nearestKeyIndex = 0;

    if (numKeys > 0){
    nearestKeyIndex = nearestKey(time).index;
    if (key(nearestKeyIndex).time > time){
    nearestKeyIndex—;
    }
    }

    if (nearestKeyIndex == 0) {
    currentTime = 0;
    } else {
    currentTime = time - key(nearestKeyIndex).time;
    }

    if (nearestKeyIndex > 0 && currentTime < 1) {
    calculatedVelocity = velocityAtTime(key(nearestKeyIndex).time - thisComp.frameDuration / 10);
    amplitude = 0.06;反弹的力度越大，值越大，反弹越强烈
    frequency = 2.0;频率，每秒反弹次数
    decay = 6.0;衰减，值数越大，越快停止
    value + calculatedVelocity amplitude Math.sin(frequency currentTime 2 Math.PI) / Math.exp(decay currentTime);
    } else {
    value;
    }

    回弹表达式一般用于：旋转、缩放、位置
    表达式添加方法：
    image.png回弹表达式注意事项：
    最后一个关键帧必须是匀速！
    image.png