我目前正在使用 PointCloud 生成粒子系统,但在其中我希望有一个 Sprite 漂浮在我的指示位置。当我尝试使用这个 Three.js 示例时:http://threejs.org/examples/#webgl_sprites我发现正交相机限制了我仍然缩放的能力。
var container, stats;
var camera, scene, renderer, particles, geometry, materials =[], i, h, color, sprite, size;
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( 55, window.innerWidth / window.innerHeight, 2, 2000 );
camera.position.z = 1000;
scene = new THREE.Scene();
scene.fog = new THREE.FogExp2( 0x000000, 0.001 );
geometry = new THREE.Geometry();
sprite = THREE.ImageUtils.loadTexture( "disc.png" );
for ( i = 0; i < 5000; i ++ ) {
var vertex = new THREE.Vector3();
vertex.x = 2000 * Math.random() - 1000;
vertex.y = 2000 * Math.random() - 1000;
vertex.z = 2000 * Math.random() - 1000;
geometry.vertices.push( vertex );
}
// size = Math.random() * 10;
material = new THREE.PointCloudMaterial( { size: 5, sizeAttenuation: false, map: sprite, alphaTest: 0.5, transparent: true } );
particles = new THREE.PointCloud( geometry, material );
scene.add( particles );
var map2 = THREE.ImageUtils.loadTexture( "astronaut.png" );
var material2 = new THREE.SpriteMaterial( { map: map2, color: 0xffffff, fog: true } );
var sprite2 = new THREE.Sprite( material2 );
sprite2.position.x = 0;
sprite2.position.y = 0;
sprite2.position.z = 498;
scene.add( sprite2 );
//
renderer = new THREE.WebGLRenderer();
renderer.setPixelRatio( window.devicePixelRatio );
renderer.setSize( window.innerWidth, window.innerHeight );
container.appendChild( renderer.domElement );
//
document.addEventListener( 'mousemove', onDocumentMouseMove, false );
document.addEventListener( 'touchstart', onDocumentTouchStart, false );
document.addEventListener( 'touchmove', onDocumentTouchMove, 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 onDocumentTouchStart( event ) {
if ( event.touches.length == 1 ) {
event.preventDefault();
mouseX = event.touches[ 0 ].pageX - windowHalfX;
mouseY = event.touches[ 0 ].pageY - windowHalfY;
}
}
function onDocumentTouchMove( event ) {
if ( event.touches.length == 1 ) {
event.preventDefault();
mouseX = event.touches[ 0 ].pageX - windowHalfX;
mouseY = event.touches[ 0 ].pageY - windowHalfY;
}
}
//
function animate() {
requestAnimationFrame( animate );
render();
}
function render() {
var time = Date.now() * 0.00005;
camera.position.x += ( mouseX - camera.position.x ) * 0.05;
camera.position.y += ( - mouseY - camera.position.y ) * 0.05;
camera.lookAt( scene.position );
h = ( 360 * ( 1.0 + time ) % 360 ) / 360;
renderer.render( scene, camera );
}
我尝试解决这个问题是:
var map2 = THREE.ImageUtils.loadTexture( "astronaut.png" );
var material2 = new THREE.SpriteMaterial( { map: map2, color: 0xffffff, fog: true } );
var sprite2 = new THREE.Sprite( material2 );
sprite2.position.x = 0;
sprite2.position.y = 0;
sprite2.position.z = 498;
scene.add( sprite2 );
现在,当我第一次加载时, Sprite 位于屏幕中央,但当我开始移动相机时, Sprite 立即消失。理想情况下,我希望 astronaut.png Sprite 与其他粒子一起移动,但如果这很困难,让他始终固定在屏幕中心也可以很好地工作。
最佳答案
我自己解决了这个问题。我创建了第二个 THREE.Geometry 和 THREE.Vector3,并用顶点定位它。
geometry2 = new THREE.Geometry();
var vertex2 = new THREE.Vector3(0, 0, -50);
geometry2.vertices.push( vertex2 );
var material2 = new THREE.PointCloudMaterial( { size: 100, sizeAttenuation: false, map: map2, alphaTest: 0.5, transparent: true } );
particles2 = new THREE.PointCloud( geometry2, material2 );
scene.add( particles2 );
关于javascript - 如何在 Three.js 中定位 Sprite ?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/31257006/