前言
前段时间想要做一个web端的图形化积木式编程（类似少儿编程）的案例，网上冲浪了一圈又一圈，终于技术选型好，然后代码一顿敲，终于出来了一个雏形。
TIPS：该案例设计主要参考iRobot Coding,只用做学习用途，侵删。
最终实现效果
最终实现效果
本文实现效果
-
点击拖拽移动物体
点击拖拽移动物体
完整代码
- 点击拖拽移动物体
<template>
<div style="height: 100%;width: 100%;">
<div>
<canvas id="renderCanvas"></canvas>
</div>
</div>
</template>
<script>
import * as BABYLON from 'babylonjs';
import * as BABYLON_MATERAIAL from "babylonjs-materials"
//全局变量
var scene = null //场景实例
var engine = null //3d引擎实例
var camera = null //摄像机实例
var plane = null //绿地
var ground = null //网格
var skybox = null //天空盒
var car = null //小车
var startingPoint = new BABYLON.Vector3(0, 0, 0)//当前点击位置
async function loadScene() {
//场景初始化，可看文章一
scene = initScene()
//加载网络模型，可看文章二
await initRobot()
//本文内容，监听拖动事件，实现点击拖动模型
dragListening()
//开启debug窗口
// scene.debugLayer.show()
}
//鼠标点击拖动监听
function dragListening() {
// 物体拖拽事件
var canvas = engine.getRenderingCanvas();
var currentMesh;//当前点击的模型网格
//判断当前点击对象是否是地板
var getGroundPosition = function () {
var pickinfo = scene.pick(scene.pointerX, scene.pointerY, function (mesh) {
return (mesh == ground || mesh == plane);
});
if (pickinfo.hit) {
return pickinfo.pickedPoint;
}
return null;
}
//鼠标点下
var onPointerDown = function (evt) {
if (evt.button !== 0) {
return;
}
//判断当前是否点击一个模型网格，如果是地板、天空盒等对象，则设置hit为false
var pickInfo = scene.pick(scene.pointerX, scene.pointerY, function (mesh) {
return (mesh !== ground && mesh !== plane && mesh !== skybox);
});
console.log("pickInfo", pickInfo)
//如果hit为true，则不为地板、天空盒等对象
if (pickInfo.hit) {
currentMesh = pickInfo.pickedMesh;//获取当前点击对象
if (currentMesh.parent == null) {
console.log("no parent")//没有父节点则就是car对象了
} else if (currentMesh.parent.name == car.name) {
//有父节点，证明现在点击的是子对象，而移动需要移动整个小车对象，所以设置当前点击mesh为父节点（即car对象）
currentMesh = currentMesh.parent
}
console.log("currentMesh", currentMesh)
//获取当前移动时地板的坐标
startingPoint = getGroundPosition(evt);
//移动物体时，暂时屏蔽相机的移动控制
if (startingPoint) { // we need to disconnect camera from canvas
setTimeout(function () {
camera.detachControl(canvas);
}, 0);
}
}
}
//鼠标点击着移动中
var onPointerMove = function (evt) {
if (!startingPoint) {
return;
}
if (!currentMesh) {
return;
}
//更新当前点击的地板位置
var current = getGroundPosition(evt);
if (!current) {
return;
}
//更新当前小车坐标位置为点击的地板位置
console.log('startingPoint', startingPoint)
var diff = current.subtract(startingPoint);
console.log('diff', diff)
currentMesh.position.addInPlace(diff);
console.log("currentMesh.name", currentMesh.name)
//更新位置信息
startingPoint = current;
}
//鼠标点击后松开
var onPointerUp = function () {
//恢复相机移动控制
if (startingPoint) {
camera.attachControl(canvas, true);
startingPoint = null;
return;
}
}
//canvas绑定监听事件
canvas.addEventListener("pointerdown", onPointerDown, false);
canvas.addEventListener("pointerup", onPointerUp, false);
canvas.addEventListener("pointermove", onPointerMove, false);
}
async function initRobot() {
console.log('initRobot')
//模型url路径
const url = "http://localhost:8887/"
//模型名称
const modelName = "sportcar.babylon"
var result = await BABYLON.SceneLoader.ImportMeshAsync(null, url, modelName, scene);
var meshes = result.meshes
console.log("meshes", meshes)
//定义一个根节点
var parent = new BABYLON.Mesh("car", scene);
const scale = 10//缩放比例
for (var mesh of meshes) {
mesh.scaling = new BABYLON.Vector3(scale, scale, scale)
mesh.parent = parent
}
//将根节点设置为全局变量
car = parent
}
function initScene() {
//获取到renderCanvas这个元素
var canvas = document.getElementById("renderCanvas");
//初始化引擎
engine = new BABYLON.Engine(canvas, true);
//初始化场景
var scene = new BABYLON.Scene(engine);
//注册一个渲染循环来重复渲染场景
engine.runRenderLoop(function () {
scene.render();
});
//浏览器窗口变化时监听
window.addEventListener("resize", function () {
engine.resize();
});
//相机初始化
camera = new BABYLON.ArcRotateCamera("Camera", 0, 0, 5, new BABYLON.Vector3(0, 0, 10), scene);
camera.setPosition(new BABYLON.Vector3(20, 200, 400));
//相机角度限制
camera.upperBetaLimit = 1.5;//最大z轴旋转角度差不多45度俯瞰
camera.lowerRadiusLimit = 50;//最小缩小比例
camera.upperRadiusLimit = 1500;//最大放大比例
//变焦速度
camera.wheelPrecision = 1; //电脑滚轮速度 越小灵敏度越高
camera.pinchPrecision = 20; //手机放大缩小速度 越小灵敏度越高
scene.activeCamera.panningSensibility = 100;//右键平移灵敏度
// 将相机和画布关联
camera.attachControl(canvas, true);
//灯光初始化
var light = new BABYLON.HemisphericLight("light1", new BABYLON.Vector3(0, 10, 0), scene);
//设置高光颜色
light.specular = new BABYLON.Color3(0, 0, 0);
//设置灯光强度
light.intensity = 1
// 绿地初始化
var materialPlane = new BABYLON.StandardMaterial("texturePlane", scene);
materialPlane.diffuseColor = new BABYLON.Color3(152 / 255.0, 209 / 255.0, 115 / 255.0)
materialPlane.backFaceCulling = false;
materialPlane.freeze()
plane = BABYLON.MeshBuilder.CreateDisc("ground", {radius: 3000}, scene);
plane.rotation.x = Math.PI / 2;
plane.material = materialPlane;
plane.position.y = -0.1;
plane.freezeWorldMatrix()
//网格地板初始化
const groundSide = 144;
ground = BABYLON.Mesh.CreateGround("ground", groundSide, groundSide, 1, scene, true);
var groundMaterial = new BABYLON_MATERAIAL.GridMaterial("grid", scene);
groundMaterial.mainColor = BABYLON.Color3.White();//底板颜色
groundMaterial.alpha = 1;//透明度
const gridLineGray = 0.95;
groundMaterial.lineColor = new BABYLON.Color3(gridLineGray, gridLineGray, gridLineGray);
groundMaterial.backFaceCulling = true; // 可看到背面
//大网格间距
groundMaterial.majorUnitFrequency = 16;
//小网格间距
groundMaterial.minorUnitVisibility = 0;
const gridOffset = 8; // 网格偏移量
groundMaterial.gridOffset = new BABYLON.Vector3(gridOffset, 0, gridOffset);
groundMaterial.freeze(); // 冻结材质，优化渲染速度
ground.material = groundMaterial
ground.freezeWorldMatrix()
//天空盒初始化
var skyMaterial = new BABYLON_MATERAIAL.SkyMaterial("skyMaterial", scene);
skyMaterial.inclination = 0
skyMaterial.backFaceCulling = false;
skybox = BABYLON.Mesh.CreateBox("skyBox", 5000.0, scene);
skybox.material = skyMaterial;
return scene
}
export default {
name: "test",
data() {
return {}
},
async mounted() {
//加载场景
await loadScene()
},
}
</script>
<style scoped>
#renderCanvas {
width: 680px;
height: 680px;
touch-action: none;
z-index: 10000;
border-radius: 10px;
}
</style>
babylonjs点击拖拽移动模型实现
本文要实现的功能比较简单，分解来看就是
1、监听点击落下，判断当前对象是否是可移动对象，如果是则将其设置为当前移动对象，并禁用摄像头控制
2、监听点击移动过程，获取点击移动过程中点击地板的位置，更新该位置为小车当前位置
3、监听点击松开，恢复摄像头控制
0、公用属性和函数
// 物体拖拽事件
var canvas = engine.getRenderingCanvas();
var currentMesh;//当前点击的模型网格
//判断当前点击对象是否是地板
var getGroundPosition = function () {
var pickinfo = scene.pick(scene.pointerX, scene.pointerY, function (mesh) {
return (mesh == ground || mesh == plane);
});
if (pickinfo.hit) {
return pickinfo.pickedPoint;
}
return null;
}
1、点击落下处理
//鼠标点下
var onPointerDown = function (evt) {
if (evt.button !== 0) {
return;
}
//判断当前是否点击一个模型网格，如果是地板、天空盒等对象，则设置hit为false
var pickInfo = scene.pick(scene.pointerX, scene.pointerY, function (mesh) {
return (mesh !== ground && mesh !== plane && mesh !== skybox);
});
console.log("pickInfo", pickInfo)
//如果hit为true，则不为地板、天空盒等对象
if (pickInfo.hit) {
currentMesh = pickInfo.pickedMesh;//获取当前点击对象
if (currentMesh.parent == null) {
console.log("no parent")//没有父节点则就是car对象了
} else if (currentMesh.parent.name == car.name) {
//有父节点，证明现在点击的是子对象，而移动需要移动整个小车对象，所以设置当前点击mesh为父节点（即car对象）
currentMesh = currentMesh.parent
}
console.log("currentMesh", currentMesh)
//获取当前移动时地板的坐标
startingPoint = getGroundPosition(evt);
//移动物体时，暂时屏蔽相机的移动控制
if (startingPoint) { // we need to disconnect camera from canvas
setTimeout(function () {
camera.detachControl(canvas);
}, 0);
}
}
}
2、点击移动过程处理
//鼠标点击着移动中
var onPointerMove = function (evt) {
if (!startingPoint) {
return;
}
if (!currentMesh) {
return;
}
//更新当前点击的地板位置
var current = getGroundPosition(evt);
if (!current) {
return;
}
//更新当前小车坐标位置为点击的地板位置
console.log('startingPoint', startingPoint)
var diff = current.subtract(startingPoint);
console.log('diff', diff)
currentMesh.position.addInPlace(diff);
console.log("currentMesh.name", currentMesh.name)
//更新位置信息
startingPoint = current;
}
3、点击松开处理
//鼠标点击后松开
var onPointerUp = function () {
//恢复相机移动控制
if (startingPoint) {
camera.attachControl(canvas, true);
startingPoint = null;
return;
}
}
4、绑定鼠标监听事件
//canvas绑定监听事件
canvas.addEventListener("pointerdown", onPointerDown, false);
canvas.addEventListener("pointerup", onPointerUp, false);
canvas.addEventListener("pointermove", onPointerMove, false);
后续计划
Babylon.js
- 自定义启动界面
- 物体重力效果
- babylonjs-gui 按钮实现
- babylonjs+ammojs 碰撞体实现
- 将3d界面放入可拖动窗口中
Blockly
- 入门使用blockly
- 自定义block块
- blockly第三方组件使用
- 接入js-interpreter，步骤运行block块
- ......(想到啥写啥)
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