diff --git a/libraries/fbx/src/FBXSerializer.cpp b/libraries/fbx/src/FBXSerializer.cpp
index f3c620c929..4ce12d30e4 100644
--- a/libraries/fbx/src/FBXSerializer.cpp
+++ b/libraries/fbx/src/FBXSerializer.cpp
@@ -1480,7 +1480,7 @@ HFMModel* FBXSerializer::extractHFMModel(const hifi::VariantHash& mapping, const
                 // of skinning information in FBX
                 QString jointID = _connectionChildMap.value(clusterID);
                 hfmCluster.jointIndex = modelIDs.indexOf(jointID);
-                if (hfmCluster.jointIndex == -1) {
+                if (hfmCluster.jointIndex == HFMCluster::INVALID_JOINT_INDEX) {
                     qCDebug(modelformat) << "Joint not in model list: " << jointID;
                     hfmCluster.jointIndex = 0;
                 }
@@ -1514,7 +1514,7 @@ HFMModel* FBXSerializer::extractHFMModel(const hifi::VariantHash& mapping, const
         {
             HFMCluster cluster;
             cluster.jointIndex = modelIDs.indexOf(modelID);
-            if (cluster.jointIndex == -1) {
+            if (cluster.jointIndex == HFMCluster::INVALID_JOINT_INDEX) {
                 qCDebug(modelformat) << "Model not in model list: " << modelID;
                 cluster.jointIndex = 0;
             }
diff --git a/libraries/fbx/src/GLTFSerializer.cpp b/libraries/fbx/src/GLTFSerializer.cpp
index fe63159543..29b65e98c0 100755
--- a/libraries/fbx/src/GLTFSerializer.cpp
+++ b/libraries/fbx/src/GLTFSerializer.cpp
@@ -1002,22 +1002,8 @@ bool GLTFSerializer::buildGeometry(HFMModel& hfmModel, const hifi::VariantHash&
     }
     
 
-    // Build transforms
-    for (int nodeIndex = 0; nodeIndex < numNodes; ++nodeIndex) {
-        auto& gltfNode = _file.nodes[nodeIndex];
-        //gltfNode.transforms.push_back(getModelTransform(gltfNode));
-        gltf::ParentIndexMap::const_iterator parentItr;
-        int curNode = nodeIndex;
-        while (parentsEnd != (parentItr = parentIndices.find(curNode))) {
-            curNode = parentItr->second;
-            auto& ancestorNode = _file.nodes[curNode];
-            //gltfNode.transforms.push_back(getModelTransform(ancestorNode));
-        }
-    }
-
     // Build joints
     HFMJoint joint;
-    joint.distanceToParent = 0;
     hfmModel.jointIndices["x"] = numNodes;
     QVector<glm::mat4> globalTransforms;
     globalTransforms.resize(numNodes);
@@ -1104,7 +1090,7 @@ bool GLTFSerializer::buildGeometry(HFMModel& hfmModel, const hifi::VariantHash&
         hfmModel.materials.emplace_back();
         HFMMaterial& hfmMaterial = hfmModel.materials.back();
         hfmMaterial._material = std::make_shared<graphics::Material>();
-        hfmMaterial.materialID =  hfmMaterial.name;
+        hfmMaterial.materialID =  matid;
         setHFMMaterial(hfmMaterial, material);
     }
 
@@ -1229,6 +1215,10 @@ bool GLTFSerializer::buildGeometry(HFMModel& hfmModel, const hifi::VariantHash&
                         success = addArrayFromAttribute(vertexAttribute, accessor, colors);
                         weightStride = GLTFAccessorType::count((GLTFAccessorType::Value)accessor.type);
                         break;
+
+                    default:
+                        success = false;
+                        break;
                 }
                 if (!success) {
                     continue;
@@ -2031,9 +2021,15 @@ bool GLTFSerializer::addArrayFromAttribute(GLTFVertexAttribute::Value vertexAttr
 
         if (!addArrayFromAccessor(accessor, outarray)) {
             qWarning(modelformat) << "There was a problem reading glTF WEIGHTS_0 data for model " << _url;
+            return false;
         }
+
+    default:
+        qWarning(modelformat) << "Unexpected attribute type" << _url;
+        return false;
     }
 
+    
     return true;
 }
 
diff --git a/libraries/hfm/src/hfm/HFM.h b/libraries/hfm/src/hfm/HFM.h
index 497bb60568..39c123e9df 100644
--- a/libraries/hfm/src/hfm/HFM.h
+++ b/libraries/hfm/src/hfm/HFM.h
@@ -122,7 +122,8 @@ public:
 /// A single binding to a joint.
 class Cluster {
 public:
-    uint32_t jointIndex;
+    static const uint32_t INVALID_JOINT_INDEX{ (uint32_t)-1 };
+    uint32_t jointIndex{ INVALID_JOINT_INDEX };
     glm::mat4 inverseBindMatrix;
     Transform inverseBindTransform;
 };