php如何接收3维数组的值

<input id="items_EMPTY_INDEX_id" name="look[item_attributes][EMPTY_INDEX][id]" value="" type="hidden" />
  <input id="items_EMPTY_INDEX_x" name="look[item_attributes][EMPTY_INDEX][x]" type="text" value="EMPTY_X" />
  <input id="items_EMPTY_INDEX_y" name="look[item_attributes][EMPTY_INDEX][y]" type="text" value="EMPTY_Y" />



php怎么接收一一接收这三个3维数组的值呢，请告诉指点

var_dump($_REQUEST);