babylon.js 学习笔记(3)
一、理解babylon.js 坐标系
const createScene = function () {
const scene = new BABYLON.Scene(engine);
const camera = new BABYLON.ArcRotateCamera("camera", -Math.PI / 2, Math.PI / 2.5, 3, new BABYLON.Vector3(0, 0, 0));
camera.attachControl(canvas, true);
const light = new BABYLON.HemisphericLight("light", new BABYLON.Vector3(1, 1, 0));
//方块1(靠左，靠下，靠前)
const box1 = BABYLON.MeshBuilder.CreateBox("box", { size: 0.4 }, scene);
//Vector(x,y,z) 表示x,y,z三轴的坐标值
box1.position = new BABYLON.Vector3(-1, -0.199, -0.4);
//方块2（放在正中央）
const box2 = BABYLON.MeshBuilder.CreateBox("box", { size: 0.4 }, scene);
box2.position = new BABYLON.Vector3(0, 0, 0);
//方块3(靠右，靠上，靠后)
const box3 = BABYLON.MeshBuilder.CreateBox("box", { size: 0.4 }, scene);
box3.position = new BABYLON.Vector3(1, 0.2, 0.4);
var ground = BABYLON.MeshBuilder.CreateGround("ground", { width: 3, height: 1.5 }, scene);
let groundMaterial = new BABYLON.StandardMaterial("Ground Material", scene);
ground.material = groundMaterial;
ground.material.diffuseColor = BABYLON.Color3.Black();
return scene;
};
在线地址：https://yjmyzz.github.io/babylon_js_study/day03/01.html
BABYLON.Vector3(x,y,z) 是一个很重要的对象，不仅能用于设置对象的位置，还能控制缩放大小，以及旋转角度。
//方块1(靠左，靠下，靠前)
const box1 = BABYLON.MeshBuilder.CreateBox("box", { size: 0.4 }, scene);
//Vector(x,y,z) 表示x,y,z三轴的坐标值
box1.position = new BABYLON.Vector3(-1, -0.199, -0.4);
box1.scaling = new BABYLON.Vector3(0.5, 1, 1);
//方块2（放在正中央）
const box2 = BABYLON.MeshBuilder.CreateBox("box", { size: 0.4 }, scene);
box2.position = new BABYLON.Vector3(0, 0, 0);
box2.scaling = new BABYLON.Vector3(1, 0.5, 1);
//绕y轴转45度
box2.rotation = new BABYLON.Vector3(0,Math.PI/4,0);
//方块3(靠右，靠上，靠后)
const box3 = BABYLON.MeshBuilder.CreateBox("box", { size: 0.4 }, scene);
box3.position = new BABYLON.Vector3(1, 0.2, 0.4);
box3.scaling = new BABYLON.Vector3(1, 1, 0.5);
box3.rotation = new BABYLON.Vector3(-Math.PI/4,0,0);
在线地址：https://yjmyzz.github.io/babylon_js_study/day03/02.html
二、画1个简单的小房子
如上图，画1个三棱柱，以及1个立方体，组合起来即可。但babylon.js中并没有创建三棱柱的api，只能创建圆柱体，还记得前面学过的吗？任何复杂的对象(即mesh)，都是一堆小三角形及各种切面的组合，三角形数越多，最终的对象越逼真。当圆柱体的边数设置为3时，即退化成三棱柱。
//Cylinder的边tessellation足够大时，即为圆柱形
const roof0 = BABYLON.MeshBuilder.CreateCylinder("roof0", {diameter: 1.3, height: 1.2, tessellation: 32},scene);
roof0.position = new BABYLON.Vector3(-1,0.26,0);
roof0.scaling = new BABYLON.Vector3(0.25,0.25,0.25);
const roof1 = BABYLON.MeshBuilder.CreateCylinder("roof1", {diameter: 1.3, height: 1.2, tessellation: 32},scene);
roof1.position = new BABYLON.Vector3(-0.5,0.26,0);
roof1.scaling = new BABYLON.Vector3(0.25,0.25,0.25);
//绕x轴转90度
roof1.rotation = new BABYLON.Vector3(Math.PI / 2,0,0);
//Cylinder的边tessellation=3时，即为三棱柱
const roof2 = BABYLON.MeshBuilder.CreateCylinder("roof2", {diameter: 1.3, height: 1.2, tessellation: 3},scene);
roof2.position = new BABYLON.Vector3(0,0.24,0);
roof2.scaling = new BABYLON.Vector3(0.4,0.4,0.4);
roof2.rotation = new BABYLON.Vector3(0,Math.PI / 2,Math.PI / 2);
//三棱柱+方块，组合成1个简单的房子
const roof = BABYLON.MeshBuilder.CreateCylinder("roof", {diameter: 1.3, height: 1.2, tessellation: 3},scene);
roof.position = new BABYLON.Vector3(0.9,0.6,0);
roof.scaling = new BABYLON.Vector3(0.4,0.4,0.4);
roof.rotation = new BABYLON.Vector3(0,Math.PI / 2,Math.PI / 2);
const box = BABYLON.MeshBuilder.CreateBox("box", { size: 0.4 }, scene);
box.position = new BABYLON.Vector3(0.9, 0.24, 0);
box.scaling = new BABYLON.Vector3(0.95, 1.2, 0.95);
在线地址：https://yjmyzz.github.io/babylon_js_study/day03/03.html
样子是有了，但是光秃秃的，比较难看，可以给它贴上壁纸，先找二张壁纸图片：
//设置屋顶及屋身的贴图材质
const roofMat = new BABYLON.StandardMaterial("roofMat");
roofMat.diffuseTexture = new BABYLON.Texture("../assets/img/roof.jpg", scene);
const boxMat = new BABYLON.StandardMaterial("boxMat");
boxMat.diffuseTexture = new BABYLON.Texture("../assets/img/floor.png");
roof.material = roofMat;
box.material = boxMat;
在线地址： https://yjmyzz.github.io/babylon_js_study/day03/04.html
房子是有窗户的，再来看看如何解决窗户的问题，答案仍然是在贴图上做文章，比如将下面这张带窗户的贴纸，在整个屋身上贴一圈即可
象不象某些地方的形象工程，哈
尝试用这个新贴图试一下：
//对比，画1个方块，用cubehouse贴图
const box2 = BABYLON.MeshBuilder.CreateBox("box", { size: 0.4 }, scene);
box2.position = new BABYLON.Vector3(1, 0.24, 0);
box2.scaling = new BABYLON.Vector3(0.95, 1.2, 0.95);
const boxMat2 = new BABYLON.StandardMaterial("boxMat2");
boxMat2.diffuseTexture = new BABYLON.Texture("../assets/img/cubehouse.png");
box2.material = boxMat2;
在线地址：https://yjmyzz.github.io/babylon_js_study/day03/05.html
好象有哪里不对，这看上去，象个快递包裹^_~，让我们想一想：
一般情况下，不用看屋身的底部和顶部（注：底部是绿色的大地，顶部被屋顶挡住了），所以可以将这张贴图切为4份，分别贴在屋身的前后左右。从CreateBox的API文档知，有1个参数faceUV可以指定box每个面的贴图：
faceUV可以使用Vector4对象做为参数：
vector (lower left x, lower left y, upper right x, upper right y)
//屋身四面的贴图坐标
const faceUV = [];
faceUV[0] = new BABYLON.Vector4(0.5, 0.0, 0.75, 1.0); //后面
faceUV[1] = new BABYLON.Vector4(0.0, 0.0, 0.25, 1.0); //前面
faceUV[2] = new BABYLON.Vector4(0.25, 0, 0.5, 1.0); //右面
faceUV[3] = new BABYLON.Vector4(0.75, 0, 1.0, 1.0); //左面
...
const box2 = BABYLON.MeshBuilder.CreateBox("box", { size: 0.4,faceUV:faceUV }, scene);
...
在线地址：https://yjmyzz.github.io/babylon_js_study/day03/06.html
为了方便后面代码复用，我们把创建地面、屋顶、屋身 这些基本逻辑，封装一下：
//调整地面/屋顶/屋身的大小及位置
const adjust = (ground, roof, box) => {
const scaling = new BABYLON.Vector3(0.5, 0.5, 0.5);
ground.scaling = scaling;
roof.scaling = scaling;
box.scaling = scaling;
box.position.y = ground.position.y + 0.25;
roof.position.y = box.position.y + 0.4;
box.position.x = -1;
roof.position.x = box.position.x;
}
//创建地面
const buildGround = () => {
const groundMat = new BABYLON.StandardMaterial("groundMat");
groundMat.diffuseColor = new BABYLON.Color3(0, 1, 0);
const ground = BABYLON.MeshBuilder.CreateGround("ground", { width: 6, height: 3 });
ground.material = groundMat;
return ground;
}
//创建屋顶
const buildRoof = () => {
const roofMat = new BABYLON.StandardMaterial("roofMat");
roofMat.diffuseTexture = new BABYLON.Texture("../assets/img/roof.jpg");
const roof = BABYLON.MeshBuilder.CreateCylinder("roof", { diameter: 1.3, height: 1.2, tessellation: 3 });
roof.material = roofMat;
roof.scaling.x = 0.75;
roof.rotation.z = Math.PI / 2;
roof.position.y = 1.22;
return roof;
}
//创建屋身
const buildBox = () => {
const boxMat = new BABYLON.StandardMaterial("boxMat");
boxMat.diffuseTexture = new BABYLON.Texture("../assets/img/cubehouse.png")
const faceUV = [];
faceUV[0] = new BABYLON.Vector4(0.5, 0.0, 0.75, 1.0); //后面
faceUV[1] = new BABYLON.Vector4(0.0, 0.0, 0.25, 1.0); //前面
faceUV[2] = new BABYLON.Vector4(0.25, 0, 0.5, 1.0); //右面
faceUV[3] = new BABYLON.Vector4(0.75, 0, 1.0, 1.0); //左面
const box = BABYLON.MeshBuilder.CreateBox("box", { faceUV: faceUV, wrap: true });
box.material = boxMat;
box.position.y = 0.5;
return box;
}
//在这里添加自己的核心代码
const createScene = function () {
const scene = new BABYLON.Scene(engine);
const camera = new BABYLON.ArcRotateCamera("camera", -Math.PI / 2, Math.PI / 2.5, 3, new BABYLON.Vector3(0, 0, 0));
camera.attachControl(canvas, true);
const light = new BABYLON.HemisphericLight("light", new BABYLON.Vector3(0.5, 0.5, 0));
const ground = buildGround();
const roof = buildRoof();
const box = buildBox();
adjust(ground, roof, box);
return scene;
};
最后，再添加1种风格的房屋做为本篇收场：
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>A Basic House</title>
<style>
html,
body {
overflow: hidden;
width: 100%;
height: 100%;
margin: 0;
padding: 0;
}
#renderCanvas {
width: 50%;
height: 50%;
position: absolute;
top: 0;
left: 0;
right: 0;
bottom: 0;
margin: auto;
touch-action: none;
}
#canvasZone {
width: 100%;
height: 100%;
}
</style>
<!-- 导入babylon核心功能 -->
<script src="../js/babylon.js"></script>
<!-- 允许scene中导入model -->
<script src="../js/babylonjs.loaders.min.js"></script>
<!-- 允许使用触屏 -->
<script src="../js/pep.js"></script>
</head>
<body>
<canvas id="renderCanvas" touch-action="none"></canvas>
<script>
const canvas = document.getElementById("renderCanvas");
const engine = new BABYLON.Engine(canvas, true);
//调整地面/屋顶/屋身的大小及位置
const adjust = (ground, roof, box) => {
const scaling = new BABYLON.Vector3(0.5, 0.5, 0.5);
ground.scaling = scaling;
roof.scaling = scaling;
box.scaling = scaling;
box.position.y = ground.position.y + 0.25;
roof.position.y = box.position.y + 0.4;
box.position.x = -0.8;
roof.position.x = box.position.x;
}
//调整-联体别墅-地面/屋顶/屋身的大小及位置
const adjustSemiHouse = (ground, roof, box) => {
const scaling = new BABYLON.Vector3(0.5, 0.5, 0.5);
roof.scaling = scaling;
box.scaling = scaling;
box.position.y = ground.position.y + 0.25;
roof.position.y = box.position.y + 0.4;
box.position.x = 0.5;
roof.position.x = box.position.x;
}
//创建地面
const buildGround = () => {
const groundMat = new BABYLON.StandardMaterial("groundMat");
groundMat.diffuseColor = new BABYLON.Color3(0, 1, 0);
const ground = BABYLON.MeshBuilder.CreateGround("ground", { width: 6, height: 3 });
ground.material = groundMat;
return ground;
}
//创建屋顶
const buildRoof = () => {
const roofMat = new BABYLON.StandardMaterial("roofMat");
roofMat.diffuseTexture = new BABYLON.Texture("../assets/img/roof.jpg");
const roof = BABYLON.MeshBuilder.CreateCylinder("roof", { diameter: 1.3, height: 1.2, tessellation: 3 });
roof.material = roofMat;
roof.scaling.x = 0.75;
roof.rotation.z = Math.PI / 2;
roof.position.y = 1.22;
return roof;
}
//创建-联体别墅-屋顶
const buildSemiHouseRoof = () => {
const roof = BABYLON.MeshBuilder.CreateCylinder("roof", { diameter: 1.3, height: 2.2, tessellation: 3 });
roof.scaling.y = 0.75;
roof.rotation.z = Math.PI / 2;
roof.position.y = 1.22;
const roofMat = new BABYLON.StandardMaterial("roofMat");
roofMat.diffuseTexture = new BABYLON.Texture("../assets/img/roof.jpg");
roof.material = roofMat;
return roof;
}
//创建屋身
const buildBox = () => {
const boxMat = new BABYLON.StandardMaterial("boxMat");
boxMat.diffuseTexture = new BABYLON.Texture("../assets/img/cubehouse.png")
const faceUV = [];
faceUV[0] = new BABYLON.Vector4(0.5, 0.0, 0.75, 1.0); //后面
faceUV[1] = new BABYLON.Vector4(0.0, 0.0, 0.25, 1.0); //前面
faceUV[2] = new BABYLON.Vector4(0.25, 0, 0.5, 1.0); //右面
faceUV[3] = new BABYLON.Vector4(0.75, 0, 1.0, 1.0); //左面
const box = BABYLON.MeshBuilder.CreateBox("box", { faceUV: faceUV, wrap: true });
box.material = boxMat;
box.position.y = 0.5;
return box;
}
//创建-联体别墅-屋身
const buildSemiHouseBox = () => {
const boxMat = new BABYLON.StandardMaterial("boxMat");
boxMat.diffuseTexture = new BABYLON.Texture("../assets/img/semihouse.png")
const faceUV = [];
faceUV[0] = new BABYLON.Vector4(0.6, 0.0, 1.0, 1.0); //rear face
faceUV[1] = new BABYLON.Vector4(0.0, 0.0, 0.4, 1.0); //front face
faceUV[2] = new BABYLON.Vector4(0.4, 0, 0.6, 1.0); //right side
faceUV[3] = new BABYLON.Vector4(0.4, 0, 0.6, 1.0); //left side
const box = BABYLON.MeshBuilder.CreateBox("box", { width: 2, height: 1, faceUV: faceUV, wrap: true });
box.material = boxMat;
box.position.y = 0.5;
return box;
}
//在这里添加自己的核心代码
const createScene = function () {
const scene = new BABYLON.Scene(engine);
const camera = new BABYLON.ArcRotateCamera("camera", -Math.PI / 2, Math.PI / 2.5, 3, new BABYLON.Vector3(0, 0, 0));
camera.attachControl(canvas, true);
const light = new BABYLON.HemisphericLight("light", new BABYLON.Vector3(0.5, 0.5, 0));
const ground = buildGround();
const roof = buildRoof();
const box = buildBox();
adjust(ground, roof, box);
const roof2 = buildSemiHouseRoof();
const box2 = buildSemiHouseBox();
adjustSemiHouse(ground, roof2, box2);
return scene;
};
const scene = createScene();
engine.runRenderLoop(function () {
scene.render();
});
window.addEventListener("resize", function () {
engine.resize();
});
</script>
</body>
</html>
在线地址：https://yjmyzz.github.io/babylon_js_study/day03/07.html
参考文档：
https://doc.babylonjs.com/features/introductionToFeatures/chap2/variation
作者：菩提树下的杨过
出处：http://yjmyzz.cnblogs.com
本文版权归作者和博客园共有，欢迎转载，但未经作者同意必须保留此段声明，且在文章页面明显位置给出原文连接，否则保留追究法律责任的权利。
出处：http://yjmyzz.cnblogs.com
本文版权归作者和博客园共有，欢迎转载，但未经作者同意必须保留此段声明，且在文章页面明显位置给出原文连接，否则保留追究法律责任的权利。
