Three.js-在3D球體周圍應用紋理（2D png圖像）顯示為黑色

Question

我正在使用THREE.js在瀏覽器中顯示3d旋轉的地球。 我還希望圖像出現在旋轉的地球周圍。

我嘗試了幾種方法，但它們根本沒有用。 我使用了圖像加載器，但什么也沒顯示。

var img = new THREE.ImageLoader();
img.load("texture/circle.png");

我基本上想要這樣的東西， http://imgur.com/AV28hq6

地球運行良好，我只需要在它上面有圓形圖像即可，如圖所示。

這是我的腳本標簽，

<script>

    var container, stats, raycaster;
    var camera, scene, renderer;
    var group;
    var mouseX = 0, mouseY = 0;

    var windowHalfX = window.innerWidth / 2;
    var windowHalfY = window.innerHeight / 2;

    init();
    animate();

    function init() {

    container = document.getElementById( 'container' );

    camera = new THREE.PerspectiveCamera( 60, window.innerWidth / window.innerHeight, 1, 2000 );
    camera.position.z = 500;

    scene = new THREE.Scene();

    group = new THREE.Object3D();
    scene.add( group );

    // earth



    var loader = new THREE.TextureLoader();
    loader.load( 'textures/1.jpg', function ( texture ) {

    var geometry = new THREE.SphereGeometry( 200, 20, 20 );

    var material = new THREE.MeshBasicMaterial( { map: texture, overdraw: true } );
    var mesh = new THREE.Mesh( geometry, material );
    group.add( mesh );
    raycaster = new THREE.Raycaster();


    } );


    // shadow

    var canvas = document.createElement( 'canvas' );
    canvas.width = 128;
    canvas.height = 128;

    var context = canvas.getContext( '2d' );
    var gradient = context.createRadialGradient(
    canvas.width / 2,
    canvas.height / 2,
    0,
    canvas.width / 2,
    canvas.height / 2,
    canvas.width / 2
    );
    //gradient.addColorStop( 0.1, 'rgba(210,210,210,1)' );
    //gradient.addColorStop( 1, 'rgba(255,255,255,1)' );

    context.fillStyle = gradient;
    context.fillRect( 0, 0, canvas.width, canvas.height );

    var texture = new THREE.Texture( canvas );
    texture.needsUpdate = true;

    var geometry = new THREE.PlaneGeometry( 300, 300, 3, 3 );
    var material = new THREE.MeshBasicMaterial( { map: texture, overdraw: true } );

    var mesh = new THREE.Mesh( geometry, material );
    mesh.position.y = - 250;
    //mesh.rotation.x = - Math.PI / 2;
    group.add( mesh );

    renderer = new THREE.CanvasRenderer();
    renderer.setSize( window.innerWidth, window.innerHeight );

    container.appendChild( renderer.domElement );

    stats = new Stats();
    stats.domElement.style.position = 'absolute';
    stats.domElement.style.top = '0px';
    container.appendChild( stats.domElement       );

    document.addEventListener( 'mousemove', onDocumentMouseMove, false );

    //

    window.addEventListener( 'resize', onWindowResize, false );

    }

    function onWindowResize() {

    windowHalfX = window.innerWidth / 2;
    windowHalfY = window.innerHeight / 2;

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

    renderer.setSize( window.innerWidth, window.innerHeight );

    }

    function onDocumentMouseMove( event ) {

    mouseX = ( event.clientX - windowHalfX );
    mouseY = ( event.clientY - windowHalfY );

    }



    function animate() {

    requestAnimationFrame( animate );

    render();
    stats.update();

    }

    function render() {

    //camera.position.x += ( mouseX - camera.position.x ) * 0.05;
    //camera.position.y += ( - mouseY - camera.position.y ) * 0.05;
    camera.lookAt( scene.position );

    group.rotation.y -= 0.001;







    renderer.render( scene, camera );

    }


    </script>

Answer 1

如果您正在尋找這樣的東西。...您的代碼可能需要更改...請檢查此鏈接。.http://jsfiddle.net/MP6BF/

var container, stats, raycaster;
var camera, scene, renderer;
var group;
var mouseX = 0, mouseY = 0;

var windowHalfX = window.innerWidth / 2;
var windowHalfY = window.innerHeight / 2;

init();
animate();

function init() {

container = document.createElement('div');
document.body.appendChild(container);

camera = new THREE.PerspectiveCamera( 60, window.innerWidth / window.innerHeight, 1, 2000 );
camera.position.z = 500;

scene = new THREE.Scene();

group = new THREE.Object3D();
scene.add( group );

// earth



var loader = new THREE.TextureLoader();
//loader.load( 'http://i.imgur.com/AV28hq6.jpg', function ( texture ) {
    loader.load('http://www.joshcarllewis.com/static/articles/html5-3d-canvas-tutorial/earth.jpg',function(texture){
var geometry = new THREE.SphereGeometry( 200, 25, 200 );

var material = new THREE.MeshBasicMaterial( { map: texture, overdraw: true } );
var mesh = new THREE.Mesh( geometry, material );
group.add( mesh );
raycaster = new THREE.Raycaster();


} );
    loader.load( 'http://i.imgur.com/AV28hq6.jpg', function ( texture ) {
var geometry = new THREE.PlaneGeometry( 600, 575, 30, 30 );
var material = new THREE.MeshBasicMaterial( { map: texture, overdraw: true } );

var mesh = new THREE.Mesh( geometry, material );
mesh.position.z =  100;
//mesh.rotation.x = - Math.PI / 2;
scene.add( mesh );
    });


// shadow

var canvas = document.createElement( 'canvas' );
canvas.width = 128;
canvas.height = 128;

var context = canvas.getContext( '2d' );
var gradient = context.createRadialGradient(
canvas.width / 2,
canvas.height / 2,
0,
canvas.width / 2,
canvas.height / 2,
canvas.width / 2
);
//gradient.addColorStop( 0.1, 'rgba(210,210,210,1)' );
//gradient.addColorStop( 1, 'rgba(255,255,255,1)' );

context.fillStyle = gradient;
context.fillRect( 0, 0, canvas.width, canvas.height );

var texture = new THREE.Texture( canvas );
texture.needsUpdate = true;

var geometry = new THREE.PlaneGeometry( 300, 300, 3, 3 );
var material = new THREE.MeshBasicMaterial( { map: texture, overdraw: true } );

var mesh = new THREE.Mesh( geometry, material );
mesh.position.y = - 250;
//mesh.rotation.x = - Math.PI / 2;
scene.add( mesh );

renderer = new THREE.CanvasRenderer();
renderer.setSize( window.innerWidth, window.innerHeight );

container.appendChild( renderer.domElement );


document.addEventListener( 'mousemove', onDocumentMouseMove, false );

//

window.addEventListener( 'resize', onWindowResize, false );

}

function onWindowResize() {

windowHalfX = window.innerWidth / 2;
windowHalfY = window.innerHeight / 2;

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

renderer.setSize( window.innerWidth, window.innerHeight );

}

function onDocumentMouseMove( event ) {

mouseX = ( event.clientX - windowHalfX );
mouseY = ( event.clientY - windowHalfY );

}



function animate() {

requestAnimationFrame( animate );

render();

}

function render() {

//camera.position.x += ( mouseX - camera.position.x ) * 0.05;
//camera.position.y += ( - mouseY - camera.position.y ) * 0.05;
camera.lookAt( scene.position );

group.rotation.y -= 0.001;







renderer.render( scene, camera );

}

Answer 2

可能是您忘了添加光嗎？

/ add subtle ambient lighting
var ambientLight = new THREE.AmbientLight(0x555555);
scene.add(ambientLight);

// add directional light source
var directionalLight = new THREE.DirectionalLight(0xffffff);
directionalLight.position.set(1, 1, 1).normalize();
scene.add(directionalLight);

希望能幫助到你！