前言
大家好，這里是 CSS 魔法使――alphardex。
之前在逛國外網站的時候，發現有些網站的文字是刻在3D圖形上的，并且能在圖形上運動，視覺效果相當不錯，于是筆者就也想用three.js來嘗試復現出這種效果
上圖只是所有效果的其中之一，接下來讓我們一起開干吧~
準備工作
筆者自行封裝的three.js模板：Three.js Starter
讀者可以點擊右下角fork一份后再開始本項目
本項目需要用到位圖字體，可以直接復制demo的HTML里的font字體代碼
一個注意點：three-bmfont-text這個庫依賴全局的three.js，因此要在JS里額外引入一次three.js，如下圖
實現思路
- 加載位圖字體文件，將其轉化為文字對象所需要的形狀和材質
- 創建文字對象
- 創建渲染目標，可以理解為canvas中的canvas，因為接下來我們要將文字對象本身當做貼圖
- 創建承載字體的容器，將文字對象作為貼圖貼上去
- 動畫
正片
搭好架子
<div class="relative w-screen h-screen"> <div class="kinetic-text w-full h-full bg-blue-1"></div> <div class="font"> <font> 一坨從demo里CV而來的字體代碼 </font> </div> </div>
:root {
--blue-color-1: #2c3e50;
}
.bg-blue-1 {
background: var(--blue-color-1);
}
import createGeometry from "https://cdn.skypack.dev/three-bmfont-text@3.0.1";
import MSDFShader from "https://cdn.skypack.dev/three-bmfont-text@3.0.1/shaders/msdf";
import parseBmfontXml from "https://cdn.skypack.dev/parse-bmfont-xml@1.1.4";
const font = parseBmfontXml(document.querySelector(".font").innerHTML);
const fontAtlas = "https://i.loli.net/2021/02/20/DcEhuYNjxCgeU42.png";
const kineticTextTorusKnotVertexShader = `（頂點著色器代碼，先空著，具體見下文）`;
const kineticTextTorusKnotFragmentShader = `（片元著色器代碼，先空著，具體見下文）`;
class KineticText extends Base {
constructor(sel: string, debug: boolean) {
super(sel, debug);
this.cameraPosition = new THREE.Vector3(0, 0, 4);
this.clock = new THREE.Clock();
this.meshConfig = {
torusKnot: {
vertexShader: kineticTextTorusKnotVertexShader,
fragmentShader: kineticTextTorusKnotFragmentShader,
geometry: new THREE.TorusKnotGeometry(9, 3, 768, 3, 4, 3)
}
};
this.meshNames = Object.keys(this.meshConfig);
this.params = {
meshName: "torusKnot",
velocity: 0.5,
shadow: 5,
color: "#000000",
frequency: 0.5,
text: "ALPHARDEX",
cameraZ: 2.5
};
}
// 初始化
async init() {
this.createScene();
this.createPerspectiveCamera();
this.createRenderer(true);
await this.createKineticText(this.params.text);
this.createLight();
this.createOrbitControls();
this.addListeners();
this.setLoop();
}
// 創建動態文字
async createKineticText(text: string) {
await this.createFontText(text);
this.createRenderTarget();
this.createTextContainer();
}
}
加載和創建字體
首先加載字體文件，并創建出形狀和材質，有了這兩樣就能創建出字體對象了
class KineticText extends Base {
loadFontText(text: string): any {
return new Promise((resolve) => {
const fontGeo = createGeometry({
font,
text
});
const loader = new THREE.TextureLoader();
loader.load(fontAtlas, (texture) => {
const fontMat = new THREE.RawShaderMaterial(
MSDFShader({
map: texture,
side: THREE.DoubleSide,
transparent: true,
negate: false,
color: 0xffffff
})
);
resolve({ fontGeo, fontMat });
});
});
}
async createFontText(text: string) {
const { fontGeo, fontMat } = await this.loadFontText(text);
const textMesh = this.createMesh({
geometry: fontGeo,
material: fontMat
});
textMesh.position.set(-0.965, -0.525, 0);
textMesh.rotation.set(ky.deg2rad(180), 0, 0);
textMesh.scale.set(0.008, 0.025, 1);
this.textMesh = textMesh;
}
}
著色器
頂點著色器
通用模板，直接CV即可
varying vec2 vUv;
varying vec3 vPosition;
void main(){
vec4 modelPosition=modelMatrix*vec4(position,1.);
vec4 viewPosition=viewMatrix*modelPosition;
vec4 projectedPosition=projectionMatrix*viewPosition;
gl_Position=projectedPosition;
vUv=uv;
vPosition=position;
}
片元著色器
利用fract函數創建重復的貼圖，加上位移距離displacement使得貼圖能隨著時間的增加而動起來，再用clamp函數來根據z軸大小限定陰影的范圍，意思是離畫面越遠則陰影越重，反之離畫面越近則陰影越輕
uniform sampler2D uTexture;
uniform float uTime;
uniform float uVelocity;
uniform float uShadow;
varying vec2 vUv;
varying vec3 vPosition;
void main(){
vec2 repeat=vec2(12.,3.);
vec2 repeatedUv=vUv*repeat;
vec2 displacement=vec2(uTime*uVelocity,0.);
vec2 uv=fract(repeatedUv+displacement);
vec3 texture=texture2D(uTexture,uv).rgb;
// texture*=vec3(uv.x,uv.y,1.);
float shadow=clamp(vPosition.z/uShadow,0.,1.);// farther darker (to 0).
vec3 color=vec3(texture*shadow);
gl_FragColor=vec4(color,1.);
}
此時文本顯示到了屏幕上
創建渲染目標
為了將字體對象本身作為貼圖，創建了一個渲染目標
class KineticText extends Base {
createRenderTarget() {
const rt = new THREE.WebGLRenderTarget(
window.innerWidth,
window.innerHeight
);
this.rt = rt;
const rtCamera = new THREE.PerspectiveCamera(45, 1, 0.1, 1000);
rtCamera.position.z = this.params.cameraZ;
this.rtCamera = rtCamera;
const rtScene = new THREE.Scene();
rtScene.add(this.textMesh);
this.rtScene = rtScene;
}
}
創建字體容器
創建一個容器，并將字體對象本身作為貼圖貼上去，再應用動畫即可完成
class KineticText extends Base {
createTextContainer() {
if (this.mesh) {
this.scene.remove(this.mesh);
this.mesh = null;
this.material!.dispose();
this.material = null;
}
this.rtScene.background = new THREE.Color(this.params.color);
const meshConfig = this.meshConfig[this.params.meshName];
const geometry = meshConfig.geometry;
const material = new THREE.ShaderMaterial({
vertexShader: meshConfig.vertexShader,
fragmentShader: meshConfig.fragmentShader,
uniforms: {
uTime: {
value: 0
},
uVelocity: {
value: this.params.velocity
},
uTexture: {
value: this.rt.texture
},
uShadow: {
value: this.params.shadow
},
uFrequency: {
value: this.params.frequency
}
}
});
this.material = material;
const mesh = this.createMesh({
geometry,
material
});
this.mesh = mesh;
}
update() {
if (this.rtScene) {
this.renderer.setRenderTarget(this.rt);
this.renderer.render(this.rtScene, this.rtCamera);
this.renderer.setRenderTarget(null);
}
const elapsedTime = this.clock.getElapsedTime();
if (this.material) {
this.material.uniforms.uTime.value = elapsedTime;
}
}
}
別忘了把相機調遠一些
this.cameraPosition = new THREE.Vector3(0, 0, 40);
風騷的動態文字出現了:)
項目地址
demo里不止本文創建的這一種形狀，大家可以隨意把玩。
總結
到此這篇關于three.js如何實現3D動態文字效果的文章就介紹到這了,更多相關three.js 3D動態文字內容請搜索服務器之家以前的文章或繼續瀏覽下面的相關文章希望大家以后多多支持服務器之家！
原文鏈接：https://juejin.cn/post/6931647184349691911
