我在看两个例子，一个是 Canvas 交互对象，另一个是鼠标工具提示。我尝试将两者结合起来在每个单独的立方体上生成文本标签，这就是我目前所拥有的。
但是，文本会随着旋转的立方体移动，并且有时会向后或向侧面显示文本。
我怎样才能像鼠标工具提示 ( http://stemkoski.github.io/Three.js/Mouse-Tooltip.html ) 示例中那样将文本固定在 Sprite 中？我试图合并 Sprite ，但我不断收到错误。我不知道该怎么做。你能解释一下我该如何去做吗？
谢谢。
到目前为止，这是我的代码:
<!DOCTYPE html>
<html lang="en">
<head>
<title>three.js canvas - interactive - cubes</title>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
<style>
body {
font-family: Monospace;
background-color: #f0f0f0;
margin: 0px;
overflow: hidden;
}
</style>
</head>
<body>
<script src="js/three.min.js"></script>
<script src="js/stats.min.js"></script>
<script>
var container, stats;
var camera, scene, projector, renderer;
var projector, mouse = { x: 0, y: 0 }, INTERSECTED;
var particleMaterial;
var currentLabel = null;
var objects = [];
init();
animate();
function init() {
container = document.createElement( 'div' );
document.body.appendChild( container );
var info = document.createElement( 'div' );
info.style.position = 'absolute';
info.style.top = '10px';
info.style.width = '100%';
info.style.textAlign = 'center';
info.innerHTML = '<a href="http://threejs.org" target="_blank">three.js</a> - clickable objects';
container.appendChild( info );
camera = new THREE.PerspectiveCamera( 70, window.innerWidth / window.innerHeight, 1, 10000 );
camera.position.set( 0, 300, 500 );
scene = new THREE.Scene();
var geometry = new THREE.CubeGeometry( 100, 100, 100 );
for ( var i = 0; i < 10; i ++ ) {
var object = new THREE.Mesh( geometry, new THREE.MeshBasicMaterial( { color: Math.random() * 0xffffff, opacity: 0.5 } ) );
object.position.x = Math.random() * 800 - 400;
object.position.y = Math.random() * 800 - 400;
object.position.z = Math.random() * 800 - 400;
object.scale.x = Math.random() * 2 + 1;
object.scale.y = Math.random() * 2 + 1;
object.scale.z = Math.random() * 2 + 1;
object.rotation.x = Math.random() * 2 * Math.PI;
object.rotation.y = Math.random() * 2 * Math.PI;
object.rotation.z = Math.random() * 2 * Math.PI;
object.label = "Object " + i;
scene.add( object );
objects.push( object );
}
var PI2 = Math.PI * 2;
particleMaterial = new THREE.ParticleCanvasMaterial( {
color: 0x000000,
program: function ( context ) {
context.beginPath();
context.arc( 0, 0, 1, 0, PI2, true );
context.closePath();
context.fill();
}
} );
projector = new THREE.Projector();
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( 'mousedown', onDocumentMouseDown, false );
//
window.addEventListener( 'resize', onWindowResize, false );
}
function onWindowResize() {
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
renderer.setSize( window.innerWidth, window.innerHeight );
}
function onDocumentMouseDown( event ) {
event.preventDefault();
var vector = new THREE.Vector3( ( event.clientX / window.innerWidth ) * 2 - 1, - ( event.clientY / window.innerHeight ) * 2 + 1, 0.5 );
projector.unprojectVector( vector, camera );
var raycaster = new THREE.Raycaster( camera.position, vector.sub( camera.position ).normalize() );
var intersects = raycaster.intersectObjects( objects );
if ( intersects.length > 0 ) {
if ( intersects[ 0 ].object != INTERSECTED )
{
// restore previous intersection object (if it exists) to its original color
if ( INTERSECTED ) {
INTERSECTED.material.color.setHex( INTERSECTED.currentHex ); }
// store reference to closest object as current intersection object
INTERSECTED = intersects[ 0 ].object;
// store color of closest object (for later restoration)
INTERSECTED.currentHex = INTERSECTED.material.color.getHex();
// set a new color for closest object
INTERSECTED.material.color.setHex( 0xffff00 );
var canvas1 = document.createElement('canvas');
var context1 = canvas1.getContext('2d');
context1.font = "Bold 40px Arial";
context1.fillStyle = "rgba(255,0,0,0.95)";
context1.fillText(INTERSECTED.label, 0, 50);
// canvas contents will be used for a texture
var texture1 = new THREE.Texture(canvas1)
texture1.needsUpdate = true;
var material1 = new THREE.MeshBasicMaterial( {map: texture1, side:THREE.DoubleSide } );
material1.transparent = true;
var mesh1 = new THREE.Mesh(
new THREE.PlaneGeometry(canvas1.width, canvas1.height),
material1
);
mesh1.position = intersects[0].point;
if (currentLabel)
scene.remove(currentLabel);
scene.add( mesh1 );
currentLabel = mesh1;
}
else // there are no intersections
{
// restore previous intersection object (if it exists) to its original color
if ( INTERSECTED ) {
console.log("hello");
INTERSECTED.material.color.setHex( INTERSECTED.currentHex );
}
// remove previous intersection object reference
// by setting current intersection object to "nothing"
INTERSECTED = null;
mesh1 = null;
mesh1.position = intersects[0].point;
scene.add( mesh1 );
}
//var particle = new THREE.Particle( particleMaterial );
//particle.position = intersects[ 0 ].point;
//particle.scale.x = particle.scale.y = 8;
//scene.add( particle );
}
/*
// Parse all the faces
for ( var i in intersects ) {
intersects[ i ].face.material[ 0 ].color.setHex( Math.random() * 0xffffff | 0x80000000 );
}
*/
}
//
function animate() {
requestAnimationFrame( animate );
render();
stats.update();
}
var radius = 600;
var theta = 0;
function render() {
theta += 0.1;
camera.position.x = radius * Math.sin( THREE.Math.degToRad( theta ) );
camera.position.y = radius * Math.sin( THREE.Math.degToRad( theta ) );
camera.position.z = radius * Math.cos( THREE.Math.degToRad( theta ) );
camera.lookAt( scene.position );
renderer.render( scene, camera );
}
</script>
</body>
最佳答案
广告牌很容易。在您的情况下，您所要做的就是将其添加到渲染循环中:
if ( currentLabel ) currentLabel.lookAt( camera.position );
关于javascript - 如何让我的文本标签始终面向相机？也许使用 Sprite ？，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/16001208/