private float forwardDistance = 5f;
    private float leftRightDistance = 3f;

    private bool InRanage(Transform attacker, Transform target) {
        // 指向目标的向量
        Vector3 dir = target.position - attacker.position;

        /* 点乘结果大于0则表示夹角小于90度   点乘:a*b=|a|*|b|*cos(夹角)
         * 这里因为attacker.forward的大小是1,所以点乘结果就等于dir*cos(夹角) ,
         * dir是斜边,则结果是邻边大小,也就是dir投射到forward的大小
         */
        float dot = Vector3.Dot(attacker.forward, dir);
        if (dot>0 && dot < forwardDistance) {  // 在正前方且小于指定距离
            float radias = Vector3.Angle(attacker.forward, dir) * Mathf.Deg2Rad;
            float x = dir.magnitude * Mathf.Sin(radias);
            if (x < leftRightDistance) {    // 左右距离在指定范围
                //Debug.Log("在范围内!");
           LeftRight(attacker, target);
                return true;
            }
        }

        return false;
    }

    private void LeftRight(Transform attacker, Transform target) {
        Vector3 dir = target.position - attacker.position;


        Vector3 cross= Vector3.Cross(attacker.forward, dir);
        if (cross.y>0) {
            Debug.Log("右边");
        } else {
            Debug.Log("左边");
        }
    }