基于WebGL架构的3D可视化平台—小区水，电，燃气管线演示

地下的管线错综复杂如何，图纸并不能完全满足实际需求，我们就用ThingJS平台来模拟一个小区水，电，天然气管线演示。
第一步，利用CampusBuilder搭建模拟场景。CampusBuilder的模型库有各种各样的模型，使我们搭建出的场景更逼真。使用CampusBuilde创建层级，之后再给层级加外立面就出现了当前的效果。详情移步：CampusBuilder3D场景制作工具
演示地址：http://www.thingjs.com/guide/sampleindex.html?name=/uploads/wechat/oLX7p05lsWJZUIxnIWsNXAzJ40X8/水电燃气管线演示.js?n=0.968666194169896

//加载场景代码
var app = new THING.App({
    // 场景地址
    "url": "http://www.thingjs.com/./uploads/wechat/oLX7p05lsWJZUIxnIWsNXAzJ40X8/scene/管线演示2",
    //背景设置
    "skyBox": "BlueSky"
});

第二步， 初始化摄像机位置，添加四个按钮，并创建四个方法。

app.on('load', function () {
    //摄像机位置初始化
    app.camera.position = [0.4374202706634094, 101.92917348318593, 97.06808820543526];
    app.camera.target = [52.75056074670042, -18.885239034825123, -20.619558480451797];
    new THING.widget.Button('水管演示', water);
    new THING.widget.Button('电线演示', electric);
    new THING.widget.Button('燃气演示', gas);
});

function water() {
}
function electric() {
}
function gas() {
}

第三步，创建管线，我们这里写水管线以后的电线，燃气管线同理。这里简单说一下PolygonLine，它继承THING.LineBase，同样有贴图属性，可以自己从本地上传图片至页面资源后使用。

var line = null;
function buildLine(points, color) {
    line = app.create({
        type: 'PolygonLine',
        points: points,
        style: {
            color: color,
        }
    });
    line.scrollUV = true;
}

function water() {
    var waterUnderPoints = []; 
    buildingOpacity(0.3);
    app.query(/building_0/).forEach(
        function (parentObj) {
            var points = [];
            points.push(parentObj.selfToWorld([5, -0.8, 0]));
            waterUnderPoints.push(points[0]);
            for (var i = 3; i <= 24; i += 3) {
                points.push(parentObj.selfToWorld([5, i, 0]));
                points.push(parentObj.selfToWorld([5, i, 3]));
                points.push(parentObj.selfToWorld([-5, i, 3]));
                points.push(parentObj.selfToWorld([-5, i, -3]));
                points.push(parentObj.selfToWorld([5, i, -3]));
                points.push(parentObj.selfToWorld([5, i, 0]));
            }
            points.push(parentObj.selfToWorld([5, 24, 0]));
            buildLine(points, '#0000FF');
        }
    );
    waterUnderPoints.push([15.32711, -0.79, -55.655339999999999]);
    buildLine(waterUnderPoints, '#0000FF');
    //renderOrder();
}

function buildingOpacity(num) {
    app.query("*").forEach(function (obj) {
        obj.style.opacity = num;
    });
}

function renderOrder(){
    app.query('.PolygonLine').forEach(
        function (obj) {
            obj.renderOrder = -10000;
        }
    );
}

这里用到了两个方法：
1） buildingOpacity(num)；
这个方法的主要作用就是为了将场景虚化，更好的展示我们的管线。
2）renderOrder();
下图是我在代码中先注释掉了renderOrder()，我们先看一下现在的效果。

下图是我在代码中加入renderOrder()，再看一下效果

起初以为是模型的问题换了模型还是没解决，之后求助了225986500这个交流群里的大神们，告诉了我renderOrder这个设置/获取渲染排序值。

最后一步，创建出电线以及燃气线就完成了。

function electric() {
    var electricUnderPoints = [];
    buildingOpacity(0.3);
    app.query(/building_0/).forEach(
        function (parentObj) {
            var points = [];
            points.push(parentObj.selfToWorld([3, -0.8, 0]));
            electricUnderPoints.push(points[0]);
            for (var i = 3; i <= 24; i += 2.5) {
                points.push(parentObj.selfToWorld([3, i, 0]));
                points.push(parentObj.selfToWorld([-3, i, 2]));
            }
            points.push(parentObj.selfToWorld([3, 24, 0]));
            buildLine(points, '#00FF00');
            console.log(points);
        }
    );
    electricUnderPoints.push([16.690666, -0.79, -55.115203999999999]);
    buildLine(electricUnderPoints, '#00FF00');
    renderOrder();
}

function gas() {
    var gasUnderPoints = [];
    buildingOpacity(0.3);
    app.query(/building_0/).forEach(
        function (parentObj) {
            var points = [];
            points.push(parentObj.selfToWorld([-6.2, -0.3, 0]));
            gasUnderPoints.unshift(points[0]);
            for (var i = 3; i <= 24; i += 3) {
                points.push(parentObj.selfToWorld([-6.2, i, 0]));
                points.push(parentObj.selfToWorld([-6.2, i, 2]));
                points.push(parentObj.selfToWorld([6.2, i, 2]));
                points.push(parentObj.selfToWorld([6.2, i, -2]));
                points.push(parentObj.selfToWorld([-6.2, i, -2]));
                points.push(parentObj.selfToWorld([-6.2, i, 0]));
            }
            points.push(parentObj.selfToWorld([-6.2, 24, 0]));
            buildLine(points, '#FF0000');
            console.log(points);
        }
    );
    gasUnderPoints.unshift([22.963023600000003, -0.3, 57.8305784]);
    buildLine(gasUnderPoints, '#FF0000');
    renderOrder();
}

最后附上完整代码：

//加载场景代码
var app = new THING.App({
    // 场景地址
    "url": "http://www.thingjs.com/./uploads/wechat/oLX7p05lsWJZUIxnIWsNXAzJ40X8/scene/管线演示2",
    //背景设置
    "skyBox": "BlueSky"
});

app.on('load', function () {
    //摄像机位置初始化
    app.camera.position = [0.4374202706634094, 101.92917348318593, 97.06808820543526];
    app.camera.target = [52.75056074670042, -18.885239034825123, -20.619558480451797];

    new THING.widget.Button('水管演示', water);
    new THING.widget.Button('电线演示', electric);
    new THING.widget.Button('燃气演示', gas);

});

function water() {
    var waterUnderPoints = []; 
    buildingOpacity(0.3);
    app.query(/building_0/).forEach(
        function (parentObj) {
            var points = [];
            points.push(parentObj.selfToWorld([5, -0.8, 0]));
            waterUnderPoints.push(points[0]);
            for (var i = 3; i <= 24; i += 3) {
                points.push(parentObj.selfToWorld([5, i, 0]));
                points.push(parentObj.selfToWorld([5, i, 3]));
                points.push(parentObj.selfToWorld([-5, i, 3]));
                points.push(parentObj.selfToWorld([-5, i, -3]));
                points.push(parentObj.selfToWorld([5, i, -3]));
                points.push(parentObj.selfToWorld([5, i, 0]));
            }
            points.push(parentObj.selfToWorld([5, 24, 0]));
            buildLine(points, '#0000FF');
        }
    );
    waterUnderPoints.push([15.32711, -0.79, -55.655339999999999]);
    buildLine(waterUnderPoints, '#0000FF');
    renderOrder();
}

function electric() {
    var electricUnderPoints = [];
    buildingOpacity(0.3);
    app.query(/building_0/).forEach(
        function (parentObj) {
            var points = [];
            points.push(parentObj.selfToWorld([3, -0.8, 0]));
            electricUnderPoints.push(points[0]);
            for (var i = 3; i <= 24; i += 2.5) {
                points.push(parentObj.selfToWorld([3, i, 0]));
                points.push(parentObj.selfToWorld([-3, i, 2]));
            }
            points.push(parentObj.selfToWorld([3, 24, 0]));
            buildLine(points, '#00FF00');
            console.log(points);
        }
    );
    electricUnderPoints.push([16.690666, -0.79, -55.115203999999999]);
    buildLine(electricUnderPoints, '#00FF00');
    renderOrder();
}

function gas() {
    var gasUnderPoints = [];
    buildingOpacity(0.3);
    app.query(/building_0/).forEach(
        function (parentObj) {
            var points = [];
            points.push(parentObj.selfToWorld([-6.2, -0.3, 0]));
            gasUnderPoints.unshift(points[0]);
            for (var i = 3; i <= 24; i += 3) {
                points.push(parentObj.selfToWorld([-6.2, i, 0]));
                points.push(parentObj.selfToWorld([-6.2, i, 2]));
                points.push(parentObj.selfToWorld([6.2, i, 2]));
                points.push(parentObj.selfToWorld([6.2, i, -2]));
                points.push(parentObj.selfToWorld([-6.2, i, -2]));
                points.push(parentObj.selfToWorld([-6.2, i, 0]));
            }
            points.push(parentObj.selfToWorld([-6.2, 24, 0]));
            buildLine(points, '#FF0000');
            console.log(points);
        }
    );
    gasUnderPoints.unshift([22.963023600000003, -0.3, 57.8305784]);
    buildLine(gasUnderPoints, '#FF0000');
    renderOrder();
}

/************************************************************************
 * common
*/

function buildingOpacity(num) {
    app.query("*").forEach(function (obj) {
        obj.style.opacity = num;
    });
}

function renderOrder(){
    app.query('.PolygonLine').forEach(
        function (obj) {
            obj.renderOrder = -10000;
        }
    );
}

var line = null;
function buildLine(points, color) {
    line = app.create({
        type: 'PolygonLine',
        points: points,
        style: {
            color: color,
        }
    });
    line.scrollUV = true;
}