在Javascript中向SVG drop-shadow for循环添加变量

Question

我想要添加多个“投影”滤镜到一个SVG中，以达到3D样式的效果，边缘是一个渐变--类似于this (稍后我将添加一个间隔来对其进行动画处理)。我已经使用this生成了一个具有70个阴影的梯度数组。

但是，我不能让"drop-shadow“属性与我的for循环一起工作。

不像"text-shadow“风格，比如我可以这样做：

var current = element.style.textShadow;
var appliedStyle = -i + 'px ' + i + 'px ' + gcolor[i];
element.style.textShadow = current+appliedStyle;

我不知道如何获取当前的"drop-shadow“属性，并将另一个过滤器连接到它。所以我想出了一个添加类的想法。这是我对它进行编码的最好尝试：

​

let text = document.querySelector(".brand-svg");

let gcolor = ["#ffb576","#ffb275","#ffb074","#ffad73","#ffab72","#ffa871","#ffa670","#ffa370","#ffa16f","#ff9e6e","#ff9c6d","#ff996c","#ff976b","#ff946a","#ff9269","#ff9068","#ff8d67","#ff8b66","#ff8865","#ff8664","#ff8363","#ff8163","#ff7e62","#ff7c61","#ff7960","#ff775f","#ff745e","#ff725d","#ff705c","#ff6d5b","#ff6b5a","#ff6859","#ff6658","#ff6357","#ff6156","#ff5e56","#ff5c55","#ff5954","#ff5753","#ff5452","#ff5251","#ff4f50","#ff4d4f","#ff4b4e","#ff484d","#ff464c","#ff434b","#ff414a","#ff3e49","#ff3c49","#ff3948","#ff3747","#ff3446","#ff3245","#ff2f44","#ff2d43","#ff2b42","#ff2841","#ff2640","#ff233f","#ff213e","#ff1e3d","#ff1c3c","#ff193c","#ff173b","#ff143a","#ff1239","#ff0f38","#ff0d37","#ff0a36"];

for (var i = 1; i <= 70; i++) {
  text.classList.add("shadowlayer"+i);
  var current = document.querySelector(".shadowlayer"+i);
  current.style.setProperty(`-webkit-filter`, `drop-shadow 0px (${-i})px (${gcolor[i]})`);
};

body {
  display: flex;
  justify-content: center;
}

.brand-svg {
  width: 400px;
}

<svg class="brand-svg" xmlns="http://www.w3.org/2000/svg" viewBox="0 0 748.17 433.89"><defs>
<style> .brand-svg path, polygon {fill:#fff;stroke:#ffb777;stroke-miterlimit:10;stroke-width:3px;}</style>
</defs>

<path class="svg-b-d" d="M746.37,26.21q-1.07-10.31-13.43-17.09T701.85,1.74c-1,0-2,0-3,0a142.7,142.7,0,0,0-37.5,5.51,200.39,200.39,0,0,0-43.71,18L559.68,57l86.6,47.6,57.94-31.84q21.79-12,32.51-24.13T746.37,26.21ZM694.43,46q-3.63,7.51-18.36,15.6l-10.41,5.73L627,46.1l10.4-5.72q14.73-8.1,28.39-10.09a51.29,51.29,0,0,1,7.33-.56,32,32,0,0,1,15.63,3.68Q698,38.51,694.43,46Z"/>

<polygon class="svg-b-n" points="539.34 112.27 583.62 136.62 493.18 137.64 449.59 161.6 536.18 209.2 579.78 185.24 536.24 161.31 625.93 159.87 669.53 135.91 582.93 88.31 539.34 112.27"/>

<path class="svg-b-a" d="M308.71,209.12l35.73,75.55,45.77-25.15-6.22-11,46.35-25.47,20,3.42,45.95-25.26L359,181.48Zm90.59,8.56-25.13,13.81-11.53-20.15Z"/>

<path class="svg-b-r" d="M326.64,290.81q1-8-7.66-12.75-8.07-4.43-20.48-4.66l-1.27,0q-11.94,0-26.85,4.31a160.09,160.09,0,0,0-32.6,13.82L173,327.12l86.6,47.61,43.6-24-30.88-17.18,57.2,2.72L377.4,310,314,308.37Q325.61,298.76,326.64,290.81Zm-47.71,17.27c-.91,1.81-3.46,3.85-7.65,6.16L254,323.74l-14.68-8.07,17.28-9.5a33.36,33.36,0,0,1,11.28-4.06,21.59,21.59,0,0,1,2.7-.18,12.06,12.06,0,0,1,5.93,1.37Q280.29,305.39,278.93,308.08Z"/>

<path class="svg-b-b" d="M186,353.17q-6.37-3.5-16.52-3.5c-1.16,0-2.37,0-3.61.1a84.43,84.43,0,0,0-27.06,6.61q8.9-6.78,10.07-13.14t-6.4-10.53a34,34,0,0,0-16.65-3.82,63.66,63.66,0,0,0-12.28,1.3q-17.93,3.53-39.14,15.19l-70.89,39L90.13,432,163,391.9q22.57-12.4,28.49-22.45T186,353.17ZM80.89,378.94l-12.24-6.73,16.9-9.28a33.73,33.73,0,0,1,10.27-4,15,15,0,0,1,2.45-.21,10.35,10.35,0,0,1,5.1,1.24c2,1.12,2.6,2.46,1.68,4.05s-3.35,3.45-7.27,5.61Zm58.23.6q-1.44,2.34-7.33,5.58L112,396,99.72,389.3l19.84-10.91q7.53-4.14,12.81-4.14a10.27,10.27,0,0,1,5,1.2C139.5,376.62,140.09,378,139.12,379.54Z"/></svg>

​

为什么这个不起作用？有没有更简单的方法来做这件事？

Answer 1

filter属性接受多个过滤器，因此您可以重复使用drop-shadow

filter: drop-shadow(30px 10px 4px #44d) drop-shadow(70px 1px 4px #f0d);

​

​

您所需要做的就是将正确的字符串传递给样式属性filter。

在你的例子中，代码看起来像这样：

let text = document.querySelector(".brand-svg");
let gcolor = ["#ffb576","#ffb275","#ffb074"];

for (var i = 0; i < gcolor.length; i++) {
  text.style.filter = `${text.style.filter} drop-shadow(0px ${-i}px 0px ${gcolor[i]})`;
}