请教各位大大,3d里面怎么让3d对象不穿透ui呢?

quick3.3的例子里面有个Sprite3D的,增加飞船后按钮会被飞船穿透,试了把按钮加到Camera上也会穿透,请教下应该怎么处理呢?

local size = cc.Director:getInstance():getWinSize() ;


   local camera = cc.Camera:createPerspective(60.0, size.width/size.height, 20.0, 1000.0);


    camera:setCameraFlag(2);    


self.layer2:addChild(camera);

    camera:addChild(uiLayer);

没有人玩3D的吗、。?