diff --git a/interface/src/avatar/Avatar.cpp b/interface/src/avatar/Avatar.cpp
index 65ab6b8d44..199c05af48 100644
--- a/interface/src/avatar/Avatar.cpp
+++ b/interface/src/avatar/Avatar.cpp
@@ -292,6 +292,21 @@ static TextRenderer* textRenderer(TextRendererType type) {
     return displayNameRenderer;
 }
 
+bool Avatar::addToScene(AvatarSharedPointer self, std::shared_ptr<render::Scene> scene, render::PendingChanges& pendingChanges) {
+    auto avatarPayload = new render::Payload<AvatarData>(self);
+    auto avatarPayloadPointer = Avatar::PayloadPointer(avatarPayload);
+    _renderItemID = scene->allocateID();
+    pendingChanges.resetItem(_renderItemID, avatarPayloadPointer);
+    _skeletonModel.addToScene(scene, pendingChanges);
+    getHead()->getFaceModel().addToScene(scene, pendingChanges);
+    return true;
+}
+
+void Avatar::removeFromScene(AvatarSharedPointer self, std::shared_ptr<render::Scene> scene, render::PendingChanges& pendingChanges) {
+    pendingChanges.removeItem(_renderItemID);
+    _skeletonModel.removeFromScene(scene, pendingChanges);
+}
+
 void Avatar::render(RenderArgs* renderArgs, const glm::vec3& cameraPosition, bool postLighting) {
     if (_referential) {
         _referential->update();
@@ -504,6 +519,20 @@ glm::quat Avatar::computeRotationFromBodyToWorldUp(float proportion) const {
 }
 
 void Avatar::renderBody(RenderArgs* renderArgs, ViewFrustum* renderFrustum, bool postLighting, float glowLevel) {
+    // check to see if when we added our models to the scene they were ready, if they were not ready, then
+    // fix them up in the scene
+    render::ScenePointer scene = Application::getInstance()->getMain3DScene();
+    render::PendingChanges pendingChanges;
+    if (_skeletonModel.needsFixupInScene()) {
+        _skeletonModel.removeFromScene(scene, pendingChanges);
+        _skeletonModel.addToScene(scene, pendingChanges);
+    }
+    if (getHead()->getFaceModel().needsFixupInScene()) {
+        getHead()->getFaceModel().removeFromScene(scene, pendingChanges);
+        getHead()->getFaceModel().addToScene(scene, pendingChanges);
+    }
+    scene->enqueuePendingChanges(pendingChanges);
+
     {
         Glower glower(renderArgs, glowLevel);
 
@@ -518,7 +547,8 @@ void Avatar::renderBody(RenderArgs* renderArgs, ViewFrustum* renderFrustum, bool
         if (postLighting) {
             getHand()->render(renderArgs, false);
         } else {
-            _skeletonModel.render(renderArgs, 1.0f);
+            // NOTE: we no longer call this here, because we've added all the model parts as renderable items in the scene
+            //_skeletonModel.render(renderArgs, 1.0f);
             renderAttachments(renderArgs);
         }
     }
diff --git a/interface/src/avatar/Avatar.h b/interface/src/avatar/Avatar.h
index b8f2d3a513..001ff8aa85 100644
--- a/interface/src/avatar/Avatar.h
+++ b/interface/src/avatar/Avatar.h
@@ -83,6 +83,12 @@ public:
     virtual void render(RenderArgs* renderArgs, const glm::vec3& cameraPosition,
         bool postLighting = false);
 
+    bool addToScene(AvatarSharedPointer self, std::shared_ptr<render::Scene> scene, 
+                            render::PendingChanges& pendingChanges);
+
+    void removeFromScene(AvatarSharedPointer self, std::shared_ptr<render::Scene> scene, 
+                                render::PendingChanges& pendingChanges);
+
     //setters
     void setDisplayingLookatVectors(bool displayingLookatVectors) { getHead()->setRenderLookatVectors(displayingLookatVectors); }
     void setIsLookAtTarget(const bool isLookAtTarget) { _isLookAtTarget = isLookAtTarget; }
diff --git a/interface/src/avatar/AvatarManager.cpp b/interface/src/avatar/AvatarManager.cpp
index 8f8a3a8ef3..49a8012cd9 100644
--- a/interface/src/avatar/AvatarManager.cpp
+++ b/interface/src/avatar/AvatarManager.cpp
@@ -63,13 +63,8 @@ void AvatarManager::init() {
     _avatarHash.insert(MY_AVATAR_KEY, _myAvatar);
 
     render::ScenePointer scene = Application::getInstance()->getMain3DScene();
-    auto avatarPayload = new render::Payload<AvatarData>(_myAvatar);
-    auto avatarPayloadPointer = Avatar::PayloadPointer(avatarPayload);
-    static_cast<Avatar*>(_myAvatar.get())->_renderItemID = scene->allocateID();
-
     render::PendingChanges pendingChanges;
-    pendingChanges.resetItem(static_cast<Avatar*>(_myAvatar.get())->_renderItemID, avatarPayloadPointer);
-
+    _myAvatar->addToScene(_myAvatar, scene, pendingChanges);    
     scene->enqueuePendingChanges(pendingChanges);
 }
 
@@ -145,18 +140,11 @@ AvatarSharedPointer AvatarManager::newSharedAvatar() {
 
 // virtual 
 AvatarSharedPointer AvatarManager::addAvatar(const QUuid& sessionUUID, const QWeakPointer<Node>& mixerWeakPointer) {
-    AvatarSharedPointer avatar = AvatarHashMap::addAvatar(sessionUUID, mixerWeakPointer);
-
+    std::shared_ptr<Avatar> avatar = std::dynamic_pointer_cast<Avatar>(AvatarHashMap::addAvatar(sessionUUID, mixerWeakPointer));
     render::ScenePointer scene = Application::getInstance()->getMain3DScene();
-    auto avatarPayload = new render::Payload<AvatarData>(avatar);
-    auto avatarPayloadPointer = Avatar::PayloadPointer(avatarPayload);
-    static_cast<Avatar*>(avatar.get())->_renderItemID = scene->allocateID();
-
     render::PendingChanges pendingChanges;
-    pendingChanges.resetItem(static_cast<Avatar*>(avatar.get())->_renderItemID, avatarPayloadPointer);
-
+    avatar->addToScene(avatar, scene, pendingChanges);    
     scene->enqueuePendingChanges(pendingChanges);
-
     return avatar;
 }
 
@@ -177,17 +165,15 @@ void AvatarManager::removeAvatarMotionState(Avatar* avatar) {
 void AvatarManager::removeAvatar(const QUuid& sessionUUID) {
     AvatarHash::iterator avatarIterator = _avatarHash.find(sessionUUID);
     if (avatarIterator != _avatarHash.end()) {
-        Avatar* avatar = reinterpret_cast<Avatar*>(avatarIterator.value().get());
-        if (avatar != _myAvatar.get() && avatar->isInitialized()) {
-            removeAvatarMotionState(avatar);
-
+        std::shared_ptr<Avatar> avatar = std::dynamic_pointer_cast<Avatar>(avatarIterator.value());
+        if (avatar != _myAvatar && avatar->isInitialized()) {
+            removeAvatarMotionState(avatar.get());
             _avatarFades.push_back(avatarIterator.value());
             _avatarHash.erase(avatarIterator);
         }
-
         render::ScenePointer scene = Application::getInstance()->getMain3DScene();
         render::PendingChanges pendingChanges;
-        pendingChanges.removeItem(avatar->_renderItemID);
+        avatar->removeFromScene(avatar, scene, pendingChanges);
         scene->enqueuePendingChanges(pendingChanges);
     }
 }
diff --git a/interface/src/avatar/Hand.h b/interface/src/avatar/Hand.h
index 524ec23aff..cb35497960 100644
--- a/interface/src/avatar/Hand.h
+++ b/interface/src/avatar/Hand.h
@@ -40,17 +40,6 @@ class Hand : public HandData {
 public:
     Hand(Avatar* owningAvatar);
     
-    struct HandBall
-    {
-        glm::vec3        position;       // the actual dynamic position of the ball at any given time
-        glm::quat        rotation;       // the rotation of the ball
-        glm::vec3        velocity;       // the velocity of the ball
-        float            radius;         // the radius of the ball
-        bool             isCollidable;   // whether or not the ball responds to collisions
-        bool             isColliding;    // ball is currently colliding
-        float            touchForce;     // a scalar determining the amount that the cursor (or hand) is penetrating the ball
-    };
-    
     void simulate(float deltaTime, bool isMine);
     void render(RenderArgs* renderArgs, bool isMine);
 
diff --git a/interface/src/avatar/Head.cpp b/interface/src/avatar/Head.cpp
index d2af14f696..c4bf5e65fc 100644
--- a/interface/src/avatar/Head.cpp
+++ b/interface/src/avatar/Head.cpp
@@ -298,7 +298,8 @@ void Head::render(RenderArgs* renderArgs, float alpha, ViewFrustum* renderFrustu
             renderLookatVectors(renderArgs, _leftEyePosition, _rightEyePosition, getCorrectedLookAtPosition());    
         }
     } else {
-        _faceModel.render(renderArgs, alpha);
+        // NOTE: we don't need to call this here because the model has been added as payload items
+        //_faceModel.render(renderArgs, alpha);
     }
 }
 
diff --git a/interface/src/avatar/MyAvatar.cpp b/interface/src/avatar/MyAvatar.cpp
index 249f8166ac..8407824750 100644
--- a/interface/src/avatar/MyAvatar.cpp
+++ b/interface/src/avatar/MyAvatar.cpp
@@ -1171,10 +1171,25 @@ void MyAvatar::attach(const QString& modelURL, const QString& jointName, const g
 }
 
 void MyAvatar::renderBody(RenderArgs* renderArgs, ViewFrustum* renderFrustum, bool postLighting, float glowLevel) {
+
     if (!(_skeletonModel.isRenderable() && getHead()->getFaceModel().isRenderable())) {
         return; // wait until both models are loaded
     }
 
+    // check to see if when we added our models to the scene they were ready, if they were not ready, then
+    // fix them up in the scene
+    render::ScenePointer scene = Application::getInstance()->getMain3DScene();
+    render::PendingChanges pendingChanges;
+    if (_skeletonModel.needsFixupInScene()) {
+        _skeletonModel.removeFromScene(scene, pendingChanges);
+        _skeletonModel.addToScene(scene, pendingChanges);
+    }
+    if (getHead()->getFaceModel().needsFixupInScene()) {
+        getHead()->getFaceModel().removeFromScene(scene, pendingChanges);
+        getHead()->getFaceModel().addToScene(scene, pendingChanges);
+    }
+    scene->enqueuePendingChanges(pendingChanges);
+
     Camera *camera = Application::getInstance()->getCamera();
     const glm::vec3 cameraPos = camera->getPosition();
 
@@ -1195,7 +1210,9 @@ void MyAvatar::renderBody(RenderArgs* renderArgs, ViewFrustum* renderFrustum, bo
 
     //  Render the body's voxels and head
     if (!postLighting) {
-        _skeletonModel.render(renderArgs, 1.0f);
+    
+        // NOTE: we no longer call this here, because we've added all the model parts as renderable items in the scene
+        //_skeletonModel.render(renderArgs, 1.0f);
         renderAttachments(renderArgs);
     }
     
diff --git a/interface/src/avatar/SkeletonModel.cpp b/interface/src/avatar/SkeletonModel.cpp
index e2f4ca51a0..2aa08d36f3 100644
--- a/interface/src/avatar/SkeletonModel.cpp
+++ b/interface/src/avatar/SkeletonModel.cpp
@@ -255,9 +255,12 @@ void SkeletonModel::applyPalmData(int jointIndex, PalmData& palm) {
 }
 
 void SkeletonModel::updateJointState(int index) {
+    if (index > _jointStates.size()) {
+        return; // bail
+    }
     JointState& state = _jointStates[index];
     const FBXJoint& joint = state.getFBXJoint();
-    if (joint.parentIndex != -1) {
+    if (joint.parentIndex != -1 && joint.parentIndex <= _jointStates.size()) {
         const JointState& parentState = _jointStates.at(joint.parentIndex);
         const FBXGeometry& geometry = _geometry->getFBXGeometry();
         if (index == geometry.leanJointIndex) {
diff --git a/libraries/entities-renderer/src/EntityTreeRenderer.cpp b/libraries/entities-renderer/src/EntityTreeRenderer.cpp
index 43f340119b..cc6693133f 100644
--- a/libraries/entities-renderer/src/EntityTreeRenderer.cpp
+++ b/libraries/entities-renderer/src/EntityTreeRenderer.cpp
@@ -501,7 +501,7 @@ void EntityTreeRenderer::render(RenderArgs* renderArgs) {
             _viewState->getShadowViewFrustum() : _viewState->getCurrentViewFrustum();
         
         // Setup batch transform matrices
-        gpu::Batch batch;
+        gpu::Batch batch; // FIX ME - this is very suspicious!
         glm::mat4 projMat;
         Transform viewMat;
         frustum->evalProjectionMatrix(projMat);
@@ -509,7 +509,7 @@ void EntityTreeRenderer::render(RenderArgs* renderArgs) {
         batch.setProjectionTransform(projMat);
         batch.setViewTransform(viewMat);
         
-        renderArgs->_batch = &batch;
+        renderArgs->_batch = &batch; // FIX ME - this is very suspicious!
 
         _tree->lockForRead();
 
@@ -525,6 +525,7 @@ void EntityTreeRenderer::render(RenderArgs* renderArgs) {
         Model::endScene(renderArgs);
         _tree->unlock();
         
+        // FIX ME - this is very suspicious!
      //   glPushMatrix();
      //   renderArgs->_context->render(batch);
      //   glPopMatrix();
diff --git a/libraries/render-utils/src/Model.cpp b/libraries/render-utils/src/Model.cpp
index 54f0fbd540..312890a188 100644
--- a/libraries/render-utils/src/Model.cpp
+++ b/libraries/render-utils/src/Model.cpp
@@ -406,6 +406,7 @@ void Model::reset() {
     }
     
     _meshGroupsKnown = false;
+    _readyWhenAdded = false; // in case any of our users are using scenes
 }
 
 bool Model::updateGeometry() {
@@ -456,6 +457,7 @@ bool Model::updateGeometry() {
         _dilatedTextures.clear();
         _geometry = geometry;
         _meshGroupsKnown = false;
+        _readyWhenAdded = false; // in case any of our users are using scenes
         initJointStates(newJointStates);
         needToRebuild = true;
     } else if (_jointStates.isEmpty()) {
@@ -704,10 +706,26 @@ void Model::recalculateMeshBoxes(bool pickAgainstTriangles) {
                             int i2 = part.quadIndices[vIndex++];
                             int i3 = part.quadIndices[vIndex++];
 
-                            glm::vec3 v0 = calculateScaledOffsetPoint(glm::vec3(mesh.modelTransform * glm::vec4(mesh.vertices[i0], 1.0f)));
-                            glm::vec3 v1 = calculateScaledOffsetPoint(glm::vec3(mesh.modelTransform * glm::vec4(mesh.vertices[i1], 1.0f)));
-                            glm::vec3 v2 = calculateScaledOffsetPoint(glm::vec3(mesh.modelTransform * glm::vec4(mesh.vertices[i2], 1.0f)));
-                            glm::vec3 v3 = calculateScaledOffsetPoint(glm::vec3(mesh.modelTransform * glm::vec4(mesh.vertices[i3], 1.0f)));
+                            glm::vec3 mv0 = glm::vec3(mesh.modelTransform * glm::vec4(mesh.vertices[i0], 1.0f));
+                            glm::vec3 mv1 = glm::vec3(mesh.modelTransform * glm::vec4(mesh.vertices[i1], 1.0f));
+                            glm::vec3 mv2 = glm::vec3(mesh.modelTransform * glm::vec4(mesh.vertices[i2], 1.0f));
+                            glm::vec3 mv3 = glm::vec3(mesh.modelTransform * glm::vec4(mesh.vertices[i3], 1.0f));
+                            
+                            // track the mesh parts in model space
+                            if (!atLeastOnePointInBounds) {
+                                thisPartBounds.setBox(mv0, 0.0f);
+                                atLeastOnePointInBounds = true;
+                            } else {
+                                thisPartBounds += mv0;
+                            }
+                            thisPartBounds += mv1;
+                            thisPartBounds += mv2;
+                            thisPartBounds += mv3;
+
+                            glm::vec3 v0 = calculateScaledOffsetPoint(mv0);
+                            glm::vec3 v1 = calculateScaledOffsetPoint(mv1);
+                            glm::vec3 v2 = calculateScaledOffsetPoint(mv2);
+                            glm::vec3 v3 = calculateScaledOffsetPoint(mv3);
                         
                             // Sam's recommended triangle slices
                             Triangle tri1 = { v0, v1, v3 };
@@ -720,14 +738,6 @@ void Model::recalculateMeshBoxes(bool pickAgainstTriangles) {
                             thisMeshTriangles.push_back(tri1);
                             thisMeshTriangles.push_back(tri2);
                             
-                            if (!atLeastOnePointInBounds) {
-                                thisPartBounds.setBox(v0, 0.0f);
-                                atLeastOnePointInBounds = true;
-                            }
-                            thisPartBounds += v0;
-                            thisPartBounds += v1;
-                            thisPartBounds += v2;
-                            thisPartBounds += v3;
                         }
                     }
 
@@ -739,21 +749,27 @@ void Model::recalculateMeshBoxes(bool pickAgainstTriangles) {
                             int i1 = part.triangleIndices[vIndex++];
                             int i2 = part.triangleIndices[vIndex++];
 
-                            glm::vec3 v0 = calculateScaledOffsetPoint(glm::vec3(mesh.modelTransform * glm::vec4(mesh.vertices[i0], 1.0f)));
-                            glm::vec3 v1 = calculateScaledOffsetPoint(glm::vec3(mesh.modelTransform * glm::vec4(mesh.vertices[i1], 1.0f)));
-                            glm::vec3 v2 = calculateScaledOffsetPoint(glm::vec3(mesh.modelTransform * glm::vec4(mesh.vertices[i2], 1.0f)));
+                            glm::vec3 mv0 = glm::vec3(mesh.modelTransform * glm::vec4(mesh.vertices[i0], 1.0f));
+                            glm::vec3 mv1 = glm::vec3(mesh.modelTransform * glm::vec4(mesh.vertices[i1], 1.0f));
+                            glm::vec3 mv2 = glm::vec3(mesh.modelTransform * glm::vec4(mesh.vertices[i2], 1.0f));
+
+                            // track the mesh parts in model space
+                            if (!atLeastOnePointInBounds) {
+                                thisPartBounds.setBox(mv0, 0.0f);
+                                atLeastOnePointInBounds = true;
+                            } else {
+                                thisPartBounds += mv0;
+                            }
+                            thisPartBounds += mv1;
+                            thisPartBounds += mv2;
+
+                            glm::vec3 v0 = calculateScaledOffsetPoint(mv0);
+                            glm::vec3 v1 = calculateScaledOffsetPoint(mv1);
+                            glm::vec3 v2 = calculateScaledOffsetPoint(mv2);
 
                             Triangle tri = { v0, v1, v2 };
 
                             thisMeshTriangles.push_back(tri);
-
-                            if (!atLeastOnePointInBounds) {
-                                thisPartBounds.setBox(v0, 0.0f);
-                                atLeastOnePointInBounds = true;
-                            }
-                            thisPartBounds += v0;
-                            thisPartBounds += v1;
-                            thisPartBounds += v2;
                         }
                     }
                     _calculatedMeshPartBoxes[QPair<int,int>(i, j)] = thisPartBounds;
@@ -819,7 +835,6 @@ namespace render {
     template <> void payloadRender(const TransparentMeshPart::Pointer& payload, RenderArgs* args) {
         if (args) {
             args->_elementsTouched++;
-            //qDebug() << "would be TransparentMeshPart: " << payload->meshIndex << "," << payload->partIndex;
             return payload->model->renderPart(args, payload->meshIndex, payload->partIndex, true);
         }
     }
@@ -843,7 +858,9 @@ namespace render {
     
     template <> const Item::Bound payloadGetBound(const OpaqueMeshPart::Pointer& payload) { 
         if (payload) {
-            return payload->model->getPartBounds(payload->meshIndex, payload->partIndex);
+            Item::Bound result = payload->model->getPartBounds(payload->meshIndex, payload->partIndex);
+            //qDebug() << "payloadGetBound(OpaqueMeshPart) " << result;
+            return result;
         }
         return render::Item::Bound();
     }
@@ -857,6 +874,10 @@ namespace render {
 
 
 bool Model::addToScene(std::shared_ptr<render::Scene> scene, render::PendingChanges& pendingChanges) {
+    if (!_meshGroupsKnown && isLoadedWithTextures()) {
+        segregateMeshGroups();
+    }
+
     bool somethingAdded = false;
 
     qDebug() << "Model::addToScene : " << this->getURL().toString();
@@ -883,6 +904,8 @@ bool Model::addToScene(std::shared_ptr<render::Scene> scene, render::PendingChan
         _renderItems << item;
         somethingAdded = true;
     }
+    
+    _readyWhenAdded = readyToAddToScene();
 
     return somethingAdded;
 }
@@ -897,9 +920,8 @@ void Model::removeFromScene(std::shared_ptr<render::Scene> scene, render::Pendin
         pendingChanges.removeItem(item);
     }
     _renderItems.clear();
-
+    _readyWhenAdded = false;
     qDebug() << "Model::removeFromScene : " << this->getURL().toString();
-
 }
 
 bool Model::render(RenderArgs* renderArgs, float alpha) {
@@ -1219,6 +1241,11 @@ Extents Model::calculateScaledOffsetExtents(const Extents& extents) const {
     return translatedExtents;
 }
 
+/// Returns the world space equivalent of some box in model space.
+AABox Model::calculateScaledOffsetAABox(const AABox& box) const {
+    return AABox(calculateScaledOffsetExtents(Extents(box)));
+}
+
 glm::vec3 Model::calculateScaledOffsetPoint(const glm::vec3& point) const {
     // we need to include any fst scaling, translation, and rotation, which is captured in the offset matrix
     glm::vec3 offsetPoint = glm::vec3(_geometry->getFBXGeometry().offset * glm::vec4(point, 1.0f));
@@ -1539,6 +1566,12 @@ void Model::snapToRegistrationPoint() {
 }
 
 void Model::simulate(float deltaTime, bool fullUpdate) {
+    /*
+    qDebug() << "Model::simulate()";
+    qDebug() << "   _translation:" << _translation;
+    qDebug() << "   _rotation:" << _rotation;
+    */
+    
     fullUpdate = updateGeometry() || fullUpdate || (_scaleToFit && !_scaledToFit)
                     || (_snapModelToRegistrationPoint && !_snappedToRegistrationPoint);
                     
@@ -1929,6 +1962,7 @@ void Model::applyNextGeometry() {
     _baseGeometry = _nextBaseGeometry;
     _geometry = _nextGeometry;
     _meshGroupsKnown = false;
+    _readyWhenAdded = false; // in case any of our users are using scenes
     _nextBaseGeometry.reset();
     _nextGeometry.reset();
 }
@@ -2216,23 +2250,15 @@ AABox Model::getPartBounds(int meshIndex, int partIndex) {
         recalculateMeshBoxes(true);
     }
     if (_calculatedMeshPartBoxesValid && _calculatedMeshPartBoxes.contains(QPair<int,int>(meshIndex, partIndex))) {
-        return _calculatedMeshPartBoxes[QPair<int,int>(meshIndex, partIndex)];
-    }
-    if (!_calculatedMeshBoxesValid) {
-        return _calculatedMeshBoxes[meshIndex];
+        return calculateScaledOffsetAABox(_calculatedMeshPartBoxes[QPair<int,int>(meshIndex, partIndex)]);
     }
     return AABox();
 }
 
 void Model::renderPart(RenderArgs* args, int meshIndex, int partIndex, bool translucent) {
-    renderSetup(args);
-
-    /*    
-    if (translucent) {
-        renderCore(args, 1.0f);
-        return;
+    if (!_readyWhenAdded) {
+        return; // bail asap
     }
-    */
     auto textureCache = DependencyManager::get<TextureCache>();
 
     gpu::Batch& batch = *(args->_batch);
@@ -2243,13 +2269,13 @@ void Model::renderPart(RenderArgs* args, int meshIndex, int partIndex, bool tran
         _transforms.push_back(Transform());
     }
 
-  //  _transforms[0] = _viewState->getViewTransform();
-   // args->_viewFrustum->evalViewTransform(_transforms[0]);
+    //  _transforms[0] = _viewState->getViewTransform();
+    // args->_viewFrustum->evalViewTransform(_transforms[0]);
 
     // apply entity translation offset to the viewTransform  in one go (it's a preTranslate because viewTransform goes from world to eye space)
-  //  _transforms[0].setTranslation(_translation);
+    //  _transforms[0].setTranslation(_translation);
 
-   // batch.setViewTransform(_transforms[0]);
+    // batch.setViewTransform(_transforms[0]);
 
 
   //  const float OPAQUE_ALPHA_THRESHOLD = 0.5f;
@@ -2259,10 +2285,15 @@ void Model::renderPart(RenderArgs* args, int meshIndex, int partIndex, bool tran
     const FBXGeometry& geometry = _geometry->getFBXGeometry();
     const QVector<NetworkMesh>& networkMeshes = _geometry->getMeshes();
 
+    // guard against partially loaded meshes
+    if (meshIndex >= networkMeshes.size() || meshIndex >= geometry.meshes.size() || meshIndex >= _meshStates.size() ) {
+        return; 
+    }
+
     const NetworkMesh& networkMesh = networkMeshes.at(meshIndex);
     const FBXMesh& mesh = geometry.meshes.at(meshIndex);
     const MeshState& state = _meshStates.at(meshIndex);
-
+    
     bool translucentMesh = translucent; // networkMesh.getTranslucentPartCount(mesh) == networkMesh.parts.size();
     bool hasTangents = !mesh.tangents.isEmpty();
     bool hasSpecular = mesh.hasSpecularTexture();
@@ -2287,6 +2318,7 @@ void Model::renderPart(RenderArgs* args, int meshIndex, int partIndex, bool tran
     
     if (meshIndex < 0 || meshIndex >= networkMeshes.size() || meshIndex > geometry.meshes.size()) {
         _meshGroupsKnown = false; // regenerate these lists next time around.
+        _readyWhenAdded = false; // in case any of our users are using scenes
         return; // FIXME!
     }
     
@@ -2328,6 +2360,11 @@ void Model::renderPart(RenderArgs* args, int meshIndex, int partIndex, bool tran
 
     qint64 offset = 0;
 
+    // guard against partially loaded meshes
+    if (partIndex >= networkMesh.parts.size() || partIndex >= mesh.parts.size()) {
+        return; 
+    }
+
     const NetworkMeshPart& networkPart = networkMesh.parts.at(partIndex);
     const FBXMeshPart& part = mesh.parts.at(partIndex);
     model::MaterialPointer material = part._material;
@@ -2352,8 +2389,13 @@ void Model::renderPart(RenderArgs* args, int meshIndex, int partIndex, bool tran
 
             Texture* diffuseMap = networkPart.diffuseTexture.data();
             if (mesh.isEye && diffuseMap) {
-                diffuseMap = (_dilatedTextures[meshIndex][partIndex] =
-                    static_cast<DilatableNetworkTexture*>(diffuseMap)->getDilatedTexture(_pupilDilation)).data();
+                // FIXME - guard against out of bounds here
+                if (meshIndex < _dilatedTextures.size()) {
+                    if (partIndex < _dilatedTextures[meshIndex].size()) {
+                        diffuseMap = (_dilatedTextures[meshIndex][partIndex] =
+                            static_cast<DilatableNetworkTexture*>(diffuseMap)->getDilatedTexture(_pupilDilation)).data();
+                    }
+                }
             }
             static bool showDiffuse = true;
             if (showDiffuse && diffuseMap) {
@@ -2623,6 +2665,7 @@ int Model::renderMeshesFromList(QVector<int>& list, gpu::Batch& batch, RenderMod
         
         if (i < 0 || i >= networkMeshes.size() || i > geometry.meshes.size()) {
             _meshGroupsKnown = false; // regenerate these lists next time around.
+            _readyWhenAdded = false; // in case any of our users are using scenes
             continue;
         }
         
diff --git a/libraries/render-utils/src/Model.h b/libraries/render-utils/src/Model.h
index 7b44dbee04..dcbdddcb0a 100644
--- a/libraries/render-utils/src/Model.h
+++ b/libraries/render-utils/src/Model.h
@@ -123,6 +123,7 @@ public:
     static void endScene(RenderArgs* args);
 
     // new Scene/Engine rendering support
+    bool needsFixupInScene() { return !_readyWhenAdded && readyToAddToScene(); }
     bool readyToAddToScene(RenderArgs* renderArgs = nullptr) { return isRenderable() && isActive() && isLoadedWithTextures(); }
     bool addToScene(std::shared_ptr<render::Scene> scene, render::PendingChanges& pendingChanges);
     void removeFromScene(std::shared_ptr<render::Scene> scene, render::PendingChanges& pendingChanges);
@@ -157,6 +158,9 @@ public:
     /// Returns the scaled equivalent of some extents in model space.
     Extents calculateScaledOffsetExtents(const Extents& extents) const;
 
+    /// Returns the world space equivalent of some box in model space.
+    AABox calculateScaledOffsetAABox(const AABox& box) const;
+
     /// Returns the scaled equivalent of a point in model space.
     glm::vec3 calculateScaledOffsetPoint(const glm::vec3& point) const;
 
@@ -542,6 +546,7 @@ private:
     QSet<std::shared_ptr<TransparentMeshPart>> _transparentRenderItems;
     QSet<std::shared_ptr<OpaqueMeshPart>> _opaqueRenderItems;
     QSet<render::ItemID> _renderItems;
+    bool _readyWhenAdded = false;
 };
 
 Q_DECLARE_METATYPE(QPointer<Model>)
diff --git a/libraries/shared/src/AABox.cpp b/libraries/shared/src/AABox.cpp
index 3c6be43850..37fba37adc 100644
--- a/libraries/shared/src/AABox.cpp
+++ b/libraries/shared/src/AABox.cpp
@@ -42,12 +42,6 @@ glm::vec3 AABox::calcCenter() const {
     return center; 
 }
 
-glm::vec3 AABox::calcTopFarLeft() const { 
-    glm::vec3 topFarLeft(_corner);
-    topFarLeft += _scale;
-    return topFarLeft; 
-};
-
 void AABox::scale(float scale) {
     _corner = _corner * scale;
     _scale = _scale * scale;
diff --git a/libraries/shared/src/AABox.h b/libraries/shared/src/AABox.h
index 9beb0a85f2..f185122534 100644
--- a/libraries/shared/src/AABox.h
+++ b/libraries/shared/src/AABox.h
@@ -47,7 +47,11 @@ public:
     float getLargestDimension() const { return glm::max(_scale.x, glm::max(_scale.y, _scale.z)); }
 
     glm::vec3 calcCenter() const;
-    glm::vec3 calcTopFarLeft() const;
+    glm::vec3 calcTopFarLeft() const { return _corner + _scale; }
+
+    const glm::vec3& getMinimum() const { return _corner; }
+    glm::vec3 getMaximum() const { return _corner + _scale; }
+
     glm::vec3 getVertex(BoxVertex vertex) const;
 
     const glm::vec3& getMinimumPoint() const { return _corner; }
diff --git a/libraries/shared/src/Extents.h b/libraries/shared/src/Extents.h
index 489d48b1c1..647f33699a 100644
--- a/libraries/shared/src/Extents.h
+++ b/libraries/shared/src/Extents.h
@@ -23,6 +23,10 @@ class AABox;
 
 class Extents {
 public:
+    Extents(const glm::vec3& minimum, const glm::vec3& maximum) : minimum(minimum), maximum(maximum)  { }
+    Extents() { reset(); }
+    Extents(const AABox& box) { reset(); add(box); }
+
     /// set minimum and maximum to FLT_MAX and -FLT_MAX respectively
     void reset();
 
@@ -58,7 +62,7 @@ public:
 
     /// \return new Extents which is original rotated around orign by rotation
     Extents getRotated(const glm::quat& rotation) const {
-        Extents temp = { minimum, maximum };
+        Extents temp(minimum, maximum);
         temp.rotate(rotation);
         return temp;
     }