three.js 全景重力感应

实现three.js 全景图 demo

使用three.js 写了球体和圆柱体版本的3D重力感应全景图，支持手指触摸和陀螺仪感应，也支持PC端的鼠标。给大家介绍一下基于移动端H5球体的实现方法，圆柱体类似。

---

设置容器和展示的样式

设置容器的宽高为全屏展示，清除body的margin,引用three.min.js（3D渲染框架） 和orienter.js (陀螺仪经纬度计算)

<div id="CanvasBody"></div>

<script src="js/three.min.js"></script>
<!--重力感应-->
<script src="js/orienter.js"></script>
<!--动画效果-->
<script src="js/tween.js"></script>
<!-- 代码 -->

body {margin: 0;}
html, body, #CanvasBody {width: 100vw;height: 100vh;overflow: hidden;}
#CanvasBody {position: relative;}

设置html的data-dpr 属性，设置html 的fontSize

设置html的fontSize,重新计算body的实际可展示尺寸，这样可以使渲染出来的画面更清晰，分辨率最完美。

(function(_window) {
    var navigatorUserAgent = navigator.userAgent;
    var iPhone = navigatorUserAgent.indexOf("iPhone");
    if (iPhone > -1) {
        var dpr = Number(window.devicePixelRatio),
                one_dpr = 1 / dpr
    } else {
        var dpr = 1,
            one_dpr = 1
    }
    var writeText = "<meta name=\"viewport\" content=\"width=device-width,initial-scale=" + one_dpr + ",maximum-scale=" + one_dpr + ",minimum-scale=" + one_dpr + ",user-scalable=no\">\n        <meta name=\"'flexible\" content=\"initial-dpr=" + dpr + "\">";
    document.write(writeText);
    var html = document.getElementsByTagName("html");
    var F0 = 75;
    html[0].setAttribute("data-dpr", dpr);
    var getFontSize = function getFontSize() {
        var windowWidth = window.innerWidth;
        html[0].style.fontSize = F0 * windowWidth / 750 + "px"
    };
    getFontSize();
   _window.addEventListener("resize", getFontSize, false)
})(window);

定义相关变量

var camera,//摄像机
            scene,//舞台
            renderer,//渲染器
            isUserInteracting = false,//用户是否正在操作
            onMouseDownMouseX = 0, onMouseDownMouseY = 0,//鼠标点击的x和Y坐标
            lon = 0, onMouseDownLon = 0, onPointerDownLon= 0.0,onPointerDownPointerX = 0,//经度
            lat = 0, onMouseDownLat = 0, onPointerDownLat= 0.0,onPointerDownPointerY = 0,//纬度
            phi = 0, theta = 0,//计算相机位置的重要参数
            o = new Orienter(),//陀螺仪方法对象
            new_longitude=0,last_longitude=0,move_longitude=0,//改变的经度的计算
            new_latitude=0,last_latitude=0,move_latitude=0,//改变的纬度的计算
            is_touch=false,is_start=false,isPlay=true,isMusicPlay=true,tsa=100.1,ppl='';

    var raycaster = new THREE.Raycaster();//拾取场景里面的物体,可判断点击或交互事件对应的元素
    var mouse = new THREE.Vector2();//二维向量的对象，鼠标计算

初始化舞台的元素和内容

图片的长宽控制在4096px以内，部分机型性能不够，渲染不了超大的图片

 function init() {/**初始化**/
        var container, mesh;//容器和素材
        container = document.getElementById( 'CanvasBody' );//容器
        camera = new THREE.PerspectiveCamera( 72, window.innerWidth / window.innerHeight, 0.01, 1100 );//相机
        camera.target = new THREE.Vector3( 0, 0, 0 );//相机位置

        scene = new THREE.Scene();//舞台
        scene.updateMatrixWorld(true);
        var geometry = new THREE.SphereGeometry(1, 32, 16);//球体

        geometry.scale( 1, 1, -1 );
        //设置球体的背景贴图
        var textureBg = new THREE.TextureLoader().load("img/bg.jpg");
        textureBg.generateMipmaps = true;
        textureBg.magFilter = THREE.LinearFilter;//设置贴纸素材的质量
        textureBg.minFilter = THREE.LinearFilter;
        var material = new THREE.MeshBasicMaterial( {
            map: textureBg,//圆柱体贴图，全景图
            //color:0xFF0000,
            //transparent: true
        } );
        mesh = new THREE.Mesh( geometry, material );
        //这里可以设置对应的动画效果
//        new TWEEN.Tween( mesh).to( {transform:"rotate(90deg)"}, 800 ).repeat( false ).delay( 300 ).yoyo( true ).easing( TWEEN.Easing.Cubic.InOut ).start();
        scene.add( mesh );

        // 旋转预设 摄影机看到的角度 Start//
        scene.rotation.set(0,0,0); //首頁

        //初始化渲染器，追加到容器
        renderer = new THREE.WebGLRenderer({precision: 'highp' ,mipmap: 'highp',antialias:false});//加上precision 和 mipmap参数，调整画面清晰度
        renderer.setPixelRatio( window.devicePixelRatio );//设置像素比
        renderer.setSize( window.innerWidth, window.innerHeight );//设置渲染窗口的大小
        container.appendChild( renderer.domElement );//追加到容器中去

        //鼠标、手机touch的各个事件
        document.addEventListener( 'mousedown', onDocumentMouseDown, false );
        document.addEventListener( 'mousemove', onDocumentMouseMove, false );
        document.addEventListener( 'mouseup', onDocumentMouseUp, false );

        document.addEventListener( 'touchstart', onDocumentTouchDown, false );
        document.addEventListener( 'touchmove', onDocumentTouchMove, false );
        document.addEventListener( 'touchend', onDocumentTouchUp, false );
        // document.addEventListener( 'wheel', onDocumentMouseWheel, false );
        //
        document.addEventListener( 'dragover', function ( event ) {
            event.preventDefault();
            event.dataTransfer.dropEffect = 'copy';
        }, false );
        document.addEventListener( 'dragenter', function ( event ) {
            document.body.style.opacity = 0.5;
        }, false );
        document.addEventListener( 'dragleave', function ( event ) {
            document.body.style.opacity = 1;
        }, false );
        document.addEventListener( 'drop', function ( event ) {
            event.preventDefault();
            var reader = new FileReader();
            reader.addEventListener( 'load', function ( event ) {
                material.map.image.src = event.target.result;
                material.map.needsUpdate = true;
            }, false );
            reader.readAsDataURL( event.dataTransfer.files[ 0 ] );
            document.body.style.opacity = 1;
        }, false );
    }

监听的各事件和方法

//监听横竖屏重新设置尺寸
    function onWindowResize() {
        camera.aspect = window.innerWidth / window.innerHeight;
        camera.updateProjectionMatrix();
        renderer.setSize( window.innerWidth, window.innerHeight );
    }
    function onDocumentMouseDown( event ) {
        event.preventDefault();
        isUserInteracting = true;
        onPointerDownPointerX = event.clientX;
        onPointerDownPointerY = event.clientY;
        onPointerDownLon = lon;
        onPointerDownLat = lat;

        // Click action
        mouse.x = ( event.clientX / renderer.domElement.clientWidth ) * 2 - 1;
        mouse.y = - ( event.clientY / renderer.domElement.clientHeight ) * 2 + 1;
        raycaster.setFromCamera( mouse, camera );
        var intersects = raycaster.intersectObjects( scene.children );//第一个是最上面一层的元素
        console.log("点击的元素",intersects);
        if ( intersects.length > 0 ) {//如果点到小圆点 就执行回调函数回调函数为goto_p
            try {
                intersects[0].object.callback();
            }
            catch(err) {}
        }
    }
    function onDocumentMouseMove( event ) {
        if ( isUserInteracting === true ) {
            lon = ( onPointerDownPointerX - event.clientX ) * 0.1 + onPointerDownLon;
            lat = ( event.clientY - onPointerDownPointerY ) * 0.1 + onPointerDownLat;
        }
    }
    function onDocumentMouseUp( event ) {
        isUserInteracting = false;
    }

    //  touch event start
    function onDocumentTouchDown( event ) {
        is_touch=true;

        event.preventDefault();
        isUserInteracting = true;
        onPointerDownPointerX = event.touches[ 0 ].clientX;
        onPointerDownPointerY = event.touches[ 0 ].clientY;
        if(is_start){
            onPointerDownLon = lon;
            onPointerDownLat = lat;
        }
        // For Click action

        mouse.x = ( onPointerDownPointerX / renderer.domElement.clientWidth ) * 2 - 1;
        mouse.y = - ( onPointerDownPointerY / renderer.domElement.clientHeight ) * 2 + 1;

        raycaster.setFromCamera( mouse, camera );
        var intersects = raycaster.intersectObjects( scene.children );
        console.log('touchDown',lon,lat);
        if ( intersects.length > 0 ) {
            try {
                intersects[0].object.callback();
            }
            catch(err) {}
        }
    }
    function onDocumentTouchMove( event ) {
        if(is_start){
            if ( isUserInteracting === true ) {

                lon = ( onPointerDownPointerX - event.touches[ 0 ].clientX ) * 0.1 + onPointerDownLon;
                lat = ( event.touches[ 0 ].clientY - onPointerDownPointerY ) * 0.1 + onPointerDownLat;
            }
        }
    }
    function onDocumentTouchUp( event ) {
        is_touch=false;
    }
    //  touch event end

    //  set
    function onDocumentTouchDown2( event ) {
        tsa = event.touches[0].clientY;
        console.log( '@:'+event.touches[0].clientY );
        event.preventDefault();

    }
    function onDocumentMouseWheel( event ) {
        camera.fov += event.deltaY * 0.05;
        camera.updateProjectionMatrix();
    }

动画播放和陀螺仪

function animate() {//播放动画
        if(isPlay){
            TWEEN.update();
            update();
            requestAnimationFrame( animate );
        }

    }
    o.onOrient = function (obj) {//重力感应计算角度
        if(is_start){
            //最新经度
            new_longitude = obj.lon;
            move_longitude=new_longitude-last_longitude;

            //最新纬度
            new_latitude = obj.lat;
            move_latitude = new_latitude-last_latitude;

            //判断经纬度
            if(move_longitude>=300){
                move_longitude=move_longitude-361;
            }else if(move_longitude<=-300){
                move_longitude=move_longitude+359;
            }


            if(move_latitude>=300){
                move_latitude=move_latitude-361;
            }else if(move_latitude<=-300){
                move_latitude=move_latitude+359;
            }

            if( is_touch ){
                move_longitude=0;
                move_latitude=0;
            }else{
                move_longitude=move_longitude*0.6;
                move_latitude=move_latitude*0.6;
            }
            //计算得出重力感应的经纬度
            lon=lon-move_longitude;
            last_longitude = obj.lon;
            lat = lat-move_latitude;
            last_latitude = obj.lat;
        }

    };

    function update() {//更新摄像机位置，旋转平移
        //lat = Math.max( -6, Math.min( 6, lat ) );//设置lat纬度的范围，只在一个范围内旋转
        phi = THREE.Math.degToRad( 90 - lat );
        theta = THREE.Math.degToRad( lon );
        camera.target.x =  500 * Math.sin( phi ) * Math.cos( theta );//X轴的坐标
        camera.target.y = 500 * Math.cos( phi );//y轴的坐标
        camera.target.z =  500 * Math.sin( phi ) * Math.sin( theta ) ;//z轴的坐标
        camera.lookAt( camera.target );
        renderer.render( scene, camera );//重新渲染
    }

执行所有

//执行所有
    is_start=true;
    init();
    o.init();
    animate();

综上，炫酷的3D重力感应H5就出来啦！