本文详细介绍了将codepen上的mediapipe facelandmarker项目成功部署到本地环境的步骤。通过整合html、css和javascript代码到一个单一文件，并修正外部资源引用路径，解决了本地运行时遇到的问题，确保项目功能完整运行，为开发者提供了在本地调试和优化codepen项目的实用指南。
在前端开发中，CodePen等在线代码编辑器为快速原型开发和分享提供了极大便利。然而，当需要将这些项目迁移到本地环境进行更深入的开发、调试或部署时，可能会遇到一些挑战，尤其是当项目依赖于特定的构建流程或外部资源时。本文将以一个MediaPipe FaceLandmarker项目为例，详细阐述如何将一个CodePen项目成功地在本地运行起来。
核心问题分析
将CodePen项目直接复制到本地文件系统通常无法正常工作，主要原因有以下几点：
- CSS预处理器依赖： CodePen支持Sass、Less等CSS预处理器。例如，@use "@material"; 这样的语法需要一个构建步骤来编译成标准CSS。直接复制到本地，浏览器无法识别。
- JavaScript模块导入机制： CodePen可能通过其内部机制或隐式地支持ES模块导入，但本地HTML文件直接使用 import ... from "..." 语法时，需要确保导入路径是可解析的，并且通常需要完整的CDN链接或本地文件路径。
- 资源路径问题： 许多CodePen项目依赖于外部CDN托管的库、字体、图片或机器学习模型文件。在本地运行时，这些路径必须是绝对的、可访问的URL。
- 文件结构与链接： CodePen通常将HTML、CSS和JS分为独立面板。本地运行时，需要将它们正确地整合到一个HTML文件中，并确保CSS和JS文件被正确链接或内联。
本地化部署步骤
要成功在本地运行CodePen项目，我们需要对代码进行以下调整：
1. 整合代码结构
最简单且直接的方式是将HTML、CSS和JavaScript代码整合到一个单一的 index.html 文件中。
- 将CSS代码放入
- 将JavaScript代码放入 <script type="module"> 标签内，放置在 <body> 结束标签之前。</script>
2. 处理CSS预处理器与外部样式
原CodePen项目中的CSS可能包含 @use "@material"; 这样的Sass语法。在本地环境中，如果没有Sass编译器，浏览器将无法解析。解决方案是：
- 移除预处理器语法： 将 @use "@material"; 这样的行移除。
-
引入标准CSS库： 如果项目依赖Material Design组件库，需要通过CDN链接引入其编译后的CSS文件。例如，在 中添加：
<link href="https://unpkg.com/material-components-web@latest/dist/material-components-web.min.css" rel="stylesheet">
3. 修正JavaScript模块导入
CodePen中的JavaScript模块导入可能依赖于其环境。在本地运行ES模块时，需要确保导入路径是有效的URL。
-
使用完整的CDN路径： 将 import vision from "@mediapipe/tasks-vision"; 这样的导入语句替换为完整的CDN URL。例如：
import vision from "https://cdn.jsdelivr.net/npm/@mediapipe/tasks-vision@0.10.0";
请注意，原始答案中的 [email protected] 是经过邮件混淆处理的，实际应替换为 tasks-vision@0.10.0。
-
修正WASM文件路径： MediaPipe等库通常需要加载WebAssembly (WASM) 文件。FilesetResolver.forVisionTasks() 方法需要正确的WASM文件目录路径。确保其指向正确的CDN路径：
const filesetResolver = await FilesetResolver.forVisionTasks( "https://cdn.jsdelivr.net/npm/@mediapipe/tasks-vision@0.10.0/wasm" );
4. 确保所有外部资源可访问
检查HTML、CSS和JavaScript中所有对外部资源的引用，如图片 ( 的 src)、模型文件 (modelAssetPath) 等，确保它们都使用完整的、可公开访问的URL。
完整示例代码
以下是经过上述修正后，可在本地直接运行的MediaPipe FaceLandmarker项目代码：
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="Cache-control" content="no-cache, no-store, must-revalidate">
<meta http-equiv="Pragma" content="no-cache">
<meta name="viewport" content="width=device-width, initial-scale=1, user-scalable=no">
<title>Face Landmarker</title>
<style>
/* 移除 @use "@material"; */
body {
font-family: helvetica, arial, sans-serif;
margin: 2em;
color: #3d3d3d;
--mdc-theme-primary: #007f8b;
--mdc-theme-on-primary: #f1f3f4;
}
h1 {
font-style: italic;
color: #ff6f00;
color: #007f8b;
}
h2 {
clear: both;
}
em {
font-weight: bold;
}
video {
clear: both;
display: block;
transform: rotateY(180deg);
-webkit-transform: rotateY(180deg);
-moz-transform: rotateY(180deg);
}
section {
opacity: 1;
transition: opacity 500ms ease-in-out;
}
header,
footer {
clear: both;
}
.removed {
display: none;
}
.invisible {
opacity: 0.2;
}
.note {
font-style: italic;
font-size: 130%;
}
.videoView,
.detectOnClick,
.blend-shapes {
position: relative;
float: left;
width: 48%;
margin: 2% 1%;
cursor: pointer;
}
.videoView p,
.detectOnClick p {
position: absolute;
padding: 5px;
background-color: #007f8b;
color: #fff;
border: 1px dashed rgba(255, 255, 255, 0.7);
z-index: 2;
font-size: 12px;
margin: 0;
}
.highlighter {
background: rgba(0, 255, 0, 0.25);
border: 1px dashed #fff;
z-index: 1;
position: absolute;
}
.canvas {
z-index: 1;
position: absolute;
pointer-events: none;
}
.output_canvas {
transform: rotateY(180deg);
-webkit-transform: rotateY(180deg);
-moz-transform: rotateY(180deg);
}
.detectOnClick {
z-index: 0;
}
.detectOnClick img {
width: 100%;
}
.blend-shapes-item {
display: flex;
align-items: center;
height: 20px;
}
.blend-shapes-label {
display: flex;
width: 120px;
justify-content: flex-end;
align-items: center;
margin-right: 4px;
}
.blend-shapes-value {
display: flex;
height: 16px;
align-items: center;
background-color: #007f8b;
}
</style>
<link href="https://unpkg.com/material-components-web@latest/dist/material-components-web.min.css" rel="stylesheet">
<script src="https://unpkg.com/material-components-web@latest/dist/material-components-web.min.js"></script>
</head>
<body>
<h1>Face landmark detection using the MediaPipe FaceLandmarker task</h1>
<section id="demos" class="invisible">
<h2>Demo: Detecting Images</h2>
<p><b>Click on an image below</b> to see the key landmarks of the face.</p>
<div class="detectOnClick">
<img src="https://storage.googleapis.com/mediapipe-assets/portrait.jpg" style="max-width:90%" crossorigin="anonymous" title="Click to get detection!" / alt="CodePen项目本地化部署指南" >
</div>
<div class="blend-shapes">
<ul class="blend-shapes-list" id="image-blend-shapes"></ul>
</div>
<h2>Demo: Webcam continuous face landmarks detection</h2>
<p>Hold your face in front of your webcam to get real-time face landmarker detection.</br>Click <b>enable webcam</b> below and grant access to the webcam if prompted.</p>
<div id="liveView" class="videoView">
<button id="webcamButton" class="mdc-button mdc-button--raised">
<span class="mdc-button__ripple"></span>
<span class="mdc-button__label">ENABLE WEBCAM</span>
</button>
<div style="position: relative;">
<video id="webcam" style="position: abso" autoplay playsinline></video>
<canvas class="output_canvas" id="output_canvas" style="position: absolute; left: 0px; top: 0px;"></canvas>
</div>
</div>
<div class="blend-shapes">
<ul class="blend-shapes-list" id="video-blend-shapes"></ul>
</div>
</section>
<script type="module">
import vision from "https://cdn.jsdelivr.net/npm/@mediapipe/tasks-vision@0.10.0";
const { FaceLandmarker, FilesetResolver, DrawingUtils } = vision;
const demosSection = document.getElementById("demos");
const imageBlendShapes = document.getElementById("image-blend-shapes");
const videoBlendShapes = document.getElementById("video-blend-shapes");
let faceLandmarker;
let runningMode = "IMAGE"; // Corrected type annotation syntax
let enableWebcamButton; // Corrected type annotation syntax
let webcamRunning = false; // Corrected type annotation syntax
const videoWidth = 480;
async function runDemo() {
const filesetResolver = await FilesetResolver.forVisionTasks(
"https://cdn.jsdelivr.net/npm/@mediapipe/tasks-vision@0.10.0/wasm"
);
faceLandmarker = await FaceLandmarker.createFromOptions(filesetResolver, {
baseOptions: {
modelAssetPath: `https://storage.googleapis.com/mediapipe-models/face_landmarker/face_landmarker/float16/1/face_landmarker.task`,
delegate: "GPU"
},
outputFaceBlendshapes: true,
runningMode,
numFaces: 1
});
demosSection.classList.remove("invisible");
}
runDemo();
const imageContainers = document.getElementsByClassName("detectOnClick");
for (let i = 0; i < imageContainers.length; i++) {
imageContainers[i].children[0].addEventListener("click", handleClick);
}
async function handleClick(event) {
if (!faceLandmarker) {
console.log("Wait for faceLandmarker to load before clicking!");
return;
}
if (runningMode === "VIDEO") {
runningMode = "IMAGE";
await faceLandmarker.setOptions({ runningMode });
}
const allCanvas = event.target.parentNode.getElementsByClassName("canvas");
for (var i = allCanvas.length - 1; i >= 0; i--) {
const n = allCanvas[i];
n.parentNode.removeChild(n);
}
const faceLandmarkerResult = faceLandmarker.detect(event.target);
const canvas = document.createElement("canvas");
canvas.setAttribute("class", "canvas");
canvas.setAttribute("width", event.target.naturalWidth + "px");
canvas.setAttribute("height", event.target.naturalHeight + "px");
canvas.style.left = "0px";
canvas.style.top = "0px";
canvas.style.width = `${event.target.width}px`;
canvas.style.height = `${event.target.height}px`;
event.target.parentNode.appendChild(canvas);
const ctx = canvas.getContext("2d");
const drawingUtils = new DrawingUtils(ctx);
for (const landmarks of faceLandmarkerResult.faceLandmarks) {
drawingUtils.drawConnectors(
landmarks,
FaceLandmarker.FACE_LANDMARKS_TESSELATION,
{ color: "#C0C0C070", lineWidth: 1 }
);
drawingUtils.drawConnectors(
landmarks,
FaceLandmarker.FACE_LANDMARKS_RIGHT_EYE,
{ color: "#FF3030" }
);
drawingUtils.drawConnectors(
landmarks,
FaceLandmarker.FACE_LANDMARKS_RIGHT_EYEBROW,
{ color: "#FF3030" }
);
drawingUtils.drawConnectors(
landmarks,
FaceLandmarker.FACE_LANDMARKS_LEFT_EYE,
{ color: "#30FF30" }
);
drawingUtils.drawConnectors(
landmarks,
FaceLandmarker.FACE_LANDMARKS_LEFT_EYEBROW,
{ color: "#30FF30" }
);
drawingUtils.drawConnectors(
landmarks,
FaceLandmarker.FACE_LANDMARKS_FACE_OVAL,
{ color: "#E0E0E0" }
);
drawingUtils.drawConnectors(landmarks, FaceLandmarker.FACE_LANDMARKS_LIPS, {
color: "#E0E0E0"
});
drawingUtils.drawConnectors(
landmarks,
FaceLandmarker.FACE_LANDMARKS_RIGHT_IRIS,
{ color: "#FF3030" }
);
drawingUtils.drawConnectors(
landmarks,
FaceLandmarker.FACE_LANDMARKS_LEFT_IRIS,
{ color: "#30FF30" }
);
}
drawBlendShapes(imageBlendShapes, faceLandmarkerResult.faceBlendshapes);
}
const video = document.getElementById("webcam");
const canvasElement = document.getElementById("output_canvas");
const canvasCtx = canvasElement.getContext("2d");
function hasGetUserMedia() {
return !!(navigator.mediaDevices && navigator.mediaDevices.getUserMedia);
}
if (hasGetUserMedia()) {
enableWebcamButton = document.getElementById("webcamButton");
enableWebcamButton.addEventListener("click", enableCam);
} else {
console.warn("getUserMedia() is not supported by your browser");
}
function enableCam(event) {
if (!faceLandmarker) {
console.log("Wait! faceLandmarker not loaded yet.");
return;
}
if (webcamRunning === true) {
webcamRunning = false;
enableWebcamButton.innerText = "ENABLE PREDICTIONS";
} else {
webcamRunning = true;
enableWebcamButton.innerText = "DISABLE PREDICTIONS";
}
const constraints = {
video: true
};
navigator.mediaDevices 
