关于瓦片地图的坐标问题求教

tmx文件如下:


......
  <object name="banana" gid="4" x="269" y="256"/>
  <object name="door" gid="6" x="3093" y="3136"/>
  <object name="playerborn" gid="5" x="161" y="119"/>
 </objectgroup>
</map>

tmx文件中的playerborn的坐标是(161,119)


    local objGroup = _tileMap:getObjectGroup("objlayer")
    local objPoint = objGroup:getObject("playerborn")
    print("objPoint's position ",objPoint.x,objPoint.y)

代码中读取tmx文件的中的object,但是取到的坐标y总是不对,


 objPoint's position     161    3081

怎么破?