一直以来在工业领域研究，根据数字孪生的要求，需要打通网络，从CLP到IOT到Dass到虚拟工厂（三维可视化），为了打通控制与反控制的状态，需要打通网络通信，对于Unity首先想到的肯定是Socket通信，这也是很多开发人员所熟悉的方法，但是MQTT通信协议在工业通信中使用很普遍，所以今天我就对MQTT通信协议在Unity使用做介绍
我这边因为要上云端，所以，我测试了两套方案
1.通过JS实现MQTT通信，再通过Unity与JS交互，实现通信
首先需要paho-mqtt.js，jquery.min.js两个脚本，网上有很多，如果是精通JS的也可以自己写，大家都知道用来干嘛的。
下面是实现连接和信息通信的代码

    <script src="./jquery.min.js"></script>
    <script src="./paho-mqtt.js"></script>
        <scrpt>
           //MQTT连接
    //选中订阅主题
    var selectedTopics = [];
    //选中发布主题
    var currentTopic;
      //客户端选项
    var option = {
        "ServerUri": "127.0.0.1",
        "ServerPort": 61623,
        "UserName": "admin",
        "Password": "password",
        "ClientId": "",
        "TimeOut": 5,
        "KeepAlive": 100,
        "CleanSession": false,
        "SSL":false
    }

      //客户端
    var client;

      //连接
    function connectFun(){
        option .ClientId = guid();
        client = new Paho.Client(option.ServerUri, option.ServerPort, option.ClientId);
        client.onConnectionLost = onConnectionLost;
        client.onMessageArrived = onMessageArrived;
        client.connect({
            invocationContext: {
                host: option.ServerUri,//IP地址
                port: option.ServerPort,//端口号
               path: client.path,
                clientId: option.ClientId//标识
            },
            timeout: option.TimeOut,//连接超时时间
            keepAliveInterval: option.KeepAlive,//心跳间隔
            cleanSession: option.CleanSession,//是否清理Session
            useSSL: option.SSL,//是否启用SSL
            userName: option.UserName,  //用户名
            password: option.Password,  //密码
            onSuccess: onConnect,//连接成功回调事件
            onFailure: one rror//连接失败回调事件
        }); 
    }

    //断开连接
    function disConnect(){
        //client.disconnect();
    }

    //订阅
    function onSubscrip(sub)
    {
        if (!client) {
            gameInstance.SendMessage("GameAPP","OnException","请连接服务");
            //alert("失败");
            return; 
        }

        selectedTopics.push(sub);
        client.subscribe(selectedTopics,0x02);
        //alert("订阅：" + sub);
        gameInstance.SendMessage("GameAPP","OnException","订阅频道：" + sub);
    }

            //发布
    function onRele(sub,info)
    {
        if (!client) {
            gameInstance.SendMessage("GameAPP","OnException","请连接服务");
            return;
        }

        var message = new Paho.Message(info);
        currentTopic = sub;
        message.destinationName = currentTopic;
        //client.send(message)
        client.publish(currentTopic,info,0x02,false);

        gameInstance.SendMessage("GameAPP","OnException","发布消息：" + info);

    }

         //接收消息事件
    function onMessageArrived(data) {
        gameInstance.SendMessage("GameAPP","OnGetInfo","接收消息：" + data.payloadString);
        //alert("消息：" + data.payloadString);
    } 

    //连接断开事件
    function onConnectionLost(e) {
        if (e.errorCode !== 0) {
           gameInstance.SendMessage("GameAPP","OnException","发布消息：" + e.errorCode);
        }
    }

    //连接成功回调事件
    function onConnect()
    {
        gameInstance.SendMessage("GameAPP","OnException","连接成功！");
    }

    function one rror(e){
        gameInstance.SendMessage("GameAPP","OnException","连接失败，请重新连接，");
    }

    //生成GUID
    function guid() {
        function S4() {
            return (((1 + Math.random()) * 0x10000) | 0).toString(16).substring(1);
        }
        return (S4() + S4() + "-" + S4() + "-" + S4() + "-" + S4() + "-" + S4() + S4() + S4());
    }

        </script>

只需要将接受的信息发给Unity，或者从Unity获取的信息发出。