Unity得到物体前面水平面随机点

        /// <summary>
        /// 得到go面前随机掉落点
        /// </summary>
        /// <param name="go"></param>
        /// <param name="angle">掉落的角度</param>
        /// <param name="maxDistance">掉落的最大距离</param>
        /// <param name="minDistance">掉落的最小距离</param>
        /// <returns> 掉落的位置</returns>
        private Vector3 RandomDrop(GameObject go, float angle, float maxDistance, float minDistance)
        {
            float randomAngle = Random.Range(-angle ,angle);
            float distance = Random.Range(minDistance ,maxDistance);
            Vector3 direction = Quaternion.AngleAxis(randomAngle, go.transform.up) *
                                go.transform.forward;
            Vector3 position = Vector3.Normalize(direction) * distance;
            return position + go.transform.position;
        }