Question

我一直在努力解决球体上圈子几何上光线投射的问题。

我知道无法使用精灵进行光线投射，这就是我使用圆形几何体的原因，但它并不是一直有效，而且光线投射并不总是适用于圆圈但是有时在他们周围。

修改：我更新了以前版本的JSBin，您可以点击任何circleGeometries它将工作 here ，运行它只输出选项卡打开以获得更好的结果

这与渲染器宽度和高度属性有关，我的球体不是全屏，这就是它失败的原因。

有没有人知道如何正确设置才能让它完美运作？

Answer 1

用于计算交叉点的公式并不是好的，这是有效的公式：

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

鼠标x和y与您可以获得的示例略有不同，现在很好。

    var vector = new THREE.Vector3(mouse.x, mouse.y, 0.5);

    projector.unprojectVector(vector, camera);
    var ray = new THREE.Raycaster(camera.position, vector.sub(
            camera.position).normalize());

    var intersects = ray.intersectObjects(objects);

    if ( intersects.length > 0 ) {
    //do something
}

Answer 2

如果您正在寻找类似的东西......您的代码可能需要进行少量更改...请查看此链接http://jsfiddle.net/ebeit303/rjJ6q/

// standard global variables
var container, scene, camera, renderer, controls, stats;
var clock = new THREE.Clock();

// custom global variables
var targetList = [];
var projector, mouse = { x: 0, y: 0 };

init();
animate();

// FUNCTIONS        
function init() 
{

    // SCENE
    scene = new THREE.Scene();
    // CAMERA
    var SCREEN_WIDTH = window.innerWidth, SCREEN_HEIGHT = window.innerHeight;
    var VIEW_ANGLE = 45, ASPECT = SCREEN_WIDTH / SCREEN_HEIGHT, NEAR = 0.1, FAR = 100000;
    camera = new THREE.PerspectiveCamera( VIEW_ANGLE, ASPECT, NEAR, FAR);
    scene.add(camera);
    camera.position.set(600,0,-1200);
    camera.lookAt(scene.position);  
    // RENDERER

        renderer = new THREE.CanvasRenderer(); 
    renderer.setSize(SCREEN_WIDTH, SCREEN_HEIGHT);
    container = document.getElementById( 'ThreeJS' );
    container.appendChild( renderer.domElement );
    // EVENTS

    // CONTROLS 

    // this material causes a mesh to use colors assigned to faces
    var faceColorMaterial = new THREE.MeshBasicMaterial( 
    { color: 0xffffff, vertexColors: THREE.FaceColors } );

    var sphereGeometry = new THREE.SphereGeometry( 500, 64, 64 );
    for ( var i = 0; i < sphereGeometry.faces.length; i++ ) 
    {
        face = sphereGeometry.faces[ i ];   
        face.color.setRGB( 0, 0, 0.8 * Math.random() + 0.2 );       
    }
    var sphere = new THREE.Mesh( sphereGeometry, faceColorMaterial );
    sphere.rotation.set(0, 14.5, 0);
    scene.add(sphere);

    //targetList.push(sphere);

    var j=0;

    for (var i =0; i<100;i+=5){
    //var circle = new THREE.CubeGeometry(5,5,5);
    var circle = new THREE.CircleGeometry(5, 8, 0, Math.PI * 2);
    //THREE.GeometryUtils.triangulateQuads(circle);
    var circleMaterial = new THREE.MeshBasicMaterial({color: 0xDEF2EF});
    circleMaterial.side = THREE.DoubleSide;

    var mesh = new THREE.Mesh(circle, circleMaterial);

    var Alon = i - 90;
    var Alat = j;

    var Aphi = Math.PI/2 - Alat * Math.PI / 180;
    var Atheta = 2 * Math.PI - Alon * Math.PI / 180;

    mesh.position.x = Math.sin(Aphi) * Math.cos(Atheta) * (501);
    mesh.position.y = Math.cos(Aphi) * (501);
    mesh.position.z = Math.sin(Aphi) * Math.sin(Atheta) * (501);    
    mesh.verticesNeedUpdate = true;
    mesh.lookAt( sphere.position );

    sphere.add(mesh);
    targetList.push(mesh);

    j++;
    }


    // initialize object to perform world/screen calculations
    projector = new THREE.Projector();

    // when the mouse moves, call the given function
    document.addEventListener( 'mousedown', onDocumentMouseDown, false );

}

function onDocumentMouseDown( event ) 
{


    // update the mouse variable
    mouse.x = ( event.clientX / window.innerWidth ) * 2 - 1;
    mouse.y = - ( event.clientY / window.innerHeight ) * 2 + 1;

    var vector = new THREE.Vector3( mouse.x, mouse.y, 1 );
    projector.unprojectVector( vector, camera );
    var ray = new THREE.Raycaster( camera.position, vector.sub( camera.position ).normalize() );

    var intersects = ray.intersectObjects( targetList );

    if ( intersects.length > 0 )
    {       

        intersects[ 0 ].object.material.color.setRGB( 0.8 * Math.random() + 0.2,
                                                     0.8 * Math.random() + 0.2,
                                                     0.8 * Math.random() + 0.2 );
    }

}


function animate() 
{

    requestAnimationFrame( animate );
    render();       
}


function render() 
{
    renderer.render( scene, camera );
}

在Three.js中的光线投射和容器

2 个答案: