def __init__(self, first, second = None):
Vector2D.__init__(self, first, second)
self.id = constants.globalId
constants.globalId += 1
## Set of adjacent nodes.
self.neighbors = set()
## Local terrain information.
self.terrain = game.map.getTerrainInfoAtGridLoc(self.toGridspace())
## Color of the node, for debugging purposes.
self.color = [random.randint(64, 255) for i in xrange(3)]
