idiom · to be emotionally stirred or have deep feelings aroused by the sight of a particular scene

看着窗外凄凉的落叶，他不免触景生情，心中涌起一阵淡淡的忧伤。

idiom · evocative of the past or descriptive of a scene that triggers memories

回到阔别多年的故乡，看到那条熟悉的小路，他不禁触景生情，想起了儿时的往事。