Question

当页面上只有一个目标div（包含renderer.domElement）时，我的Three.js脚本运行正常。只要我在目标div上方添加另一个固定高度和宽度的div，ray.intersectObjects就会返回null。我怀疑我为光线创建的矢量是否会导致问题。这是代码。

var vector = new THREE.Vector3( ( event.clientX / divWidth ) * 2 - 1, -( event.clientY / divHeight ) * 2 + 1, 0.5 );

projector.unprojectVector( vector, camera );

var ray = new THREE.Ray( camera.position, vector.subSelf( camera.position ).normalize() );

var intersects = ray.intersectObjects( myObjects, true );

关于如何解决这个问题的任何想法。

编辑：现在是THREE.Raycaster（three.js r.56）

Answer 1

简短的回答是你必须考虑画布的offset。

答案很长，取决于代码的编写方式，所以我会给你两个答案，这些答案应该涵盖基础。

有很多可能的组合，所以你可能需要进行实验。此外，不同的浏览器可能采取不同的行动。

假设你的HTML是这样的：

#canvas {
    width: 200px;
    height: 200px;
    margin: 100px;
    padding: 0px;
    position: static; /* fixed or static */
    top: 100px;
    left: 100px;
}

<body>
    <div id="canvas">
</body>

你的JS是这样的：

var CANVAS_WIDTH = 200,
CANVAS_HEIGHT = 200;

var container = document.getElementById( 'canvas' );
document.body.appendChild( container );

renderer = new THREE.WebGLRenderer();
renderer.setSize( CANVAS_WIDTH, CANVAS_HEIGHT );
container.appendChild( renderer.domElement );

方法1 要使以下方法正常工作，请设置画布位置 static ;保证金＆gt; 0和填充＆gt; 0可以

mouse.x = ( ( event.clientX - renderer.domElement.offsetLeft ) / renderer.domElement.clientWidth ) * 2 - 1;
mouse.y = - ( ( event.clientY - renderer.domElement.offsetTop ) / renderer.domElement.clientHeight ) * 2 + 1;

方法2 对于此备用方法，请设置画布位置 fixed ;设置顶部＆gt; 0，左设置＆gt; 0;填充必须为0;保证金＆gt; 0可以

mouse.x = ( ( event.clientX - container.offsetLeft ) / container.clientWidth ) * 2 - 1;
mouse.y = - ( ( event.clientY - container.offsetTop ) / container.clientHeight ) * 2 + 1;

如果你想试验，这是一个小提琴：http://jsfiddle.net/cn7ecoaa/

编辑：小提琴更新为three.js r.84

Answer 2

enent.clientX 是客户端窗口偏移量，因此要计算鼠标位置，我们还必须使用renderer元素客户端窗口偏移量。使用element.getBoundingClientRect（）来获取元素rect偏移窗口。

var rect = renderer.domElement.getBoundingClientRect();
mouse.x = ( ( event.clientX - rect.left ) / ( rect.width - rect.left ) ) * 2 - 1;
mouse.y = - ( ( event.clientY - rect.top ) / ( rect.bottom - rect.top) ) * 2 + 1;

＆＃13;

<html>
<head>
<script src="http://threejs.org/build/three.min.js"></script>

    <link rel="stylesheet" href="http://libs.baidu.com/bootstrap/3.0.3/css/bootstrap.min.css" />


<style>
body {
    font-family: Monospace;
    background-color: #fff;
    margin: 0px;
    overflow: hidden;
}

#canvas {
    background-color: #000;
    width: 200px;
    height: 200px;
    border: 1px solid black;
    margin: 10px;
    padding: 0px;
    top: 10px;
    left: 100px;
}

.border {
    padding:10px; 
    margin:10px;
}

</style>
</head>
<body>
<div class="border">
	<div class="border">
		<div id="canvas"></div>
	</div>
</div>
<script>
// Three.js ray.intersects with offset canvas

var container, camera, scene, renderer, mesh,

    objects = [],
    
    count = 0,

    CANVAS_WIDTH = 200,
    CANVAS_HEIGHT = 200;

// info
info = document.createElement( 'div' );
info.style.position = 'absolute';
info.style.top = '30px';
info.style.width = '100%';
info.style.textAlign = 'center';
info.style.color = '#f00';
info.style.backgroundColor = 'transparent';
info.style.zIndex = '1';
info.style.fontFamily = 'Monospace';
info.innerHTML = 'INTERSECT Count: ' + count;
info.style.userSelect = "none";
info.style.webkitUserSelect = "none";
info.style.MozUserSelect = "none";
document.body.appendChild( info );

container = document.getElementById( 'canvas' );

renderer = new THREE.WebGLRenderer();
renderer.setSize( CANVAS_WIDTH, CANVAS_HEIGHT );
container.appendChild( renderer.domElement );

scene = new THREE.Scene();

camera = new THREE.PerspectiveCamera( 45, CANVAS_WIDTH / CANVAS_HEIGHT, 1, 1000 );
camera.position.y = 250;
camera.position.z = 500;
camera.lookAt( scene.position );
scene.add( camera );

scene.add( new THREE.AmbientLight( 0x222222 ) );

var light = new THREE.PointLight( 0xffffff, 1 );
camera.add( light );

mesh = new THREE.Mesh( 
	new THREE.BoxGeometry( 200, 200, 200, 1, 1, 1 ), 
	new THREE.MeshPhongMaterial( { color : 0x0080ff } 
) );
scene.add( mesh );
objects.push( mesh );

// find intersections
var raycaster = new THREE.Raycaster();
var mouse = new THREE.Vector2();

// mouse listener
document.addEventListener( 'mousedown', function( event ) {
    
 var rect = renderer.domElement.getBoundingClientRect();
mouse.x = ( ( event.clientX - rect.left ) / ( rect.width - rect.left ) ) * 2 - 1;
mouse.y = - ( ( event.clientY - rect.top ) / ( rect.bottom - rect.top) ) * 2 + 1;
  
	raycaster.setFromCamera( mouse, camera );

    intersects = raycaster.intersectObjects( objects );

    if ( intersects.length > 0 ) {
        
        info.innerHTML = 'INTERSECT Count: ' + ++count;
        
    }

}, false );

function render() {

    mesh.rotation.y += 0.01;
    
    renderer.render( scene, camera );

}

(function animate() {

    requestAnimationFrame( animate );

    render();

})();

</script>
</body>
</html>

＆＃13;

Answer 3

WestLangley，非常感谢你的解释。它像往常一样非常有用。

在我的情况下，我把我的图表放在div中，所以我必须这样做：

    var offset = $('.rightBlock').offset();


    mouse.x = ( ( event.clientX - offset.left ) / renderer.domElement.width ) * 2 - 1;
    mouse.y = - ( ( event.clientY - offset.top ) / renderer.domElement.height ) * 2 + 1;

其中rightBlock是我的容器，只占屏幕的70％。

你激励我并帮助我解决这个有问题的问题！非常感谢。

通过添加div，THREE.js Ray Intersect失败

3 个答案: