THREE.JS 场景世界坐标和平面二维坐标互转

allenjiao

3104人浏览 · 2018-09-19 14:42:09

allenjiao · 2018-09-19 14:42:09 发布

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>场景世界坐标转</title>
<style type="text/css">
html, body {
margin: 0;
height: 100%;
}

canvas {
display: block;
}

.title{
position: absolute;
padding: 10px;
background: rgba(255, 255, 255, 0.5);
line-height: 1;
border-radius: 5px;
}

</style>
</head>

<body οnlοad="draw();">

<div class="title one">第一个盒子</div>
<div class="title two">第二个盒子</div>
<div class="title three">第三个盒子</div>

</body>

<script src="https://cdn.bootcss.com/three.js/91/three.min.js"></script>
<script src="https://cdn.bootcss.com/jquery/3.3.1/jquery.min.js"></script>
<script src="/lib/js/controls/OrbitControls.js"></script>
<script src="/lib/js/libs/stats.min.js"></script>
<script src="https://cdn.bootcss.com/dat-gui/0.7.1/dat.gui.min.js"></script>
<script src="/lib/js/Detector.js"></script>

<script>
var renderer, camera, scene, gui, light, stats, controls;
var cube, cube2, cube3;

function initRender() {
renderer = new THREE.WebGLRenderer({antialias: true});
renderer.setPixelRatio(window.devicePixelRatio);
renderer.setSize(window.innerWidth, window.innerHeight);
renderer.setClearColor(0xeeeeee);
renderer.shadowMap.enabled = true;
//告诉渲染器需要阴影效果
document.body.appendChild(renderer.domElement);
}

function initCamera() {
camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 1000);
camera.position.set(0, 0, 15 );
}

function initScene() {
//给场景添加天空盒子纹理
var cubeTextureLoader = new THREE.CubeTextureLoader();
cubeTextureLoader.setPath( '/lib/textures/cube/space/' );
//六张图片分别是朝前的（posz）、朝后的（negz）、朝上的（posy）、朝下的（negy）、朝右的（posx）和朝左的（negx）。
var cubeTexture = cubeTextureLoader.load( [
'right.jpg', 'left.jpg',
'top.jpg', 'bottom.jpg',
'front.jpg', 'back.jpg'
] );

scene = new THREE.Scene();

scene.background = cubeTexture;
}

//初始化dat.GUI简化试验流程
function initGui() {
//声明一个保存需求修改的相关数据的对象
gui = {
};
var datGui = new dat.GUI();
//将设置属性添加到gui当中，gui.add(对象，属性，最小值，最大值）
}

function initLight() {
scene.add(new THREE.AmbientLight(0x444444));

light = new THREE.DirectionalLight(0xffffff);
light.position.set(0, 20, 20 );

light.castShadow = true;
light.shadow.camera.top = 10;
light.shadow.camera.bottom = -10;
light.shadow.camera.left = -10;
light.shadow.camera.right = 10;

//告诉平行光需要开启阴影投射
light.castShadow = true;

scene.add(light);
}

function initModel() {

//辅助工具
var helper = new THREE.AxesHelper(50);
scene.add(helper);

var material = new THREE.MeshStandardMaterial({color:0x00ffff});

//添加立方体
var geometry = new THREE.BoxBufferGeometry( 1, 1, 1 );

//添加第一个
cube = new THREE.Mesh(geometry, material);
scene.add(cube);

//添加第二个
cube2 = new THREE.Mesh(geometry, material);
cube2.position.set(3, 3, -2);
scene.add(cube2);

//添加第三个
cube3 = new THREE.Mesh(geometry, material);
cube3.position.set(-3, 3, 2);
scene.add(cube3);

}

//初始化性能插件
function initStats() {
stats = new Stats();
document.body.appendChild(stats.dom);
}

function initControls() {

controls = new THREE.OrbitControls(camera, renderer.domElement);
//设置控制器的中心点
//controls.target.set( 0, 5, 0 );
// 如果使用animate方法时，将此函数删除
//controls.addEventListener( 'change', render );
// 使动画循环使用时阻尼或自转意思是否有惯性
controls.enableDamping = true;
//动态阻尼系数就是鼠标拖拽旋转灵敏度
//controls.dampingFactor = 0.25;
//是否可以缩放
controls.enableZoom = true;
//是否自动旋转
controls.autoRotate = false;
controls.autoRotateSpeed = 0.5;
//设置相机距离原点的最远距离
controls.minDistance = 1;
//设置相机距离原点的最远距离
controls.maxDistance = 2000;
//是否开启右键拖拽
controls.enablePan = true;
}

//每帧额外的运算
function render() {
//获取到窗口的一半高度和一半宽度
let halfWidth = window.innerWidth / 2;
let halfHeight = window.innerHeight / 2;

let vector1 = cube.position.clone().project(camera);
let vector2 = cube2.position.clone().project(camera);
let vector3 = cube3.position.clone().project(camera);

//修改第一个的div的位置
$(".one").css({
left:vector1.x * halfWidth + halfWidth,
top:-vector1.y * halfHeight + halfHeight
});

$(".two").css({
left:vector2.x * halfWidth + halfWidth,
top:-vector2.y * halfHeight + halfHeight
});

$(".three").css({
left:vector3.x * halfWidth + halfWidth,
top:-vector3.y * halfHeight + halfHeight
});

}

//窗口变动触发的函数
function onWindowResize() {

camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
renderer.setSize(window.innerWidth, window.innerHeight);

}

function animate() {
//每帧额外的运算
render();

//更新性能插件
stats.update();

controls.update();

renderer.render(scene, camera);

requestAnimationFrame(animate);
}

function draw() {
//兼容性判断
if (!Detector.webgl) Detector.addGetWebGLMessage();
initGui();
initRender();
initScene();
initCamera();
initLight();
initModel();
initControls();
initStats();

animate();
window.onresize = onWindowResize;
}

</script>
</html>