两种方式，建议采用代码，修改设置可能会在其他使用射线的地方鬼畜

使用代码…

        /// <summary>
        /// 射线碰撞检测，正向与反向检测
        /// </summary>
        private bool CheckCloud()
        {
            RaycastHit hit;
            Ray rayForward = new Ray(LinBroth.transform.position, LinBroth.transform.TransformDirection(Vector3.forward));

            if (Physics.Raycast(rayForward, out hit, 3000))
            {
                Debug.DrawRay(LinBroth.transform.position, LinBroth.transform.TransformDirection(Vector3.forward) * hit.distance, Color.yellow);
                Debug.Log("Did Hit+正向射线");
                return true;
            }

            //反向射线
            Ray rayback = Reverse(rayForward, 3000);
            if (Physics.Raycast(rayback, out hit, 3000))
            {
                Debug.DrawRay(LinBroth.transform.position, LinBroth.transform.TransformDirection(Vector3.forward) * hit.distance, Color.yellow);
                Debug.Log("Did Hit+反向射线");
                return true;
            }
            return false;
        }

        /// <summary>
        /// 反转射线
        /// </summary>
        public Ray Reverse(Ray ray, float distance)
        {
            return new Ray(
                ray.origin + ray.direction * distance,
                -ray.direction);
        }

修改设置

在Unity2018.1.18上不大好用。