diff --git a/functions.py b/functions.py
index 70ade4a5..8cbea083 100644
--- a/functions.py
+++ b/functions.py
@@ -827,6 +827,8 @@ def isosurface(data, level):
     *data*   3D numpy array of scalar values
     *level*  The level at which to generate an isosurface
     
+    Returns a list of faces; each face is a list of three vertexes and each vertex is a tuple of three floats.
+    
     This function is SLOW; plenty of room for optimization here.
     """
 
diff --git a/opengl/MeshData.py b/opengl/MeshData.py
index b9f8f1ec..7ac24aeb 100644
--- a/opengl/MeshData.py
+++ b/opengl/MeshData.py
@@ -1,4 +1,5 @@
 from pyqtgraph.Qt import QtGui
+import pyqtgraph.functions as fn
 
 class MeshData(object):
     """
@@ -37,6 +38,12 @@ class MeshData(object):
         else:
             self._setIndexedFaces(faces, vertexes)
     
+    def setMeshColor(self, color):
+        """Set the color of the entire mesh. This removes any per-face or per-vertex colors."""
+        color = fn.Color(color)
+        self._meshColor = color.glColor()
+        self._vertexColors = None
+        self._faceColors = None
     
     def _setUnindexedFaces(self, faces):
         verts = {}
@@ -107,7 +114,8 @@ class MeshData(object):
             for i, face in enumerate(self._faces):
                 ## compute face normal
                 pts = [self._vertexes[vind] for vind in face]
-                norm = QtGui.QVector3D.crossProduct(pts[1]-pts[0], pts[2]-pts[0]).normalized()
+                norm = QtGui.QVector3D.crossProduct(pts[1]-pts[0], pts[2]-pts[0])
+                norm = norm / norm.length()  ## don't use .normalized(); doesn't work for small values.
                 self._faceNormals.append(norm)
         return self._faceNormals
     
@@ -126,7 +134,7 @@ class MeshData(object):
                 norm = QtGui.QVector3D()
                 for fn in norms:
                     norm += fn
-                norm.normalize()
+                norm = norm / norm.length()  ## don't use .normalize(); doesn't work for small values.
                 self._vertexNormals.append(norm)
         return self._vertexNormals
         
@@ -152,3 +160,19 @@ class MeshData(object):
         """
         pass
         
+    def save(self):
+        """Serialize this mesh to a string appropriate for disk storage"""
+        import pickle
+        names = ['_vertexes', '_edges', '_faces', '_vertexFaces', '_vertexNormals', '_faceNormals', '_vertexColors', '_edgeColors', '_faceColors', '_meshColor']
+        state = {n:getattr(self, n) for n in names}
+        return pickle.dumps(state)
+        
+    def restore(self, state):
+        """Restore the state of a mesh previously saved using save()"""
+        import pickle
+        state = pickle.loads(state)
+        for k in state:
+            setattr(self, k, state[k])
+        
+        
+        
\ No newline at end of file
diff --git a/opengl/items/GLMeshItem.py b/opengl/items/GLMeshItem.py
index b82c4d3d..149baafb 100644
--- a/opengl/items/GLMeshItem.py
+++ b/opengl/items/GLMeshItem.py
@@ -20,8 +20,11 @@ class GLMeshItem(GLGraphicsItem):
         """
         See MeshData for initialization arguments.
         """
-        self.data = MeshData()
-        self.data.setFaces(faces, vertexes)
+        if isinstance(faces, MeshData):
+            self.data = faces
+        else:
+            self.data = MeshData()
+            self.data.setFaces(faces, vertexes)
         GLGraphicsItem.__init__(self)
         
     def initializeGL(self):