// Nav层名字-->层的值，1、2、4、8、16    public static int AgentLayerNameToValue(string name)    {        int idx = NavMesh.GetNavMeshLayerFromName(name);        return 0x1 << idx;    }    // Nav层名字-->层索引，0、1、2、3、4    public static int AgentLayerNameToIndex(string name)    {        return NavMesh.GetNavMeshLayerFromName(name);    }    // 获取角色当前所在的层值，1、2、4、8、16    public static int GetAgentLayer(NavMeshAgent agent)    {        NavMeshHit hit;        // 不要使用agent.raduis为采样范围，因为当该值为0时，函数将返回0        bool reach = NavMesh.SamplePosition(agent.transform.position, out hit, 1f, -1);        return hit.mask;    }    public static Vector3 SampleNavMeshPosition(Vector3 logicPosition, out bool reachable)    {        NavMeshHit hit;        reachable = NavMesh.SamplePosition(logicPosition, out hit, 1f, -1);        return reachable ? hit.position : logicPosition;    }    // 开启导航层    public static void EnableNavMeshLayer(NavMeshAgent agent, string layerName)    {        if (agent == null)            return;        int layerValue = NavMesh.GetNavMeshLayerFromName(layerName);        if (layerValue == -1)            return;        int mask = agent.walkableMask | 0x1 << layerValue;        WalkArbiter.SetWalkableMask(agent, mask);    }    // 关闭导航层    public static void DisableNavMeshLayer(NavMeshAgent agent, string layerName)    {        if (agent == null)            return;        int layerValue = NavMesh.GetNavMeshLayerFromName(layerName);        if (layerValue == -1)            return;        int mask = agent.walkableMask & ~(0x1 << layerValue);        WalkArbiter.SetWalkableMask(agent, mask);    }    // 检查某个层是否为开启    public static bool IsNavMeshLayerOpen(NavMeshAgent agent, string layerName)    {        int layerValue = NavMesh.GetNavMeshLayerFromName(layerName);        if (layerValue == -1)            return true;        int ret = agent.walkableMask & (0x1 << layerValue);        return ret > 0 ? true : false;    }