滚动线 Animation - HTML,CSS,JS

Question

我正在尝试使用 SVG 线 Animation 对字母H进行 output 字母 H，我被困在一个部分，我不确定在哪里编辑/修改元素，所以它输出字母H 我想通过SVG Drawing On Scroll output 这张图片：

这似乎有点太复杂了，我最初的尝试是修改<path元素，但我得到了一个不同的意外 output。 我使用了来自codepen的SVG Drawing On Scroll模板，我想将上面的滚动图像修改为output。 我想知道我是否可以在这方面得到一些帮助。 有什么建议么？

模板代码：

 // Get a reference to the <path> var path = document.querySelector('#star-path'); // Get length of path... ~577px in this case var pathLength = path.getTotalLength(); // Make very long dashes (the length of the path itself) path.style.strokeDasharray = pathLength + ' ' + pathLength; // Offset the dashes so the it appears hidden entirely path.style.strokeDashoffset = pathLength; // Jake Archibald says so // https://jakearchibald.com/2013/animated-line-drawing-svg/ path.getBoundingClientRect(); // When the page scrolls... window.addEventListener("scroll", function(e) { // What % down is it? // https://stackoverflow.com/questions/2387136/cross-browser-method-to-determine-vertical-scroll-percentage-in-javascript/2387222#2387222 // Had to try three or four differnet methods here. Kind of a cross-browser nightmare. var scrollPercentage = (document.documentElement.scrollTop + document.body.scrollTop) / (document.documentElement.scrollHeight - document.documentElement.clientHeight); // Length to offset the dashes var drawLength = pathLength * scrollPercentage; // Draw in reverse path.style.strokeDashoffset = pathLength - drawLength; // When complete, remove the dash array, otherwise shape isn't quite sharp // Accounts for fuzzy math if (scrollPercentage >= 0.99) { path.style.strokeDasharray = "none"; } else { path.style.strokeDasharray = pathLength + ' ' + pathLength; } });

 body { /* feel free to change height */ height: 5000px; background: linear-gradient( to bottom, orange, darkblue ); } h1 { font-family: "HelveticaNeue-Light", "Helvetica Neue Light", "Helvetica Neue", Helvetica, Arial, "Lucida Grande", sans-serif; font-weight: 300; color: white; text-transform: uppercase; text-align: center; font-size: 22px; letter-spacing: 5px; font-weight: 100; padding: 25px 15px; text-shadow: 1px 1px 1px #333; } #star-svg { position: fixed; top: 50%; left: 50%; width: 150px; height: 150px; margin: -75px 0 0 -75px; } Resources

 <h1>Scroll-to-draw</h1> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100.6 107.6" id="star-svg"> <path fill="none" stroke="white" stroke-width="2" id="star-path" d="M43.7,65.8L19.9,83.3c-2.9,1.9-5.1,3.2-7.9,3.2c-5.7,0-10.5-5.1-10.5-10.8 c0-4.8,3.8-8.2,7.3-9.8l27.9-12L8.8,41.4c-3.8-1.6-7.3-5.1-7.3-9.8c0-5.7,5.1-10.5,10.8-10.5c2.9,0,4.8,1,7.6,3.2l23.8,17.4 l-3.2-28.2c-1-6.7,3.5-12,9.8-12c6.3,0,10.8,5.1,9.8,11.7L57,41.8l23.8-17.4c2.9-2.2,5.1-3.2,7.9-3.2c5.7,0,10.5,4.8,10.5,10.5 c0,5.1-3.5,8.2-7.3,9.8L63.9,53.8l27.9,12c3.8,1.6,7.3,5.1,7.3,10.1c0,5.7-5.1,10.5-10.8,10.5c-2.5,0-4.8-1.3-7.6-3.2L57,65.8 l3.2,28.2c1,6.7-3.5,12-9.8,12c-6.3,0-10.8-5.1-9.8-11.7L43.7,65.8z"/> </svg>

Answer 1

您需要在像Inkscape这样的 SVG 编辑器中跟踪您的图片。

安装 Inkscape，导入您的图片，然后使用线条或节点工具以尽可能少的点跟踪轮廓。 然后保存 SVG 并在里面查找路径。

这是经过简化后我最终得到的路径： M 0,0 V 66 H 13 V 37 H 40 V 66 H 53 V 0 H 40 V 26 H 13 V 0 Z

这是带有更新路径的示例代码：

 // Get a reference to the <path> var path = document.querySelector('#star-path'); // Get length of path... ~577px in this case var pathLength = path.getTotalLength(); // Make very long dashes (the length of the path itself) path.style.strokeDasharray = pathLength + ' ' + pathLength; // Offset the dashes so the it appears hidden entirely path.style.strokeDashoffset = pathLength; // Jake Archibald says so // https://jakearchibald.com/2013/animated-line-drawing-svg/ path.getBoundingClientRect(); // When the page scrolls... window.addEventListener("scroll", function(e) { // What % down is it? // https://stackoverflow.com/questions/2387136/cross-browser-method-to-determine-vertical-scroll-percentage-in-javascript/2387222#2387222 // Had to try three or four differnet methods here. Kind of a cross-browser nightmare. var scrollPercentage = (document.documentElement.scrollTop + document.body.scrollTop) / (document.documentElement.scrollHeight - document.documentElement.clientHeight); // Length to offset the dashes var drawLength = pathLength * scrollPercentage; // Draw in reverse path.style.strokeDashoffset = pathLength - drawLength; // When complete, remove the dash array, otherwise shape isn't quite sharp // Accounts for fuzzy math if (scrollPercentage >= 0.99) { path.style.strokeDasharray = "none"; } else { path.style.strokeDasharray = pathLength + ' ' + pathLength; } });

 body { /* feel free to change height */ height: 5000px; background: linear-gradient( to bottom, orange, darkblue ); } h1 { font-family: "HelveticaNeue-Light", "Helvetica Neue Light", "Helvetica Neue", Helvetica, Arial, "Lucida Grande", sans-serif; font-weight: 300; color: white; text-transform: uppercase; text-align: center; font-size: 22px; letter-spacing: 5px; font-weight: 100; padding: 25px 15px; text-shadow: 1px 1px 1px #333; } #star-svg { position: fixed; top: 50%; left: 50%; width: 150px; height: 150px; margin: -75px 0 0 -75px; } Resources

 <h1>Scroll-to-draw</h1> <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 200 250" id="star-svg"> <path fill="none" stroke="white" stroke-width="2" id="star-path" d="M 0,0 V 66 H 13 V 37 H 40 V 66 H 53 V 0 H 40 V 26 H 13 V 0 Z"/> </svg>