diff --git a/constants.py b/constants.py
index 2efb773f..cac15811 100644
--- a/constants.py
+++ b/constants.py
@@ -53,6 +53,9 @@ RIGHT  = np.array(( 1., 0., 0.))
 LEFT   = np.array((-1., 0., 0.))
 IN     = np.array(( 0., 0.,-1.))
 OUT    = np.array(( 0., 0., 1.))
+X_AXIS = np.array(( 1., 0., 0.))
+Y_AXIS = np.array(( 0., 1., 0.))
+Z_AXIS = np.array(( 0., 0., 1.))
 
 TOP        = SPACE_HEIGHT*UP
 BOTTOM     = SPACE_HEIGHT*DOWN
diff --git a/mobject/mobject.py b/mobject/mobject.py
index cf01b713..6618d1aa 100644
--- a/mobject/mobject.py
+++ b/mobject/mobject.py
@@ -296,6 +296,7 @@ class Mobject(Container):
                 aligned_edge = ORIGIN,
                 submobject_to_align = None,
                 index_of_submobject_to_align = None,
+                coor_mask = np.array([1,1,1]),
                 ):
         if isinstance(mobject_or_point, Mobject):
             mob = mobject_or_point
@@ -315,7 +316,7 @@ class Mobject(Container):
         else:
             aligner = self
         point_to_align = aligner.get_critical_point(aligned_edge - direction)
-        self.shift(target_point - point_to_align + buff*direction)
+        self.shift((target_point - point_to_align + buff*direction)*coor_mask)
         return self
 
     def align_to(self, mobject_or_point, direction = ORIGIN, alignment_vect = UP):
@@ -403,13 +404,14 @@ class Mobject(Container):
             submob.scale(1./factor)
         return self
 
-    def move_to(self, point_or_mobject, aligned_edge = ORIGIN):
+    def move_to(self, point_or_mobject, aligned_edge = ORIGIN,
+                coor_mask = np.array([1,1,1])):
         if isinstance(point_or_mobject, Mobject):
             target = point_or_mobject.get_critical_point(aligned_edge)
         else:
             target = point_or_mobject
         point_to_align = self.get_critical_point(aligned_edge)
-        self.shift(target - point_to_align)
+        self.shift((target - point_to_align)*coor_mask)
         return self
 
     def replace(self, mobject, dim_to_match = 0, stretch = False):