碰撞过滤器不起作用。

嗨，我正在尝试让这个碰撞过滤器起作用，但我有点卡住了...

local bad1CollisionFilter1 = { categoryBits = 1, maskBits = 3 }

if ( temp.imgpath == "BCloud1.png" ) then
 physics.addBody( randomStar, { density=2.9, friction=0.5, bounce=0.3, radius=16, filter=bad1CollisionFilter1 } )
end

local collision = function( bad1CollisionFilter1 )
 if bad1CollisionFilter1.phase == 'began' then
   print("你好，我是CollisionFilter1")
 end
end

任何有助于让它起作用的帮助都将不胜感激！