Moved some code to the right place.

math/spvo.py

@@ -12,18 +12,18 @@ Thanks to this "compression", there are no zero values on places where there is
 
 
 class Node:
-    def __init__(self):
+    def __init__(self, data=None):
         self.children = [None] * 8
         self.leaf = True
 
+        self.data = data
+
 
 class SparseVoxelOctree:
-    def __init__(self, data=None):
+    def __init__(self):
         self.root_node = Node()
         self.origin = (0, 0, 0)
 
-        self.data = data
-
     def _get_child_index(self, x, y, z, size):
         index = 0