diff --git a/libraries/hfm/src/hfm/HFM.h b/libraries/hfm/src/hfm/HFM.h
index 51c5f929d8..d4d6dd33d0 100644
--- a/libraries/hfm/src/hfm/HFM.h
+++ b/libraries/hfm/src/hfm/HFM.h
@@ -158,7 +158,7 @@ public:
     QVector<int> quadTrianglesIndices; // original indices from the FBX mesh of the quad converted as triangles
     QVector<int> triangleIndices; // original indices from the FBX mesh
 
-    QString materialID;
+    QString materialID; // DEPRECATED
 };
 
 class Material {
@@ -238,14 +238,14 @@ public:
     QVector<glm::vec3> colors;
     QVector<glm::vec2> texCoords;
     QVector<glm::vec2> texCoords1;
-    QVector<uint16_t> clusterIndices;
-    QVector<uint16_t> clusterWeights;
+    QVector<uint16_t> clusterIndices; // DEPRECATED (see hfm::Shape::dynamicTransform, hfm::DynamicTransform::deformers, hfm::Deformer)
+    QVector<uint16_t> clusterWeights; // DEPRECATED (see hfm::Shape::dynamicTransform, hfm::DynamicTransform::deformers, hfm::Deformer)
     QVector<int32_t> originalIndices;
 
-    QVector<Cluster> clusters;
+    QVector<Cluster> clusters; // DEPRECATED (see hfm::Shape::dynamicTransform, hfm::DynamicTransform::clusters)
 
-    Extents meshExtents;
-    glm::mat4 modelTransform;
+    Extents meshExtents; // DEPRECATED (see hfm::Shape::transformedExtents)
+    glm::mat4 modelTransform; // DEPRECATED (see hfm::Shape::transform, hfm::TransformNode, hfm::Model::transforms)
 
     QVector<Blendshape> blendshapes;
 
@@ -317,6 +317,8 @@ public:
     uint32_t meshPart { UNDEFINED_KEY };
     uint32_t material { UNDEFINED_KEY };
     uint32_t transform { UNDEFINED_KEY }; // The static transform node when not taking into account rigging/skinning
+    // TODO: Have all serializers calculate hfm::Shape::transformedExtents in world space where they previously calculated hfm::Mesh::meshExtents. Change all code that uses hfm::Mesh::meshExtents to use this instead.
+    Extents transformedExtents; // The precise extents of the meshPart vertices in world space, after the transform node and parent transform nodes are applied, while not taking into account rigging/skinning
     uint32_t dynamicTransform { UNDEFINED_KEY };
 };