非谓语动词问题,Thx~请看下面两个句子：（Looked） at in his way,the situation do

非谓语动词问题,Thx~
请看下面两个句子：
（Looked） at in his way,the situation doesn't seem so desperate.
参考书解释为,这里的主语是the situation,动作是look,二者之间不是主谓关系,而是动宾关系,用的应该是过去分词形式.
_Judging__ from the appearance,it is very peaceful; but in fact,a war will break out soon.
这里填的是动名词,可是,我觉得judge与主语之间也有主谓关系呀.
Q：到底什么时候用动名词,什么时候用不定式呢?真的有点晕
还有,上面所说的主谓关系,应该用什么词?