@Override
        public float apply(float value) {
            if (value < (1f / 2.75f)) {
                return (7.5625f * value * value);
            } else if (value < (2f / 2.75f)) {
                return (7.5625f * (value -= (1.5f / 2.75f)) * value + 0.75f);
            } else if (value < (2.5 / 2.75)) {
                return (7.5625f * (value -= (2.25f / 2.75f)) * value + 0.9375f);
            } else {
                return (7.5625f * (value -= (2.625f / 2.75f)) * value + 0.984375f);
            }
        }
a function that starts quickly, then bounces several times
jme3-core/src/main/java/com/jme3/math/Easing.java