从 OpenVid 描述中单独抽取 walk、turn、追逐、旋转等动作词，再与速度、方向和镜头响应组合。先做动作词表，再写完整提示词，能减少风格词对运动判断的干扰。 Extract motion verbs such as walk, turn, chase, and rotate from OpenVid descriptions, then combine them with speed, direction, and camera response. Build the motion vocabulary before adding style words.