diff --git a/hecl/blender/hecl/hmdl/__init__.py b/hecl/blender/hecl/hmdl/__init__.py
index 8707018b1..b88a70a78 100644
--- a/hecl/blender/hecl/hmdl/__init__.py
+++ b/hecl/blender/hecl/hmdl/__init__.py
@@ -329,7 +329,10 @@ def cookcol(writebuf, mesh_obj):
         edge_idxs = []
         for loopi in p.loop_indices:
             edge_idxs.append(copy_mesh.loops[loopi].edge_index)
-        writebuf(struct.pack('IIII', edge_idxs[0], edge_idxs[1], edge_idxs[2], p.material_index))
+        l0 = copy_mesh.loops[p.loop_indices[0]]
+        e0 = copy_mesh.edges[l0.edge_index]
+        flip = l0.vertex_index != e0.vertices[0]
+        writebuf(struct.pack('IIIIb', edge_idxs[0], edge_idxs[1], edge_idxs[2], p.material_index, flip))
 
     # Delete copied mesh from scene
     bpy.context.scene.objects.unlink(copy_obj)
diff --git a/hecl/extern/boo b/hecl/extern/boo
index 1259255f3..2db777eea 160000
--- a/hecl/extern/boo
+++ b/hecl/extern/boo
@@ -1 +1 @@
-Subproject commit 1259255f34f3b5bf370fd8b1a87d52a3de87ec57
+Subproject commit 2db777eead15d599d774820b8065c8125bfa2907
diff --git a/hecl/include/hecl/Blender/BlenderConnection.hpp b/hecl/include/hecl/Blender/BlenderConnection.hpp
index 718a9bb17..8dd7402fe 100644
--- a/hecl/include/hecl/Blender/BlenderConnection.hpp
+++ b/hecl/include/hecl/Blender/BlenderConnection.hpp
@@ -671,6 +671,7 @@ public:
             {
                 uint32_t edges[3];
                 uint32_t matIdx;
+                bool flip;
                 Triangle(BlenderConnection& conn);
             };
             std::vector<Triangle> trianges;
diff --git a/hecl/lib/Blender/BlenderConnection.cpp b/hecl/lib/Blender/BlenderConnection.cpp
index 7831706ff..f4fcdb3bf 100644
--- a/hecl/lib/Blender/BlenderConnection.cpp
+++ b/hecl/lib/Blender/BlenderConnection.cpp
@@ -1092,7 +1092,7 @@ BlenderConnection::DataStream::ColMesh::Edge::Edge(BlenderConnection& conn)
 
 BlenderConnection::DataStream::ColMesh::Triangle::Triangle(BlenderConnection& conn)
 {
-    conn._readBuf(this, 16);
+    conn._readBuf(this, 17);
 }
 
 BlenderConnection::DataStream::World::Area::Dock::Dock(BlenderConnection& conn)