def initFog(self):
f = Fog("World Fog")
f.setColor(0.5,0.5,0.5)
f.setLinearOnsetPoint(0,0,0)
f.setLinearOpaquePoint(0,0,-Thing.REVERTS_VISIBLE * 3)#THING_REVERT_DISTANCE)
self.renderer.attachNewNode(f)
self.renderer.setFog(f)
