自从大二初次接触前端以来，一直都有记markdown笔记的习惯.又因为掘金最近有一个活动.所以开了这个专栏。我会写一些业务相关的小技巧和前端知识中的重点内容之类的整理一下发上来。难免有点地方不够细致。欢迎大家指教
这篇文章 主要 是 我在做 大屏项目，threejs与后台项目的实操
2.0概述
讲一下我three.js的关于机器人监控的实现思路，相应的知识点列在下面，想实现可以去到threejs的官网： threejs.org/docs/index.... 进行学习(qs：吐槽一下three的文档写的比unity的文档好多了，unity那是人可以读的？)
然后抽离了一份基于我们这个项目的demo，开源一份基于three.js，express，vue集合的示例代码。我管他叫大demo： gitee.com/Electrolux/...
接着说一下我们的机器人监控的几个功能和对应的知识点：
-
1.第一人称，第三人称切换。第一人称可以操作第一人称进行移动，第三人称进行视图的自由移动 - 这里的知识点主要是PointerLockControls(指针选择器-第一人称)+OrbitControls(第三人称) 。示例代码可以参考： gitee.com/Electrolux/...。
双击屏幕就可以进行wsad和jump跳跃
-
2.agv追踪硬件数据进行入库出库操作 - 这里有两个核心方法
第一个是设置行进路线，第二个是进行运动
行进路线的核心方法是：
java//运动行驶的范围 var curve = new THREE.CatmullRomCurve3( [ new THREE.Vector3(200, 20, -120), new THREE.Vector3(200, 20, -80), new THREE.Vector3(200, 20, -60), new THREE.Vector3(200, 20, 40), new THREE.Vector3(-100, 20, 40), new THREE.Vector3(-100, 20, -60), new THREE.Vector3(-100, 20, -130), ], true ); const vertices = curve.getPoints(100); var curvepath = new THREE.BufferGeometry().setFromPoints(vertices);运动的核心方法是：
arduinofunction Move(curve, truck) { progress += move_rate; if (curve) { const point = curve.getPoint(progress); // 下一个要走的点的位置 const point_next = curve.getPoint(progress + move_rate); if (point && point.x) { // console.log(point) truck.position.set(point.x, point.y, point.z); // 向下一个要走的点方向看齐 truck.lookAt(point_next.x, point_next.y, point_next.z); //重要：第一人称视角 if (!truck) { camera.position.set(point.x, point.y + 45, point.z); camera.lookAt(point_next.x, point_next.y + 45, point_next.z); } } } // 重要：将标签跟随汽车移动显示 if (dynamicSprite) { dynamicSprite.position.set( truck.position.x, truck.position.y, truck.position.z ); dynamicSprite.translateY(100); } } -
停车时间标签跟随3d主体(精灵跟随)- 主要的知识点是 CSS2DRenderer+CSS2DObject+Sprite
小demo： gitee.com/Electrolux/...
-
管理员聊天功能（websocket）- 知识点就是发布者订阅者，相关代码可以看大demo
-
vr查看，基本信息查看。这里看大demo。知识点其实也是RGBELoader+OrbitControls
-
点击3d场景的时候，可以进行交互。知识点是Raycaster射线选择器（我在大demo中集成了一个clickpick方法）
好了，基本功能大概就那么多，因为篇幅原因写不了太多。代码和实现基本都在demo中： gitee.com/Electrolux/...
2.1 基础知识点
2.1.1 摄像机
2.1.1.1.场景(scene)：
这里面包括你的obj，fbx等3d模型和其对应的材质（material），PointLight（环境光），skybox（天空盒），controller(控制器-这玩意主要是控制你的视角)。这些构成了你three中的基本的主体。
2.1.1.2.相机(camera):
这里面我们主要用 透视相机（PerspectiveCamera）。我们对它主要就是设置初始位置，和初始化视角
2.1.1.3.render(渲染器)：
用requestAnaniton进行调用就好了
2.2 基本效果实现的代码
2.2.1 加载天空盒
javascript
function initskyboxsun25deg() {
const starUrls = [
require("/public/static/images/skyboxsun25deg/px.jpg"), // right
require("/public/static/images/skyboxsun25deg/nx.jpg"), // left
require("/public/static/images/skyboxsun25deg/py.jpg"), // top
require("/public/static/images/skyboxsun25deg/ny.jpg"), // bottom
require("/public/static/images/skyboxsun25deg/pz.jpg"), // back
require("/public/static/images/skyboxsun25deg/nz.jpg"), // front
];
scene.background = new THREE.CubeTextureLoader().load(starUrls);
}
initskyboxsun25deg()2.2.2 加载Gui
csharp
//引入gui
var gui;
import { GUI } from "three/examples/jsm/libs/lil-gui.module.min.js";
function initGui(status) {
//1.设置基本属性
gui = new GUI();
gui.domElement.classList.add();
gui.domElement.style.cssText = "position:absolute;top:0px;right:0px;";
// 2.设置属性，以下面为例子。意思就是
// mesh.position.x 这个数值在-3到3之间调节，间隔是0.01
gui.add(mesh.position, 'x', -3, 3, 0.01).name('x的宽度')
gui.add(mesh.position, 'y', -3, 3, 0.01).name('y的角度')
gui.add(material, 'wireframe').name('设置线框')
//gui.addColor
gui.addColor(material, 'color').name('颜色')
// gui.add(width, 'y').min(300).max(600).step(0.01).name('宽度')
}
initGui(1)
2.2.3 2d标签跟随移动（关键代码）
ini
import { CSS2DObject, CSS2DRenderer } from "three/examples/jsm/renderers/CSS2DRenderer";
function addCssLabel() {
if (css2dLabelArray.length > 0) {
for (const label of css2dLabelArray) {
label.parent.remove(label);
}
css2dLabelArray.splice(0);
} else {
const labelObj = scene.children.filter((item) =>
// item.name.includes("cube")
item.name.includes("cube")
);
labelObj.forEach((ele) => {
const css2dLabel = document.createElement("div");
css2dLabel.innerHTML = `<div style="text-align: center">名字</div><div class=".labelText">已停放23时</div>`;
const label = new CSS2DObject(css2dLabel);
// label.name = `${ele.name}csslabel`;
label.name = `csslabel`;
css2dLabel.classList.add("css2dLabel");
css2dLabelArray.push(label);
ele.add(label);
// document.body.appendChild(css2dLabel);
// i += 1;
});
}
}
addCssLabel();
//重要：2d标签的渲染，这里的宽高要一致
var labelRenderer = new CSS2DRenderer();
labelRenderer.setSize(width, height);
labelRenderer.domElement.style.position = "absolute";
labelRenderer.domElement.style.top = "0px";
//重要：这一步让轨道控制器和css2d 控制器兼容
labelRenderer.domElement.style.pointerEvents = 'none';
document.body.appendChild(labelRenderer.domElement);
var renderer = new THREE.WebGLRenderer();
renderer.setSize(width, height); //设置渲染区域尺寸
function render() {
Move(curve, mesh);
labelRenderer.render(scene, camera);
renderer.render(scene, camera); //执行渲染操作
// mesh.rotateY(0.01);//每次绕y轴旋转0.01弧度
requestAnimationFrame(render); //请求再次执行渲染函数render，渲染下一帧
}
render();
export {renderer}
调用的时候
import { renderer } from "./cube_curve_run_csslabel.js";
document.body.appendChild(renderer.domElement);2.2.4 精灵（可以盯着摄像头）
可以避免一些观感上面的不适应：
ini
var param = {
width: 200,
height: 200,
text: "10M/s",
name: "dynamicLabel",
x: 100,
y: 90,
z: 20,
};
var dynamicSprite;
function canvasMed(canvas, param, content) {
const ctl = canvas
ctl.fillStyle = "rgba(255, 255, 153, 1.0)";
ctl.fillRect(0, 0, param.width, param.height);
ctl.textAlign = "center";
ctl.textBaseline = "middle";
ctl.font = "bold 60px Arial";
ctl.lineWidth = 60;
ctl.fillStyle = "rgba(25, 25, 25, 1.0)";
ctl.fillText(content, param.x, param.y);
}
canvas.height = param.height;
canvas.width = param.width;
canvasMed(panel, param, param.text);
const texture = new THREE.Texture(canvas);
texture.needsUpdate = true;
const spriteMaterial = new THREE.SpriteMaterial({
map: texture,
});
dynamicSprite = new THREE.Sprite(spriteMaterial);
dynamicSprite.position.set(
mesh.position.x + param.x,
mesh.position.y + param.y,
mesh.position.z + param.z
);
dynamicSprite.translateY(100);
dynamicSprite.name = param.name;
//重要：这里跳转这里调大小
dynamicSprite.scale.set(50, 50, 50);
//重要：精灵跟随模式
scene.add(dynamicSprite);
function Move(curve, truck) {
progress += move_rate;
if (curve) {
const point = curve.getPoint(progress);
// 下一个要走的点的位置
const point_next = curve.getPoint(progress + move_rate);
if (point && point.x) {
// console.log(point)
truck.position.set(point.x, point.y, point.z);
// 向下一个要走的点方向看齐
truck.lookAt(point_next.x, point_next.y, point_next.z);
//重要：第一人称视角
if (!truck) {
camera.position.set(point.x, point.y + 45, point.z);
camera.lookAt(point_next.x, point_next.y + 45, point_next.z);
// // controls.position0.set(point.x, point.y + 45, point.z);
// // 将控制器看齐下一个点的位置(摆正车头的位置)
// this.controls.target.set(point_next.x, point_next.y + 45, point_next.z);
}
}
}
// 重要：将标签跟随汽车移动显示
if (dynamicSprite) {
dynamicSprite.position.set(
truck.position.x,
truck.position.y,
truck.position.z
);
dynamicSprite.translateY(100);
}
}
2.2.5 添加光源
csharp
/**
* 光源设置
*/
//点光源 :把所有物体渲染成相同的颜色
// 白光
var pointLight = new THREE.PointLight(0xffffff); //创建一个白色的点光源
pointLight.position.set(0, 0, 150);
scene.add(pointLight);
// scene.add(point); //点光源添加到场景中
//环境光
var ambient = new THREE.AmbientLight(0xffffff, 1);
scene.add(ambient);2.2.6 交互示例
这里的知识点主要是Raycaster，也就是雷达选择器。特别要注意的是这里没有用到CSS2DRenderer这个渲染也可以达到类似的效果。但是CSS2DRenderer是在3d世界中标签。这里的是在vue的2d界面新建一个dom元素然后展现它
首先我们在父组件简单定义一个东西,由clickpick把数据传入到父组件去
javascript
<el-card style="width: 300px" class="label">
<div v-for="(info, index) in dataInfo" :key="index">
<span>{{ info.key }}</span>
<span style="display: inline-block; margin-left: 50px">{{ info.value }}</span>
<el-divider />
</div>
</el-card>
import { clickPick } from "/public/static/js/clickPick";
clickPick(this); 传进去就行了clickpick.js中
ini
import * as THREE from "three";
// import { OutlineEffect } from 'three/examples/jsm/effects/OutlineEffect.js';
export const clickPick = (_this) => {
const rayCaster = new THREE.Raycaster();
const mouse = new THREE.Vector2();
let x, y;
const selectedObjects = [];
const label = document.querySelector(".label");
window.addEventListener("click", onMouseClick);
window.addEventListener("dblclick", onMouseDbClick);
// 点击卡片的显示位置
// var that =this
function showCard(element, x, y) {
element.style.display = "block";
element.style.position = "absolute";
element.style.left = `${x}px`;
element.style.top = `${y}px`;
console.log(x, y)
}
function onMouseClick(e) {
if (e.changedTouches) {
x = e.changedTouches[0].pageX;
y = e.changedTouches[0].pageY;
} else {
x = e.clientX;
y = e.clientY;
}
const rect = _this.container.getBoundingClientRect(); // 拿到div相对屏幕坐标的偏移量
/**
* 当前场景并不是全屏渲染的 所以屏幕坐标转化为世界坐标的公式有所变化
*/
console.log(rect.left, "左偏移量", rect.top, "上偏移量")
console.log(this.container.clientWidth, "宽度", rect.top, "高度")
// mouse.x = ((x - rect.left) / this.container.clientWidth) * 2 - 1;
// mouse.y = -((y - rect.top) / this.container.clientHeight) * 2 + 1;
mouse.x = ((x - rect.left) / 500) * 2 - 1;
mouse.y = -((y - rect.top) / 500) * 2 + 1;
// 通过摄像机和鼠标位置来更新射线
rayCaster.setFromCamera(mouse, _this.camera);
// 第二个参数表示是否检查他的后代
const intersects = rayCaster.intersectObjects([_this.scene]);
if (intersects.length > 0) {
console.log("这是射线选择器选中的物体名称", intersects[0].object.name)
const object_name = intersects[0].object.name;
//重要：
switch (object_name.substring(0, 3)) {
case "mes":
//重要：一次显示所有的标签，数据从父级去拿到
// _this.trucklist.forEach((e) => {
// if (e.name === object_name) {
// _this.dataInfo = [
// { key: "车辆名称", value: e.name },
// { key: "行驶公里数", value: e.kilmeters },
// ];
// }
// });
for (let i = 0; i < intersects.length; i++) {
intersects[i].object.material.color.set(0xff0000);
_this.dataInfo = [
{ key: "车辆名称", value: intersects[i].object.name },
];
showCard(label, mouse.x, mouse.y);
}
showCard(label, x, y);
break;
default:
selectedObjects.pop();
break;
}
if (object_name.includes("sprite")) {
const parentDiv = document.createElement("div");
parentDiv.className = "parentVideo";
parentDiv.style.position = "absolute";
parentDiv.style.display = "none";
parentDiv.style.backgroundColor = "rgba(25, 25, 25, 0.5)";
const titleDiv = document.createElement("div");
titleDiv.style.cssText =
"height: 24px;inline-height: 24px;float: left;color: #FFFFFF;font-size:20px;margin:10px 0 10px 20px";
titleDiv.textContent = "监控录像";
const closeDiv = document.createElement("div");
closeDiv.className = "videoImg";
titleDiv.addEventListener("click", () => {
const videoDiv = document.querySelectorAll(".parentVideo");
console.log(videoDiv)
for (const e of videoDiv) {
e.remove();
}
});
parentDiv.appendChild(titleDiv);
parentDiv.appendChild(closeDiv);
const videoLabel = document.createElement("video");
videoLabel.autoplay = true;
videoLabel.muted = true;
videoLabel.controls = true;
videoLabel.loop = true;
videoLabel.style.width = "80%";
videoLabel.style.height = "350px";
const videoSource = document.createElement("source");
videoSource.src = "static/video/watch.mp4";
videoSource.type = "video/mp4";
videoLabel.appendChild(videoSource);
parentDiv.appendChild(videoLabel);
document.body.appendChild(parentDiv);
showCard(parentDiv, x, y);
} else {
selectedObjects.pop();
selectedObjects.push(intersects[0].object);
}
// _this.effectController.A = object_name;
}
}
function onMouseDbClick(event) {
if (event.changedTouches) {
x = event.changedTouches[0].pageX;
y = event.changedTouches[0].pageY;
} else {
x = event.clientX;
y = event.clientY;
}
event.preventDefault();
const vector = new THREE.Vector3(); //三维坐标对象
vector.set(mouse.x, mouse.y, 0.5);
vector.unproject(_this.camera);
const rect = _this.container.getBoundingClientRect(); //拿到div相对屏幕坐标的偏移量
//屏幕坐标转标准设备坐标(世界坐标系) x和y应在-1和1之间
mouse.x = ((x - rect.left) / this.container.clientWidth) * 2 - 1;
mouse.y = -((y - rect.top) / this.container.clientHeight) * 2 + 1;
// 通过摄像机和鼠标位置更新射线 camera表示射线来源的摄像机
rayCaster.setFromCamera(mouse, _this.camera);
const intersects = rayCaster.intersectObjects([_this.scene], true);
if (intersects[0]) {
const soName = intersects[0].object.name;
if (soName.substring(0, 3) === "xxxxxxxxxx") {
_this.$router.push({
path: "/xxxxxxxxxxxx",
query: {
name: soName,
},
});
} else {
// return;
}
}
}
};
2.2.7 监听键盘事件
ini
window.addEventListener('keydown', onKeyDown);
window.addEventListener('keyup', onKeyUp);
//定义键盘事件
const onKeyDown = function (event) {
// controls.unlock();
console.log(event.code)
switch (event.code) {
case 'ArrowUp':
case 'KeyW':
moveForward = true;
break;
case 'ArrowLeft':
case 'KeyA':
moveLeft = true;
break;
case 'ArrowDown':
case 'KeyS':
moveBackward = true;
break;
case 'ArrowRight':
case 'KeyD':
moveRight = true;
break;
case 'Space':
if (canJump === true) velocity.y += 350;
canJump = false;
break;
}
};
const onKeyUp = function (event) {
// controls.unlock();
switch (event.code) {
case 'ArrowUp':
case 'KeyW':
moveForward = false;
break;
case 'ArrowLeft':
case 'KeyA':
moveLeft = false;
break;
case 'ArrowDown':
case 'KeyS':
moveBackward = false;
break;
case 'ArrowRight':
case 'KeyD':
moveRight = false;
break;
}
};2.2.8 控制物体运动
scss
//重要：创造运动轨道，运动路线
var curve = new THREE.CatmullRomCurve3(
[
new THREE.Vector3(200, 20, -120),
new THREE.Vector3(200, 20, -80),
new THREE.Vector3(200, 20, -60),
new THREE.Vector3(200, 20, 40),
new THREE.Vector3(-100, 20, 40),
new THREE.Vector3(-100, 20, -60),
new THREE.Vector3(-100, 20, -130),
],
true
);
//分成100份
const vertices = curve.getPoints(100);
var curvepath = new THREE.BufferGeometry().setFromPoints(vertices);
const lineMaterial = new THREE.LineBasicMaterial({
color: 0xffffff,
transparent: 0,
opacity: 1,
});
const curveMesh2 = new THREE.Line(curvepath, lineMaterial);
//场景中添加行驶路线，这里就显示一条白色的行驶路线
scene.add(curveMesh2);
function Move(curve, truck) {
progress += move_rate;
if (curve) {
const point = curve.getPoint(progress);
// 下一个要走的点的位置
const point_next = curve.getPoint(progress + move_rate);
if (point && point.x) {
// console.log(point)
truck.position.set(point.x, point.y, point.z);
// 向下一个要走的点方向看齐
truck.lookAt(point_next.x, point_next.y, point_next.z);
//重要：第一人称视角
if (!truck) {
camera.position.set(point.x, point.y + 45, point.z);
camera.lookAt(point_next.x, point_next.y + 45, point_next.z);
// // controls.position0.set(point.x, point.y + 45, point.z);
// // 将控制器看齐下一个点的位置(摆正车头的位置)
// this.controls.target.set(point_next.x, point_next.y + 45, point_next.z);
}
}
}
// 重要：将标签跟随汽车移动显示
// if (dynamicSprite) {
// dynamicSprite.position.set(truck.position.x, truck.position.y, truck.position.z);
// dynamicSprite.translateY(100);
// }
}
function render() {
Move(curve, mesh);
labelRenderer.render(scene, camera);
renderer.render(scene, camera); //执行渲染操作
// mesh.rotateY(0.01);//每次绕y轴旋转0.01弧度
requestAnimationFrame(render); //请求再次执行渲染函数render，渲染下一帧
}
render();
2.2.9 加载模型
obj模型的加载
scss
// 初始化模型
function initModelMed(url) {
return new Promise((resolve, reject) => {
new MTLLoader().setPath("/static/obj/").load(`${url}.mtl`, (materials) => {
materials.preload();
new OBJLoader()
.setMaterials(materials)
.setPath("/static/obj/")
.load(`${url}.obj`, (obj) => {
if (obj) {
// this.objList = obj;
// this.loading = false;
obj.children.forEach((child) => {
child.geometry.computeBoundingBox();
const centroid = new THREE.Vector3();
centroid.addVectors(
child.geometry.boundingBox.min,
child.geometry.boundingBox.max
);
centroid.multiplyScalar(0.5);
centroid.applyMatrix4(child.matrixWorld);
child.geometry.center(centroid.x, centroid.y, centroid.z);
child.position.set(centroid.x, centroid.y, centroid.z);
});
scene.add(obj);
resolve(obj);
} else {
reject("error");
}
});
});
});
}
// initModelMed("city")fbx模型的加载
typescript
import { FBXLoader } from "three/examples/jsm/loaders/FBXLoader";
const loader = new FBXLoader();
loader.load("/model/city.FBX", (object) => {
// 模型缩放
object.scale.set(0.001, 0.001, 0.001);
scene.add(object);
// clickObjects = object
console.log(object);
});2.2.10 第一人称第三人称的切换
知识点：这里要双击界面进行解锁。这段代码太长了，就放个链接