如何使用SVG在网页上制作手写文字动画？

Question

如何使用SVG在网页上制作手写文字动画？

10

我正在尝试对我创建并保存为SVG的文本进行动画处理。到目前为止，我只能够使描边动画化，但这不是我想要实现的效果。我该如何实现像下面这两个例子中的动画效果？

http://codepen.io/se7ensky/pen/waoMyx
https://codepen.io/munkholm/pen/EaZJQE

这是我目前为止的成果：

.test {
  width: 300px
  /*   margin:0 auto; */
}

.l1 {
  animation: dash 15s 1;
  stroke-linecap: round;
  stroke-miterlimit: 10;
  stroke-dasharray: 300;
  stroke-dashoffset: 300;
  animation-fill-mode: forwards;
  /*fill: none;*/
}

.l2 {
  stroke-dasharray: 300;
  stroke-dashoffset: 300;
  animation: dash 20s linear forwards;
  -webkit-animation-delay: 1s;
  /* Chrome, Safari, Opera */
  animation-delay: 1s;
}

.l3 {
  stroke-dasharray: 300;
  stroke-dashoffset: 300;
  animation: dash 25s linear forwards;
  -webkit-animation-delay: 2.5s;
  /* Chrome, Safari, Opera */
  animation-delay: 2.5s;
}

.l4 {
  stroke-dasharray: 300;
  stroke-dashoffset: 300;
  animation: dash 25s linear forwards;
  -webkit-animation-delay: 4.5s;
  /* Chrome, Safari, Opera */
  animation-delay: 4.5s;
}

@keyframes dash {
  to {
    stroke-dashoffset: 0;
  }
}

<?xml version="1.0" encoding="utf-8"?>
<!-- Generator: Adobe Illustrator 19.0.1, SVG Export Plug-In . SVG Version: 6.00 Build 0)  -->
<svg class="test" version="1.1" id="Layer_1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" x="0px" y="0px" viewBox="0 0 30.1 21.8" style="enable-background:new 0 0 30.1 21.8;" xml:space="preserve">
    <g>
     <path class="text l1" d="M16.5,9.2c-0.2-0.2-0.2-1,0.1-1.5c0.1-0.1,0.2-0.3,0.3-0.4c-1.6,0-3.2-0.3-4.7-0.1C10.8,7.3,9.5,8,9.3,8.9
      c-0.1,0.6,0.5,0.8,0.7,1c0.1,0.1,0,0.2-0.1,0.1C9.5,10,8.7,9.4,9,8.7c0,0,0-0.1,0-0.2c0.3-1.2,1.7-1.8,3.3-1.9
      c1.8-0.1,3.9,0.4,4.8,0.4c0.2-0.2,0.4-0.4,0.5-0.4c0.3-0.1,0.6,0.1,0.3,0.4c-0.1,0.1-0.4,0.3-0.6,0.5c-0.4,0.4-0.8,1-0.5,1.5
      C16.8,9.2,16.7,9.3,16.5,9.2z M12.1,12.8c0.1,0.1-0.1,0.3-0.1,0.3c-0.2,0.3-0.5,0.8-0.8,0.8c-0.1,0-0.5-0.1-0.5-0.1
      c-0.1-0.8,1.5-3.5,1.9-4.2c0.2-0.3,0.1-0.4,0.1-0.5c0.1-0.4,0.9-1.4,1.5-1.4c0.2,0,0.8,0.2,0.7,0.5c0,0-0.1-0.1-0.2-0.1
      c-1.1,0-2.9,3.6-3.4,4.7c-0.3,0.7,0.1,0.6,0.4,0.3C11.8,13,12,12.8,12.1,12.8z" fill="red" stroke="#000" stroke-miterlimit="10" stroke-width="0.5" />
     <path class="text l2" d="M14.4,12.3c-0.2,0-0.3-0.2-0.1-0.2c0.4,0,1.1-0.4,1.5-0.8c0.2-0.2,0.6-0.5,0.5-0.8c0-0.3-0.4-0.2-0.6-0.1
      c-0.7,0.3-1.7,1.3-2,2.2c-0.3,1,0.6,1,1.4,0.7c0.9-0.4,1.7-1,2.1-1.7c0-0.1,0.1-0.1,0.1,0c0.1,0,0.1,0.1,0,0.1
      c-0.5,0.8-1.2,1.5-2.1,1.8c-1.2,0.5-2.8,0-2.1-1.5c0.4-0.8,2.2-2.4,3.1-2.1c0.5,0.2,0.4,0.8,0.2,1.1C16.1,11.8,15,12.2,14.4,12.3z" fill="none" stroke="#000" stroke-miterlimit="5" stroke-width="0.5"
      />
     <path class="text l3" d="M17.3,13.6c-0.2,0.2-0.1,0.5,0.4,0.4c0.6-0.2,1.5-0.9,1.5-1.6c0-0.3-0.7-0.6-0.9-0.7c-0.2-0.1-0.3-0.3-0.4-0.4
      c-0.1,0.2-0.3,0.5-0.5,0.8c-0.1,0.1-0.3,0-0.2-0.1c0.3-0.5,0.6-0.9,0.6-1.1c0.1-0.9,1.7-1.7,2.6-1.7c0.5,0,1,0.3,0.7,0.8
      c-0.1,0.2-0.2,0.3-0.4,0.4c-0.1,0-0.2,0-0.1-0.2c0.2-0.2,0.3-0.6,0-0.6c-0.4,0-1,0.2-1.3,0.4c-0.4,0.2-0.7,0.4-1,0.9
      c-0.3,0.3-0.2,0.6,0.1,0.8c0.8,0.5,1.8,0.8,0.9,1.8c-0.4,0.5-1.1,0.7-1.7,0.9c-0.2,0-0.7,0.1-0.9-0.1c-0.1-0.1,0-0.3,0.2-0.5
      c0.1-0.1,0.3-0.3,0.6-0.3c0.1,0,0.1,0.1,0,0.1C17.5,13.4,17.3,13.5,17.3,13.6z" fill="none" stroke="#000" stroke-miterlimit="5" stroke-width="0.5"/>
     <path class="text l4" d="M23.6,10.2c-0.2,0.1-0.8,0.1-1.4,0.2c-0.2,0.3-0.3,0.5-0.3,0.6c-0.4,0.7-0.7,1.4-0.7,1.7c-0.1,0.5,0.2,0.8,0.6,0.6
      c0.4-0.2,1.3-1,1.8-1.7c0.1-0.1,0.2,0,0.1,0.1c-0.2,0.4-1,1.2-1.6,1.6c-0.4,0.3-1.3,0.6-1.5-0.1c-0.1-0.3,0.1-0.9,0.4-1.5
      c-0.1,0.1-0.2,0.3-0.5,0.6c-0.1,0.1-0.2,0-0.1-0.2c0.4-0.5,0.7-1,0.9-1.2c0,0,0.1-0.2,0.3-0.5c-0.1,0-0.2,0-0.3,0
      c-0.1,0-0.2-0.1-0.2-0.3c0.1-0.2,0.4-0.2,0.6-0.2c0,0,0,0,0,0l0.6-1.1c0.3-0.5,0.3-0.6,0.5-0.7c0.2,0,0.4,0,0.5,0.1
      c0.1,0.1,0,0.4-0.1,0.5C23.2,9,23.1,9,23,9.1l-0.6,1l0.2,0c0.4,0,0.7-0.1,1.1-0.1C23.9,10,24.1,10.1,23.6,10.2z" fill="none" stroke="#000" stroke-miterlimit="5" stroke-width="0.5"/>
    </g>
    <g></g>
    <g></g>
    <g></g>
    <g></g>
    <g></g>
    <g></g>
</svg>

在 CodePen 上查看

- nb_ck

【我的手写动画】 - Naga Sai A

请确认链接。 - Naga Sai A

任何对这个问题感兴趣的人可能也会对我的问题“我可以使用CSS动画路径来动画绘制字形吗？”感兴趣，该问题已被标记为此问题的重复。 - Graham Hannington

2个回答

2

这个例子看起来是由svg路径和延迟动画组合而成的。

CSS-Tricks的这篇博客解释得很好（请注意，为了使它起作用，svg必须有描边）：https://css-tricks.com/svg-line-animation-works/ 这里有一个关于stroke-dashoffset的指南（在示例中使用），可能会有用： https://css-tricks.com/almanac/properties/s/stroke-dashoffset/

- Diego

谢谢您的回答，我理解了stroke-dashoffset的工作原理。我的问题是如何从文本创建一个带有描边但没有填充的SVG。这样我就可以只对描边进行动画处理。我已经更新了我的链接，附上了示例。希望这能更清楚地说明我想要实现什么。 - nb_ck

你需要编辑实际的SVG文件，只保留线条...我看到你使用Illustrator生成了这张图片，所以尝试在Illustrator上编辑SVG文件。这可能意味着需要编辑实际的形状，如果需要更多帮助，可以尝试在这里提问http://graphicdesign.stackexchange.com。 - Diego

1

我没有时间提供解释，但这个代码笔是我如何使这种技术对我有效的示例。如果我不那么挑剔地逐个动画每个字母（在前一个字母有足够时间部分绘制后），它可能会更简单。（例如，使用Google脚本字体Parisienne，动画F所需的时间比o长2.1倍。）此演示文稿说明了StrokeDashArray和StrokeDashOffset的效果。（无需Illustrator） - ashleedawg

网页内容由stack overflow 提供, 点击上面的

可以查看英文原文，
原文链接

- Paul LeBeau · Accepted Answer

Se7ensky动画的工作原理是使用标准的虚线动画技术，但是通过描绘与手绘标志相似的轮廓剪辑动画笔画。

因此，标准虚线动画技术的工作方式如下。您需要使用标准线条:

<svg>
  <path d="M 10,75 L 290,75" stroke="red" stroke-width="50"/>
</svg>

然后您为其添加破折号样式，并动画化其位置（stroke-dashoffset）。

.pen {
  stroke-dasharray: 280 280;
  stroke-dashoffset: 280;
  animation-duration: 2s;
  animation-name: draw;
  animation-iteration-count: infinite;
  animation-direction: alternate;
  animation-timing-function: linear;
}

@keyframes draw {
  from {
    stroke-dashoffset: 280;
  }

  to {
    stroke-dashoffset: 0;
  }
}

<svg>
  <path class="pen" d="M 10,75 L 290,75" stroke="red" stroke-width="50"/>
</svg>

最后，为了得到Se7ensky示例中漂亮的变量描边宽度，您需要使用标志的轮廓来剪裁该线。

因此，假设下面的简单路径代表您的标志：

<svg>
  <path stroke="black" stroke-width="1" fill="lightgrey"
        d="M 40,50
           C 110,55 195,60, 265,55
           C 290,55 290,85 265,85
           C 195,85 110,85 40,100
           C 0,100 0,50 40,50 Z"/>
</svg>

我们将其转换为clipPath元素，并使用它将我们的动画描边剪切成我们logo的形状：

.pen {
  stroke-dasharray: 280 280;
  stroke-dashoffset: 280;
  animation-duration: 2s;
  animation-name: draw;
  animation-iteration-count: infinite;
  animation-direction: alternate;
  animation-timing-function: linear;
}

@keyframes draw {
  from {
    stroke-dashoffset: 280;
  }

  to {
    stroke-dashoffset: 0;
  }
}

<svg>
  <clipPath id="logo">
    <path d="M 40,50
             C 110,55 195,60, 265,55
             C 290,55 290,85 265,85
             C 195,85 110,85 40,100
             C 0,100 0,50 40,50 Z"/>
  </clipPath>
  
  <path class="pen" d="M 10,75 L 290,75" stroke="red" stroke-width="50" clip-path="url(#logo)"/>
</svg>

为了复制他们的示例，您需要在SVG中添加表示笔写下徽标字母路径的连续路径（如果需要，可以添加多个路径）。

然后使用dashoffset技术对这条路径进行动画处理，并使用原始徽标进行剪裁。

更新

这里是一个最终演示，具有更逼真的字母形状：

// Simple code to enable and disable the clipping path
var chk = document.getElementById("chk");
var penpath = document.getElementById("penpath");

chk.addEventListener("input", function(evt) {
  if (evt.target.checked) {
    penpath.classList.add("clipped");
  } else {
    penpath.classList.remove("clipped");
  }
});

.pen {
  fill: none;
  stroke: red;
  stroke-width: 18;
  stroke-linecap: round;

  stroke-dasharray: 206 206;
  stroke-dashoffset: 206;
  animation-duration: 2s;
  animation-name: draw;
  animation-iteration-count: infinite;
  animation-direction: alternate;
  animation-timing-function: linear;
}

.clipped {
  clip-path: url(#logo);
}

@keyframes draw {
  from {
    stroke-dashoffset: 206;
  }

  to {
    stroke-dashoffset: 0;
  }
}

<svg>
  <defs>
    <clipPath id="logo">
      <path d="m85.77 49.77c-10.59 8.017-27.38 21.95-41.58 21.95-6.396 0-12.99-2.481-12.39-9.735l0.3998-4.199c38.38-12.03 48.17-26.15 48.17-35.5 0-7.635-7.995-9.162-14.39-9.162-25.98-0.1909-54.97 25.39-54.17 50.39 0.3998 12.6 7.196 25.01 21.79 25.01 19.79 0 41.78-17.94 53.97-31.5zm-52.37-1.336c5.397-12.6 16.99-21.76 26.98-24.24 1.399-0.3818 2.399 0.7635 2.399 2.1 0.1999 3.245-11.79 16.42-29.38 22.14z"/>
    </clipPath>
  </defs>
  
  <path id="penpath" d="m39.02 51.1c5.361-1.771 10.04-4.182 15.98-7.857 6.019-3.933 9.841-7.728 12.77-10.71 1.403-1.369 12.03-15.97-7.857-13.93-9.824 1.01-19.62 8.3-26.16 14.91-6.538 6.61-10.42 14.51-11.96 22.23-2.559 12.76 1.807 26.19 21.07 23.48 13.96-1.965 32.59-14.55 43.66-25.54" class="pen clipped"/>
</svg>


<p>
<input id="chk" type="checkbox" checked="true"/> <label for="chk">Enable clipping path</label>
</p>