案例查看地址：http://www.wjceo.com/blog/threejs/2018-05-03/155.html
简介
凹凸贴图用于为材质增加厚度。我们用到的凹凸贴图是一张灰度图，当然你也可以使用彩色图。像素的密集程度定义的是凹凸的高度，但是凹凸图只包含像素的相对高度，没有任何倾斜的方向信息。所以使用凹凸贴图所能表达的深度信息有限。
实现案例
首先，我们需要生成两个texture纹理对象，一个是正常的贴图，另一个用于凹凸贴图：
var bump =
new THREE.TextureLoader().load(
"/lib/textures/brick_bump.jpg");
var normal =
new THREE.TextureLoader().load(
"/lib/textures/brick_diffuse.jpg");
然后，赋值给一个带有相关属性的material即可：
var material1
= new THREE
.MeshPhongMaterial({
map:normal
});
material1
.bumpMap
= bump;
material1
.bumpScale
= 0.03;
在代码中我们可以通过调节bumpScale的值来设置对material的影响。
全部代码
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title
</title>
<style type="text/css">
html, body {
margin: 0;
height: 100%;
}
canvas {
display: block;
}
</style>
</head>
<body onload="draw();">
</body>
<script src="https://cdn.bootcss.com/three.js/91/three.min.js"></script>
<script src="/lib/js/controls/OrbitControls.js"></script>
<script src="https://cdn.bootcss.com/stats.js/r17/Stats.min.js"></script>
<script src="https://cdn.bootcss.com/dat-gui/0.7.1/dat.gui.min.js"></script>
<script src="/lib/js/Detector.js"></script>
<script>
var renderer, camera, scene, gui, light, stats, controls, cube1, cube2;
function initRender() {
renderer = new THREE.WebGLRenderer({antialias: true});
renderer.setPixelRatio(window.devicePixelRatio);
renderer.setSize(window.innerWidth, window.innerHeight);
renderer.setClearColor(0xeeeeee);
renderer.shadowMap.enabled = true;
document.body.appendChild(renderer.domElement);
}
function initCamera() {
camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 200);
camera.position.set(0, 5, 15 );
}
function initScene() {
scene = new THREE.Scene();
scene.background = new THREE.Color( 0xa0a0a0 );
scene.fog = new THREE.Fog( 0xa0a0a0, 5, 50 );
}
function initGui() {
gui = {
bump:0.03,
animation:false
};
var datGui = new dat.GUI();
datGui.add(gui, "bump", -1, 1).onChange(function (e) {
cube1.material.bumpScale = e;
});
datGui.add(gui, "animation");
}
function initLight() {
scene.add(new THREE.AmbientLight(0x444444));
light = new THREE.DirectionalLight(0xffffff);
light.position.set(0, 20, 10 );
light.castShadow = true;
light.shadow.camera.top = 10;
light.shadow.camera.bottom = -10;
light.shadow.camera.left = -10;
light.shadow.camera.right = 10;
light.castShadow = true;
scene.add(light);
}
function initModel() {
var helper = new THREE.AxesHelper(50);
scene.add(helper);
var mesh = new THREE.Mesh( new THREE.PlaneBufferGeometry( 200, 200 ), new THREE.MeshPhongMaterial( { color: 0xffffff, depthWrite: false } ) );
mesh.rotation.x = - Math.PI / 2;
mesh.receiveShadow = true;
scene.add( mesh );
var grid = new THREE.GridHelper( 200, 50, 0x000000, 0x000000 );
grid.material.opacity = 0.2;
grid.material.transparent = true;
scene.add( grid );
var bump = new THREE.TextureLoader().load("/lib/textures/brick_bump.jpg");
var normal = new THREE.TextureLoader().load("/lib/textures/brick_diffuse.jpg");
var material1 = new THREE.MeshPhongMaterial({
map:normal
});
material1.bumpMap = bump;
material1.bumpScale = 0.03;
var geometry = new THREE.CubeGeometry(8, 8, 4);
cube1 = new THREE.Mesh(geometry, material1);
cube1.position.set(-5, 5, 0);
scene.add(cube1);
var material2 = new THREE.MeshPhongMaterial({
map:normal
});
cube2 = new THREE.Mesh(geometry, material2);
cube2.position.set(5, 5, 0);
scene.add(cube2);
}
function initStats() {
stats = new Stats();
document.body.appendChild(stats.dom);
}
function initControls() {
controls = new THREE.OrbitControls(camera, renderer.domElement);
controls.target.set( 0, 5, 0 );
controls.enableDamping = true;
controls.enableZoom = true;
controls.autoRotate = false;
controls.autoRotateSpeed = 0.5;
controls.minDistance = 1;
controls.maxDistance = 2000;
controls.enablePan = true;
}
function render() {
if(gui.animation){
cube1.rotation.y += 0.01;
cube2.rotation.y -= 0.01;
}
controls.update();
}
function onWindowResize() {
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
renderer.setSize(window.innerWidth, window.innerHeight);
}
function animate() {
render();
stats.update();
renderer.render(scene, camera);
requestAnimationFrame(animate);
}
function draw() {
if (!Detector.webgl) Detector.addGetWebGLMessage();
initGui();
initRender();
initScene();
initCamera();
initLight();
initModel();
initControls();
initStats();
animate();
window.onresize = onWindowResize;
}
</script>
</html>
