我一般是三人和三维图形的初学者。这主要是我的学习练习。
我试图展示具有金属外观的十二面体，但是大约一半的脸是黑色的并且没有反射。其他面孔看起来是正确的。
我知道有一个内置函数可以生成十二面体，也可以计算法线，但我想手动检查我的理解。
起初我认为顶点法线可能存在一些问题，但是使用VertexNormalsHelper，看起来法线都指向正确的方向。
任何人都可以告诉我哪里出错了？非常感谢！
代码：
<!DOCTYPE html>
<html lang="en">
<head>
<title>shiny dodecahedron</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 {
background:#000;
color:#fff;
padding:0;
margin:0;
font-weight: bold;
overflow:hidden;
}
a { color: #ffffff; }
#info {
position: absolute;
top: 0px; width: 100%;
color: #ffffff;
padding: 5px;
font-family:Monospace;
font-size:13px;
text-align:center;
}
#vt { display:none }
#vt, #vt a { color:orange; }
</style>
</head>
<body>
<div id="info">
<span id="description">Dodecahedron standard material demo.</span>
</div>
<script src="js/three.js"></script>
<script src="js/controls/OrbitControls.js"></script>
<script src="js/Detector.js"></script>
<script src="js/libs/stats.min.js"></script>
<script src='js/libs/dat.gui.min.js'></script>
<script>
if ( ! Detector.webgl ) Detector.addGetWebGLMessage();
var stats;
var camera, scene, renderer;
var settings = {
metalness: 1.0,
roughness: 0.4,
ambientIntensity: 0.2
};
var mesh, material;
var directionalLight, ambientLight;
var mouseX = 0;
var mouseY = 0;
var windowHalfX = window.innerWidth / 2;
var windowHalfY = window.innerHeight / 2;
var height = 500; // of camera frustum
var r = 0.0;
var GOLDEN_RATIO = (1 + Math.sqrt(5)) / 2;
var scaleFactor = 1/(1+GOLDEN_RATIO);
var explicitDodecahedronVertices = new Float32Array([
(2*Math.cos(2*0*Math.PI/5)), (2*Math.sin(2*0*Math.PI/5)), GOLDEN_RATIO+1, // 0
(2*Math.cos(2*1*Math.PI/5)), (2*Math.sin(2*1*Math.PI/5)), GOLDEN_RATIO+1, // 1
(2*Math.cos(2*2*Math.PI/5)), (2*Math.sin(2*2*Math.PI/5)), GOLDEN_RATIO+1, // 2
(2*Math.cos(2*3*Math.PI/5)), (2*Math.sin(2*3*Math.PI/5)), GOLDEN_RATIO+1, // 3
(2*Math.cos(2*4*Math.PI/5)), (2*Math.sin(2*4*Math.PI/5)), GOLDEN_RATIO+1, // 4
(2*GOLDEN_RATIO*Math.cos(2*0*Math.PI/5)), (2*GOLDEN_RATIO*Math.sin(2*0*Math.PI/5)), GOLDEN_RATIO-1, // 5
(2*GOLDEN_RATIO*Math.cos(2*1*Math.PI/5)), (2*GOLDEN_RATIO*Math.sin(2*1*Math.PI/5)), GOLDEN_RATIO-1, // 6
(2*GOLDEN_RATIO*Math.cos(2*2*Math.PI/5)), (2*GOLDEN_RATIO*Math.sin(2*2*Math.PI/5)), GOLDEN_RATIO-1, // 7
(2*GOLDEN_RATIO*Math.cos(2*3*Math.PI/5)), (2*GOLDEN_RATIO*Math.sin(2*3*Math.PI/5)), GOLDEN_RATIO-1, // 8
(2*GOLDEN_RATIO*Math.cos(2*4*Math.PI/5)), (2*GOLDEN_RATIO*Math.sin(2*4*Math.PI/5)), GOLDEN_RATIO-1, // 9
(-2*GOLDEN_RATIO*Math.cos(2*0*Math.PI/5)), (-2*GOLDEN_RATIO*Math.sin(2*0*Math.PI/5)), -(GOLDEN_RATIO-1), // 10
(-2*GOLDEN_RATIO*Math.cos(2*1*Math.PI/5)), (-2*GOLDEN_RATIO*Math.sin(2*1*Math.PI/5)), -(GOLDEN_RATIO-1), // 11
(-2*GOLDEN_RATIO*Math.cos(2*2*Math.PI/5)), (-2*GOLDEN_RATIO*Math.sin(2*2*Math.PI/5)), -(GOLDEN_RATIO-1), // 12
(-2*GOLDEN_RATIO*Math.cos(2*3*Math.PI/5)), (-2*GOLDEN_RATIO*Math.sin(2*3*Math.PI/5)), -(GOLDEN_RATIO-1), // 13
(-2*GOLDEN_RATIO*Math.cos(2*4*Math.PI/5)), (-2*GOLDEN_RATIO*Math.sin(2*4*Math.PI/5)), -(GOLDEN_RATIO-1), // 14
(-2*Math.cos(2*0*Math.PI/5)), (-2*Math.sin(2*0*Math.PI/5)), -(GOLDEN_RATIO+1), // 15
(-2*Math.cos(2*1*Math.PI/5)), (-2*Math.sin(2*1*Math.PI/5)), -(GOLDEN_RATIO+1), // 16
(-2*Math.cos(2*2*Math.PI/5)), (-2*Math.sin(2*2*Math.PI/5)), -(GOLDEN_RATIO+1), // 17
(-2*Math.cos(2*3*Math.PI/5)), (-2*Math.sin(2*3*Math.PI/5)), -(GOLDEN_RATIO+1), // 18
(-2*Math.cos(2*4*Math.PI/5)), (-2*Math.sin(2*4*Math.PI/5)), -(GOLDEN_RATIO+1), // 19
]);
var dodecahedronFaceIndexes = new Uint8Array([
// one of pair of opposite pentagons parallel to xy plane
// 0, 1, 2, 3, 4
1, 3, 0,
1, 2, 3,
0, 3, 4,
// 0, 4, 5, 9, 12
4, 12, 0,
12, 5, 0,
12, 4, 9,
// 3, 4, 8, 9, 11
3, 11, 4,
3, 8, 11,
4, 11, 9,
// 2, 3, 7, 8, 10
2, 10, 3,
2, 7, 10,
3, 10, 8,
// 1, 2, 6, 7, 14
1, 14, 2,
1, 6, 14,
2, 14, 7,
// 0, 1, 5, 6, 13
0, 13, 1,
0, 5, 13,
1, 13, 6,
// 15, 16, 17, 18, 19
15, 18, 16,
15, 19, 18,
16, 18, 17,
// 15, 19, 10, 14, 7
15, 7, 19,
15, 10, 7,
19, 7, 14,
// 18, 19, 13, 14, 6
19, 6, 18,
6, 13, 18,
6, 19, 14,
// 17, 18, 12, 13, 5
18, 5, 17,
5, 12, 17,
5, 18, 13,
// 16, 17, 11, 12, 9
17, 9, 16,
9, 11, 16,
9, 17, 12,
// 15, 16, 10, 11, 8
16, 8, 15,
8, 10, 15,
8, 16, 11
]);
var vertices;
var normals;
function ComputeVerticesNormals(){
localVertices = [];
localNormals = [];
for (var i = 0; i < dodecahedronFaceIndexes.length; i += 3)
{
var i1 = dodecahedronFaceIndexes[i] * 3;
var i2 = dodecahedronFaceIndexes[i + 1] * 3;
var i3 = dodecahedronFaceIndexes[i + 2] * 3;
// get the vertices for this triangular pentagon segement
var ax = explicitDodecahedronVertices[i1];
var ay = explicitDodecahedronVertices[i1 + 1];
var az = explicitDodecahedronVertices[i1 + 2];
var bx = explicitDodecahedronVertices[i2];
var by = explicitDodecahedronVertices[i2 + 1];
var bz = explicitDodecahedronVertices[i2 + 2];
var cx = explicitDodecahedronVertices[i3];
var cy = explicitDodecahedronVertices[i3 + 1];
var cz = explicitDodecahedronVertices[i3 + 2];
// calc normals
var ux = bx - ax;
var uy = by - ay;
var uz = bz - az;
var vx = bx - cx;
var vy = by - cy;
var vz = bz - cz;
var nx = (uz * vy) - (uy * vz);
var ny = (ux * vz) - (uz * vx);
var nz = (uy * vx) - (ux * vy);
// append vertices, normals to list
localVertices.push(ax, ay, az, bx, by, bz, cx, cy, cz);
localNormals.push(nx, ny, nz, nx, ny, nz, nx, ny, nz)
}
vertices = Float32Array.from(localVertices);
normals = Float32Array.from(localNormals);
}
init();
animate();
function init() {
var container = document.createElement( 'div' );
document.body.appendChild( container );
renderer = new THREE.WebGLRenderer();
renderer.setPixelRatio( window.devicePixelRatio );
renderer.setSize( window.innerWidth, window.innerHeight );
container.appendChild( renderer.domElement );
renderer.gammaInput = true;
renderer.gammaOutput = true;
//
scene = new THREE.Scene();
var aspect = window.innerWidth / window.innerHeight;
camera = new THREE.OrthographicCamera( - height * aspect, height * aspect, height, - height, 1, 10000 );
camera.position.z = 400;
scene.add( camera );
controls = new THREE.OrbitControls( camera, renderer.domElement );
controls.enableZoom = false;
controls.enableDamping = true;
// lights
ambientLight = new THREE.AmbientLight( 0xffffff, settings.ambientIntensity );
scene.add( ambientLight );
directionalLight = new THREE.DirectionalLight( 0xffffff, 0.5 );
directionalLight.position.set(-50*32,0,0);
scene.add( directionalLight );
var path = "https://threejs.org/examples/textures/cube/SwedishRoyalCastle/";
var format = '.jpg';
var urls = [
path + 'px' + format, path + 'nx' + format,
path + 'py' + format, path + 'ny' + format,
path + 'pz' + format, path + 'nz' + format
];
var loader = new THREE.CubeTextureLoader();
loader.setCrossOrigin( 'anonymous' );
var reflectionCube = loader.load( urls );
reflectionCube.format = THREE.RGBFormat;
scene.background = reflectionCube;
material = new THREE.MeshStandardMaterial( {
color: 0x888888,
roughness: settings.roughness,
metalness: settings.metalness,
side: THREE.FrontSide,
envMap: reflectionCube
} );
var geometry = new THREE.BufferGeometry();
ComputeVerticesNormals();
geometry.addAttribute( 'position', new THREE.BufferAttribute( vertices, 3 ) );
geometry.addAttribute( 'normal', new THREE.BufferAttribute( normals, 3 ) );
geometry.center();
mesh = new THREE.Mesh( geometry, material );
mesh.scale.multiplyScalar( 100 );
scene.add( mesh );
var vnh = new THREE.VertexNormalsHelper( mesh, 100, 0x00ff00, 1 );
scene.add (vnh);
stats = new Stats();
container.appendChild( stats.dom );
//
window.addEventListener( 'resize', onWindowResize, false );
}
function onWindowResize() {
var aspect = window.innerWidth / window.innerHeight;
camera.left = - height * aspect;
camera.right = height * aspect;
camera.top = height;
camera.bottom = - height;
camera.updateProjectionMatrix();
renderer.setSize( window.innerWidth, window.innerHeight );
}
//
function animate() {
requestAnimationFrame( animate );
controls.update();
stats.begin();
render();
stats.end();
}
function render() {
renderer.render( scene, camera );
}
</script>
</body>
</html>
答案 0 :(得分：0)
感谢WestLangley的评论，我意识到错误是我对THREE.OrbitControls的理解。我错误地认为相机是静止的，模型是旋转的，而实际上它是相反的 - 模型是静态的，相机在模型周围移动。