Resolve None matrix in deferred renderer

Author: einarf

demosys/deferred/renderer.py

@@ -12,9 +12,10 @@
 class PointLight:
     """A point light and its properties"""
     def __init__(self, position, radius):
+        self.matrix = None
         self._position = position
+        self.position = position
         self.radius = radius
-        self.matrix = None
 
     @property
     def position(self):