网格的光线投射硬面 -- Three.js

问题描述

我在three.js中创建了一个盒子

i created a box in three.js

var scene = new THREE.Scene();
var camera = new THREE.PerspectiveCamera( 100, window.innerWidth/window.innerHeight, 0.1, 1000 );
camera.position.set(5, 5, 10);

var geo = new THREE.BoxGeometry(5,2,5);

var mat = new THREE.MeshBasicMaterial({color:0xff0ff0, wireframe:false, vertexColors: THREE.FaceColors});

var mesh = new THREE.Mesh( geo, mat);
scene.add(mesh);

var renderer = new THREE.WebGLRenderer();
renderer.setSize( window.innerWidth, window.innerHeight );
document.body.appendChild( renderer.domElement );
renderer.render(scene, camera);

之后我想将光线投射到鼠标悬停的立方体面上.因此我创建了这个函数

After that i want to raycast to cubes faces which mouse over on.Thus i created this function

var raycaster = new THREE.Raycaster();
var mouse = new THREE.Vector2();

function onMouseMove( event ) {
    mouse.x = ( event.clientX / window.innerWidth ) * 2 - 1;
    mouse.y = - ( event.clientY / window.innerHeight ) * 2 + 1;

    raycaster.setFromCamera( mouse, camera );

    var intersects = raycaster.intersectObject( mesh);

    for ( var i = 0; i < intersects.length; i++ ) {
        intersects[ i ].face.color.setHex( 0xDDC2A3);
        mesh.geometry.colorsNeedUpdate = true;
    }

    renderer.render( scene, camera );
}

window.addEventListener( 'mousemove', onMouseMove, false );

它几乎工作正常.我的意思是，它会改变半边脸的颜色.你知道，由 BoxGeometry() 创建的网格有 12 个 Face3.我想要完整的脸或硬脸或Face4，由Face3+Face3.知道我怎么能做到这一点吗?

It nearly works correct. i mean, it changes color of the half of the face. You know, the mesh which created by BoxGeometry() has 12 Face3. I want the complete face or hard-face or Face4 which took shape by Face3+Face3. Any idea how i can accomplish this?

推荐答案

仅适用于现成的非缓冲区几何图形，例如 .. BoxGeometry、SphereGeometry、CircleGeometry 等...

Only works for ready-built, non-Buffer geometries like .. BoxGeometry, SphereGeometry, CircleGeometry etc...

var intersects = raycaster.intersectObject( mesh);

for ( var i = 0; i < intersects.length; i++ ) {

    var faceIndex = intersects[i].faceIndex;

    if(faceIndex == 0 || (faceIndex % 2) == 0) {
        intersects[i].object.geometry.faces[faceIndex].color.setHex( 0xD1B3B3);
        intersects[i].object.geometry.faces[faceIndex + 1].color.setHex( 0xD1B3B3);
        intersects[i].object.geometry.colorsNeedUpdate = true;

    }else {
        intersects[i].object.geometry.faces[faceIndex].color.setHex( 0xD1B3B3);
        intersects[i].object.geometry.faces[faceIndex - 1].color.setHex( 0xD1B3B3);
        intersects[i].object.geometry.colorsNeedUpdate = true;
    }

}

renderer.render(scene, camera);

这篇关于网格的光线投射硬面 -- Three.js的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！