Reduce reflecting surface inital angle

geom/demos/reflection.py

@@ -11,7 +11,7 @@ class Reflection:
     title = "Reflection"
 
     def __init__(self):
-        self.s_angle = -pi/4
+        self.s_angle = -pi/8
 
     def handle_key_down(self, key):
         pass
@@ -35,6 +35,7 @@ class Reflection:
         s = sub(*s_end, *s_start)
 
         # the incoming ray, towards reflection surface
+        # it's important that it is pointing towards the reflecting surface
         incoming = sub(0, 0, *get_cursor_pos())
 
         # surface normal