如果json文件有三四百kb以上，那么构建寻路的时候会非常卡，甚至阻塞模型加载，这时候可以使用worker来构建新的线程避免阻塞页面的模型
使用worker处理阻塞问题
navWorker.js: 这个文件放在src中在运行的时候会报错找不到，所以worker代码必须放在bin目录下，但是在bin目录下又无法读取Laya,window,NevMesh等全局变量，所以，必须在这里引入NevMesh.js来执行计算

(function (){if ('function' === typeof importScripts) {importScripts("../NevMesh.js");self.addEventListener('message', function (e) {let floorNum = e.data[1];let navUrl = e.data[2];console.log('new worker msg:', floorNum)var xmlreq = new XMLHttpRequest();xmlreq.responseType = "json";xmlreq.onload = function (e) {var data = e.currentTarget.response;let zoneNodes = NevMesh.buildNodesByJson(data);self.postMessage([floorNum, zoneNodes]);}xmlreq.open("get",navUrl);xmlreq.send();}, false);}}())

主线程代码

initNavMesh() {let self = this;let { buildingName, currFloor, isStack, buildingInfo } = this.sceneInfo;if (isStack) {for (var key in buildingInfo) {// 多层路线构建if (NevMesh.zoneNodes[key] || this.workList.includes(key)) {} else {this.workList.push(key);nWork(key);}}if (this.workList.length === 0) this.initComplete();} else {if (NevMesh.zoneNodes[currFloor]) {this.initComplete();} else if (this.workList.includes(currFloor)) {} else {this.workList.push(currFloor);nWork(currFloor);}}function nWork(key) {// 构建需要提示var worker = new Laya.Browser.window.Worker("js/navWorker.js");worker.onmessage = function (oEvent): void {let floorNum = oEvent.data[0];let zoneNodes = oEvent.data[1];NevMesh.setZoneData(floorNum, zoneNodes);let id = self.workList.findIndex((val) => {return val === floorNum;});self.workList.splice(id, 1);if (self.workList.length === 0) {self.initComplete();if (isStack) {// self.findPathByPos(false);// self.findDemo(false);} else {// self.findPathByPos(true, floorNum);}}console.log(`${buildingName}/${floorNum} 导航数据构建完毕`);};worker.postMessage(["start", key, `../meshes/${buildingName}/${key}.json`]);// meshes文件夹要放在bin目录下，如果放在src里会找不到}}