{
"bullet":{
    "x": "0",
    "y": "0",
    "r": "4",
    "dirx":"0",
    "diry":"-1",
    "vx": "0",
    "vy": "0",
    "child": {},        
    "link":{},
    "collisionDetection": "AintersectB",
    "effect": [],
    "behavior": ["movableBehavior","fallingBehavior","bulletBehavior"],
    "tag": ["solid","bullet"]
}
}