diff --git a/interface/src/Application.cpp b/interface/src/Application.cpp
index 9c861006b6..de9b134b83 100644
--- a/interface/src/Application.cpp
+++ b/interface/src/Application.cpp
@@ -2975,6 +2975,11 @@ void Application::updateLOD() {
     }
 }
 
+void Application::pushPreRenderLambda(void* key, std::function<void()> func) {
+    std::unique_lock<std::mutex> guard(_preRenderLambdasLock);
+    _preRenderLambdas[key] = func;
+}
+
 // Called during Application::update immediately before AvatarManager::updateMyAvatar, updating my data that is then sent to everyone.
 // (Maybe this code should be moved there?)
 // The principal result is to call updateLookAtTargetAvatar() and then setLookAtPosition().
@@ -3451,6 +3456,16 @@ void Application::update(float deltaTime) {
             QMetaObject::invokeMethod(DependencyManager::get<AudioClient>().data(), "sendDownstreamAudioStatsPacket", Qt::QueuedConnection);
         }
     }
+
+    {
+        PROFILE_RANGE_EX("PreRenderLambdas", 0xffff0000, (uint64_t)0);
+
+        std::unique_lock<std::mutex> guard(_preRenderLambdasLock);
+        for (auto& iter : _preRenderLambdas) {
+            iter.second();
+        }
+        _preRenderLambdas.clear();
+    }
 }
 
 
diff --git a/interface/src/Application.h b/interface/src/Application.h
index f20d72fcb6..31c865ad90 100644
--- a/interface/src/Application.h
+++ b/interface/src/Application.h
@@ -211,6 +211,8 @@ public:
     render::EnginePointer getRenderEngine() override { return _renderEngine; }
     gpu::ContextPointer getGPUContext() const { return _gpuContext; }
 
+    virtual void pushPreRenderLambda(void* key, std::function<void()> func) override;
+
     const QRect& getMirrorViewRect() const { return _mirrorViewRect; }
 
     void updateMyAvatarLookAtPosition();
@@ -510,6 +512,9 @@ private:
     bool _cursorNeedsChanging { false };
 
     QThread* _deadlockWatchdogThread;
+
+    std::map<void*, std::function<void()>> _preRenderLambdas;
+    std::mutex _preRenderLambdasLock;
 };
 
 #endif // hifi_Application_h
diff --git a/interface/src/ui/overlays/ModelOverlay.cpp b/interface/src/ui/overlays/ModelOverlay.cpp
index 010698800b..adf08934f0 100644
--- a/interface/src/ui/overlays/ModelOverlay.cpp
+++ b/interface/src/ui/overlays/ModelOverlay.cpp
@@ -18,22 +18,22 @@
 QString const ModelOverlay::TYPE = "model";
 
 ModelOverlay::ModelOverlay()
-    : _model(std::make_shared<Rig>()),
+    : _model(std::make_shared<Model>(std::make_shared<Rig>())),
       _modelTextures(QVariantMap()),
       _updateModel(false)
 {
-    _model.init();
+    _model->init();
     _isLoaded = false;
 }
 
 ModelOverlay::ModelOverlay(const ModelOverlay* modelOverlay) :
     Volume3DOverlay(modelOverlay),
-    _model(std::make_shared<Rig>()),
+    _model(std::make_shared<Model>(std::make_shared<Rig>())),
     _modelTextures(QVariantMap()),
     _url(modelOverlay->_url),
     _updateModel(false)
 {
-    _model.init();
+    _model->init();
     if (_url.isValid()) {
         _updateModel = true;
         _isLoaded = false;
@@ -44,27 +44,27 @@ void ModelOverlay::update(float deltatime) {
     if (_updateModel) {
         _updateModel = false;
         
-        _model.setSnapModelToCenter(true);
-        _model.setScale(getDimensions());
-        _model.setRotation(getRotation());
-        _model.setTranslation(getPosition());
-        _model.setURL(_url);
-        _model.simulate(deltatime, true);
+        _model->setSnapModelToCenter(true);
+        _model->setScale(getDimensions());
+        _model->setRotation(getRotation());
+        _model->setTranslation(getPosition());
+        _model->setURL(_url);
+        _model->simulate(deltatime, true);
     } else {
-        _model.simulate(deltatime);
+        _model->simulate(deltatime);
     }
-    _isLoaded = _model.isActive();
+    _isLoaded = _model->isActive();
 }
 
 bool ModelOverlay::addToScene(Overlay::Pointer overlay, std::shared_ptr<render::Scene> scene, render::PendingChanges& pendingChanges) {
     Volume3DOverlay::addToScene(overlay, scene, pendingChanges);
-    _model.addToScene(scene, pendingChanges);
+    _model->addToScene(scene, pendingChanges);
     return true;
 }
 
 void ModelOverlay::removeFromScene(Overlay::Pointer overlay, std::shared_ptr<render::Scene> scene, render::PendingChanges& pendingChanges) {
     Volume3DOverlay::removeFromScene(overlay, scene, pendingChanges);
-    _model.removeFromScene(scene, pendingChanges);
+    _model->removeFromScene(scene, pendingChanges);
 }
 
 void ModelOverlay::render(RenderArgs* args) {
@@ -73,9 +73,9 @@ void ModelOverlay::render(RenderArgs* args) {
     // fix them up in the scene
     render::ScenePointer scene = qApp->getMain3DScene();
     render::PendingChanges pendingChanges;
-    if (_model.needsFixupInScene()) {
-        _model.removeFromScene(scene, pendingChanges);
-        _model.addToScene(scene, pendingChanges);
+    if (_model->needsFixupInScene()) {
+        _model->removeFromScene(scene, pendingChanges);
+        _model->addToScene(scene, pendingChanges);
     }
     scene->enqueuePendingChanges(pendingChanges);
 
@@ -100,7 +100,7 @@ void ModelOverlay::setProperties(const QVariantMap& properties) {
         if (newScale.x <= 0 || newScale.y <= 0 || newScale.z <= 0) {
             setDimensions(scale);
         } else {
-            _model.setScaleToFit(true, getDimensions());
+            _model->setScaleToFit(true, getDimensions());
             _updateModel = true;
         }
     }
@@ -120,7 +120,7 @@ void ModelOverlay::setProperties(const QVariantMap& properties) {
             QUrl newTextureURL = textureMap[key].toUrl();
             qDebug() << "Updating texture named" << key << "to texture at URL" << newTextureURL;
             
-            QMetaObject::invokeMethod(&_model, "setTextureWithNameToURL", Qt::AutoConnection,
+            QMetaObject::invokeMethod(_model.get(), "setTextureWithNameToURL", Qt::AutoConnection,
                                       Q_ARG(const QString&, key),
                                       Q_ARG(const QUrl&, newTextureURL));
 
@@ -134,7 +134,7 @@ QVariant ModelOverlay::getProperty(const QString& property) {
         return _url.toString();
     }
     if (property == "dimensions" || property == "scale" || property == "size") {
-        return vec3toVariant(_model.getScaleToFitDimensions());
+        return vec3toVariant(_model->getScaleToFitDimensions());
     }
     if (property == "textures") {
         if (_modelTextures.size() > 0) {
@@ -155,13 +155,13 @@ bool ModelOverlay::findRayIntersection(const glm::vec3& origin, const glm::vec3&
                                         float& distance, BoxFace& face, glm::vec3& surfaceNormal) {
     
     QString subMeshNameTemp;
-    return _model.findRayIntersectionAgainstSubMeshes(origin, direction, distance, face, surfaceNormal, subMeshNameTemp);
+    return _model->findRayIntersectionAgainstSubMeshes(origin, direction, distance, face, surfaceNormal, subMeshNameTemp);
 }
 
 bool ModelOverlay::findRayIntersectionExtraInfo(const glm::vec3& origin, const glm::vec3& direction,
                                         float& distance, BoxFace& face, glm::vec3& surfaceNormal, QString& extraInfo) {
     
-    return _model.findRayIntersectionAgainstSubMeshes(origin, direction, distance, face, surfaceNormal, extraInfo);
+    return _model->findRayIntersectionAgainstSubMeshes(origin, direction, distance, face, surfaceNormal, extraInfo);
 }
 
 ModelOverlay* ModelOverlay::createClone() const {
diff --git a/interface/src/ui/overlays/ModelOverlay.h b/interface/src/ui/overlays/ModelOverlay.h
index 0b67f7ed37..36ff75cb6a 100644
--- a/interface/src/ui/overlays/ModelOverlay.h
+++ b/interface/src/ui/overlays/ModelOverlay.h
@@ -41,11 +41,11 @@ public:
 
 private:
 
-    Model _model;
+    ModelPointer _model;
     QVariantMap _modelTextures;
     
     QUrl _url;
     bool _updateModel;
 };
 
-#endif // hifi_ModelOverlay_h
\ No newline at end of file
+#endif // hifi_ModelOverlay_h
diff --git a/libraries/animation/src/Rig.cpp b/libraries/animation/src/Rig.cpp
index a2b664d064..6a8f190808 100644
--- a/libraries/animation/src/Rig.cpp
+++ b/libraries/animation/src/Rig.cpp
@@ -1056,7 +1056,9 @@ void Rig::updateEyeJoint(int index, const glm::vec3& modelTranslation, const glm
 
         // limit rotation
         const float MAX_ANGLE = 30.0f * RADIANS_PER_DEGREE;
-        deltaQuat = glm::angleAxis(glm::clamp(glm::angle(deltaQuat), -MAX_ANGLE, MAX_ANGLE), glm::axis(deltaQuat));
+        if (fabsf(glm::angle(deltaQuat)) > MAX_ANGLE) {
+            deltaQuat = glm::angleAxis(glm::clamp(glm::angle(deltaQuat), -MAX_ANGLE, MAX_ANGLE), glm::axis(deltaQuat));
+        }
 
         // directly set absolutePose rotation
         _internalPoseSet._absolutePoses[index].rot = deltaQuat * headQuat;
diff --git a/libraries/animation/src/Rig.h b/libraries/animation/src/Rig.h
index 1f9a02d8ab..3a27b9304b 100644
--- a/libraries/animation/src/Rig.h
+++ b/libraries/animation/src/Rig.h
@@ -221,6 +221,8 @@ public:
 
     void setEnableInverseKinematics(bool enable);
 
+    const glm::mat4& getGeometryToRigTransform() const { return _geometryToRigTransform; }
+
  protected:
     bool isIndexValid(int index) const { return _animSkeleton && index >= 0 && index < _animSkeleton->getNumJoints(); }
     void updateAnimationStateHandlers();
diff --git a/libraries/model/src/model/Geometry.cpp b/libraries/model/src/model/Geometry.cpp
index df86ba2a8f..2bb6cfa436 100755
--- a/libraries/model/src/model/Geometry.cpp
+++ b/libraries/model/src/model/Geometry.cpp
@@ -111,7 +111,7 @@ Box Mesh::evalPartBound(int partNum) const {
     return box;
 }
 
-Box Mesh::evalPartBounds(int partStart, int partEnd, Boxes& bounds) const {
+Box Mesh::evalPartsBound(int partStart, int partEnd) const {
     Box totalBound;
     auto part = _partBuffer.cbegin<Part>() + partStart;
     auto partItEnd = _partBuffer.cbegin<Part>() + partEnd;
diff --git a/libraries/model/src/model/Geometry.h b/libraries/model/src/model/Geometry.h
index f9d9b0eeb4..a3e95c68c0 100755
--- a/libraries/model/src/model/Geometry.h
+++ b/libraries/model/src/model/Geometry.h
@@ -108,9 +108,9 @@ public:
 
     // evaluate the bounding box of A part
     Box evalPartBound(int partNum) const;
-    // evaluate the bounding boxes of the parts in the range [start, end[ and fill the bounds parameter
-    // the returned box is the bounding box of ALL the evaluated part bounds.
-    Box evalPartBounds(int partStart, int partEnd, Boxes& bounds) const;
+    // evaluate the bounding boxes of the parts in the range [start, end]
+    // the returned box is the bounding box of ALL the evaluated parts bound.
+    Box evalPartsBound(int partStart, int partEnd) const;
 
     static gpu::Primitive topologyToPrimitive(Topology topo) { return static_cast<gpu::Primitive>(topo); }
 
diff --git a/libraries/render-utils/src/AbstractViewStateInterface.h b/libraries/render-utils/src/AbstractViewStateInterface.h
index 815cb45423..7c7c263562 100644
--- a/libraries/render-utils/src/AbstractViewStateInterface.h
+++ b/libraries/render-utils/src/AbstractViewStateInterface.h
@@ -46,6 +46,8 @@ public:
     virtual render::ScenePointer getMain3DScene() = 0;
     virtual render::EnginePointer getRenderEngine() = 0;
 
+    virtual void pushPreRenderLambda(void* key, std::function<void()> func) = 0;
+
     // FIXME - we shouldn't assume that there's a single instance of an AbstractViewStateInterface
     static AbstractViewStateInterface* instance();
     static void setInstance(AbstractViewStateInterface* instance);
diff --git a/libraries/render-utils/src/MeshPartPayload.cpp b/libraries/render-utils/src/MeshPartPayload.cpp
index 854630abf0..d295b07caf 100644
--- a/libraries/render-utils/src/MeshPartPayload.cpp
+++ b/libraries/render-utils/src/MeshPartPayload.cpp
@@ -58,7 +58,6 @@ void MeshPartPayload::updateMeshPart(const std::shared_ptr<const model::Mesh>& d
         auto vertexFormat = _drawMesh->getVertexFormat();
         _hasColorAttrib = vertexFormat->hasAttribute(gpu::Stream::COLOR);
         _drawPart = _drawMesh->getPartBuffer().get<model::Mesh::Part>(partIndex);
-
         _localBound = _drawMesh->evalPartBound(partIndex);
     }
 }
@@ -352,7 +351,23 @@ void ModelMeshPartPayload::initCache() {
 
 
 void ModelMeshPartPayload::notifyLocationChanged() {
-    _model->_needsUpdateClusterMatrices = true;
+
+}
+
+void ModelMeshPartPayload::updateTransformForSkinnedMesh(const Transform& transform, const Transform& offsetTransform, const QVector<glm::mat4>& clusterMatrices) {
+    ModelMeshPartPayload::updateTransform(transform, offsetTransform);
+
+    if (clusterMatrices.size() > 0) {
+        _worldBound = AABox();
+        for (auto& clusterMatrix : clusterMatrices) {
+            AABox clusterBound = _localBound;
+            clusterBound.transform(clusterMatrix);
+            _worldBound += clusterBound;
+        }
+
+        // clusterMatrix has world rotation but not world translation.
+        _worldBound.translate(transform.getTranslation());
+    }
 }
 
 ItemKey ModelMeshPartPayload::getKey() const {
@@ -377,12 +392,6 @@ ItemKey ModelMeshPartPayload::getKey() const {
     return builder.build();
 }
 
-Item::Bound ModelMeshPartPayload::getBound() const {
-    // NOTE: we can't cache this bounds because we need to handle the case of a moving
-    // entity or mesh part.
-    return _model->getPartBounds(_meshIndex, _partIndex, _transform.getTranslation(), _transform.getRotation());
-}
-
 ShapeKey ModelMeshPartPayload::getShapeKey() const {
     assert(_model->isLoaded());
     const FBXGeometry& geometry = _model->getFBXGeometry();
diff --git a/libraries/render-utils/src/MeshPartPayload.h b/libraries/render-utils/src/MeshPartPayload.h
index 9f73a46a93..41869ec7e3 100644
--- a/libraries/render-utils/src/MeshPartPayload.h
+++ b/libraries/render-utils/src/MeshPartPayload.h
@@ -74,15 +74,15 @@ namespace render {
 class ModelMeshPartPayload : public MeshPartPayload {
 public:
     ModelMeshPartPayload(Model* model, int meshIndex, int partIndex, int shapeIndex, const Transform& transform, const Transform& offsetTransform);
-    
+
     typedef render::Payload<ModelMeshPartPayload> Payload;
     typedef Payload::DataPointer Pointer;
 
     void notifyLocationChanged() override;
+    void updateTransformForSkinnedMesh(const Transform& transform, const Transform& offsetTransform, const QVector<glm::mat4>& clusterMatrices);
 
     // Render Item interface
     render::ItemKey getKey() const override;
-    render::Item::Bound getBound() const override;
     render::ShapeKey getShapeKey() const override; // shape interface
     void render(RenderArgs* args) const override;
 
@@ -101,4 +101,11 @@ public:
     bool _isBlendShaped{ false };
 };
 
+namespace render {
+    template <> const ItemKey payloadGetKey(const ModelMeshPartPayload::Pointer& payload);
+    template <> const Item::Bound payloadGetBound(const ModelMeshPartPayload::Pointer& payload);
+    template <> const ShapeKey shapeGetShapeKey(const ModelMeshPartPayload::Pointer& payload);
+    template <> void payloadRender(const ModelMeshPartPayload::Pointer& payload, RenderArgs* args);
+}
+
 #endif // hifi_MeshPartPayload_h
diff --git a/libraries/render-utils/src/Model.cpp b/libraries/render-utils/src/Model.cpp
index 545d239549..8d59d5f736 100644
--- a/libraries/render-utils/src/Model.cpp
+++ b/libraries/render-utils/src/Model.cpp
@@ -130,25 +130,60 @@ void Model::setOffset(const glm::vec3& offset) {
 }
 
 void Model::enqueueLocationChange() {
-    render::ScenePointer scene = AbstractViewStateInterface::instance()->getMain3DScene();
 
-    Transform transform;
-    transform.setTranslation(_translation);
-    transform.setRotation(_rotation);
+    // queue up this work for later processing, at the end of update and just before rendering.
+    // the application will ensure only the last lambda is actually invoked.
+    void* key = (void*)this;
+    std::weak_ptr<Model> weakSelf = shared_from_this();
+    AbstractViewStateInterface::instance()->pushPreRenderLambda(key, [weakSelf]() {
 
-    Transform offset;
-    offset.setScale(_scale);
-    offset.postTranslate(_offset);
+        // do nothing, if the model has already been destroyed.
+        auto self = weakSelf.lock();
+        if (!self) {
+            return;
+        }
 
-    render::PendingChanges pendingChanges;
-    foreach (auto itemID, _renderItems.keys()) {
-        pendingChanges.updateItem<MeshPartPayload>(itemID, [transform, offset](MeshPartPayload& data) {
-            data.updateTransform(transform, offset);
-            data.notifyLocationChanged();
-        });
-    }
+        render::ScenePointer scene = AbstractViewStateInterface::instance()->getMain3DScene();
 
-    scene->enqueuePendingChanges(pendingChanges);
+        Transform modelTransform;
+        modelTransform.setScale(self->_scale);
+        modelTransform.setTranslation(self->_translation);
+        modelTransform.setRotation(self->_rotation);
+
+        Transform modelMeshOffset;
+        if (self->isLoaded()) {
+            // includes model offset and unitScale.
+            modelMeshOffset = Transform(self->_rig->getGeometryToRigTransform());
+        } else {
+            modelMeshOffset.postTranslate(self->_offset);
+        }
+
+        // only apply offset only, collision mesh does not share the same unit scale as the FBX file's mesh.
+        Transform collisionMeshOffset;
+        collisionMeshOffset.postTranslate(self->_offset);
+
+        render::PendingChanges pendingChanges;
+        foreach (auto itemID, self->_modelMeshRenderItems.keys()) {
+            pendingChanges.updateItem<ModelMeshPartPayload>(itemID, [modelTransform, modelMeshOffset](ModelMeshPartPayload& data) {
+
+                // 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());
+
+                // update the model transform and bounding box for this render item.
+                const Model::MeshState& state = data._model->_meshStates.at(data._meshIndex);
+                data.updateTransformForSkinnedMesh(modelTransform, modelMeshOffset, state.clusterMatrices);
+            });
+        }
+
+        foreach (auto itemID, self->_collisionRenderItems.keys()) {
+            pendingChanges.updateItem<MeshPartPayload>(itemID, [modelTransform, collisionMeshOffset](MeshPartPayload& data) {
+                // update the model transform for this render item.
+                data.updateTransform(modelTransform, collisionMeshOffset);
+            });
+        }
+
+        scene->enqueuePendingChanges(pendingChanges);
+    });
 }
 
 void Model::initJointTransforms() {
@@ -497,8 +532,11 @@ void Model::setVisibleInScene(bool newValue, std::shared_ptr<render::Scene> scen
         _isVisible = newValue;
 
         render::PendingChanges pendingChanges;
-        foreach (auto item, _renderItems.keys()) {
-            pendingChanges.resetItem(item, _renderItems[item]);
+        foreach (auto item, _modelMeshRenderItems.keys()) {
+            pendingChanges.resetItem(item, _modelMeshRenderItems[item]);
+        }
+        foreach (auto item, _collisionRenderItems.keys()) {
+            pendingChanges.resetItem(item, _modelMeshRenderItems[item]);
         }
         scene->enqueuePendingChanges(pendingChanges);
     }
@@ -514,14 +552,25 @@ bool Model::addToScene(std::shared_ptr<render::Scene> scene, render::PendingChan
 
     bool somethingAdded = false;
 
-    foreach (auto renderItem, _renderItemsSet) {
+    foreach (auto renderItem, _modelMeshRenderItemsSet) {
+        auto item = scene->allocateID();
+        auto renderPayload = std::make_shared<ModelMeshPartPayload::Payload>(renderItem);
+        pendingChanges.resetItem(item, renderPayload);
+        pendingChanges.updateItem<ModelMeshPartPayload>(item, [](ModelMeshPartPayload& data) {
+            data.notifyLocationChanged();
+        });
+        _modelMeshRenderItems.insert(item, renderPayload);
+        somethingAdded = true;
+    }
+
+    foreach (auto renderItem, _collisionRenderItemsSet) {
         auto item = scene->allocateID();
         auto renderPayload = std::make_shared<MeshPartPayload::Payload>(renderItem);
         pendingChanges.resetItem(item, renderPayload);
         pendingChanges.updateItem<MeshPartPayload>(item, [](MeshPartPayload& data) {
             data.notifyLocationChanged();
         });
-        _renderItems.insert(item, renderPayload);
+        _collisionRenderItems.insert(item, renderPayload);
         somethingAdded = true;
     }
 
@@ -541,7 +590,19 @@ bool Model::addToScene(std::shared_ptr<render::Scene> scene,
 
     bool somethingAdded = false;
 
-    foreach (auto renderItem, _renderItemsSet) {
+    foreach (auto renderItem, _modelMeshRenderItemsSet) {
+        auto item = scene->allocateID();
+        auto renderPayload = std::make_shared<ModelMeshPartPayload::Payload>(renderItem);
+        renderPayload->addStatusGetters(statusGetters);
+        pendingChanges.resetItem(item, renderPayload);
+        pendingChanges.updateItem<ModelMeshPartPayload>(item, [](ModelMeshPartPayload& data) {
+            data.notifyLocationChanged();
+        });
+        _modelMeshRenderItems.insert(item, renderPayload);
+        somethingAdded = true;
+    }
+
+    foreach (auto renderItem, _collisionRenderItemsSet) {
         auto item = scene->allocateID();
         auto renderPayload = std::make_shared<MeshPartPayload::Payload>(renderItem);
         renderPayload->addStatusGetters(statusGetters);
@@ -549,7 +610,7 @@ bool Model::addToScene(std::shared_ptr<render::Scene> scene,
         pendingChanges.updateItem<MeshPartPayload>(item, [](MeshPartPayload& data) {
             data.notifyLocationChanged();
         });
-        _renderItems.insert(item, renderPayload);
+        _collisionRenderItems.insert(item, renderPayload);
         somethingAdded = true;
     }
 
@@ -559,11 +620,16 @@ bool Model::addToScene(std::shared_ptr<render::Scene> scene,
 }
 
 void Model::removeFromScene(std::shared_ptr<render::Scene> scene, render::PendingChanges& pendingChanges) {
-    foreach (auto item, _renderItems.keys()) {
+    foreach (auto item, _modelMeshRenderItems.keys()) {
         pendingChanges.removeItem(item);
     }
-    _renderItems.clear();
-    _renderItemsSet.clear();
+    _modelMeshRenderItems.clear();
+    _modelMeshRenderItemsSet.clear();
+    foreach (auto item, _collisionRenderItems.keys()) {
+        pendingChanges.removeItem(item);
+    }
+    _collisionRenderItems.clear();
+    _collisionRenderItemsSet.clear();
     _meshGroupsKnown = false;
     _readyWhenAdded = false;
 }
@@ -1175,10 +1241,14 @@ void Model::segregateMeshGroups() {
         return;
     }
 
-    Q_ASSERT(_renderItems.isEmpty()); // We should not have any existing renderItems if we enter this section of code
-    Q_ASSERT(_renderItemsSet.isEmpty()); // We should not have any existing renderItemsSet if we enter this section of code
+    // We should not have any existing renderItems if we enter this section of code
+    Q_ASSERT(_modelMeshRenderItems.isEmpty());
+    Q_ASSERT(_modelMeshRenderItemsSet.isEmpty());
+    Q_ASSERT(_collisionRenderItems.isEmpty());
+    Q_ASSERT(_collisionRenderItemsSet.isEmpty());
 
-    _renderItemsSet.clear();
+    _modelMeshRenderItemsSet.clear();
+    _collisionRenderItemsSet.clear();
 
     Transform transform;
     transform.setTranslation(_translation);
@@ -1204,9 +1274,9 @@ void Model::segregateMeshGroups() {
                     _collisionHullMaterial->setMetallic(0.02f);
                     _collisionHullMaterial->setRoughness(0.5f);
                 }
-                _renderItemsSet << std::make_shared<MeshPartPayload>(networkMesh, partIndex, _collisionHullMaterial, transform, offset);
+                _collisionRenderItemsSet << std::make_shared<MeshPartPayload>(networkMesh, partIndex, _collisionHullMaterial, transform, offset);
             } else {
-                _renderItemsSet << std::make_shared<ModelMeshPartPayload>(this, i, partIndex, shapeID, transform, offset);
+                _modelMeshRenderItemsSet << std::make_shared<ModelMeshPartPayload>(this, i, partIndex, shapeID, transform, offset);
             }
 
             shapeID++;
@@ -1229,13 +1299,21 @@ bool Model::initWhenReady(render::ScenePointer scene) {
         offset.setScale(_scale);
         offset.postTranslate(_offset);
 
-        foreach (auto renderItem, _renderItemsSet) {
+        foreach (auto renderItem, _modelMeshRenderItemsSet) {
+            auto item = scene->allocateID();
+            auto renderPayload = std::make_shared<ModelMeshPartPayload::Payload>(renderItem);
+            _modelMeshRenderItems.insert(item, renderPayload);
+            pendingChanges.resetItem(item, renderPayload);
+            pendingChanges.updateItem<ModelMeshPartPayload>(item, [transform, offset](MeshPartPayload& data) {
+                data.notifyLocationChanged();
+            });
+        }
+        foreach (auto renderItem, _collisionRenderItemsSet) {
             auto item = scene->allocateID();
             auto renderPayload = std::make_shared<MeshPartPayload::Payload>(renderItem);
-            _renderItems.insert(item, renderPayload);
+            _collisionRenderItems.insert(item, renderPayload);
             pendingChanges.resetItem(item, renderPayload);
-            pendingChanges.updateItem<MeshPartPayload>(item, [transform,offset](MeshPartPayload& data) {
-                data.updateTransform(transform, offset);
+            pendingChanges.updateItem<MeshPartPayload>(item, [transform, offset](MeshPartPayload& data) {
                 data.notifyLocationChanged();
             });
         }
diff --git a/libraries/render-utils/src/Model.h b/libraries/render-utils/src/Model.h
index 785b902b3a..e4a8fa3b36 100644
--- a/libraries/render-utils/src/Model.h
+++ b/libraries/render-utils/src/Model.h
@@ -44,6 +44,7 @@ namespace render {
     typedef unsigned int ItemID;
 }
 class MeshPartPayload;
+class ModelMeshPartPayload;
 class ModelRenderLocations;
 
 inline uint qHash(const std::shared_ptr<MeshPartPayload>& a, uint seed) {
@@ -375,8 +376,12 @@ protected:
     bool _renderCollisionHull;
 
 
-    QSet<std::shared_ptr<MeshPartPayload>> _renderItemsSet;
-    QMap<render::ItemID, render::PayloadPointer> _renderItems;
+    QSet<std::shared_ptr<MeshPartPayload>> _collisionRenderItemsSet;
+    QMap<render::ItemID, render::PayloadPointer> _collisionRenderItems;
+
+    QSet<std::shared_ptr<ModelMeshPartPayload>> _modelMeshRenderItemsSet;
+    QMap<render::ItemID, render::PayloadPointer> _modelMeshRenderItems;
+
     bool _readyWhenAdded { false };
     bool _needsReload { true };
     bool _needsUpdateClusterMatrices { true };
diff --git a/libraries/shared/src/AABox.cpp b/libraries/shared/src/AABox.cpp
index 0b453e6f36..a3afa220c9 100644
--- a/libraries/shared/src/AABox.cpp
+++ b/libraries/shared/src/AABox.cpp
@@ -17,6 +17,8 @@
 #include "GeometryUtil.h"
 #include "NumericalConstants.h"
 
+const glm::vec3 AABox::INFINITY_VECTOR(std::numeric_limits<float>::infinity());
+
 AABox::AABox(const AACube& other) :
     _corner(other.getCorner()), _scale(other.getScale(), other.getScale(), other.getScale()) {
 }
@@ -34,7 +36,7 @@ AABox::AABox(const glm::vec3& corner, const glm::vec3& dimensions) :
     _corner(corner), _scale(dimensions) {
 };
 
-AABox::AABox() : _corner(std::numeric_limits<float>::infinity()), _scale(0.0f) {
+AABox::AABox() : _corner(INFINITY_VECTOR), _scale(0.0f) {
 };
 
 glm::vec3 AABox::calcCenter() const {
@@ -475,8 +477,15 @@ AABox AABox::clamp(float min, float max) const {
 }
 
 AABox& AABox::operator += (const glm::vec3& point) {
-    _corner = glm::min(_corner, point);
-    _scale = glm::max(_scale, point - _corner);
+
+    if (isInvalid()) {
+        _corner = glm::min(_corner, point);
+    } else {
+        glm::vec3 maximum(_corner + _scale);
+        _corner = glm::min(_corner, point);
+        maximum = glm::max(maximum, point);
+        _scale = maximum - _corner;
+    }
 
     return (*this);
 }
@@ -484,17 +493,31 @@ AABox& AABox::operator += (const glm::vec3& point) {
 AABox& AABox::operator += (const AABox& box) {
     if (!box.isInvalid()) {
         (*this) += box._corner;
-       _scale = glm::max(_scale, box.calcTopFarLeft() - _corner);
+        (*this) += box.calcTopFarLeft();
     }
     return (*this);
 }
 
+void AABox::embiggen(float scale) {
+    _corner += scale * (-0.5f * _scale);
+    _scale *= scale;
+}
+
+void AABox::embiggen(const glm::vec3& scale) {
+    _corner += scale * (-0.5f * _scale);
+    _scale *= scale;
+}
+
+void AABox::scale(float scale) {
+    _corner *= scale;
+    _scale *= scale;
+}
+
 void AABox::scale(const glm::vec3& scale) {
     _corner *= scale;
     _scale *= scale;
 }
 
-
 void AABox::rotate(const glm::quat& rotation) {
     auto minimum = _corner;
     auto maximum = _corner + _scale;
@@ -544,3 +567,47 @@ void AABox::transform(const Transform& transform) {
     rotate(transform.getRotation());
     translate(transform.getTranslation());
 }
+
+void AABox::transform(const glm::mat4& matrix) {
+    auto minimum = _corner;
+    auto maximum = _corner + _scale;
+
+    glm::vec3 bottomLeftNear(minimum.x, minimum.y, minimum.z);
+    glm::vec3 bottomRightNear(maximum.x, minimum.y, minimum.z);
+    glm::vec3 bottomLeftFar(minimum.x, minimum.y, maximum.z);
+    glm::vec3 bottomRightFar(maximum.x, minimum.y, maximum.z);
+    glm::vec3 topLeftNear(minimum.x, maximum.y, minimum.z);
+    glm::vec3 topRightNear(maximum.x, maximum.y, minimum.z);
+    glm::vec3 topLeftFar(minimum.x, maximum.y, maximum.z);
+    glm::vec3 topRightFar(maximum.x, maximum.y, maximum.z);
+
+    glm::vec3 bottomLeftNearTransformed = transformPoint(matrix, bottomLeftNear);
+    glm::vec3 bottomRightNearTransformed = transformPoint(matrix, bottomRightNear);
+    glm::vec3 bottomLeftFarTransformed = transformPoint(matrix, bottomLeftFar);
+    glm::vec3 bottomRightFarTransformed = transformPoint(matrix, bottomRightFar);
+    glm::vec3 topLeftNearTransformed = transformPoint(matrix, topLeftNear);
+    glm::vec3 topRightNearTransformed = transformPoint(matrix, topRightNear);
+    glm::vec3 topLeftFarTransformed = transformPoint(matrix, topLeftFar);
+    glm::vec3 topRightFarTransformed = transformPoint(matrix, topRightFar);
+
+    minimum = glm::min(bottomLeftNearTransformed,
+        glm::min(bottomRightNearTransformed,
+        glm::min(bottomLeftFarTransformed,
+        glm::min(bottomRightFarTransformed,
+        glm::min(topLeftNearTransformed,
+        glm::min(topRightNearTransformed,
+        glm::min(topLeftFarTransformed,
+        topRightFarTransformed)))))));
+
+    maximum = glm::max(bottomLeftNearTransformed,
+        glm::max(bottomRightNearTransformed,
+        glm::max(bottomLeftFarTransformed,
+        glm::max(bottomRightFarTransformed,
+        glm::max(topLeftNearTransformed,
+        glm::max(topRightNearTransformed,
+        glm::max(topLeftFarTransformed,
+        topRightFarTransformed)))))));
+
+    _corner = minimum;
+    _scale = maximum - minimum;
+}
diff --git a/libraries/shared/src/AABox.h b/libraries/shared/src/AABox.h
index ec06c60121..30bde2d717 100644
--- a/libraries/shared/src/AABox.h
+++ b/libraries/shared/src/AABox.h
@@ -58,7 +58,6 @@ public:
     const glm::vec3& getMinimumPoint() const { return _corner; }
     glm::vec3 getMaximumPoint() const { return calcTopFarLeft(); }
 
-
     bool contains(const glm::vec3& point) const;
     bool contains(const AABox& otherBox) const;
     bool touches(const AABox& otherBox) const;
@@ -93,10 +92,19 @@ public:
     void scale(float scale);
     void scale(const glm::vec3& scale);
 
+    /// make the AABox bigger (scale about it's center)
+    void embiggen(float scale);
+    void embiggen(const glm::vec3& scale);
+
     // Transform the extents with transform
     void transform(const Transform& transform);
 
-    bool isInvalid() const { return _corner == glm::vec3(std::numeric_limits<float>::infinity()); }
+    // Transform the extents with matrix
+    void transform(const glm::mat4& matrix);
+
+    static const glm::vec3 INFINITY_VECTOR;
+
+    bool isInvalid() const { return _corner == INFINITY_VECTOR; }
 
 private:
     glm::vec3 getClosestPointOnFace(const glm::vec3& point, BoxFace face) const;
diff --git a/tests/shared/src/AABoxTests.cpp b/tests/shared/src/AABoxTests.cpp
index fd709a488c..b9ab95bb09 100644
--- a/tests/shared/src/AABoxTests.cpp
+++ b/tests/shared/src/AABoxTests.cpp
@@ -151,3 +151,21 @@ void AABoxTests::testTouchesSphere() {
     }
 }
 
+void AABoxTests::testScale() {
+    AABox box1(glm::vec3(2.0f), glm::vec3(1.0f));
+    QCOMPARE(box1.contains(glm::vec3(0.0f)), false);
+    box1.scale(glm::vec3(10.0f));
+    QCOMPARE(box1.contains(glm::vec3(0.0f)), false);
+    QCOMPARE(box1.contains(glm::vec3(2.0f * 10.0f)), true);
+
+    AABox box2(glm::vec3(2.0f), glm::vec3(1.0f));
+    QCOMPARE(box2.contains(glm::vec3(0.0f)), false);
+    box2.embiggen(glm::vec3(10.0f));
+    QCOMPARE(box2.contains(glm::vec3(0.0f)), true);
+
+    AABox box3;
+    box3 += glm::vec3(0.0f, 0.0f, 0.0f);
+    box3 += glm::vec3(1.0f, 1.0f, 1.0f);
+    box3 += glm::vec3(-1.0f, -1.0f, -1.0f);
+    QCOMPARE(box3.contains(glm::vec3(0.5f, 0.5f, 0.5f)), true);
+}
diff --git a/tests/shared/src/AABoxTests.h b/tests/shared/src/AABoxTests.h
index fe7afede57..c777f8e94f 100644
--- a/tests/shared/src/AABoxTests.h
+++ b/tests/shared/src/AABoxTests.h
@@ -23,6 +23,7 @@ private slots:
     void testCtorsAndSetters();
     void testContainsPoint();
     void testTouchesSphere();
+    void testScale();
 };
 
 #endif // hifi_AABoxTests_h