei)glFramebuffer->_colorBuffers.size(), glFramebuffer->_colorBuffers.data());
         }
diff --git a/libraries/gpu-gl-common/src/gpu/gl/GLBackendPipeline.cpp b/libraries/gpu-gl-common/src/gpu/gl/GLBackendPipeline.cpp
index 05ded3eece..7a06b3af86 100644
--- a/libraries/gpu-gl-common/src/gpu/gl/GLBackendPipeline.cpp
+++ b/libraries/gpu-gl-common/src/gpu/gl/GLBackendPipeline.cpp
@@ -23,9 +23,9 @@ using namespace gpu;
 using namespace gpu::gl;
 
 void GLBackend::do_setPipeline(const Batch& batch, size_t paramOffset) {
-    PipelinePointer pipeline = batch._pipelines.get(batch._params[paramOffset + 0]._uint);
+    const auto& pipeline = batch._pipelines.get(batch._params[paramOffset + 0]._uint);
 
-    if (_pipeline._pipeline == pipeline) {
+    if (compare(_pipeline._pipeline, pipeline)) {
         return;
     }
 
@@ -34,7 +34,7 @@ void GLBackend::do_setPipeline(const Batch& batch, size_t paramOffset) {
 
     // null pipeline == reset
     if (!pipeline) {
-        _pipeline._pipeline.reset();
+        reset(_pipeline._pipeline);
 
         _pipeline._program = 0;
         _pipeline._cameraCorrection = false;
@@ -73,7 +73,7 @@ void GLBackend::do_setPipeline(const Batch& batch, size_t paramOffset) {
         }
 
         // Remember the new pipeline
-        _pipeline._pipeline = pipeline;
+        assign(_pipeline._pipeline, pipeline);
     }
 
     // THis should be done on Pipeline::update...
@@ -81,7 +81,7 @@ void GLBackend::do_setPipeline(const Batch& batch, size_t paramOffset) {
         glUseProgram(_pipeline._program);
         if (_pipeline._cameraCorrection) {
             // Invalidate uniform buffer cache slot
-            _uniform._buffers[gpu::slot::buffer::CameraCorrection] = {};
+            _uniform._buffers[gpu::slot::buffer::CameraCorrection].reset();
             auto& cameraCorrectionBuffer = _transform._viewCorrectionEnabled ?
                 _pipeline._cameraCorrectionBuffer._buffer : 
                 _pipeline._cameraCorrectionBufferIdentity._buffer;
@@ -112,7 +112,7 @@ void GLBackend::updatePipeline() {
             _pipeline._stateSignatureCache |= _pipeline._state->_signature;
 
             // And perform
-            for (auto command : _pipeline._state->_commands) {
+            for (const auto& command : _pipeline._state->_commands) {
                 command->run(this);
             }
         } else {
@@ -134,23 +134,17 @@ void GLBackend::resetPipelineStage() {
     _pipeline._invalidProgram = false;
     _pipeline._program = 0;
     _pipeline._programShader = nullptr;
-    _pipeline._pipeline.reset();
+    reset(_pipeline._pipeline);
     glUseProgram(0);
 }
 
-GLBackend::UniformStageState::BufferState::BufferState(const BufferPointer& buffer, GLintptr offset, GLsizeiptr size)
-  : buffer(buffer), offset(offset), size(size) {}
-
 void GLBackend::releaseUniformBuffer(uint32_t slot) {
-    auto& buf = _uniform._buffers[slot];
-    if (buf.buffer) {
-        auto* object = Backend::getGPUObject<GLBuffer>(*buf.buffer);
-        if (object) {
-            glBindBufferBase(GL_UNIFORM_BUFFER, slot, 0);  // RELEASE
-            (void)CHECK_GL_ERROR();
-        }
-        buf = UniformStageState::BufferState();
+    auto& bufferState = _uniform._buffers[slot];
+    if (valid(bufferState.buffer)) {
+        glBindBufferBase(GL_UNIFORM_BUFFER, slot, 0);  // RELEASE
+        (void)CHECK_GL_ERROR();
     }
+    bufferState.reset();
 }
 
 void GLBackend::resetUniformStage() {
@@ -165,18 +159,20 @@ void GLBackend::bindUniformBuffer(uint32_t slot, const BufferPointer& buffer, GL
         return;
     }
 
-    UniformStageState::BufferState bufferState{ buffer, offset, size };
 
+    auto& currentBufferState = _uniform._buffers[slot];
     // check cache before thinking
-    if (_uniform._buffers[slot] == bufferState) {
+    if (currentBufferState.compare(buffer, offset, size)) {
         return;
     }
 
     // Grab the true gl Buffer object
     auto glBO = getBufferIDUnsynced(*buffer);
     if (glBO) {
-        glBindBufferRange(GL_UNIFORM_BUFFER, slot, glBO, bufferState.offset, bufferState.size);
-        _uniform._buffers[slot] = bufferState;
+        glBindBufferRange(GL_UNIFORM_BUFFER, slot, glBO, offset, size);
+        assign(currentBufferState.buffer, buffer);
+        currentBufferState.offset = offset;
+        currentBufferState.size = size;
         (void)CHECK_GL_ERROR();
     } else {
         releaseUniformBuffer(slot);
@@ -193,7 +189,7 @@ void GLBackend::do_setUniformBuffer(const Batch& batch, size_t paramOffset) {
         return;
     }
 
-    BufferPointer uniformBuffer = batch._buffers.get(batch._params[paramOffset + 2]._uint);
+    const auto& uniformBuffer = batch._buffers.get(batch._params[paramOffset + 2]._uint);
     GLintptr rangeStart = batch._params[paramOffset + 1]._uint;
     GLsizeiptr rangeSize = batch._params[paramOffset + 0]._uint;
 
@@ -201,16 +197,12 @@ void GLBackend::do_setUniformBuffer(const Batch& batch, size_t paramOffset) {
 }
 
 void GLBackend::releaseResourceTexture(uint32_t slot) {
-    auto& tex = _resource._textures[slot];
-    if (tex) {
-        auto* object = Backend::getGPUObject<GLTexture>(*tex);
-        if (object) {
-            GLuint target = object->_target;
-            glActiveTexture(GL_TEXTURE0 + slot);
-            glBindTexture(target, 0);  // RELEASE
-            (void)CHECK_GL_ERROR();
-        }
-        tex.reset();
+    auto& textureState = _resource._textures[slot];
+    if (valid(textureState._texture)) {
+        glActiveTexture(GL_TEXTURE0 + slot);
+        glBindTexture(textureState._target, 0);  // RELEASE
+        (void)CHECK_GL_ERROR();
+        reset(textureState._texture);
     }
 }
 
@@ -232,14 +224,14 @@ void GLBackend::do_setResourceBuffer(const Batch& batch, size_t paramOffset) {
         return;
     }
 
-    auto resourceBuffer = batch._buffers.get(batch._params[paramOffset + 0]._uint);
+    const auto& resourceBuffer = batch._buffers.get(batch._params[paramOffset + 0]._uint);
 
     if (!resourceBuffer) {
         releaseResourceBuffer(slot);
         return;
     }
     // check cache before thinking
-    if (_resource._buffers[slot] == resourceBuffer) {
+    if (compare(_resource._buffers[slot], resourceBuffer)) {
         return;
     }
 
@@ -248,7 +240,7 @@ void GLBackend::do_setResourceBuffer(const Batch& batch, size_t paramOffset) {
 
     // If successful bind then cache it
     if (bindResourceBuffer(slot, resourceBuffer)) {
-        _resource._buffers[slot] = resourceBuffer;
+        assign(_resource._buffers[slot], resourceBuffer);
     } else {  // else clear slot and cache
         releaseResourceBuffer(slot);
         return;
@@ -293,14 +285,15 @@ void GLBackend::do_setResourceFramebufferSwapChainTexture(const Batch& batch, si
     }
     auto index = batch._params[paramOffset + 2]._uint;
     auto renderBufferSlot = batch._params[paramOffset + 3]._uint;
-    auto resourceFramebuffer = swapChain->get(index);
-    auto resourceTexture = resourceFramebuffer->getRenderBuffer(renderBufferSlot);
+    const auto& resourceFramebuffer = swapChain->get(index);
+    const auto& resourceTexture = resourceFramebuffer->getRenderBuffer(renderBufferSlot);
     setResourceTexture(slot, resourceTexture);
 }
 
 void GLBackend::setResourceTexture(unsigned int slot, const TexturePointer& resourceTexture) {
+    auto& textureState = _resource._textures[slot];
     // check cache before thinking
-    if (_resource._textures[slot] == resourceTexture) {
+    if (compare(textureState._texture, resourceTexture)) {
         return;
     }
 
@@ -310,15 +303,12 @@ void GLBackend::setResourceTexture(unsigned int slot, const TexturePointer& reso
     // Always make sure the GLObject is in sync
     GLTexture* object = syncGPUObject(resourceTexture);
     if (object) {
+        assign(textureState._texture, resourceTexture);
         GLuint to = object->_texture;
-        GLuint target = object->_target;
+        textureState._target = object->_target;
         glActiveTexture(GL_TEXTURE0 + slot);
-        glBindTexture(target, to);
-
+        glBindTexture(textureState._target, to);
         (void)CHECK_GL_ERROR();
-
-        _resource._textures[slot] = resourceTexture;
-
         _stats._RSAmountTextureMemoryBounded += (int)object->size();
 
     } else {
@@ -343,7 +333,7 @@ void GLBackend::do_setResourceTextureTable(const Batch& batch, size_t paramOffse
 int GLBackend::ResourceStageState::findEmptyTextureSlot() const {
     // start from the end of the slots, try to find an empty one that can be used
     for (auto i = MAX_NUM_RESOURCE_TEXTURES - 1; i > 0; i--) {
-        if (!_textures[i]) {
+        if (!valid(_textures[i]._texture)) {
             return i;
         }
     }
diff --git a/libraries/gpu-gl-common/src/gpu/gl/GLBackendTexture.cpp b/libraries/gpu-gl-common/src/gpu/gl/GLBackendTexture.cpp
index ca4e328612..f4fb3fcf2c 100644
--- a/libraries/gpu-gl-common/src/gpu/gl/GLBackendTexture.cpp
+++ b/libraries/gpu-gl-common/src/gpu/gl/GLBackendTexture.cpp
@@ -66,7 +66,7 @@ GLTexture* GLBackend::syncGPUObject(const TexturePointer& texturePointer) {
 }
 
 void GLBackend::do_generateTextureMips(const Batch& batch, size_t paramOffset) {
-    TexturePointer resourceTexture = batch._textures.get(batch._params[paramOffset + 0]._uint);
+    const auto& resourceTexture = batch._textures.get(batch._params[paramOffset + 0]._uint);
     if (!resourceTexture) {
         return;
     }
diff --git a/libraries/gpu-gl-common/src/gpu/gl/GLPipeline.cpp b/libraries/gpu-gl-common/src/gpu/gl/GLPipeline.cpp
index 1b479dceb8..a099e6e66a 100644
--- a/libraries/gpu-gl-common/src/gpu/gl/GLPipeline.cpp
+++ b/libraries/gpu-gl-common/src/gpu/gl/GLPipeline.cpp
@@ -24,7 +24,7 @@ GLPipeline* GLPipeline::sync(GLBackend& backend, const Pipeline& pipeline) {
     }
 
     // No object allocated yet, let's see if it's worth it...
-    ShaderPointer shader = pipeline.getProgram();
+    const auto& shader = pipeline.getProgram();
 
     // If this pipeline's shader has already failed to compile, don't try again
     if (shader->compilationHasFailed()) {
@@ -37,7 +37,7 @@ GLPipeline* GLPipeline::sync(GLBackend& backend, const Pipeline& pipeline) {
         return nullptr;
     }
 
-    StatePointer state = pipeline.getState();
+    const auto& state = pipeline.getState();
     GLState* stateObject = GLState::sync(*state);
     if (stateObject == nullptr) {
         return nullptr;
diff --git a/libraries/gpu-gl/src/gpu/gl41/GL41Backend.h b/libraries/gpu-gl/src/gpu/gl41/GL41Backend.h
index f4078f5479..e5f7415107 100644
--- a/libraries/gpu-gl/src/gpu/gl41/GL41Backend.h
+++ b/libraries/gpu-gl/src/gpu/gl41/GL41Backend.h
@@ -161,7 +161,7 @@ protected:
     void updateTransform(const Batch& batch) override;
 
     // Resource Stage
-    bool bindResourceBuffer(uint32_t slot, BufferPointer& buffer) override;
+    bool bindResourceBuffer(uint32_t slot, const BufferPointer& buffer) override;
     void releaseResourceBuffer(uint32_t slot) override;
 
     // Output stage
diff --git a/libraries/gpu-gl/src/gpu/gl41/GL41BackendBuffer.cpp b/libraries/gpu-gl/src/gpu/gl41/GL41BackendBuffer.cpp
index ac5d5ee0c9..d5193f892a 100644
--- a/libraries/gpu-gl/src/gpu/gl41/GL41BackendBuffer.cpp
+++ b/libraries/gpu-gl/src/gpu/gl41/GL41BackendBuffer.cpp
@@ -100,7 +100,7 @@ GLBuffer* GL41Backend::syncGPUObject(const Buffer& buffer) {
     return GL41Buffer::sync<GL41Buffer>(*this, buffer);
 }
 
-bool GL41Backend::bindResourceBuffer(uint32_t slot, BufferPointer& buffer) {
+bool GL41Backend::bindResourceBuffer(uint32_t slot, const BufferPointer& buffer) {
     GLuint texBuffer = GL41Backend::getResourceBufferID((*buffer));
     if (texBuffer) {
         glActiveTexture(GL_TEXTURE0 + GL41Backend::RESOURCE_BUFFER_SLOT0_TEX_UNIT + slot); 
@@ -108,7 +108,7 @@ bool GL41Backend::bindResourceBuffer(uint32_t slot, BufferPointer& buffer) {
 
         (void)CHECK_GL_ERROR();
 
-        _resource._buffers[slot] = buffer;
+        assign(_resource._buffers[slot], buffer);
 
         return true;
     }
@@ -117,10 +117,11 @@ bool GL41Backend::bindResourceBuffer(uint32_t slot, BufferPointer& buffer) {
 }
 
 void GL41Backend::releaseResourceBuffer(uint32_t slot) {
-    auto& buf = _resource._buffers[slot];
-    if (buf) {
+    auto& bufferReference = _resource._buffers[slot];
+    auto buffer = acquire(bufferReference);
+    if (buffer) {
         glActiveTexture(GL_TEXTURE0 + GL41Backend::RESOURCE_BUFFER_SLOT0_TEX_UNIT + slot); 
         glBindTexture(GL_TEXTURE_BUFFER, 0);
-        buf.reset();
+        reset(bufferReference);
     }
 }
diff --git a/libraries/gpu-gl/src/gpu/gl41/GL41BackendInput.cpp b/libraries/gpu-gl/src/gpu/gl41/GL41BackendInput.cpp
index c61ffb09e5..2b985c122e 100644
--- a/libraries/gpu-gl/src/gpu/gl41/GL41BackendInput.cpp
+++ b/libraries/gpu-gl/src/gpu/gl41/GL41BackendInput.cpp
@@ -35,14 +35,15 @@ void GL41Backend::updateInput() {
 
     if (_input._invalidFormat || _input._invalidBuffers.any()) {
 
+        auto format = acquire(_input._format);
         if (_input._invalidFormat) {
             InputStageState::ActivationCache newActivation;
 
             _stats._ISNumFormatChanges++;
 
             // Check expected activation
-            if (_input._format) {
-                for (auto& it : _input._format->getAttributes()) {
+            if (format) {
+                for (auto& it : format->getAttributes()) {
                     const Stream::Attribute& attrib = (it).second;
                     uint8_t locationCount = attrib._element.getLocationCount();
                     for (int i = 0; i < locationCount; ++i) {
@@ -69,15 +70,15 @@ void GL41Backend::updateInput() {
         }
 
         // now we need to bind the buffers and assign the attrib pointers
-        if (_input._format) {
+        if (format) {
             bool hasColorAttribute{ false };
 
-            const Buffers& buffers = _input._buffers;
-            const Offsets& offsets = _input._bufferOffsets;
-            const Offsets& strides = _input._bufferStrides;
+            const auto& buffers = _input._buffers;
+            const auto& offsets = _input._bufferOffsets;
+            const auto& strides = _input._bufferStrides;
 
-            const Stream::Format::AttributeMap& attributes = _input._format->getAttributes();
-            auto& inputChannels = _input._format->getChannels();
+            const auto& attributes = format->getAttributes();
+            const auto& inputChannels = format->getChannels();
             int numInvalids = (int)_input._invalidBuffers.count();
             _stats._ISNumInputBufferChanges += numInvalids;
             
diff --git a/libraries/gpu-gl/src/gpu/gl45/GL45Backend.h b/libraries/gpu-gl/src/gpu/gl45/GL45Backend.h
index a100faf432..30656b47c7 100644
--- a/libraries/gpu-gl/src/gpu/gl45/GL45Backend.h
+++ b/libraries/gpu-gl/src/gpu/gl45/GL45Backend.h
@@ -262,7 +262,7 @@ protected:
     void updateTransform(const Batch& batch) override;
 
     // Resource Stage
-    bool bindResourceBuffer(uint32_t slot, BufferPointer& buffer) override;
+    bool bindResourceBuffer(uint32_t slot, const BufferPointer& buffer) override;
     void releaseResourceBuffer(uint32_t slot) override;
 
     // Output stage
diff --git a/libraries/gpu-gl/src/gpu/gl45/GL45BackendBuffer.cpp b/libraries/gpu-gl/src/gpu/gl45/GL45BackendBuffer.cpp
index 6d17923ebd..cb0591c31c 100644
--- a/libraries/gpu-gl/src/gpu/gl45/GL45BackendBuffer.cpp
+++ b/libraries/gpu-gl/src/gpu/gl45/GL45BackendBuffer.cpp
@@ -60,14 +60,14 @@ GLBuffer* GL45Backend::syncGPUObject(const Buffer& buffer) {
 }
 
 
-bool GL45Backend::bindResourceBuffer(uint32_t slot, BufferPointer& buffer) {
+bool GL45Backend::bindResourceBuffer(uint32_t slot, const BufferPointer& buffer) {
     GLBuffer* object = syncGPUObject((*buffer));
     if (object) {
         glBindBufferBase(GL_SHADER_STORAGE_BUFFER, slot, object->_id);
 
         (void)CHECK_GL_ERROR();
 
-        _resource._buffers[slot] = buffer;
+        assign(_resource._buffers[slot], buffer);
 
         return true;
     }
@@ -76,11 +76,10 @@ bool GL45Backend::bindResourceBuffer(uint32_t slot, BufferPointer& buffer) {
 }
 
 void GL45Backend::releaseResourceBuffer(uint32_t slot) {
-    auto& buf = _resource._buffers[slot];
-    if (buf) {
+    auto& bufferReference = _resource._buffers[slot];
+    auto buffer = acquire(bufferReference);
+    if (buffer) {
         glBindBufferBase(GL_SHADER_STORAGE_BUFFER, slot, 0);
-        buf.reset();
+        reset(bufferReference);
     }
 }
-
-
diff --git a/libraries/gpu-gl/src/gpu/gl45/GL45BackendInput.cpp b/libraries/gpu-gl/src/gpu/gl45/GL45BackendInput.cpp
index 7cd8756ead..5285e62d3e 100644
--- a/libraries/gpu-gl/src/gpu/gl45/GL45BackendInput.cpp
+++ b/libraries/gpu-gl/src/gpu/gl45/GL45BackendInput.cpp
@@ -28,7 +28,7 @@ void GL45Backend::resetInputStage() {
 
 void GL45Backend::updateInput() {
     bool isStereoNow = isStereo();
-    // track stereo state change potentially happening wihtout changing the input format
+    // track stereo state change potentially happening without changing the input format
     // this is a rare case requesting to invalid the format
 #ifdef GPU_STEREO_DRAWCALL_INSTANCED
     _input._invalidFormat |= (isStereoNow != _input._lastUpdateStereoState);
@@ -39,13 +39,14 @@ void GL45Backend::updateInput() {
         InputStageState::ActivationCache newActivation;
 
         // Assign the vertex format required
-        if (_input._format) {
+        auto format = acquire(_input._format);
+        if (format) {
             bool hasColorAttribute{ false };
 
             _input._attribBindingBuffers.reset();
 
-            const Stream::Format::AttributeMap& attributes = _input._format->getAttributes();
-            auto& inputChannels = _input._format->getChannels();
+            const auto& attributes = format->getAttributes();
+            const auto& inputChannels = format->getChannels();
             for (auto& channelIt : inputChannels) {
                 auto bufferChannelNum = (channelIt).first;
                 const Stream::Format::ChannelMap::value_type::second_type& channel = (channelIt).second;
diff --git a/libraries/gpu-gles/src/gpu/gles/GLESBackend.h b/libraries/gpu-gles/src/gpu/gles/GLESBackend.h
index c757de0a72..56ae41da31 100644
--- a/libraries/gpu-gles/src/gpu/gles/GLESBackend.h
+++ b/libraries/gpu-gles/src/gpu/gles/GLESBackend.h
@@ -157,7 +157,7 @@ protected:
     void updateTransform(const Batch& batch) override;
 
     // Resource Stage
-    bool bindResourceBuffer(uint32_t slot, BufferPointer& buffer) override;
+    bool bindResourceBuffer(uint32_t slot, const BufferPointer& buffer) override;
     void releaseResourceBuffer(uint32_t slot) override;
 
     // Output stage
diff --git a/libraries/gpu-gles/src/gpu/gles/GLESBackendBuffer.cpp b/libraries/gpu-gles/src/gpu/gles/GLESBackendBuffer.cpp
index 7dd08df409..5e4da4d1fe 100644
--- a/libraries/gpu-gles/src/gpu/gles/GLESBackendBuffer.cpp
+++ b/libraries/gpu-gles/src/gpu/gles/GLESBackendBuffer.cpp
@@ -72,14 +72,14 @@ GLBuffer* GLESBackend::syncGPUObject(const Buffer& buffer) {
     return GLESBuffer::sync<GLESBuffer>(*this, buffer);
 }
 
-bool GLESBackend::bindResourceBuffer(uint32_t slot, BufferPointer& buffer) {
+bool GLESBackend::bindResourceBuffer(uint32_t slot, const BufferPointer& buffer) {
     GLBuffer* object = syncGPUObject((*buffer));
     if (object) {
         glBindBufferBase(GL_SHADER_STORAGE_BUFFER, slot, object->_id);
 
         (void)CHECK_GL_ERROR();
 
-        _resource._buffers[slot] = buffer;
+        assign(_resource._buffers[slot], buffer);
 
         return true;
     }
@@ -88,10 +88,10 @@ bool GLESBackend::bindResourceBuffer(uint32_t slot, BufferPointer& buffer) {
 }
 
 void GLESBackend::releaseResourceBuffer(uint32_t slot) {
-    auto& buf = _resource._buffers[slot];
-    if (buf) {
+    auto& bufferReference = _resource._buffers[slot];
+    if (valid(bufferReference)) {
         glBindBufferBase(GL_SHADER_STORAGE_BUFFER, slot, 0);
-        buf.reset();
+        reset(bufferReference);
     }
 }
 
diff --git a/libraries/gpu/src/gpu/Batch.cpp b/libraries/gpu/src/gpu/Batch.cpp
index b6714e2f1a..745f1d1845 100644
--- a/libraries/gpu/src/gpu/Batch.cpp
+++ b/libraries/gpu/src/gpu/Batch.cpp
@@ -498,7 +498,7 @@ void Batch::setupNamedCalls(const std::string& instanceName, NamedBatchData::Fun
     captureNamedDrawCallInfo(instanceName);
 }
 
-BufferPointer Batch::getNamedBuffer(const std::string& instanceName, uint8_t index) {
+const BufferPointer& Batch::getNamedBuffer(const std::string& instanceName, uint8_t index) {
     NamedBatchData& instance = _namedData[instanceName];
     if (instance.buffers.size() <= index) {
         instance.buffers.resize(index + 1);
diff --git a/libraries/gpu/src/gpu/Batch.h b/libraries/gpu/src/gpu/Batch.h
index b49d14e5a1..8e607a189e 100644
--- a/libraries/gpu/src/gpu/Batch.h
+++ b/libraries/gpu/src/gpu/Batch.h
@@ -119,7 +119,7 @@ public:
     void multiDrawIndexedIndirect(uint32 numCommands, Primitive primitiveType);
 
     void setupNamedCalls(const std::string& instanceName, NamedBatchData::Function function);
-    BufferPointer getNamedBuffer(const std::string& instanceName, uint8_t index = 0);
+    const BufferPointer& getNamedBuffer(const std::string& instanceName, uint8_t index = 0);
 
     // Input Stage
     // InputFormat
diff --git a/libraries/gpu/src/gpu/Framebuffer.cpp b/libraries/gpu/src/gpu/Framebuffer.cpp
index 8bb9be4a76..e88d986da6 100755
--- a/libraries/gpu/src/gpu/Framebuffer.cpp
+++ b/libraries/gpu/src/gpu/Framebuffer.cpp
@@ -203,11 +203,12 @@ uint32 Framebuffer::getNumRenderBuffers() const {
     return nb;
 }
 
-TexturePointer Framebuffer::getRenderBuffer(uint32 slot) const {
+const TexturePointer& Framebuffer::getRenderBuffer(uint32 slot) const {
+    static const TexturePointer EMPTY;
     if (!isSwapchain() && (slot < getMaxNumRenderBuffers())) {
         return _renderBuffers[slot]._texture;
     } else {
-        return TexturePointer();
+        return EMPTY;
     }
 
 }
@@ -297,9 +298,10 @@ bool Framebuffer::setDepthStencilBuffer(const TexturePointer& texture, const For
     return false;
 }
 
-TexturePointer Framebuffer::getDepthStencilBuffer() const {
+const TexturePointer& Framebuffer::getDepthStencilBuffer() const {
+    static const TexturePointer EMPTY;
     if (isSwapchain()) {
-        return TexturePointer();
+        return EMPTY;
     } else {
         return _depthStencilBuffer._texture;
     }
diff --git a/libraries/gpu/src/gpu/Framebuffer.h b/libraries/gpu/src/gpu/Framebuffer.h
index fbbec50a28..44e945883f 100755
--- a/libraries/gpu/src/gpu/Framebuffer.h
+++ b/libraries/gpu/src/gpu/Framebuffer.h
@@ -95,7 +95,7 @@ public:
     static Framebuffer* createShadowmap(uint16 width);
 
     bool isSwapchain() const;
-    SwapchainPointer getSwapchain() const { return _swapchain; }
+    const SwapchainPointer& getSwapchain() const { return _swapchain; }
 
     uint32 getFrameCount() const;
 
@@ -105,13 +105,13 @@ public:
     const TextureViews& getRenderBuffers() const { return _renderBuffers; }
 
     int32 setRenderBuffer(uint32 slot, const TexturePointer& texture, uint32 subresource = 0);
-    TexturePointer getRenderBuffer(uint32 slot) const;
+    const TexturePointer& getRenderBuffer(uint32 slot) const;
     uint32 getRenderBufferSubresource(uint32 slot) const;
 
     bool setDepthBuffer(const TexturePointer& texture, const Format& format, uint32 subresource = 0);
     bool setStencilBuffer(const TexturePointer& texture, const Format& format, uint32 subresource = 0);
     bool setDepthStencilBuffer(const TexturePointer& texture, const Format& format, uint32 subresource = 0);
-    TexturePointer getDepthStencilBuffer() const;
+    const TexturePointer& getDepthStencilBuffer() const;
     uint32 getDepthStencilBufferSubresource() const;
     Format getDepthStencilBufferFormat() const;
 
diff --git a/libraries/render-utils/src/CauterizedModel.cpp b/libraries/render-utils/src/CauterizedModel.cpp
index c4631c3676..ffb652f923 100644
--- a/libraries/render-utils/src/CauterizedModel.cpp
+++ b/libraries/render-utils/src/CauterizedModel.cpp
@@ -86,7 +86,7 @@ void CauterizedModel::createRenderItemSet() {
             // Create the render payloads
             int numParts = (int)mesh->getNumParts();
             for (int partIndex = 0; partIndex < numParts; partIndex++) {
-                if (!fbxGeometry.meshes[i].blendshapes.empty()) {
+                if (!fbxGeometry.meshes[i].blendshapes.empty() && _blendedVertexBuffers.find(i) == _blendedVertexBuffers.end()) {
                     initializeBlendshapes(fbxGeometry.meshes[i], i);
                 }
                 auto ptr = std::make_shared<CauterizedMeshPartPayload>(shared_from_this(), i, partIndex, shapeID, transform, offset);
@@ -97,6 +97,7 @@ void CauterizedModel::createRenderItemSet() {
                 shapeID++;
             }
         }
+        _blendedVertexBuffersInitialized = true;
     } else {
         Model::createRenderItemSet();
     }
diff --git a/libraries/render-utils/src/Model.cpp b/libraries/render-utils/src/Model.cpp
index ba2bd28852..b9ed43c339 100644
--- a/libraries/render-utils/src/Model.cpp
+++ b/libraries/render-utils/src/Model.cpp
@@ -302,15 +302,22 @@ bool Model::updateGeometry() {
         assert(_meshStates.empty());
 
         const FBXGeometry& fbxGeometry = getFBXGeometry();
+        int i = 0;
         foreach (const FBXMesh& mesh, fbxGeometry.meshes) {
             MeshState state;
             state.clusterDualQuaternions.resize(mesh.clusters.size());
             state.clusterMatrices.resize(mesh.clusters.size());
             _meshStates.push_back(state);
+            if (!mesh.blendshapes.empty() && _blendedVertexBuffers.find(i) == _blendedVertexBuffers.end()) {
+                initializeBlendshapes(mesh, i);
+            }
+            i++;
         }
+        _blendedVertexBuffersInitialized = true;
         needFullUpdate = true;
         emit rigReady();
     }
+
     return needFullUpdate;
 }
 
@@ -1027,6 +1034,10 @@ void Model::removeFromScene(const render::ScenePointer& scene, render::Transacti
     _modelMeshMaterialNames.clear();
     _modelMeshRenderItemShapes.clear();
 
+    _blendedVertexBuffers.clear();
+    _normalsAndTangents.clear();
+    _blendedVertexBuffersInitialized = false;
+
     _addedToScene = false;
 
     _renderInfoVertexCount = 0;
@@ -1273,8 +1284,7 @@ QStringList Model::getJointNames() const {
 class Blender : public QRunnable {
 public:
 
-    Blender(ModelPointer model, int blendNumber, const Geometry::WeakPointer& geometry,
-        const QVector<FBXMesh>& meshes, const QVector<float>& blendshapeCoefficients);
+    Blender(ModelPointer model, int blendNumber, const Geometry::WeakPointer& geometry, const QVector<float>& blendshapeCoefficients);
 
     virtual void run() override;
 
@@ -1283,37 +1293,37 @@ private:
     ModelPointer _model;
     int _blendNumber;
     Geometry::WeakPointer _geometry;
-    QVector<FBXMesh> _meshes;
     QVector<float> _blendshapeCoefficients;
 };
 
-Blender::Blender(ModelPointer model, int blendNumber, const Geometry::WeakPointer& geometry,
-        const QVector<FBXMesh>& meshes, const QVector<float>& blendshapeCoefficients) :
+Blender::Blender(ModelPointer model, int blendNumber, const Geometry::WeakPointer& geometry, const QVector<float>& blendshapeCoefficients) :
     _model(model),
     _blendNumber(blendNumber),
     _geometry(geometry),
-    _meshes(meshes),
     _blendshapeCoefficients(blendshapeCoefficients) {
 }
 
 void Blender::run() {
-    DETAILED_PROFILE_RANGE_EX(simulation_animation, __FUNCTION__, 0xFFFF0000, 0, { { "url", _model->getURL().toString() } });
     QVector<glm::vec3> vertices;
     QVector<NormalType> normalsAndTangents;
-    if (_model) {
+    if (_model && _model->isLoaded()) {
+        DETAILED_PROFILE_RANGE_EX(simulation_animation, __FUNCTION__, 0xFFFF0000, 0, { { "url", _model->getURL().toString() } });
         int offset = 0;
         int normalsAndTangentsOffset = 0;
-        foreach (const FBXMesh& mesh, _meshes) {
-            if (mesh.blendshapes.isEmpty()) {
+        auto meshes = _model->getFBXGeometry().meshes;
+        int meshIndex = 0;
+        foreach (const FBXMesh& mesh, meshes) {
+            auto modelMeshNormalsAndTangents = _model->_normalsAndTangents.find(meshIndex++);
+            if (mesh.blendshapes.isEmpty() || modelMeshNormalsAndTangents == _model->_normalsAndTangents.end()) {
                 continue;
             }
 
             vertices += mesh.vertices;
-            normalsAndTangents += mesh.normalsAndTangents;
+            normalsAndTangents += modelMeshNormalsAndTangents->second;
             glm::vec3* meshVertices = vertices.data() + offset;
             NormalType* meshNormalsAndTangents = normalsAndTangents.data() + normalsAndTangentsOffset;
             offset += mesh.vertices.size();
-            normalsAndTangentsOffset += mesh.normalsAndTangents.size();
+            normalsAndTangentsOffset += modelMeshNormalsAndTangents->second.size();
             const float NORMAL_COEFFICIENT_SCALE = 0.01f;
             for (int i = 0, n = qMin(_blendshapeCoefficients.size(), mesh.blendshapes.size()); i < n; i++) {
                 float vertexCoefficient = _blendshapeCoefficients.at(i);
@@ -1353,9 +1363,8 @@ void Blender::run() {
     }
     // post the result to the ModelBlender, which will dispatch to the model if still alive
     QMetaObject::invokeMethod(DependencyManager::get<ModelBlender>().data(), "setBlendedVertices",
-                              Q_ARG(ModelPointer, _model), Q_ARG(int, _blendNumber),
-                              Q_ARG(const Geometry::WeakPointer&, _geometry), Q_ARG(const QVector<glm::vec3>&, vertices),
-                              Q_ARG(const QVector<NormalType>&, normalsAndTangents));
+                              Q_ARG(ModelPointer, _model), Q_ARG(int, _blendNumber), Q_ARG(QVector<glm::vec3>, vertices),
+                              Q_ARG(QVector<NormalType>, normalsAndTangents));
 }
 
 void Model::setScaleToFit(bool scaleToFit, const glm::vec3& dimensions, bool forceRescale) {
@@ -1526,18 +1535,15 @@ bool Model::maybeStartBlender() {
     if (isLoaded()) {
         const FBXGeometry& fbxGeometry = getFBXGeometry();
         if (fbxGeometry.hasBlendedMeshes()) {
-            QThreadPool::globalInstance()->start(new Blender(getThisPointer(), ++_blendNumber, _renderGeometry,
-                fbxGeometry.meshes, _blendshapeCoefficients));
+            QThreadPool::globalInstance()->start(new Blender(getThisPointer(), ++_blendNumber, _renderGeometry, _blendshapeCoefficients));
             return true;
         }
     }
     return false;
 }
 
-void Model::setBlendedVertices(int blendNumber, const Geometry::WeakPointer& geometry,
-        const QVector<glm::vec3>& vertices, const QVector<NormalType>& normalsAndTangents) {
-    auto geometryRef = geometry.lock();
-    if (!geometryRef || _renderGeometry != geometryRef || blendNumber < _appliedBlendNumber) {
+void Model::setBlendedVertices(int blendNumber, const QVector<glm::vec3>& vertices, const QVector<NormalType>& normalsAndTangents) {
+    if (!isLoaded() || blendNumber < _appliedBlendNumber || !_blendedVertexBuffersInitialized) {
         return;
     }
     _appliedBlendNumber = blendNumber;
@@ -1546,26 +1552,28 @@ void Model::setBlendedVertices(int blendNumber, const Geometry::WeakPointer& geo
     int normalAndTangentIndex = 0;
     for (int i = 0; i < fbxGeometry.meshes.size(); i++) {
         const FBXMesh& mesh = fbxGeometry.meshes.at(i);
-        if (mesh.blendshapes.isEmpty()) {
+        auto meshNormalsAndTangents = _normalsAndTangents.find(i);
+        if (mesh.blendshapes.isEmpty() || meshNormalsAndTangents == _normalsAndTangents.end()) {
             continue;
         }
 
         const auto vertexCount = mesh.vertices.size();
         const auto verticesSize = vertexCount * sizeof(glm::vec3);
-        const auto& buffer = _blendedVertexBuffers[i];
-        assert(buffer && _blendedVertexBuffersInitialized);
-        buffer->resize(mesh.vertices.size() * sizeof(glm::vec3) + mesh.normalsAndTangents.size() * sizeof(NormalType));
-        buffer->setSubData(0, verticesSize, (gpu::Byte*) vertices.constData() + index * sizeof(glm::vec3));
-        buffer->setSubData(verticesSize, mesh.normalsAndTangents.size() * sizeof(NormalType), (const gpu::Byte*) normalsAndTangents.data() + normalAndTangentIndex * sizeof(NormalType));
+        const auto& buffer = _blendedVertexBuffers.find(i);
+        assert(buffer != _blendedVertexBuffers.end());
+        buffer->second->resize(mesh.vertices.size() * sizeof(glm::vec3) + meshNormalsAndTangents->second.size() * sizeof(NormalType));
+        buffer->second->setSubData(0, verticesSize, (gpu::Byte*) vertices.constData() + index * sizeof(glm::vec3));
+        buffer->second->setSubData(verticesSize, meshNormalsAndTangents->second.size() * sizeof(NormalType), (const gpu::Byte*) normalsAndTangents.data() + normalAndTangentIndex * sizeof(NormalType));
 
         index += vertexCount;
-        normalAndTangentIndex += mesh.normalsAndTangents.size();
+        normalAndTangentIndex += meshNormalsAndTangents->second.size();
     }
 }
 
 void Model::deleteGeometry() {
     _deleteGeometryCounter++;
     _blendedVertexBuffers.clear();
+    _normalsAndTangents.clear();
     _blendedVertexBuffersInitialized = false;
     _meshStates.clear();
     _rig.destroyAnimGraph();
@@ -1599,6 +1607,7 @@ const render::ItemIDs& Model::fetchRenderItemIDs() const {
 }
 
 void Model::initializeBlendshapes(const FBXMesh& mesh, int index) {
+    _blendedVertexBuffers[index] = std::make_shared<gpu::Buffer>();
     QVector<NormalType> normalsAndTangents;
     normalsAndTangents.resize(2 * mesh.normals.size());
 
@@ -1627,12 +1636,10 @@ void Model::initializeBlendshapes(const FBXMesh& mesh, int index) {
         }
     });
     const auto verticesSize = mesh.vertices.size() * sizeof(glm::vec3);
-    _blendedVertexBuffers[index] = std::make_shared<gpu::Buffer>();
     _blendedVertexBuffers[index]->resize(mesh.vertices.size() * sizeof(glm::vec3) + normalsAndTangents.size() * sizeof(NormalType));
     _blendedVertexBuffers[index]->setSubData(0, verticesSize, (const gpu::Byte*) mesh.vertices.constData());
     _blendedVertexBuffers[index]->setSubData(verticesSize, normalsAndTangents.size() * sizeof(NormalType), (const gpu::Byte*) normalsAndTangents.data());
-    mesh.normalsAndTangents = normalsAndTangents;
-    _blendedVertexBuffersInitialized = true;
+    _normalsAndTangents[index] = normalsAndTangents;
 }
 
 void Model::createRenderItemSet() {
@@ -1673,7 +1680,7 @@ void Model::createRenderItemSet() {
         // Create the render payloads
         int numParts = (int)mesh->getNumParts();
         for (int partIndex = 0; partIndex < numParts; partIndex++) {
-            if (!fbxGeometry.meshes[i].blendshapes.empty()) {
+            if (!fbxGeometry.meshes[i].blendshapes.empty() && _blendedVertexBuffers.find(i) == _blendedVertexBuffers.end()) {
                 initializeBlendshapes(fbxGeometry.meshes[i], i);
             }
             _modelMeshRenderItems << std::make_shared<ModelMeshPartPayload>(shared_from_this(), i, partIndex, shapeID, transform, offset);
@@ -1683,6 +1690,7 @@ void Model::createRenderItemSet() {
             shapeID++;
         }
     }
+    _blendedVertexBuffersInitialized = true;
 }
 
 bool Model::isRenderable() const {
@@ -1775,35 +1783,38 @@ ModelBlender::~ModelBlender() {
 }
 
 void ModelBlender::noteRequiresBlend(ModelPointer model) {
+    Lock lock(_mutex);
     if (_pendingBlenders < QThread::idealThreadCount()) {
         if (model->maybeStartBlender()) {
             _pendingBlenders++;
+            return;
         }
-        return;
     }
 
-    {
-        Lock lock(_mutex);
-        _modelsRequiringBlends.insert(model);
-    }
+    _modelsRequiringBlends.insert(model);
 }
 
-void ModelBlender::setBlendedVertices(ModelPointer model, int blendNumber, const Geometry::WeakPointer& geometry,
-                                      const QVector<glm::vec3>& vertices, const QVector<NormalType>& normalsAndTangents) {
+void ModelBlender::setBlendedVertices(ModelPointer model, int blendNumber, QVector<glm::vec3> vertices, QVector<NormalType> normalsAndTangents) {
     if (model) {
-        model->setBlendedVertices(blendNumber, geometry, vertices, normalsAndTangents);
+        model->setBlendedVertices(blendNumber, vertices, normalsAndTangents);
     }
-    _pendingBlenders--;
     {
         Lock lock(_mutex);
-        for (auto i = _modelsRequiringBlends.begin(); i != _modelsRequiringBlends.end();) {
+        _pendingBlenders--;
+        _modelsRequiringBlends.erase(model);
+        std::set<ModelWeakPointer, std::owner_less<ModelWeakPointer>> modelsToErase;
+        for (auto i = _modelsRequiringBlends.begin(); i != _modelsRequiringBlends.end(); i++) {
             auto weakPtr = *i;
-            _modelsRequiringBlends.erase(i++); // remove front of the set
             ModelPointer nextModel = weakPtr.lock();
             if (nextModel && nextModel->maybeStartBlender()) {
                 _pendingBlenders++;
-                return;
+                break;
+            } else {
+                modelsToErase.insert(weakPtr);
             }
         }
+        for (auto& weakPtr : modelsToErase) {
+            _modelsRequiringBlends.erase(weakPtr);
+        }
     }
 }
diff --git a/libraries/render-utils/src/Model.h b/libraries/render-utils/src/Model.h
index e7534f5b89..447f75dd9d 100644
--- a/libraries/render-utils/src/Model.h
+++ b/libraries/render-utils/src/Model.h
@@ -144,8 +144,7 @@ public:
     bool maybeStartBlender();
 
     /// Sets blended vertices computed in a separate thread.
-    void setBlendedVertices(int blendNumber, const Geometry::WeakPointer& geometry,
-        const QVector<glm::vec3>& vertices, const QVector<NormalType>& normalsAndTangents);
+    void setBlendedVertices(int blendNumber, const QVector<glm::vec3>& vertices, const QVector<NormalType>& normalsAndTangents);
 
     bool isLoaded() const { return (bool)_renderGeometry && _renderGeometry->isGeometryLoaded(); }
     bool isAddedToScene() const { return _addedToScene; }
@@ -345,7 +344,7 @@ public:
     void addMaterial(graphics::MaterialLayer material, const std::string& parentMaterialName);
     void removeMaterial(graphics::MaterialPointer material, const std::string& parentMaterialName);
 
-    bool areBlendedVertexBuffersInitialized(int index) { return _blendedVertexBuffersInitialized; }
+    std::unordered_map<int, QVector<NormalType>> _normalsAndTangents;
 
 public slots:
     void loadURLFinished(bool success);
@@ -521,8 +520,7 @@ public:
     bool shouldComputeBlendshapes() { return _computeBlendshapes; }
 
 public slots:
-    void setBlendedVertices(ModelPointer model, int blendNumber, const Geometry::WeakPointer& geometry,
-        const QVector<glm::vec3>& vertices, const QVector<NormalType>& normalsAndTangents);
+    void setBlendedVertices(ModelPointer model, int blendNumber, QVector<glm::vec3> vertices, QVector<NormalType> normalsAndTangents);
     void setComputeBlendshapes(bool computeBlendshapes) { _computeBlendshapes = computeBlendshapes; }
 
 private: